TWI673761B - Methods of doping semiconductor substrate and depositing boron and carbon containing film - Google Patents

Abstract

The present invention provides a method for depositing a film containing boron and carbon. In some embodiments, Provided is a method for depositing a BC film having desired properties such as conformality and etch rate. One or more precursors containing boron and / or carbon can be decomposed on the substrate at a temperature of less than about 400 ° C. One or more of the boron and carbon-containing films may have a thickness of less than about 30 Angstroms. A method of doping a semiconductor substrate is provided. The doped semiconductor substrate may include: depositing a boron and carbon film on the semiconductor substrate by exposing the substrate to a vapor phase boron precursor at a process temperature of about 300 ° C to about 450 ° C, wherein the boron precursor includes boron, carbon, And hydrogen; and annealing the boron and carbon films at a temperature of about 800 ° C to about 1200 ° C.

Description

Method for doping semiconductor substrate and depositing boron and carbon-containing film method [Cross Reference to Related Applications]

This application is a partial continuation of U.S. Patent Application No. 14 / 515,341, filed on October 15, 2014, and entitled `` DEPOSITION OF BORON AND CARBON CONTAINING MATERIALS '' , Said U.S. patent application claims U.S. Provisional Application No. 61 / 891,813, filed on October 16, 2013 and entitled "DEPOSITION OF CONFORMAL SILICON NITRIDE BASED MATERIALS" Rights, the disclosure of each of the U.S. patent applications and the U.S. provisional applications are incorporated herein by reference in their entirety.

The present invention relates generally to the field of semiconductor device manufacturing, and more specifically, to the deposition of materials containing boron and carbon.

For example, boron and carbon-containing materials such as boron and carbon films can have various uses, including those in the semiconductor industry. Silicon nitride materials can be modified to include boron and carbon groups For example, a silicon nitride film containing boron and carbon components is formed. Boron and carbon films and silicon nitride films containing boron and carbon components can have various applications in the manufacturing process of semiconductor devices.

As the physical geometry of semiconductor devices shrinks, it is desirable to deposit a film on a three-dimensional structure having a high aspect ratio. Therefore, it is desirable to obtain a deposition process that provides a conformal coverage film that can exhibit a three-dimensional structure with a high aspect ratio. Further, it is desirable to obtain a film that exhibits favorable etch selectivity to one or more other materials in a semiconductor device and / or an etch rate desired in a dry etching and / or wet etching process.

In some aspects, a method of forming a silicon nitride film including boron and carbon is provided. In some embodiments, a method for depositing a silicon nitride-based film containing boron and carbon on a substrate in a reaction space may include: contacting the substrate with a gas-phase silicon reactant to form a layer on a surface of the substrate Reactants; contacting the surface of the substrate containing the silicon reactant with a nitrogen reactant; and contacting the substrate with a gas-phase boron and / or carbon reactant. In some embodiments, at least one of contacting the substrate with a gas-phase silicon reactant, contacting the silicon reactant with a nitrogen precursor, and contacting the substrate with a gas-phase boron reactant is performed two or more times. Times.

A method for depositing a silicon nitride film containing boron and carbon on a substrate in a reaction space may include: exposing the substrate to a gas phase silicon precursor; for example, removing the substrate from the reaction space by using a purge gas and / or a vacuum. Removing excess silicon precursors and reaction byproducts; contacting the remaining silicon reactants on the substrate surface with nitrogen precursors; and The substrate is exposed to a vapor phase boron precursor. In certain embodiments, exposing the substrate to a gas phase silicon precursor, exposing the substrate to a purge gas and / or vacuum, contacting the adsorbed silicon reactant with a nitrogen precursor, and exposing the substrate to Exposing the substrate to at least one of the vapor phase boron precursors is performed two or more times.

In some aspects, a method of forming a boron carbon film is provided. In some embodiments, a method for depositing a boron and carbon film on a substrate in a reaction space may include: contacting the substrate with a vapor-phase boron precursor at a process temperature of about 325 ° C to about 400 ° C to form the substrate A boron and carbon film is formed on the substrate, and the gas phase boron precursor is decomposed on the substrate.

In some embodiments, a method of forming a boron and carbon film on a substrate in a reaction space may include: contacting a three-dimensional structure on the substrate with a vapor-phase boron precursor at a process temperature of less than about 400 ° C to form A boron and carbon film is formed on the three-dimensional structure, wherein the boron and carbon film has a step coverage of greater than about 80%. In some embodiments, the method may include purging the reaction space after contacting the three-dimensional structure on the substrate with a vapor-phase boron precursor.

In some aspects, a method of doping a semiconductor substrate may include: said exposing said semiconductor substrate to a vapor phase boron precursor at a process temperature of about 300 ° C to about 450 ° C in said reaction space. A boron and carbon film is deposited on the semiconductor substrate, wherein the gas phase boron precursor may include boron, carbon, and hydrogen. The boron and carbon films may be annealed at a temperature of about 800 ° C to about 1200 ° C.

In some aspects, the method of doping the semiconductor substrate may include: using a chemical vapor deposition process to deposit a boron and carbon film on the semiconductor substrate in the reaction space. can For example, the boron and carbon films are annealed in a nitrogen environment. In some embodiments, no cover layer is formed on the boron and carbon film before annealing. In some embodiments, depositing the boron and carbon film may include: exposing a semiconductor substrate including a three-dimensional structure to a vapor phase boron precursor in an inert gas environment at a process temperature greater than about 300 ° C; and After the three-dimensional structure on the semiconductor substrate is exposed to the vapor-phase boron precursor, the reaction space is purged.

In some aspects, a method for depositing a film containing boron and carbon on a substrate in a reaction space may include: contacting the substrate with a vapor-phase boron precursor at a process temperature of about 250 ° C to about 400 ° C to The boron and carbon-containing film is formed on the substrate. In some embodiments, the gas phase boron precursor is decomposed on the substrate.

In some embodiments, the boron and carbon films have a thickness of less than about 30 Angstroms.

In order to summarize the present invention and the advantages achieved over the prior art, certain objectives and advantages are described herein. It should be understood, of course, that not all such objectives or advantages need to be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the invention may be implemented or carried out in a manner that achieves or optimizes one advantage or set of advantages without necessarily achieving other goals or advantages.

All such embodiments are intended to be within the scope of the invention as disclosed herein. Reading the following detailed description with reference to the accompanying drawings, these and other embodiments will become readily apparent to those skilled in the art, and the present invention is not limited to any specific embodiments disclosed.

100‧‧‧Process

102, 104‧‧‧ blocks

200‧‧‧flow chart

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500‧‧‧ trench structure

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504‧‧‧ middle section

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700‧‧‧Process flow

702, 704, 706, ‧‧‧ blocks

800‧‧‧ manufacturing process

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804‧‧‧Process

806, 808, 810, 814, 816‧‧‧ blocks

812‧‧‧Process

1300‧‧‧Trench Structure

1302‧‧‧ film

1400‧‧‧Trench Structure

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1500‧‧‧Trench Structure

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1504‧‧‧ middle section

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A, B, C, D‧‧‧Etching performance curve

These and other features of the invention are illustrated with reference to the drawings of certain embodiments. Features, aspects, and advantages, the drawings are intended to illustrate certain embodiments and are not intended to limit the invention.

FIG. 1 shows a flowchart of an example of a process for depositing a boron and carbon film according to an embodiment.

2A and 2B illustrate examples of a film stack including a boron and a carbon film.

FIG. 3 shows a flowchart of another example of a process for depositing boron and carbon films according to an embodiment.

FIG. 4 is a graph of growth rates of boron and carbon films versus process temperature according to an embodiment.

FIG. 5 is a diagram illustrating a Fourier transform infrared spectroscopy (FTIR) spectrum of a boron and carbon film deposited according to an embodiment.

6A to 6D are scanning electron microscope (SEM) images of boron and carbon films deposited on a trench structure with a high aspect ratio.

FIG. 7 is a graph illustrating the removal rates of boron and carbon films when the boron and carbon films are exposed to a wet etchant according to some embodiments.

FIG. 8 is a graph illustrating the boron and carbon film deposition rates as a function of temperature according to some embodiments.

9A is a scanning transmission electron microscope (STEM) image of a cross-sectional view of a boron and carbon film deposited according to an embodiment.

FIG. 9B is a table showing the composition of the boron and the carbon film shown in FIG. 9A.

FIG. 10 shows that compared to a borosilicate glass (BSG) film, A diagram of Secondary Ion Mass Spectrometry (SIMS) analysis of the boron concentration at various depths in the silicon layer in the examples where the boron and carbon films are used as dopant films as described herein.

FIG. 11 is a diagram showing a Fourier transform infrared spectroscopy (FTIR) spectrum of an aged boron and carbon film exposed to the environment around the clean room.

FIG. 12 is a table showing optical properties and deposition efficiency of examples of boron and carbon films according to the embodiment.

FIG. 13 illustrates a flowchart of an example of a process for depositing a silicon nitride film containing boron and carbon according to an embodiment.

FIG. 14 shows a flowchart of an example of a process for depositing a silicon nitride film containing boron and carbon according to another embodiment.

FIG. 15A is a graph showing the composition of an example of a silicon nitride film containing boron and carbon in a deposition process as a percentage of a triethylboron (TEB) pulse.

15B is a graph of a film growth rate of an example of a silicon nitride film including boron and carbon in a deposition process as a percentage of a TEB pulse.

FIG. 16 shows an FTIR spectrum of an example of a silicon nitride film containing boron and carbon.

FIG. 17 shows X-ray reflectivity (XRR) data of an example of a silicon nitride film containing boron and carbon deposited according to an embodiment disclosed herein.

FIG. 18 is a graph of a film etching rate of an example of a silicon nitride film including boron and carbon in a deposition process as a function of a fraction of a TEB pulse.

19A to 19D are etchings showing examples of a silicon nitride film containing boron and carbon SEM image of effectiveness.

20A to 20D are SEM images showing an etching performance of an example of a silicon nitride film including a boron and a carbon component.

21A to 21D are SEM images showing a step coverage of an example of a silicon nitride film containing a boron and a carbon component.

Although certain embodiments and examples are set forth below, those skilled in the art will understand that the present invention extends beyond the specifically disclosed embodiments and / or uses and the obvious embellishments and equivalents of the embodiments. Therefore, it is intended that the scope of the invention disclosed herein should not be limited by any of the specific embodiments described below.

Films containing boron and carbon can have a variety of desirable properties, including chemical stability, mechanical strength, and thermal and electrical properties. Therefore, such films have a variety of applications in many technical fields, including applications in the semiconductor industry, medical industry, military industry, aerospace industry and nuclear industry. For example, boron carbon films are used as neutron detectors in the manufacture of semiconductor devices and in the manufacture of microelectromechanical systems (MEMS). Boron-carbon films can be used in the tribological coating of MEMS devices and / or as sacrificial films in semiconductor device manufacturing processes. In some embodiments, a film containing boron and carbon can be used as a cover layer, an etch stop layer, a layer that facilitates photolithography patterning processes, and / or a doped layer (e.g., used as a boron dopant source ). Other uses outside the semiconductor field will be apparent to those skilled in the art.

In some embodiments, a film consisting essentially of boron and carbon is provided (e.g., Ultra-thin boron and carbon films) and methods of making such materials. For example, in certain embodiments, a boron and carbon film having a thickness in a sub-nanometer range is provided.

In other embodiments, films including boron and / or carbon and other components and methods of making such films are disclosed. For example, in some embodiments, a silicon nitride film including a boron and carbon component may be formed. The silicon nitride film containing boron and carbon can have various applications including applications in semiconductor devices. The silicon nitride film containing boron and carbon components may form a part of a semiconductor device (for example, a fin field-effect transistor (FinFET)) and / or may be part of a process for manufacturing a semiconductor device. For example, a silicon nitride film containing boron and carbon components can be deposited on three-dimensional (3-D) features during the fabrication process of a semiconductor device, such as a barrier material used as a gate feature of a transistor (such as As a spacer material for gate characteristics in a multi-gate transistor such as a fin-type field effect transistor) and / or as a sacrificial layer in a semiconductor device manufacturing process.

As described herein, in certain embodiments, a boron and carbon (BC) film can be used as a dopant film in a semiconductor device fabrication process. For example, boron and carbon films can provide dopant sources for semiconductor substrates such as silicon substrates. In some embodiments, a film consisting essentially of boron and carbon can be used as a solid state diffusion (SSD) layer, where boron can be used as a dopant. For example, a boron and carbon film can be deposited on a substrate, and the deposited boron and carbon film can then be subjected to an annealing process to drive boron from the boron and carbon film into the underlying substrate.

Overlays are commonly used in traditional solid-state doping schemes to reduce or prevent dopants from diffusing out before, after, or during the annealing process. However, in some embodiments, the boron and carbon solid-state diffusion layer can be advantageously used as a dopant film, and there is no or substantially no cover layer directly on the boron and carbon solid-state diffusion layer. The capping layer used in conventional solid-state doping schemes may include oxides and / or nitrides. For example, a conventional capping layer may include oxides of Group 13, 14 or 15 elements (including silicon oxide (eg, SiO ₂ )) and silicon nitride.

In some embodiments, a film consisting essentially of boron and carbon can be used as a cover layer formed on the solid-state diffusion layer. For example, a conventionally formed solid diffusion layer (including a conventionally formed boron-containing solid diffusion layer) can be deposited on a silicon substrate, and a boron and carbon capping layer can be deposited on a conventionally formed solid diffusion layer to The film stack is then subjected to a thermal annealing process to drive dopants into the underlying silicon substrate. In some embodiments, a boron and carbon capping layer used in combination with a conventionally formed solid diffusion layer may advantageously provide a desired dopant concentration within the underlying substrate.

One or more processes described herein can be used to form a boron carbon film and / or a silicon nitride film comprising boron and carbon, wherein the film has one or more desired characteristics, such as conformal coverage of a three-dimensional feature Desired degree, desired dry etch rate, desired wet etch rate, and / or desired etch selectivity to another material. In some embodiments, a boron carbon film and / or a silicon nitride film comprising boron and carbon formed according to one or more processes described herein may exhibit a desired etch selectivity relative to silicon oxide. Unless otherwise specified, the silicon oxide described herein may have any of a number of stoichiometric ratios of silicon to oxygen, and those skilled in the art will understand that this is typical for silicon oxide. In some embodiments, the silicon oxide may include, but is not limited to, silicon dioxide (SiO ₂ ). The silicon oxide may be formed according to any of a variety of suitable methods as will be understood by those skilled in the art, and may include, for example, thermal silicon oxide (TOX) (for example, a TOX layer in a semiconductor device), chemistry Silica, and / or natural silica. For example, films deposited according to one or more processes described herein (such as boron and carbon films or silicon nitride films containing boron and carbon) can exhibit improved step coverage, Reduced etching rates (e.g., resistance to wet etchant such as a dilute hydrofluoric acid (HF or dHF) solution (e.g., 0.5% by weight HF solution)), and / or reduced wetness to silicon oxide Etch rate. For example, one or more of the boron carbon films and / or silicon nitride films containing boron and carbon described herein may exhibit a reduced resistance to thermal silicon oxide compared to similar films deposited by other methods ( TOX) wet etch rate (for example, such that the ratio of the wet etch rate of the silicon nitride-based film to the wet etch rate of TOX is less than about 1, including less than about 0.5).

In certain embodiments, the boron and carbon films described herein can be used with another material to enhance the etch selectivity of the resulting structure formed from the boron and carbon film and the other material. For example, in some embodiments, the boron and carbon films described herein can be used as an etch stop layer under another layer, or as a cover layer over another layer, where the boron and carbon films are more Other layers are more resistant to certain wet etchants (eg, a diluted HF solution).

In some embodiments, the silicon nitride film containing the boron and carbon components may have a desired dielectric constant (κ-value), such as a spacer material suitable for use as a transistor gate feature. In some embodiments, the silicon nitride film including the boron and carbon components may have less than about 7 (Including between about 4.8 and about 7, and between about 4.8 and about 6), as described below.

Boron and carbon film

As described herein, a film composed primarily of boron and carbon and formed according to one or more processes described herein (as described below, also referred to as a boron carbon film or BC film) can advantageously exhibit a variety of Desired characteristics. In certain embodiments, the boron and carbon films can advantageously exhibit the desired conformality when deposited on three-dimensional (3-D) features of the substrate, such as 3-D features with high aspect ratios. Level. For example, boron and carbon films are deposited at about 3: 1 or higher than 3: 1 (including about 10: 1 or higher than 10: 1, about 20: 1 or higher than 20: 1, about 25: 1) Or higher than 25: 1, about 40: 1 or higher than 40: 1, about 50: 1 or higher than 50: 1, or about 80: 1 or higher than 80: 1), It may have a conformality of greater than about 90%, including greater than about 95%. In some embodiments, the boron and carbon films when deposited have an aspect ratio of about 20: 1 or greater than 20: 1 (including about 40: 1 or greater than 40: 1 and about 80: 1 or greater than 80: 1) It is characterized by having a conformality of greater than about 90% (including greater than about 95%).

In some embodiments, the boron and carbon films may exhibit a reduced wet etch rate relative to thermal silicon oxide. For example, boron and carbon films can exhibit reduced wet etch rates in dilute hydrofluoric acid solution (dHF) (e.g., etch rates less than about 0.3 times the etch rate of TOX films exposed to dHF) ). In some embodiments, the boron and carbon films may have a negligible wet etch rate in diluted HF. In certain embodiments, the boron and carbon films have less than about 0.2 nanometers per minute (nm / min), preferably less than about 0.1 nanometers per minute, and more preferably less than about 0.05 nanometers in diluted HF. / Minute wet etch rate. In some embodiments, the boron and carbon films may include nitric acid (HNO ₃ ), sodium hydroxide (NaOH), hydrochloric acid (HCI), sulfuric acid (H ₂ SO ₄ ), and / or phosphoric acid (H ₃ PO ₄ ). The etchant exhibits an etch rate of less than about 0.2 nm / minute, preferably less than about 0.1 nm / minute, and more preferably less than about 0.05 nm / minute. In some embodiments, the wet etch rate is below a detection limit using one of the enumerated etchants.

In certain embodiments, the film density, the boron and carbon in accordance with one or more of the processes described herein is formed having a desired (e.g., about 2.0 g / cc (g / cm ³⁾ to about 2.5 g / cubic (Cm of film density) while exhibiting desired etching resistance. For example, boron and carbon films can have a wet etch rate as described herein while having a film density of about 2.0 grams / cubic centimeter to about 2.5 grams / cubic centimeter.

In some embodiments, the boron and carbon films may exhibit one or more of these desired characteristics before undergoing a post-deposition process (such as the post-deposition process described in more detail herein). In some embodiments, a post-deposition process further enhances one or more of these desired characteristics.

In some embodiments, the boron and carbon films deposited on a silicon-containing surface (e.g., on the surface of a silicon-based layer such as a silicon layer, a silicon nitride layer, a silicate layer) may be Boron and carbon films deposited on surfaces formed from different materials, such as materials that do not contain silicon, exhibit increased uniformity and / or conformality. For example, boron and carbon films deposited on a silicon nitride (SiN) surface (eg, on a surface of a silicon nitride layer, such as on a silicon nitride substrate) may exhibit increased uniformity. Without being limited by any particular theory or mode of operation, the silicon surface and the boron and carbon films Improved interactions between one or more of the components may advantageously promote increased uniformity and / or conformality of the deposited film.

As described above, the boron and carbon films usually mainly include boron and carbon. For convenience and simplicity, the chemical formulas of boron and carbon films are commonly referred to herein as BC. However, those skilled in the art will understand that the actual chemical formula of the BC membrane may be B _x C. In certain embodiments, for example, x may vary from about 0.1 to about 25. In some cases, x preferably varies from about 1 to about 10, and more preferably from about 1 to about 2. For example, x may be about 1.5.

In some embodiments, the chemical vapor deposition (CVD) process is performed at a temperature of less than about 400 ° C. and at about 0.001 Torr to about 760 Torr (including from about 1 Torr to about 10 Torr, or about 0.001 Torr to Boron and carbon films are deposited on the substrate under a pressure of about 10 Torr. The CVD process includes decomposing one or more boron precursors (eg, boron reactants) on the substrate surface. In some embodiments, the boron precursor may include both boron and carbon. Therefore, in some embodiments, a CVD process for depositing boron and carbon films may include: decomposing a single boron precursor containing both boron and carbon in a deposition process without any additional precursors. In some embodiments, the CVD process includes: decomposing two or more precursors on a substrate surface to form a boron and carbon film. In certain embodiments, at least one of the two or more precursors includes boron (B). In certain embodiments, at least one of the two or more precursors comprises carbon (C). In certain embodiments, the two or more precursors can each include boron and carbon. For example, a CVD process for depositing boron and carbon films may include: decomposing two or more precursors, each of the two or more precursors including both boron and carbon. in In some embodiments, the CVD process does not include any additional precursors other than the boron precursor (eg, does not include any precursors used to provide boron and carbon in the carbon film, respectively).

In some embodiments, no plasma is used or substantially used in the deposition of boron and carbon films (eg, no or substantially no plasma is used for boron and carbon film growth). In some embodiments, the CVD process may be a pulsed thermal CVD process in which multiple pulses of a single boron precursor are provided to deposit a film having a desired thickness. In certain embodiments, a single pulse of the boron precursor is provided to deposit a film having a desired thickness. The thermal CVD process may include no plasma or substantially no plasma during the decomposition of the precursor. In certain embodiments, a purge step may be performed between boron precursor pulses, such as to remove excess reactants and / or reaction byproducts from the reaction space. In some embodiments, the substrate may be moved to a space where the substrate is not exposed to the precursor.

In some embodiments, the boron precursor pulse may include one or more carrier gases, such as nitrogen and / or noble gas (eg, argon, helium, neon, and / or xenon). In some embodiments, the boron precursor pulse comprises a mixture of two or more carrier gases. In certain embodiments, a mixture of two or more carrier gases comprises argon and / or hydrogen. For example, a mixture of two or more carrier gases may include two or more gases selected from the group consisting of nitrogen, helium, neon, xenon, argon, and hydrogen.

In some embodiments, the process for depositing a boron and carbon film includes a single carrier gas and a single boron precursor, wherein the single boron precursor includes both boron and carbon. In some such embodiments, the process does not include any other precursors or carrier gas. For example, a single carrier gas may include nitrogen (N ₂ ) or an inert gas (such as argon (Ar) gas or helium (He) gas). For example, the boron precursor pulse used in the process may include a single boron precursor and nitrogen (N ₂ ), argon (Ar) gas, or helium (He) gas. In some embodiments, a process for depositing a boron and carbon film includes a carrier gas mixture and a single boron precursor, wherein the single boron precursor includes both boron and carbon. In certain such embodiments, the process does not include any other gases other than a carrier gas mixture and a single boron precursor. In such embodiments, the carrier gas mixture may include nitrogen (N ₂ ) and an inert gas. For example, the carrier gas mixture may include nitrogen (N ₂ ) and argon (Ar), or nitrogen (N ₂ ) and helium (He). For example, the boron precursor pulse used in the process may include a single boron precursor and nitrogen (N ₂ ) and argon (Ar) gas or a single boron precursor and nitrogen (N ₂ ) and helium (He) gas.

As described in more detail below, in certain embodiments, the CVD process is a cyclic deposition process in which reactants are provided cyclically. For example, depositing a boron and carbon film on a substrate may include two or more deposition cycles in which the substrate is contacted with a reactant to achieve a desired film thickness. In other embodiments, the CVD process may be a continuous flow process. For example, depositing a boron and carbon film on a substrate may include continuously or substantially continuously exposing the substrate to a reactant for a single time period to achieve a desired film thickness.

FIG. 1 shows a flowchart illustrating a process 100 for forming a boron and carbon (BC) film. At a block 102, the substrate is exposed to one or more gas-phase boron reactants (eg, boron and / or carbon precursors). The carrier gas may be used to transport the one or more gas phase boron reactants to the substrate. In some embodiments, although the carrier gas does not or does not substantially cause the growth of boron and carbon films, the carrier gas may promote one or more between the reactants and / or between the reactants and the substrate surface Interactions for the formation of boron And carbon film.

In some embodiments, the substrate is exposed to a single gas phase boron reactant. In certain embodiments, a single gas phase boron reactant comprises both boron (B) and carbon (C). In some embodiments, the substrate is exposed to two or more gas phase reactants. For example, at least one of the two or more gas phase reactants includes carbon (C), and at least one of the two or more gas phase reactants includes boron (B) .

In some embodiments, the carrier gas may include an inert carrier gas, such as argon (Ar), nitrogen (N ₂ ), helium (He), xenon (Xe), and / or neon (Ne). In certain embodiments, the carrier gas may include a mixture of two or more gases, including two or more gases selected from the group consisting of nitrogen, helium, neon, xenon, argon, and hydrogen. In block 104, the step of exposing the substrate to a carrier gas and one or more gas phase boron reactants may be repeated multiple times, such as in a pulsed CVD process. For example, the substrate may be exposed to a carrier gas and the one or more gas phase boron reactants for a first duration, and the exposure step may be repeated about 5 to about 5,000 times, including about 100 to About 3,000 times (including about 1,000 times and about 2,000 times). In certain embodiments, the exposure step can be repeated less than about 100 times, including from about 1 to about 100 times, about 2 to about 50 times, about 3 to about 20 times, or about 5 times. Times to about 10 times.

The duration may be the same in each of multiple iterations or cycles or may vary between one or more cycles. The number of repetitions can be selected, for example, to facilitate the deposition of boron and carbon films having a desired thickness. In some embodiments, the one or more gas phase boron reactant streams may be stopped into the reaction space after the substrate is exposed to a carrier gas and the one or more gas phase boron reactants. In some embodiments, the substrate A step of purging and / or transporting a substrate to a space away from the reactants after exposure to a carrier gas and the one or more gas phase boron reactants (e.g., the substrate is not exposed or substantially not exposed to The reactant). The purge step can be used to remove one or more excess reactants and / or reaction byproducts from the reactor chamber. In some embodiments, the purge step and / or the substrate transfer step follows each time the substrate is exposed to a carrier gas and the one or more gas phase boron reactants. For example, after each exposure of the substrate to the reactants in each cycle, the substrate can be moved to a space free of reactants or substantially free of reactants, or excess reactants in the reactor can be purged and removed. And / or reaction by-products. In certain embodiments, the purging step includes continuously flowing a carrier gas (e.g., causing the carrier gas (e.g., at least one component of a multi-component carrier gas) to be at the same flow rate as during the reactant pulse or Continuous flow at different flow rates). For example, the process 100 for depositing boron and carbon films may include continuously flowing a carrier gas and periodically flowing the one or more gas-phase boron reactants.

In some embodiments, a process for depositing a boron and carbon (BC) film may include a chemical vapor deposition (CVD) process. Referring to FIG. 1, in some embodiments, the process 100 includes a thermal CVD process performed at a reduced process temperature (eg, a temperature of less than about 400 ° C.). The thermal CVD process may be a process in which a plasma is not applied or substantially not applied, for example, to facilitate decomposition of a precursor for depositing a film. Process temperatures as mentioned herein may include the temperature of the reactor chamber susceptor, the wall of the reactor chamber, and / or the temperature of the substrate itself. For example, in some embodiments, the process 100 for depositing boron and carbon films may be performed at a process temperature of up to about 400 ° C. In some embodiments, the Process 100 can be performed at a process temperature of about 325 ° C to about 400 ° C, preferably about 350 ° C to about 400 ° C, and most preferably about 375 ° C to about 400 ° C. Without being limited by any particular theory or mode of operation, the deposition of boron and carbon films at temperatures less than about 400 ° C can advantageously facilitate deposition in a surface reaction limited regime to facilitate the formation of The one or more desired properties of the boron and carbon films (eg, increased conformality performance, increased uniformity, and / or reduced etch rate).

In certain embodiments, the deposition of the boron and carbon (BC) film may be performed at a process temperature of about 200 ° C to about 450 ° C (including, for example, about 250 ° C to about 400 ° C or about 400 ° C to about 425 ° C).

In certain embodiments, boron and carbon (BC) can be performed, for example, in a single wafer reactor at process temperatures up to about 450 ° C (including about 300 ° C to about 450 ° C or about 400 ° C to about 425 ° C). ) Film deposition. For example, in some embodiments, the boron and carbon films can be deposited at a process temperature of about 400 ° C to about 450 ° C (eg, at about 430 ° C). For example, the deposition of boron and carbon films can be performed in a single wafer reactor at a process temperature of about 400 ° C to about 425 ° C.

In some embodiments, the deposition of boron and carbon (BC) films can be performed at process temperatures up to about 400 ° C. For example, in certain embodiments, batch processing may be performed at a process temperature of about 250 ° C to about 400 ° C, preferably about 275 ° C to about 375 ° C, and more preferably about 300 ° C to about 350 ° C. Deposition of boron and carbon (BC) films is performed in the processing reactor.

According to some embodiments of the invention, the pressure in the reactor chamber during processing is The force is maintained at about 0.001 Torr to about 760 Torr, including about 0.01 Torr to about 50 Torr, preferably about 0.1 Torr to about 10 Torr, and more preferably about 1 Torr to about 10 Torr. In certain embodiments, the deposition of boron and carbon films may be performed at a reactor chamber pressure of about 0.5 Torr to about 8 Torr. For example, the reactor chamber pressure may be about 6 Torr. The selected reaction chamber pressure can be used to facilitate the formation of the required boron and carbon films. In certain embodiments, the chamber pressure may be selected based on the configuration of the reactor chamber (eg, a batch processing reactor or a single wafer reactor). In certain embodiments, the batch reactor may have a reactor chamber pressure from about 0.001 Torr to about 10 Torr. In some embodiments, the chamber pressure may be selected to provide a boron and carbon film with the desired conformality and / or etch rate performance.

As described above, the carrier gas may include an inert carrier gas, such as nitrogen (N ₂ ), helium (He), xenon (Xe), and / or neon (Ne). For example, block 102 shown in FIG. 1 may include exposing the substrate to one or more boron reactants and nitrogen. Without being limited by any particular theory or mode of operation, nitrogen, helium, xenon, and neon can exhibit increased thermal conductivity (e.g., compared to other inert carrier gases such as argon (Ar)). Higher thermal conductivity), thereby facilitating the decomposition of the one or more boron and / or carbon precursors. In addition, without being limited by any particular theory or mode of operation, a carrier gas with increased thermal conductivity may facilitate the decomposition of the one or more boron and / or carbon precursors in the high aspect ratio features of the 3-D substrate surface To facilitate the formation of conformal and / or etch-resistant boron and carbon films on high aspect ratio features. For example, use a carrier gas including nitrogen, helium, xenon, and / or neon (including a carrier gas containing two or more of nitrogen, helium, xenon, neon, argon, and / or hydrogen (Mixtures) may facilitate the formation of conformal and / or etch-resistant boron and carbon films.

In some embodiments, the carrier gas may include argon (Ar). For example, block 102 shown in FIG. 1 may include exposing the substrate to one or more gas-phase boron reactants and argon.

In certain embodiments, the flow of one or more of the gas-phase boron reactants into the reaction space may be continuous or substantially continuous. For example, the process 100 for depositing a boron and carbon (BC) film may include a continuous flow thermal CVD process. For example, the one or more gas-phase boron reactants can be continuously flowed into the reaction chamber until the required boron and carbon film thicknesses are achieved. In certain embodiments, the flow rate of the boron reactant and / or carrier gas may be varied during a continuous flow thermal CVD process to provide the desired boron and carbon films. In some embodiments, the process temperature and / or reactor chamber pressure may be varied during a continuous flow thermal CVD process to provide the desired boron and carbon films.

In some embodiments, the process 100 for depositing a boron and carbon (BC) film includes a pulsed thermal CVD process. In some embodiments, the process 100 may include a cyclic deposition process. For example, the cycle of process 100 may include, for example, bringing the substrate into contact with the reactants for a desired time by pulsed supply of the reactants into the reactor chamber. The reactant pulse may include a carrier gas (eg, argon, nitrogen, helium, and / or neon) and at least one or more boron reactants. In some embodiments, the reactant pulses are repeated multiple times to deposit a boron and carbon film having a desired thickness and / or composition (eg, repeated multiple cycles, each cycle including the reactant pulses).

In certain embodiments, steps in which the substrate is not exposed to the reactants, such as a purge step and / or transporting the substrate to a non-reactant or substantially non-reactant, may be performed after one or more reactant pulses. Steps in space. For example, the first The substrate may first be transported to a space that is free of reactants or substantially free of reactants, and then any excess reactants and / or reaction byproducts in the reactor chamber may be purged out. In some embodiments, a purge step and / or a step of transporting the substrate to a space free of reactants or substantially free of reactants may be performed after each of the plurality of reactant pulses. The purge step can be used to remove one or more excess reactants and / or reaction byproducts from the reactor chamber. For example, the purge step may include flowing one or more purge gases through the reactor chamber, and / or (e.g., by evacuating the reactor chamber) to empty the reactor chamber to remove or substantially Remove excess reactants and / or reaction byproducts. In some embodiments, the purge gas comprises an inert gas. In some embodiments, the purge gas comprises nitrogen. In some embodiments, the purge gas comprises an inert gas. In some embodiments, the purge gas comprises argon.

In certain embodiments, the step of stopping the one or more gas-phase boron reaction streams into the reactor chamber to continuously flow the carrier gas may be performed after the reactant pulse. For example, the purge step may include continuously flowing a carrier gas (e.g., at a flow rate that is the same as or different from the flow rate during the reactant pulse, such as a higher flow rate) to remove the reaction from the reaction chamber Thing. In some embodiments, the purge step may include continuously flowing at least one component of a carrier gas comprising a mixture of two or more gases to remove excess reactants from the reactor chamber. In some embodiments, the process 100 for depositing boron and carbon films may include continuously flowing a carrier gas while the one or more gas-phase boron reactants alternately flow.

The duration of the reactant pulse may be selected to provide the required amount of one or more boron reactants and / or the required amount of deposition into the reactor chamber. In some embodiments The reactant pulse may have a duration of about 0.1 seconds to about 5 seconds (including about 0.1 seconds to about 1 second). For example, a reactant pulse may have a duration of about 0.5 seconds. In some embodiments, the reactant pulse may have a duration of about 0.3 seconds.

In certain embodiments, the interval between reactant pulses can be from about 1 second to about 15 seconds. In certain embodiments, the interval includes a purge step that removes excess reactants and / or reaction byproducts from the reactor chamber. In some embodiments, the spacing includes the step of transporting the substrate to a space that is free of reactants or substantially free of reactants. For example, the interval may include a step of transporting the substrate to a space free of reactants or substantially free of reactants, and having a duration of about 0.5 seconds to about 15 seconds (including about 1 second to about 10 seconds). Purge step. For example, the purge step may have a duration of about 5 seconds. In certain embodiments, the purge step may have a duration of about 1 second.

In certain embodiments, the duration of the reactant pulses and / or the interval between the reactant pulses (e.g., including, for example, the duration of a purge step) may be selected based on a substrate having a boron and carbon film deposited thereon Surface area, the aspect ratio of the three-dimensional (3-D) structure with boron and carbon films deposited thereon, and / or the configuration of the reactor chamber. For example, the reactant pulses and / or the interval between the reactant pulses may have an increased duration for depositing a boron and carbon film on a larger surface area, a 3-D structure with an increased aspect ratio, And / or deposition in a batch processing reactor. In certain embodiments, the increased duration of the reactant pulses and / or the interval between the reactant pulses is selected to characterize ultrahigh aspect ratios (including, for example, having about 40: 1 and greater than 40: 1 (including about 80: 1 And features with aspect ratios greater than 80: 1).

In certain embodiments, the one or more boron reactants are supplied to the reactor chamber from a corresponding source container in which the reactants are stored in the form of vapor. The vapor pressure of each reactant may facilitate delivery of the reactants into the reactor chamber. For example, vaporization techniques can be used to provide gasification reactants into the reactor chamber. In some embodiments, the source container can be maintained at a temperature of about 20 ° C to about 25 ° C. For example, by controlling the degree to which the supply valve for supplying gasification reactants to the reactor chamber remains open, the mass flow rate of the gasification reaction stream into the reactor chamber can be controlled.

In certain embodiments, a suitable boron reactant may comprise one or more compounds containing a BC bond. In certain embodiments, a suitable boron reactant may include a boron compound having at least one organic ligand. In some embodiments, the organic ligand may have a double bond and / or a triple bond. In certain embodiments, the organic ligand may be a cyclic ligand. In some embodiments, the organic ligand may include a delocalized electron. In certain embodiments, a suitable boron reactant may comprise a trialkylboron compound. In certain embodiments, a suitable boron reactant may include triethylboron (B (C ₂ H ₅ ) ₃ , triethylboron, TEB). In certain embodiments, a suitable reactant may comprise boron trimethyl boron _{(B (CH 3) 3,} trimethylboron, TMB). In certain embodiments, a suitable boron reactant may comprise three having a linear or branched alkyl group (including, for example, a linear or branched C3-C8, and more preferably a linear or branched C3-C5) Alkyl boron compounds. Suitable boron reactants may include various other boron-containing reactants. In certain embodiments, the boron reactant may include boron halide, alkyl boron, and / or borane. In some embodiments, the boron reactant may include boron halide, borane halide, and complexes thereof. By way of example, a suitable boron halide may have a boron to halide ratio of about 0.5 to about 1.

Suitable boranes may include compounds according to Formula I or Formula II.

B _n H _{n + x} (Chemical Formula I)

Where n is an integer from 1 to 10, preferably from 2 to 6, and x is an even number, and is preferably 4, 6, or 8.

B _n H _m (Formula II)

Where n is an integer of 1 to 10, preferably 2 to 6, and m is an integer of 1 to 10, preferably 2 to 6, different from n.

Examples of the above-mentioned borane according to Chemical Formula I include a nido-borane (B _n H _{n + 4} ), an arachno-borane (B _n H _{n + 6} ), and an open-web ( hyph) -borane (B _n H _{n + 8} ). Examples of the borane according to Chemical Formula II include a conjuncto-borane (B _n H _m ). In addition, a borane complex such as (CH ₃ CH ₂ ) ₃ N--BH ₃ can be used.

In certain embodiments, suitable boron reactants may include borane halides, specifically fluoride, bromide, and chloride. An example of a suitable compound is B ₂ H ₅ Br. Other examples include boron halides with high boron / halide ratios, such as B ₂ F ₄ , B ₂ C ₁₄ and B ₂ Br ₄ . Boron halide complexes can also be used.

In certain embodiments, halogenogenoborane according to Formula III may be a suitable boron reactant.

B _n X _n (Chemical Formula III)

Wherein X is chlorine (Cl) or bromine (Br), and n is an integer of 4 or 8 to 12 when X is chlorine, or n is an integer of 7 to 10 when X is bromine.

In certain embodiments, a carborane according to Formula IV may be a suitable boron reactant.

C ₂ B _n H _{n + x} (Chemical Formula IV)

Examples of carborane according to Chemical Formula IV include closo-carborane (C ₂ B _n H _{n + 2} ), nested-carborane (C ₂ B _n H _{n + 4} ), and spider web Formula-carborane (C ₂ B _n H _{n + 6} ).

In certain embodiments, the amine-borane adduct according to Chemical Formula V may be a suitable boron reactant.

R ₃ NBX ₃ (chemical formula V)

Wherein R is straight or branched C1 to C10, preferably C1 to C4 alkyl or H, and X is straight or branched C1 to C10, preferably C1 to C4 alkyl, H or halogen.

In certain embodiments, an aminoborane according to formula VI where one or more of the substituents on the boron is an amine group may be a suitable boron reactant.

R ₂ N (chemical formula VI)

Wherein R is a linear or branched C1 to C10, preferably C1 to C4 alkyl group or a substituted or unsubstituted aryl group.

An example of a suitable aminoborane is (CH ₃ ) ₂ NB (CH ₃ ) ₂ .

In certain embodiments, a suitable boron reactant may include borazine (--BH--NH--) ₃ and / or a volatile derivative thereof.

In certain embodiments, an alkylboron or alkylborane may be a suitable boron reactant, where the alkyl group is typically a linear or branched C1 to C10 alkyl group, preferably C2 to C4 alkyl.

According to some embodiments, a process for depositing a boron and carbon (BC) film includes a pulsed thermal CVD process performed at a process temperature of about 375 ° C to about 400 ° C and a pressure of about 0.5 torr to about 3 torr . The process may include contacting the substrate with a reactant pulse containing nitrogen as a carrier gas and triethylboron (TEB) as a boron and carbon reactant. The supply of TEB may be drawn from a source container used to store TEB at a temperature of about 20 ° C to about 25 ° C (eg, a needle valve used to flow TEB into the reactor chamber may be rotated about two turns to remain open). The reactant pulse may have a duration of about 0.5 seconds. In some embodiments, a single cycle of the process may include a period of time following the reactant pulse in which the substrate is not exposed to the reactant, such as a purge step. The purge step may include flowing nitrogen instead of reactants for a duration of, for example, about 5 seconds. The process may include repeating a cycle including a purge step after reactant pulses to achieve a boron and carbon film having a desired thickness and / or composition. For example, the cycle can be repeated up to about 1,000 times, about 1,500 times, about 2,000 times, or about 5,000 times. In certain embodiments, the cycle may be repeated about 2 to about 1,000 times, including about 2 to about 2,000 times, about 3 to about 2,000 times, or about 5 to about 5,000 times. In certain embodiments, the cycle may be repeated from about 50 to about 2,000 times. In certain embodiments, the cycle may be repeated from about 100 times to about 1,500 times. In some embodiments, the cycle can be repeated up to about 100 times. In certain embodiments, the cycle may be repeated about 1 to about 100 times, about 10 to about 100 times. In certain embodiments, the cycle can be repeated about 2 to about 50 times, about 3 to about 20 times, or about 5 to about 10 times.

One or more boron and carbon (BC) films formed according to one or more processes described herein can advantageously exhibit the desired conformality when deposited on a high aspect ratio feature on a 3-D substrate surface, for example, And / or desired etch rate performance (eg, wet etch rate performance, such as wet etch rate performance in a diluted HF solution). The film may also exhibit a reduced film density, such as a film density of about 2.0 grams / cubic centimeter (g / cm ³ ) to about 2.5 grams / cubic centimeter. In some embodiments, for example, when a boron and carbon film is formed having a thickness of about 3: 1 or higher than 3: 1 (including about 10: 1 or higher than 10: 1, about 25: 1 or higher than 25: 1) On a 3-D structure with an aspect ratio of about 50: 1 or higher than 50: 1), the boron and carbon films can exhibit greater than about 80%, preferably greater than about 90%, and more preferably greater than about 95 % Conformality. In some embodiments, when the boron and carbon film is formed on a substrate having an aspect ratio of about 20: 1 or greater than 20: 1, about 40: 1 or greater than 40: 1, or about 80: 1 or greater than 80: 1 In 3-D structures, boron and carbon films can exhibit conformality of greater than about 80%, preferably greater than about 90%, and more preferably greater than about 95%. For example, one or more boron and carbon films formed according to one or more processes described herein when deposited on a 3-D substrate surface has a high aspect ratio (including up to about 250: 1 (including about 150: 1 and Aspect ratio (approximately 100: 1)) can exhibit a conformality performance greater than about 95%.

As described herein, in certain embodiments, a boron and carbon (BC) film can be used as a sacrificial film in a semiconductor device fabrication process. For example, boron and carbon films can be selectively removed during the etching process. In some embodiments, the boron and carbon films may form part of the fabricated semiconductor device. For example, boron and carbon films may be more resistant to etching than one or more other materials used in the fabrication of semiconductor devices. In some implementations For example, the boron and carbon films can be etched by a dry etching process and / or a wet etching process. In some embodiments, an etch process including chlorine (Cl) and / or fluorine (F) (e.g., a chlorine and / or fluorine-containing plasma process) may be used to selectively remove sacrificial materials during fabrication of a semiconductor device. Boron and carbon film. In certain embodiments, the boron and carbon films may be more resistant to one or more etchant, including wet etchant such as a diluted HF solution.

In some embodiments, the boron and carbon films may exhibit a desired wet etch selectivity, such as a wet etch selectivity to a thermal silicon oxide (TOX) layer. For example, the boron and carbon films can be more resistant to wet etching than the thermal silicon oxide layer, so that the ratio of the wet etching rate of the boron and carbon film to the wet etching rate of the thermal silicon oxide layer is less than about 1 (for example, in In a diluted HF solution), less than about 0.5, or less than about 0.3. In some embodiments, the ratio of the wet etch rate of the boron and carbon films to the wet etch rate of the thermal silicon oxide layer may be less than about 0.1. In some embodiments, the ratio of the wet etch rate of the boron and carbon films to the wet etch rate of the thermal silicon oxide layer may be less than about 0.05.

In certain embodiments, the boron and carbon films may advantageously exhibit a desired wet etch rate, including the etch rate in a diluted HF solution. For example, boron and carbon films may advantageously exhibit less than about 0.2 nanometers per minute (nm / min) (including preferably less than about 0.1 nanometers per minute, more preferably less than about 0.05 nanometers per minute, and Optimally less than about 0.02 nm / minute). As will be explained in more detail below, ultra-thin boron and carbon materials deposited according to one or more processes described herein may advantageously exhibit the required resistance to wet etchant such as diluted HF. In some embodiments, the ultra-thin boron and carbon films can withstand or substantially withstand diluted HF for more than about 30 seconds, preferably more than about 60 seconds, or more preferably more than about 120 seconds. In some implementations In the example, the ultra-thin boron and carbon films can withstand or substantially withstand diluted HF exposure for up to about 5 minutes, or up to about 10 minutes. For example, ultra-thin boron and carbon films can exhibit less than about 0.1 nanometers / minute, less than about 0.05 nanometers / minute, or less than about 0.02 nanometers / minute when exposed to diluted HF for at least the number of times indicated. Etch rate. In some embodiments, the ultra-thin boron and carbon films can tolerate or substantially tolerate dilute HF exposure for longer than 10 minutes.

In some embodiments, the boron and carbon films can exhibit less than about 0.2 nm / min (including preferably less than about 0.1 nm / min, more preferably Wet etch rate of less than about 0.05 nanometers / minute, and optimally less than about 0.02 nanometers / minute: phosphoric acid at a concentration of about 85% by weight at about room temperature (eg, a temperature of about 25 ° C) H ₃ PO ₄ ) solution, a nitric acid HNO ₃ solution (for example, a solution having a HNO ₃ concentration of about 65% to about 75% by weight) concentrated at about 80 ° C., at about room temperature (for example, about 25 ° C. Temperature) 5.5% by weight of hydrofluoric acid (HF), and the ratio of nitric acid: hydrofluoric acid: water (HNO ₃ : HF: H ₂ O) at about room temperature (for example, a temperature of about 25 ° C.) is about 1 : A 1: 5 solution, an aqueous NaOH solution having a sodium hydroxide (NaOH) concentration of about 10% by weight at about room temperature (for example, a temperature of about 25 ° C), a solution at about room temperature (for example, a temperature of about 25 ° C) HCl solution (e.g., a solution having a HCl concentration of about 35% to about 40% by weight), and a sulfuric acid solution (H) concentrated at about room temperature (e.g., a temperature of about 25 ° C). ₂ S O ₄ ) (for example, a solution having a H ₂ SO ₄ concentration greater than about 90% by weight).

In some embodiments, the boron and carbon films can be selectively removed. In some In an embodiment, the boron and carbon film may have an etching selectivity of about 5 or more for another material in the device (for example, a film having a different composition), including about 10 or more than 10, about 20 or more than 20, Or a selectivity of about 50 or greater.

In some embodiments, for example, a portion of the boron and carbon film deposited on the sidewalls of the three-dimensional structure may exhibit the desired etch rate compared to the etching rate of a portion of the film deposited on the top surface of the three-dimensional feature. In some embodiments, a portion of the boron and carbon film deposited on the sidewall of the three-dimensional structure may exhibit a uniform or substantially uniform etch as a portion of the boron and carbon film deposited on the top surface of the structure rate. For example, a ratio of an etching rate of a sidewall portion of the boron and the carbon film to an etching rate of a top surface portion of the boron and the carbon film may be less than about 4, including less than about 2, and about 1.5. In some examples, the ratio is about one. In some embodiments, the boron and carbon films can maintain uniformity of the top and side portions of the boron and carbon films after being exposed to one or more plasma processes, such as the plasma post-deposition process described herein. degree.

One or more process parameters for the boron and carbon (BC) film growth process can be adjusted to achieve the required boron and carbon film characteristics. For example, the boron reactant, the duration of the reactant pulse, the duration of the purge step, the process temperature, and / or the number of iterations of the reactant pulse can be determined to provide a boron and carbon film containing the desired characteristics . In some embodiments, one or more parameters of one cycle of the reactant pulse and purge step may be different from another cycle (e.g., one cycle of the reactant pulse and purge step as described with reference to FIG. 1) One or more parameters. In some embodiments, the boron reactant may have a B-C bond. In certain embodiments, the boron reactant comprises at least one organic ligand, such as a hydrocarbon ligand, including a boron reactant comprising an alkyl group.

As described herein, one or more processes described herein can be used to form ultra-thin boron and carbon films on a substrate, where the boron and carbon films have a thickness in the sub-nanometer range. In some embodiments, the ultra-thin boron and carbon films may have a thickness of less than about 30 Angstroms (Å), less than about 20 Angstroms, less than about 15 Angstroms, less than about 10 Angstroms, or less than about 7 Angstroms. In some embodiments, the ultra-thin boron and carbon films may have a thickness of less than about 5 Angstroms. In some embodiments, the ultra-thin boron and carbon films may have a thickness of less than about 3 angstroms (eg, about 1 angstrom).

In some embodiments, although ultra-thin boron and carbon films are referred to herein as films, they may not form a continuous layer on the substrate. For example, the ultra-thin boron and carbon film may not completely cover all surfaces of the substrate material on which the ultra-thin boron and carbon film is formed. In some embodiments, the ultra-thin boron and carbon films may include pinholes. The thickness of the ultra-thin boron and carbon films described herein refers to the average thickness of the films. In some embodiments, ultra-thin boron and carbon films can form continuous layers on a substrate.

In some embodiments, the ultra-thin boron and carbon films may be formed according to one or more cyclic processes described herein (such as the cyclic pulsed CVD process described herein). In some embodiments, ultra-thin boron and carbon films can be deposited by a pulsed thermal CVD process. For example, the cycle of a pulsed CVD process for forming ultra-thin boron and carbon films may include exposing the substrate to one or more boron precursors for a certain duration, followed by (e.g., by removing the substrate to A precursor-free or substantially precursor-free environment, and / or a space where the substrate is not exposed to the boron precursor by performing a purge step). As described herein, the one or more boron precursors can be supplied into the reaction space in the presence of a carrier gas. In some embodiments, ultra-thin boron and carbon films can be implemented by It is formed from about 1 to about 100 cycles, preferably about 2 to about 50 cycles, and more preferably about 3 to about 20 cycles. In some embodiments, ultra-thin boron and carbon films can be formed using about 5 to about 10 cycles.

In some embodiments, the deposition rate per cycle of the ultra-thin boron and carbon film may depend on the composition of the material on which the ultra-thin boron and carbon material is deposited. For example, the deposition rate on an aluminum nitride (AlN) substrate in an ultra-thin boron and carbon film process can be lower than when a similar or identical ultra-thin boron and carbon film deposition process is performed on a silicon nitride (SiN) substrate. Deposition rate.

In some embodiments, the process for forming ultra-thin boron and carbon films may include flowing one or more boron precursors continuously or substantially continuously during the deposition process. For example, the process may include a continuous flow thermal CVD process. In some embodiments, a continuous flow process may provide a shorter process (e.g., because a purge step is removed) than a process that includes multiple pulses of reactants. In some embodiments, a continuous flow process may provide improved uniformity over a pulsed process. In some embodiments, continuous flow may be selected to provide the required accuracy in controlling the precursor dose and / or precursor concentration in the reaction space. In certain embodiments, continuous flow may be selected based on the configuration of the reactor chamber. For example, a continuous flow process may be selected for a reactor chamber having a relatively large reaction space volume. In certain embodiments, a continuous flow process may be selected for a batch processing reactor. In some embodiments, a continuous flow process may be selected for a reactor chamber with relatively high accuracy in terms of dose control. For example, a continuous flow process may be selected for a particular CVD reaction chamber.

In some embodiments, ultra-thin boron and carbon materials can be used in a single wafer reactor Middle formation. In some embodiments, ultra-thin boron and carbon films can be formed in a batch processing reactor. For example, a deposition process for forming ultra-thin boron and carbon films can be performed in a vertical batch processing reactor. For example, a batch processing reactor can be used to process a wafer load of about 25 wafers to about 200 wafers, preferably about 50 wafers to about 150 wafers.

As mentioned above, in some embodiments, the process temperature for depositing ultra-thin boron and carbon films in a batch processing reactor may be about 250 ° C to about 400 ° C, preferably about 275 ° C to about 375 ° C. And more preferably about 300 ° C to about 350 ° C.

In some embodiments, the ultra-thin boron and carbon films may exhibit a 1 sigma (1σ) unevenness of less than about 5%, and preferably less than about 2%. For example, ultra-thin boron and carbon films deposited on a 300 millimeter (mm) wafer using one or more processes described herein may exhibit a 1σ unevenness of less than about 2%. In some embodiments, relatively low process temperatures can be used to achieve relatively low uniformity performance.

In some embodiments, ultra-thin boron and carbon films can be used to enhance the etch selectivity performance of structures that include ultra-thin boron and carbon films and another different material. For example, the another material may include a material having a relatively small resistance to certain etchant, including certain wet etchant, such as diluted HF. The use of ultra-thin boron and carbon films with the another different material can advantageously facilitate the formation of the resulting structure with the required etching properties and the required properties of the other different material. For example, ultra-thin boron and carbon films can be used with aluminum nitride and / or aluminum oxide to provide a structure that exhibits the desired electrical and / or optical properties while providing a substrate with the desired etching characteristics. Made of structure.

In some embodiments, the another material may include one or more of a nitride, a carbide, an oxide, and / or a mixture thereof. In certain embodiments, the another material may include one or more of nitrides, carbides, and / or oxides of metals and / or semi-metals. In some embodiments, the another material may include one or more of metal and / or semi-metal nitrides. For example, the one or more nitrides may include silicon nitride, germanium nitride, and / or aluminum nitride. In some embodiments, the another material may include one or more of a metal and / or semi-metal carbide. In certain embodiments, the another material may include one or more of metal and / or semi-metal oxides. For example, the one or more oxides may include germanium oxide and / or silicon oxide.

In some embodiments, the another material may be formed using an atomic layer deposition (ALD) process and / or a CVD process (including a plasma enhanced ALD process and / or a CVD process). In some embodiments, the other material is preferably formed using an ALD process and more preferably a low temperature ALD process (eg, a process temperature of up to about 400 ° C). In some embodiments, the another material may be formed in the same tool (e.g., a cluster tool) as the ultra-thin boron and carbon materials. For example, the reaction chamber for depositing ultra-thin boron and carbon materials can be located on the same clustering tool as the reaction chamber for depositing the other material, so that the substrate can be exposed without exposure to the surrounding air Next (eg, "in situ") perform transfers between reaction chambers. In some embodiments, the same reaction chamber can be used to deposit both ultra-thin boron and carbon materials and the other material, and the substrate is not deposited between the ultra-thin boron and carbon materials and the other material. Exposure to ambient air.

In some embodiments, the other material may be deposited first and may be An ultra-thin boron and carbon film is deposited on another material. For example, the other material may be a substrate having an ultra-thin boron and carbon film deposited thereon. For example, ultra-thin boron and carbon films can be used as a cover layer for the other material. In some embodiments, an ultra-thin boron and carbon film may be deposited first, and the another material may be deposited on the ultra-thin boron and carbon film. For example, ultra-thin boron and carbon films can be used as the etch stop layer for the other material. The use of an ultra-thin boron and carbon film as a cover layer and / or an etch stop layer for the other material may facilitate fine-tuning the etching properties of the resulting structure.

In some embodiments, ultra-thin boron and carbon films having a thickness of less than about 30 angstroms, about 20 angstroms, about 15 angstroms, about 10 angstroms, about 7 angstroms, about 5 angstroms, or about 3 angstroms can withstand or It is substantially resistant to removal by diluted HF. An ultra-thin boron and carbon film having such a thickness can be used as an etch stop layer of another material deposited on the ultra-thin boron and carbon film and / or a cover layer of another material deposited with the ultra-thin boron and carbon film . In some embodiments, ultra-thin boron and carbon materials deposited using about 1 to about 100 deposition cycles (including up to about 50 cycles, about 20 cycles, or about 10 cycles) can exhibit Resistance or substantial resistance to etching by diluted HF. Ultra-thin boron and carbon films deposited using less than about 100 deposition cycles can be used as an etch stop layer for another material deposited on ultra-thin boron and carbon films, and / or used to deposit ultra-thin boron and carbon Carbon film is another layer of material.

As described above, in some embodiments, a boron and carbon (BC) film can be used as a dopant film such as a solid state diffusion (SSD) layer. In some embodiments where a boron and carbon film is used as a dopant film, a cover layer is not required on the boron and carbon film. In some embodiments, the boron and carbon (BC) film itself can be used as a cover layer on different SSD layers to dope the substrate. The boron and carbon dopant films can be formed according to one or more processes described herein. For example, a process for depositing a solid diffusion layer of boron and carbon and / or a cover layer of boron and carbon may include a pulsed thermal CVD process. In some embodiments, the thermal CVD process may include contacting a surface on which the boron and carbon films are deposited with one or more reactant pulses including one or more boron reactants described herein. For example, the reactant pulse may include a boron reactant containing a BC bond, including a boron reactant including an organic ligand, such as a trialkylboron (eg, triethylboron (B (C ₂ H ₅ ) ₃ , TEB), and / or trimethylboron (B (CH ₃ ) ₃ , TMB)). In some embodiments, the reactant pulse comprises a carrier gas such as argon. For example, a cycle of a thermal CVD process for depositing a solid diffusion layer of boron and carbon and / or a cover layer of boron and carbon may include a reactant pulse comprising TEB and argon, wherein a purge is performed after the reactant pulse A step of purging comprising flowing argon gas without flowing a TEB stream such that argon gas flows continuously through the cycle and TEB flows only during a portion of the cycle. In certain embodiments, the cycle can be repeated up to about 1,000 times, about 1,500 times, about 2,000 times, or about 5,000 times. In certain embodiments, the cycle can be repeated up to about 2 times to about 1,000 times, including about 2 times to about 2,000 times, about 3 times to about 2,000 times, or about 5 times to about 5,000 times. In certain embodiments, the cycle may be repeated about 10 to about 1000 times. In certain embodiments, the cycle may be repeated from about 50 to about 2,000 times. In certain embodiments, the cycle may be repeated from about 100 times to about 1,500 times.

In certain embodiments, the reactant pulse may have a duration of about 0.1 seconds to about 5 seconds (including about 0.1 seconds to about 1 second). For example, a reactant pulse may have Duration of about 0.3 seconds. In some embodiments, the purge step may have a duration of about 0.5 seconds to about 10 seconds, inclusive. For example, the purge step may have a duration of about 1 second.

In some embodiments, a process for depositing a solid diffusion layer of boron and carbon and / or a cover layer of boron and carbon may be at about 300 ° C to about 450 ° C (including about 350 ° C to about 450 ° C or about 400 ° C to about 450 ° C). For example, a solid boron and carbon diffusion layer and / or a boron and carbon capping layer may be deposited at a temperature of about 430 ° C. In some embodiments, the boron and carbon solid-state diffusion layer and / or boron and carbon capping layer may be deposited at a reactor chamber pressure of about 0.5 torr to about 10 torr (eg, about 6 torr).

In some embodiments, the thickness of the boron and carbon films can be selected to provide the required doping on the underlying substrate. For example, the thickness of the solid diffusion layer of boron and carbon and / or the cover layer of boron and carbon can be selected to achieve the required substrate doping. In some embodiments, the boron and carbon solid-state diffusion layer may have a thickness of up to about 5 nanometers (nm). In some embodiments, the boron and carbon solid-state diffusion layer may have a thickness of about 4 nanometers or about 3 nanometers. For example, the boron and carbon solid-state diffusion layer may have a thickness of about 1 nanometer. In some embodiments, a film stack including a boron and carbon solid-state diffusion layer on a substrate and having no or substantially no cover layer may have a thickness of less than about 4 nanometers. In certain embodiments, the boron and carbon capping layer may have a thickness of up to about 5 nanometers (including up to about 4 nanometers or about 3 nanometers). For example, the boron and carbon capping layer may have a thickness of about 1 nanometer. In some embodiments, a 1 nm thick boron and carbon solid diffusion layer on a substrate is included with no or substantially no film stack or 1 nm thick on a conventional boron-containing solid diffusion layer The film stack of boron and carbon overlays provides Required doping. In certain embodiments, a film stack having a thickness of up to about 4 nanometers and including a solid boron and carbon diffusion layer on a substrate with or without a covering layer, or having a thickness of up to about 4 nanometers and A film stack including a boron and carbon capping layer on a conventional boron-containing solid diffusion layer can provide the required doping to the underlying substrate.

One or more process parameters for the boron and carbon dopant film growth process can be adjusted to achieve the desired boron and carbon dopant film characteristics, such as to provide the required boron concentration in the dopant film to achieve The required doping to the underlying substrate. One or more process parameters for the boron and carbon dopant film growth process can be adjusted to achieve the required boron and carbon film thickness to provide the required doping to the underlying substrate. For example, the selection of boron reactants, the duration of the reactant pulses, the duration of the purge step, the process temperature, and / or the number of iterations of the reactant pulses can be determined to provide the desired characteristics (such as Carbon film thickness) of boron and carbon films. In some embodiments, one or more parameters of one cycle of the reactant pulse and purge step may be different from another cycle (e.g., one cycle of the reactant pulse and purge step as described with reference to FIG. 1) One or more parameters to deposit a film with the desired characteristics.

In some embodiments, a thermal annealing process is performed after depositing boron and a carbon film dopant film. For example, a thermal annealing process may be performed after a desired film stack for a solid state doping scheme (eg, a film stack including a boron and carbon solid diffusion layer or a film stack including a boron and carbon capping layer) has been formed. The thermal annealing process drives the boron dopant into the underlying substrate and can be performed at a process temperature of about 800 ° C to about 1500 ° C (including about 800 ° C to about 1200 ° C). In some embodiments, the annealing process may be performed in an environment containing nitrogen (N ₂ ) and / or helium (He). In some embodiments, the thermal annealing process may include hydrogen (H ₂ ). In some embodiments, an environment containing hydrogen (H ₂ ) may, for example, increase the diffusion of boron into the substrate compared to a thermal annealing process that does not use hydrogen (H ₂ ). In some embodiments, the thermal annealing process may have a duration of about 0.5 seconds to about 5 seconds (including about 0.5 seconds to about 3 seconds). For example, the thermal annealing process may be performed in a nitrogen-containing environment (eg, a N ₂ environment) at a process temperature of about 1000 ° C. for about 1 second. The thermal annealing process can be performed multiple times to achieve the desired boron dopant profile within the underlying substrate. For example, the thermal annealing process can be performed once to achieve the desired dopant distribution. For example, the thermal annealing process can be performed twice to achieve the desired dopant distribution.

2A and 2B illustrate examples of a film stack including a boron and carbon (BC) film. FIG. 2A illustrates a boron and carbon dopant film deposited directly on a silicon substrate. For example, the boron and carbon film can be a solid state diffusion (SSD) layer deposited directly on the silicon substrate, so that subjecting the boron and carbon film to the thermal annealing process can drive boron from the boron and carbon film into the silicon substrate. To provide a dopant to the substrate.

In some embodiments, an undoped layer may be formed on the substrate, and a boron and carbon solid-state diffusion layer may be formed on the undoped layer. In some embodiments, the undoped layer may include silicon oxide. For example, a boron and carbon solid diffusion layer can be deposited on a silicon oxide layer formed on a silicon substrate. Without being limited by any particular theory or mode of operation, an undoped layer may facilitate the control of substrate doping. For example, forming an undoped silicon oxide layer on a substrate so that boron and carbon solid diffusion layers are not directly deposited on the substrate can provide the desired boron concentration distribution in the substrate after annealing. In some embodiments, the undoped layer may have about 0.5 nanometers to about 4 nanometers (including about 0.5 nm to about 3 nm, about 0.5 nm to about 2 nm, or about 0.5 nm to about 1 nm). For example, in some embodiments, the undoped silicon oxide layer may have a thickness of about 0.5 nm to about 4 nm.

As described herein, boron and carbon films can be used as cover layers in solid-state doping. For example, a conventional dopant film can be formed on a substrate and a boron and carbon capping layer can be formed on the conventional dopant film. In some embodiments, the conventional dopant film may be a boron-doped film. FIG. 2B shows a first boron doped film on a silicon substrate and a different second boron and carbon film on the boron doped film. The first boron-doped film may include a conventionally formed boron-containing solid diffusion layer, such as a BSG layer. The second boron and carbon film on the conventionally formed boron doped film may be a cover layer. In some embodiments, the capping layer inhibits the dopant from diffusing outward from the underlying boron-doped film. For example, the first boron dopant film can be directly formed on a silicon substrate and the second boron and carbon capping layer can be directly deposited on the boron doped film by a process as described herein. In some embodiments, the boron and carbon capping layers may be deposited on the boron-doped film and not or substantially not exposed to the ambient air (e.g., in processes used to deposit boron-doped films and for There is no air exposure between the processes of depositing boron and carbon coatings). For example, the boron and carbon capping layer may be deposited on the boron-doped film in an in-situ sequential deposition process. The film stack shown in FIG. 2B may undergo a thermal annealing process to drive boron from the boron-doped film and / or the boron and carbon capping layer into the silicon substrate.

FIG. 3 illustrates a flowchart 200 of another example of a process for forming a boron and carbon (BC) film according to some embodiments. In block 202, the substrate is exposed to a boron and carbon film growth process. The boron and carbon film growth process may include a deposition process such as a pulsed thermal CVD process for depositing a boron and carbon film having a desired thickness and / or composition. Give For example, the boron and carbon film growth process may include repeating a cycle including a reactant pulse and a subsequent purge step (for example, the reactant pulse and purge step as described with reference to FIG. 1). The cycle can be repeated multiple times to achieve the desired boron and carbon film thickness and / or composition.

In block 204, a post-deposition process may be performed on the deposited boron and carbon films. In some embodiments, the post-deposition process includes a plasma process. For example, the processing process may include contacting the deposited boron and carbon films with one or more energized substances for a certain duration. In some embodiments, the post-deposition process includes contacting a substrate including a boron and carbon film with a plasma. For example, the substrate may be contacted with a plasma generated using a nitrogen-containing compound (for example, nitrogen), an inert gas, and / or an oxygen-containing compound (for example, oxygen and / or ozone). In some embodiments, a purge step may be performed after the post-deposition process. For example, the purge step may include flowing nitrogen and / or one or more inert gases. In some embodiments, purging the reactor chamber after the post-deposition treatment process may include turning off the plasma power while continuing to flow one or more of the gases used to generate the plasma for the post-deposition treatment process. For example, during the purge step, while the plasma power is turned off, one or more gases used to generate the plasma for the post-deposition treatment process can be continuously flowed into the reactor, as described during the purge step The flow rate of the one or more gases is the same as or different from that during the post-deposition process.

In some embodiments, exposing the boron and carbon film to a plasma post-deposition process may be beneficial, for example, to further reduce the treated boron compared to the etching rate of the boron and carbon film formed without performing the post-deposition process. And the etching rate of the carbon film. Not subject to Restrictions on specific theories or modes of operation, exposing boron and carbon films to the post-plasma deposition process as described herein can increase the density of boron and carbon films, thereby providing a boron and carbon film compared to untreated boron and carbon films. And treated boron and carbon films that exhibit reduced etch rates. In some embodiments, after exposing the boron and carbon film to a plasma post-deposition process, the etching rate of a portion of the boron and carbon film deposited on the sidewalls of the three-dimensional structure may exhibit as A portion of the boron and carbon film on the top surface is uniformly or substantially uniformly etched (e.g., after exposing the boron and carbon film to a plasma process of a post-deposition process, for example, compared to a post-deposition process The previous etching rate of the film can maintain the uniformity of the etching rate between the top of the boron and carbon film and the side wall portion thereof). For example, after the plasma post-deposition process, the ratio of the etching rate of the sidewall portions of the boron and carbon film to the etching rate of the top surface portion of the boron and carbon film may be less than about 4, including less than about 2, about 1.5. In some examples, the ratio is about one.

As described herein, in some embodiments, the post-plasma deposition process may include: contacting the deposited boron and carbon film with a nitrogen-containing plasma (eg, contacting the deposited boron and carbon film with a nitrogen-containing free radical) And / or ions). One or more nitrogen-containing compounds can be used to generate a nitrogen-containing plasma, such as a nitrogen-containing compound without hydrogen (H). For example, the post-plasma deposition process may include energetic species produced using nitrogen (N ₂ ).

In some embodiments, the post-plasma deposition process includes exposing the boron and carbon film to a nitrogen-containing plasma for about 1 second (s) to about 500 seconds, 10 seconds to about 300 seconds (including about 10 seconds). To about 100 seconds, or about 10 seconds to about 50 seconds). Can be at a process temperature of about 100 ° C to about 500 ° C (including about 200 ° C to about 500 ° C, and about 200 ° C to about 400 ° C) and at about 0.1 Torr to about 20 Torr (including about 1 Torr to about 10 Torr) , And a pressure of about 1 Torr to about 8 Torr) to perform a nitrogen-containing plasma post-deposition process. In certain embodiments, the plasma power used to generate the nitrogen-containing plasma may be about 50 watts (W) to about 2000 watts, including about 50 watts to about 1000 watts, about 100 watts to about 400 watts, and About 200 watts to about 400 watts.

In some embodiments, the post-plasma deposition process includes: contacting the deposited boron and carbon film with an inert gas-containing plasma (eg, contacting the deposited boron and carbon film with free radicals and / or ions containing an inert gas). ). For example, the plasma post-deposition process may include a plasma including a high-energy substance generated by using helium (He) gas, argon (Ar) gas, and / or neon (Ne) gas. In some embodiments, the post-plasma deposition process includes exposing the boron and carbon film to a plasma containing an inert gas for a duration of about 10 seconds to about 300 seconds (including about 10 seconds to about 100 seconds). It can be at a process temperature of about 100 ° C to about 500 ° C (including about 200 ° C to about 500 ° C and about 200 ° C to about 400 ° C) and at about 0.1 to about 20 torr (including about 1 to about 10 torr and An inert gas-containing post-plasma deposition process is performed at a pressure of about 1 Torr to about 8 Torr). In some embodiments, the plasma power used to generate the inert gas-containing plasma may be about 50 Watts (W) to about 2000 Watts, including about 50 Watts to about 1000 Watts, about 100 Watts to about 400 Watts, And about 200 watts to about 400 watts.

In some embodiments, the post-plasma deposition process includes: contacting the deposited boron and carbon films with an oxygen (O) -containing plasma (eg, contacting the deposited boron and carbon films with oxygen-containing free radicals and / or ion). In certain embodiments, oxygen-containing compounds such as oxygen (O ₂ ) and / or ozone (O ₃ ) may be used to generate an oxygen-containing plasma. In some embodiments, the post-plasma deposition process may include exposing the boron and carbon film to an oxygen-containing plasma for a duration of about 10 seconds to about 300 seconds (including about 10 seconds to about 100 seconds). Can be at a process temperature of about 100 ° C to about 500 ° C (including about 200 ° C to about 500 ° C, and about 200 ° C to about 400 ° C) and at about 0.1 Torr to about 20 Torr (including about 1 Torr to about 10 Torr) And a pressure of about 1 Torr to about 8 Torr) to perform an oxygen-containing plasma post-deposition process. In some embodiments, the plasma power used to generate the oxygen-containing plasma may be from about 50 Watts (W) to about 2000 Watts, including from about 50 Watts to about 1000 Watts, from about 100 Watts to about 400 Watts, and About 200 watts to about 400 watts.

In some embodiments, an oxygen-containing plasma (eg, generated using oxygen and / or ozone) post-deposition process can increase the refractive index of the boron and carbon films. In certain embodiments, the oxygen-containing plasma post-deposition process can reduce the thickness of the boron and carbon films (e.g., the thickness of the processed film can be less than the thickness of the film before exposure to the post-deposition process ). Without being limited by any particular theory or mode of operation, exposing boron and carbon films to an oxygen-containing plasma can be beneficial for replacing the hydrogen (H) and / or carbon (C) components of the film with oxygen (O), such as A BO _x containing film was produced. Without further being limited by any particular theory or mode of operation, changes in the composition of the boron and carbon films (such as replacing the hydrogen (H) and / or carbon (C) components of the film with oxygen (O)) can be performed by the film reduction and / or decreasing the refractive index of the film thickness (e.g., by increasing the film density and / or remove volatile substances BO _x) to reflect. For example, exposing boron and carbon films to an oxygen-containing plasma under certain conditions can result in complete or substantially complete removal of the deposited boron and carbon films (e.g., plasma for boron and carbon films) Etching).

In some embodiments, the plasma post-deposition process may be performed once after depositing a boron and carbon film having a desired thickness and / or composition. In some embodiments, after each iteration of multiple cycles of the deposition process for depositing boron and carbon films (e.g., in the cycle of the reactant pulse and purge steps as described with reference to FIG. 1) After repeated multiple times), a post-plasma deposition process is performed. For example, a plasma post-deposition process can be performed after every 1, 2, 5, 10, 100, 1,000 cycles of a boron and carbon film deposition process. Other numbers of cycles may be suitable. In some embodiments, the ratio of the number of cycles of a process for depositing boron and carbon films to the number of cycles of a plasma post-deposition process for forming boron and carbon films with desired characteristics (e.g., Y: X The ratio) may be about 5,000: 1 to about 1: 1, including about 2,000: 1 to about 50: 1. In some embodiments, the ratio of the number of cycles of the process of depositing boron and carbon film to the number of cycles of the post-plasma deposition process may be about 1,500: 1 to about 1: 1, including about 1,000: 1 to about 1: 1. About 500: 1 to about 1: 1, about 100: 1 to about 1: 1, about 50: 1 to about 1: 1, and about 20: 1 to about 1: 1.

In some embodiments, one or more parameters of the plasma post-deposition process can be adjusted to facilitate the formation of boron and carbon films with desired characteristics. For example, the duration of the process, plasma power, pressure, plasma composition, and / or number of repetitions may be selected to facilitate the production of boron and carbon films with desired etching characteristics.

A suitable reaction chamber for one or more boron and carbon (BC) film deposition processes described herein may be part of a clustering tool in which various processes in the formation of integrated circuits are performed. In some embodiments, it may be in a batch reactor (including, for example, a mini-batch reactor) (e.g., having 8 substrates or less Substrate reactors) and / or furnace batch processing reactors (e.g., reactors with a capacity of 50 or more substrates) to perform one or more boron and carbon film deposition processes described herein . In some embodiments, one or more boron and carbon film deposition processes described herein can be performed in a single wafer reactor. In certain embodiments, a space reactor chamber may be suitable. In certain embodiments, a reactor chamber having a cross-flow configuration may be suitable (e.g., to provide a gas flow parallel or substantially parallel to the surface of a substrate located in the reactor chamber). Reactor chamber). In certain embodiments, a reactor chamber having a showerhead configuration may be suitable (e.g., a reactor chamber to provide a gas flow that is perpendicular or substantially perpendicular to the surface of a substrate located in the reactor chamber) ).

In some embodiments, the boron and carbon films used as dopant films are not subjected to a post-plasma deposition process. For example, boron and carbon dopant films may not be subjected to one or more post-plasma depositions as described herein before subsequent processing (e.g., before a thermal annealing process used to drive dopants into the underlying substrate) Processing process.

Exemplary single wafer reactors are commercially available under the trade names Pulsar® 2000 and Pulsar® 3000 from ASM USA, Phoenix, AZ, and under the trade name Eagle® ) XP and Eagle® XP8 are commercially available from ASM Japan Co., Ltd. of Tokyo, Japan. Exemplary batch ALD reactors are commercially available under the trade names A400 ^™ and A412 ^™ from ASM Europe Ltd. of Almere, Netherlands.

Examples of BC film

FIG. 4 illustrates the growth of boron and carbon (BC) films deposited according to some embodiments. Graph of long rate (in Angstroms / cycle) versus process temperature (in degrees Celsius). A pulsed thermal CVD process was used to deposit a boron and carbon (BC) film as shown in Figure 4 in a Pulsar® 3000 reactor chamber with a cross-flow configuration. One cycle of the pulsed thermal CVD process includes a reactant pulse having a duration of about 0.5 seconds, and a subsequent purge step having a duration of about 5 seconds. Reactant pulses include: supplying TEB and nitrogen into the reactor chamber. The TEB is supplied into the reactor chamber by a vapor extraction method by supplying vaporized TEB from a source container maintained at a temperature of about 20 ° C. The pressure in the reactor chamber was maintained at about 0.1 Torr to about 10 Torr during the reactant pulse. The purge step includes flowing nitrogen through the reactor chamber. The growth rates of boron and carbon films deposited according to the pulsed thermal CVD process were measured at process temperatures of about 375 ° C, about 400 ° C, and about 450 ° C. As shown in FIG. 4, the growth rate of the boron and carbon films at each cycle increases as the process temperature increases. As shown in FIG. 4, the boron and carbon films deposited by such a pulsed thermal CVD process may have a linear or substantially linear relationship with the process temperature.

The composition of the boron and carbon (BC) films deposited at a process temperature of about 400 ° C. according to the process described with reference to FIG. 4 was measured by Rutherford backscattering spectrometry (RBS), and found that The composition of the boron and carbon film has a boron and carbon stoichiometry of about B _0.608 C _0.392 or B _1.5 C. The refractive index of the boron and carbon films deposited at a process temperature of about 400 ° C. according to the process described with reference to FIG. 4 was measured by a spectroscopic ellipsometry. The refractive index was found to be about 1.98 at a wavelength of about 633 nanometers (nm). Measured the wet etching rate performance of the film deposited according to the process described with reference to FIG. 4 at a process temperature of about 400 ° C. in a dilute hydrofluoric acid solution (for example, a 0.5% by weight HF aqueous solution), and found that The membrane was surprisingly resistant to diluted HF solutions. It was found that, for example, after exposure to a diluted HF solution for up to about 10 minutes (eg, immersion in dHF for up to about 10 minutes), the wet etch rate in the diluted HF solution was negligible. In certain embodiments, negligible etch rates are observed after exposures of up to about 30 minutes or longer. It was found that the wet etching rate of these films in a dilute hydrofluoric acid solution was less than 0.3 times the etching rate of thermal silicon oxide (TOX).

FIG. 5 shows a Fourier transform infrared spectroscopy (FTIR) analysis of a boron and carbon (BC) film deposited at a process temperature of about 400 ° C. according to the process described with reference to FIG. 4. FTIR analysis revealed the presence of CH, BH, BC, BB, and CC bonds in the boron and carbon films. For example, a peak at about 2902 cm ^-1 may contribute to a CH bond, and a peak at about 2573 cm ^-1 may contribute to a BH bond in a film. The peak at 1201 cm ^-1 and the peak at 1051 cm ^-1 indicate the presence of BC, BB, and CC bonds.

A boron and carbon (BC) film was deposited on a blanket wafer having a diameter of about 300 millimeters (mm) using a process as described with reference to FIG. 4 at a process temperature of about 400 ° C. Deposition was performed in a Pulsar® 3000 reactor chamber with a cross-flow configuration. After applying 1,000 cycles of the pulsed thermal CVD process shown in FIG. 4, the average film thickness was measured to be about 35.58 nm. The deposited boron and carbon films show, for example, an increase in thickness toward the center of the wafer compared to, for example, the edge of the wafer, such as the leading edge of the wafer (for example, a portion of the wafer edge further from the wafer recess). Not subject to any particular theory Or the limitation of the operation mode, such a thickness distribution may indicate a surface reaction limited growth mechanism, and the thickness variation may be caused by a temperature change of the pedestal on which the wafer is positioned. Limited surface reaction growth can favorably improve the film's conformality performance for the deposition of boron and carbon films on 3-D features.

A boron and carbon (BC) film was deposited on a blanket wafer in a Pulsar® 3000 reactor chamber with a cross-flow configuration at a process temperature of about 450 ° C. After applying 1,000 cycles of the pulsed thermal CVD process shown in FIG. 4, the average thickness of the deposited boron and carbon films is about 81.88 nm. Compared with the boron and carbon films deposited at about 400 ° C, the films deposited at about 450 ° C exhibit an increased thickness. The deposited boron and carbon film has, for example, an increased thickness closer to the leading edge of the blanket wafer than the boron and carbon film deposited at 400 ° C. Without being limited by any particular theory or mode of operation, the increased thickness near the leading edge may indicate a mass-transport limited film growth mechanism, as opposed to a surface reaction-limited growth mechanism.

FIGS. 6A to 6D are scanning electron microscopy (SEM) cross-sectional views of a boron and carbon (BC) film deposited on the high-aspect-ratio trench structure 500 using the deposition process described with reference to FIG. 4. image. The boron and carbon films were deposited at a process temperature of about 400 ° C in a Pulsar® 3000 reactor chamber and by applying 1,500 cycles of a reagent pulse as described with reference to FIG. 4 and a subsequent purge step. FIG. 6A shows an SEM image of the high-aspect-ratio trench structure 500 at a magnification of 15k ×. FIG. 6B shows a SEM image of the upper portion 502 of the high-aspect-ratio trench structure 500 at 100 k × magnification. FIG. 6C shows the magnification at 100k × Next, the SEM image of the middle section 504 of the high-aspect-ratio trench structure 500, and FIG. 6D shows the SEM image of the lower portion 506 of the high-aspect-ratio trench structure 500 at 100k × magnification. The thicknesses of the deposited boron and carbon films in each of the upper, middle, and lower portions of the high-aspect-ratio trench structure are shown in FIGS. 6B, 6C, and 6D, respectively. As shown in FIGS. 6A to 6D, a relatively uniform film thickness is achieved on each side of the high-aspect-ratio trench structure located at the upper, middle, and lower portions of the trench structure, for example, confirming the deposition of boron and carbon films. Improved conformality. For example, the film thickness measured in the upper portion 502 of the high-aspect ratio trench structure 500 is about 72 nanometers, and the film thickness measured in the middle section 504 of the trench structure 500 is about 69 nanometers, and The thickness of the film measured at the lower portion 506 of the structure 500 is about 69 nanometers, for example, confirming that a conformality greater than or equal to about 95% is achieved. Without being limited by any particular theory or mode of operation, depositing a boron and carbon film at a process temperature of about 400 ° C or below can facilitate the deposition of the film in a surface-restricted system to improve the deposition Conformality of the film.

FIG. 7 shows the removal rate of various boron and carbon (BC) films when exposed to a 0.5% by weight HF solution (diluted HF solution) as a function of the number of deposition cycles used to form corresponding boron and carbon films Graph. The y-axis shows the thickness (in Angstroms (Å)) of the boron and carbon films that were removed after exposure to diluted HF for about 60 seconds. The x-axis shows the number of deposition cycles used to form the corresponding boron and carbon films, and the removal of boron and carbon films deposited using 1 cycle, 10 cycles, 20 cycles, and 30 cycles was measured rate. The etch performance of boron and carbon films deposited on four different substrates after exposure to diluted HF is shown. The etch performance curve A in FIG. 7 corresponds to a silicon nitride (SiN) deposited on a low process temperature process. Boron and carbon film. The etch performance curve B corresponds to a boron and carbon film deposited on natural silicon oxide. The etch performance curve C corresponds to a boron and carbon film deposited on aluminum nitride (AlN), wherein the aluminum nitride is subjected to air interruption after the aluminum nitride is formed and before the boron and carbon film is deposited on the aluminum nitride ( air break). The etching performance curve D of FIG. 7 corresponds to a boron and carbon film deposited on aluminum nitride (AlN), wherein the aluminum nitride is not caused after the aluminum nitride is formed and before the boron and carbon film is deposited on the aluminum nitride. Withstand air interruption.

The boron and carbon films shown in Figure 7 were deposited in a batch processing reactor with a 120 wafer load. The film is deposited by supplying a corresponding number of deposition cycles into the reactor chamber. Each of the cycles of the boron and carbon film deposition process includes a boron precursor pulse having a duration of about 5 seconds, wherein the boron precursor pulse includes flowing TEB and nitrogen (N ₂ ) into the reactor chamber Nitrogen (N ₂ ) was used as the inert carrier gas. Each cycle is performed at a process temperature of about 350 ° C and includes a purge step after the boron precursor pulse. The purge step has a duration of about 18 seconds and includes flowing nitrogen (N ₂ ) into the reactor chamber.

As shown in FIG. 7, the boron and carbon films generally exhibit increased resistance to removal by diluted HF as the number of deposition cycles used to form the film increases. The boron and carbon films deposited on the low temperature process silicon oxide using 10 deposition cycles and more than 10 deposition cycles exhibit resistance to removal by exposure to diluted HF for 60 seconds. At the same time, boron and carbon films deposited on natural silicon oxide using 20 deposition cycles and above exhibited resistance to removal by exposure to diluted HF for 60 seconds. Boron and carbon films deposited on aluminum nitride subjected to air interruption using 20 deposition cycles and above Demonstrated resistance to removal by exposure to diluted HF for 60 seconds while simultaneously depositing boron and carbon films on aluminum nitride without interruption by air using 30 deposition cycles Demonstrated resistance to removal by exposure to diluted HF for 60 seconds.

FIG. 8 is a graph showing the deposition rate of boron and carbon (BC) films as a function of process temperature, wherein the reactant pulse used for the deposition process includes TEB and argon. The deposition rate in nanometers per minute (nm / min) is shown on the y-axis, and the process temperature corresponding to each plotted deposition rate in degrees Celsius is shown on the x-axis. A pulsed thermal CVD process was used to deposit the boron and carbon films shown in Figure 8 in the Eagle ^® 12 reactor. One cycle of the pulsed thermal CVD process includes a reactant pulse with a duration of about 0.3 seconds and a subsequent purge step with a duration of about 1 second. Reactant pulses include supplying TEB and argon into the reactor chamber. The TEB is supplied into the reactor chamber by a vapor extraction method by supplying vaporized TEB from a source container maintained at a temperature of about 20 ° C. The pressure in the reactor chamber was maintained at about 0.1 Torr to about 10 Torr during the reactant pulse. The purge step includes flowing argon through the reactor chamber. The growth rates of boron and carbon films deposited according to the pulsed thermal CVD process were measured at process temperatures of about 350 ° C, about 400 ° C, about 420 ° C, and about 430 ° C. As shown in FIG. 8, the growth rate of the boron and carbon films at each cycle increases as the process temperature increases. As shown in FIG. 8, the boron and carbon films deposited using such a pulsed thermal CVD process using TEB and argon can have a non-linear relationship with the process temperature. For example, the film growth rate at a process temperature of about 430 ° C is significantly higher than the film growth rate at a process temperature of about 350 ° C. In some embodiments, such boron and carbon films may be dopant films including boron and carbon solid diffusion layers and / or capping layers.

FIG. 9A shows a scanning transmission electron microscopy (scanning transmission electron microscopy, at 180k × magnification) of a cross-sectional view of a boron and carbon film deposited using the process described above with reference to FIG. 8 at a process temperature of about 430 ° C. STEM) image. The boron and carbon films exhibit conformal coverage of the trench characteristics. As shown in FIG. 9A, a boron and carbon film is directly deposited on the substrate.

FIG. 9B is a table providing the composition of the boron and carbon (BC) films shown in FIG. 9A. As shown in the table, the boron and carbon films mainly include boron, carbon, and hydrogen. The boron and carbon film contains approximately 35 atomic% of boron (B), approximately 33 atomic% of carbon (C), approximately 28 atomic% of hydrogen (H), approximately 2 atomic% of nitrogen (N), and approximately 2 atomic% Of oxygen (O).

FIG. 10 is a graph showing boron concentrations at various depths in the silicon layer after annealing the boron and carbon films deposited on the silicon layer by the above process. Secondary ion mass spectrometry (Secondary Ion Mass Spectrometry, SIMS) was used to measure the boron concentration. The boron concentration in atom / cm 3 (atoms / cm ³ ) is shown on the y-axis, and the depth in nanometers (nm) measured from the top surface of the silicon layer is shown on the x-axis. A boron and carbon film having a thickness of about 1 nm is directly deposited on a silicon substrate using a process described with reference to FIG. 8 at a process temperature of about 415 ° C. The film including the boron and carbon solid diffusion layers was then subjected to a thermal annealing process performed at a process temperature of about 1000 ° C. in a nitrogen (N ₂ ) environment for a duration of about 1 second.

As shown in FIG. 10, a 1 nm thick boron and carbon solid diffusion layer is used to achieve a boron concentration or doping degree of about 2E + 20 atoms / cm3 at the surface of the silicon substrate. The boron concentration achieved using boron and carbon solid-state diffusion layers is significantly higher than using conventional solid-state diffusion layers. Boron concentration obtained from a state diffusion layer and a conventional cover layer (for example, a 3 nm silicon dioxide cover layer on a 1 nm borosilicate glass (BSG) solid-state diffusion layer). For example, the boron concentration achieved using the boron and carbon solid-state diffusion layer is significantly higher than the boron concentration obtained using a conventional solid-state diffusion layer and a conventional cover layer having a depth of up to about 40 nm.

FIG. 11 is a graph showing aging analysis of boron and carbon films using Fourier transform infrared spectroscopy (FTIR). Using the process described with reference to FIG. 8, boron and carbon films are deposited at a process temperature of about 415 ° C. FTIR analysis was performed on the boron and carbon films after the films were deposited for about seven days. The boron and carbon films are exposed to ambient air, such as the environment around a clean room, for a duration of seven days.

The FTIR analysis shown in FIG. 11 shows that the characteristics of the boron and carbon films remain unchanged or substantially unchanged over the course of about 7 days, and thus exhibit the required chemical stability after deposition. For example, FTIR analysis shows that the membrane does not absorb a large amount of water from the air. A boron and carbon film that can exhibit the required stability after deposition (eg, exhibit negligible absorption of moisture when exposed to ambient air) can be used as a cover layer in a solid-state doping scheme. As described herein, a boron and carbon capping layer can be deposited onto a conventional solid-state diffusion layer, such as a borosilicate glass (BSG) layer, to provide the desired doping to a semiconductor substrate. Without being bound by any particular theory or mode of operation, boron and carbon films that exhibit negligible moisture absorption when exposed to ambient air can be used as solid diffusion layers without or substantially without a coating.

FIG. 12 is a table showing the optical properties and deposition efficiency of an example of a boron and carbon film deposited at a process temperature of about 415 ° C. using the process described with reference to FIG. 8. The film is subjected to thermal annealing at a process temperature of about 1000 ° C. under a nitrogen (N ₂ ) environment for a duration of about 1 second. As shown in the table, the deposition process provides a deposition rate of about 0.045 nanometers / cycle and about 2.091 nanometers / minute. The 1 Sigma (1σ) unevenness of the deposited film was about 18.42%.

The refractive indices of boron and carbon films are measured by a spectroscopic ellipsometer. As shown in the table of Figure 12, the film exhibited an average refractive index of about 1.805 at a wavelength of about 633 nanometers (nm).

Silicon nitride film containing boron and carbon

As described herein, a silicon nitride film containing boron and carbon components can be deposited, and the silicon nitride film containing boron and carbon components can have various applications, including applications in the fabrication of semiconductor devices. Atomic layer deposition (ALD) is used to deposit silicon nitride-based films having desired characteristics at a reduced temperature (for example, at a temperature of less than about 500 ° C), for example, to provide a process with a reduced thermal budget. For difficult. A silicon nitride film deposited by a conventional process at a lower process temperature can provide a film having the following characteristics: poor film quality, a three-dimensional (3-D) structure with a silicon nitride film deposited thereon Poor film conformality, undesirably high dry etch rates, and / or undesirably low etch selectivity (e.g., etch selectivity to another material in a semiconductor device, including thermal silicon oxide materials), So that the silicon nitride film can withstand one or more subsequent thermal silicon oxide etching steps used in the device manufacturing process).

For convenience and simplicity, the chemical formula of the silicon nitride film is commonly referred to herein as SiN. However, those skilled in the art should understand that the actual chemical formula of silicon nitride may be SiNx, where x varies from about 0.5 to about 2.0, as long as some Si-N bonds are formed. In some cases, x preferably varies from about 0.9 to about 1.7, more preferably from about 1.0 to about 1.5, and most preferably from about 1.2 to about 1.4. Silicon nitride is generally formed in which Si has an oxidation state of + IV, and the amount of nitride in the material may vary.

For convenience and simplicity, the chemical formula of a silicon nitride film containing boron and carbon components is commonly referred to herein as SiN (B, C). However, those skilled in the art should understand that the actual chemical formula of SiN (B, C) can be SiN _x (B _y , C _z ). In certain embodiments, for example, x may vary from about 0.5 to about 3.0, as long as certain Si-N bonds are formed. In some cases, x preferably varies from about 1.0 to about 2.0 and more preferably from about 1.3 to about 1.8. In certain embodiments, y may be between about 0.1 to about 5.0, including preferably from about 0.3 to about 3.0, and more preferably from about 0.5 to about 1.5. For example, y may be about 1.5. In certain embodiments, z may be from about 0.1 to about 5.0, including preferably from about 0.2 to about 2.5, and more preferably from about 0.3 to about 1.3. For example, z may be about 1.0.

One or more methods described herein may include an atomic layer deposition (ALD) process and / or a chemical vapor deposition (CVD) process, and may be used to form silicon nitride-based films, such as silicon nitride containing boron and carbon components Film SiN (B, C). In some embodiments, the silicon nitride film containing boron and carbon components has improved conformal coverage of three-dimensional (3-D) features, a desired dry etch rate, a desired wet etch rate, and / or One or more of the desired etch selectivities for another material, such as a thermal silicon oxide layer (TOX) in a semiconductor device. For example, a silicon nitride film containing boron and carbon components deposited according to one or more processes described herein (e.g., for use in, for example, semiconductor transistors (including multi-gates such as fin field-effect transistors) Gate transistor) Applications such as bulkhead materials) can exhibit improved step coverage, reduced etch rates in wet etchant (e.g., for example, diluted hydrofluoric acid (HF or dHF) solutions (e.g., 0.5% by weight Resistance to wet etchant such as HF solution), and / or reduced wet etch rate for thermally oxidized silicon materials (e.g., wet etch rate of silicon nitride film to thermal oxidized silicon materials The ratio of the wet etch rate is less than about 1, including less than about 0.5). In some embodiments, the silicon nitride film including the boron and carbon components may have a desired dielectric constant (κ-value), such as a dielectric constant less than about 7 (including less than about 6 and less than about 5.5). For example, a silicon nitride film including a boron and carbon component may have a dielectric constant between about 4.8 and about 6, including between about 4.8 and about 5.5.

In some embodiments, a silicon nitride ALD deposition process can be used to deposit a silicon nitride (SiN) film having a desired thickness and composition. ALD-type processes are based on controlled self-limiting surface reactions. Gas phase reactions are avoided by contacting the substrate with the reactants alternately and sequentially. The gas phase reactants are separated from each other in the reaction chamber, for example, by removing excess reactants and / or reactant by-products from the reaction chamber between the reactant pulses. For example, the ALD deposition process may include: contacting the substrate with a silicon reactant so that the silicon reactant is adsorbed on the substrate surface, and then contacting the substrate with a nitrogen reactant. The silicon reactant may include a silicon-containing compound that may contribute silicon to the growth of the silicon nitride film. The nitrogen reactant may include a nitrogen-containing compound that may contribute nitrogen to the growth of the silicon nitride film. Exposing the substrate to a silicon reactant and a nitrogen reactant can be repeated as many times as necessary to achieve a film having a desired thickness and composition. After each contact step, the substrate can be removed from the substrate, for example, by purging the reaction space with an inert gas. Excessive reactants were removed nearby. For example, the reactor chamber may be purged between reactant pulses. The flow rate and time of each reactant are fine-tunable, as is the purge step to allow control of the dopant concentration and depth distribution in the film. In certain embodiments, the substrate may be moved to a space that is free of reactants or substantially free of reactants before purging to remove excess reactants and / or reaction byproducts from the reactor chamber.

In some embodiments, an ALD process for depositing a silicon nitride (SiN) film may include one or more cycles, each cycle including at least two distinct processes or stages. Providing and removing reactants from the reaction space can be considered a stage. In a first process or stage, a first reactant containing silicon is provided, and the first reactant forms at most about one single layer on a substrate surface. This reactant is also referred to herein as a "silicon precursor" or "silicon reactant". In a second process or stage, a second reactant including a nitrogen-containing compound is provided, and the second reactant reacts with the adsorbed silicon precursor to form SiN. This second reactant may also be referred to as a "nitrogen precursor" or "nitrogen reactant". As described herein, the second reactant may include ammonia (NH ₃ ) and / or another suitable nitrogen-containing compound. Additional processes or stages can be added as needed, and stages can be removed as needed to adjust the composition of the final film. In some embodiments for depositing a silicon nitride (SiN) film, one or more deposition cycles typically begin by providing a silicon precursor and then a nitrogen precursor. In some embodiments, one or more deposition cycles begin by providing a nitrogen precursor and then a silicon precursor. One or more of the reactants may be provided by means of a carrier gas such as nitrogen (N ₂ ), argon (Ar), and / or helium (He).

In some embodiments, a process for depositing a silicon nitride (SiN (B, C)) film containing boron and carbon components and having desired characteristics may include an ALD process and a CVD process. A mixed process of both processes. For example, a process for forming a silicon nitride film including a boron and carbon component may include an ALD portion for depositing silicon nitride and a CVD portion for bonding the boron and carbon component to the grown film. In some embodiments, the silicon nitride and the boron and carbon components may form a continuous film in which the silicon nitride and the boron and carbon components do not form a distinguished layer or substantially do not form a distinguished layer.

In some embodiments, a plasma is not used in the deposition of a silicon nitride film containing boron and carbon components. For example, a process for depositing a silicon nitride film containing boron and carbon components may include both a thermal ALD process and a thermal CVD process (including a pulsed thermal CVD process). In some embodiments, a plasma of a nitrogen precursor is used in an ALD process for depositing silicon nitride. For example, a plasma-enhanced atomic layer deposition (PEALD) process including a plasma containing a nitrogen precursor can be used to deposit silicon nitride, and the PEALD process can be used to combine boron and carbon. The components are combined by a thermal CVD process that combines the components into silicon nitride.

In some embodiments, a process for depositing a silicon nitride (SiN (B, C)) film containing boron and carbon components may include the following processes: an ALD process for depositing a silicon nitride (SiN) film ( For example, it includes an ALD process in which a substrate is alternately and sequentially contacted with a silicon reactant (for example, including octachlorotrisilane (Si ₃ Cl ₈ , OCTS)) and a nitrogen reactant (for example, including ammonia (NH ₃ )), And a decomposition process in which one or more boron reactants are decomposed on the substrate surface to introduce boron and carbon components into the silicon nitride film (for example, using one or more boron reactants (for example, containing triethylboron (B ( C ₂ H ₅ ) ₃ , TEB)) and a CVD process in which TEB is decomposed). In some embodiments, the ALD process for depositing a SiN film may include: contacting the substrate with a silicon reactant including hexachlorodisilanes (Si ₂ Cl ₆ , HCDS). In some embodiments, the CVD process for introducing boron and carbon components may include: contacting the substrate with a substrate including three methyl boron (B (CH ₃ ) ₃ , TMB) or three ethyl boron (TEB) Boron reactant for alkyl boron. In some embodiments, excess may be removed by a purge step after each process (e.g., the purge step may be performed after a silicon reactant pulse, a nitrogen reactant pulse, and / or a boron reactant pulse). Reactants and / or reaction by-products. For example, excess silicon reactants and / or reaction byproducts can be removed from the reaction space before the nitrogen reactants are introduced, so that the nitrogen reactants react with the adsorbed silicon reactants to form a single layer of silicon nitride on the substrate. . In some embodiments, the substrate may be moved to a space that is free of reactants or substantially free of reactants prior to purging the reaction space.

In some embodiments, a pulsed CVD process is used for the decomposition process. In some embodiments, a pulsed CVD process is used in which multiple short pulses of a boron reactant are provided. In certain embodiments, a single, longer pulse of the boron reactant is provided. In some embodiments, the conditions are selected to form SiN by surface reaction (ALD) under the same conditions while decomposing boron reactants (CVD). In some embodiments, the pulsed CVD process for introducing the boron and carbon components into the SiN film facilitates the integration of the boron-carbon process. In some embodiments, a pulsed CVD process for introducing boron and carbon components into a SiN film is beneficial to enhance control over the amount of boron and carbon components incorporated into the SiN film. In some embodiments, a boron reactant may also be provided under ALD conditions.

According to certain embodiments of the present invention, the pressure of the reaction chamber is maintained at about 0.01 Torr to about 50 Torr, preferably about 0.1 Torr to about 10 Torr during processing.

One or more parameters of a process for depositing a silicon nitride film and / or a process for introducing boron and carbon components may be adjusted to provide a film having desired characteristics. For example, the flow rate of one or more boron reactants and / or the process temperature of a CVD process for introducing boron and carbon components can be adjusted. For example, the duration of a reactant pulse used to provide one or more boron reactants in a pulsed CVD process can be adjusted. In some embodiments, one or more parameters of the ALD process used to deposit the SiN film may be adjusted, such as process temperature, reactor chamber pressure, and / or reactant exposure duration.

In some embodiments, a process for depositing a silicon nitride film containing boron and carbon components may include one or more cycles of a process for providing a silicon nitride (SiN) film (e.g., a repeating SiN process) ), And / or one or more cycles of a process for introducing boron and carbon components (eg, repeating a boron-carbon process). In some embodiments, the number of repeats of the SiN process and the number of repeats of the boron-carbon process may be fine-tuned to provide a film having desired characteristics. In some embodiments, the ratio of the number of repetitions of the SiN process to the number of repetitions of the boron-carbon process is selected to produce the desired film composition. In some embodiments, the SiN process cycle is repeated 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, or more for each boron carbon process cycle. repeatedly. In some embodiments, multiple iterations of the SiN process cycle are followed by multiple iterations of the boron-carbon process cycle, wherein the number of iterations of the SiN process cycle is different from that of the boron-carbon process cycle.

In some embodiments, the process for depositing a silicon nitride film containing boron and carbon components may include multiple iterations including an ALD process for depositing a silicon nitride (SiN) film and / or for introducing Repeated sequencing of boron and carbon components in CVD processes (sequence), the total number of repetitions in each of the ALD process, the CVD process, and / or the sequencing of both the ALD process and the CVD process is selected to provide the desired characteristics and / or the required boron And carbon components. For example, the boron and carbon content can be adjusted to provide a film with the desired etch performance (eg, wet etch rate and / or dry etch rate) and / or conformality performance. In some embodiments, the number of repetitions of the CVD process may be selected based on one or more parameters of the CVD process and / or the ALD process. In some embodiments, the number of repetitions of the ALD process may be selected based on one or more parameters of the ALD process and / or the CVD process. In some embodiments, the sequence including the multiple iterations of the ALD process cycle and the multiple iterations of the CVD process cycle may be repeated to provide a film having a desired composition and / or thickness.

In some embodiments, the process for depositing a silicon nitride film containing boron and carbon components does not include a plasma enhanced process. That is, no plasma is used during the entire process. For example, the process may include both a thermal ALD process and a pulsed thermal CVD process (eg, thermal decomposition of one or more boron reactants, such as decomposition of TEB).

FIG. 13 is a flowchart of an example of a process flow 700 for forming a silicon nitride film (eg, a SiN (B, C) film) containing boron and carbon components. In block 702, the substrate may be exposed to one or more gas-phase silicon reactants (eg, one or more silicon precursors). A layer of silicon reactant is formed on the substrate surface. In some embodiments, the one or more gas-phase silicon reactants can be adsorbed onto a surface of a substrate. In certain embodiments, the one or more silicon reactants decompose at least partially at the substrate surface. At block 704, the substrate may be exposed to one or more gas-phase nitrogen reactants (eg, nitrogen precursors). For example, the one or more nitrogen reactants may be The surface of the board interacts with the one or more silicon reactants (e.g., the one or more nitrogen reactants can react with the one or more silicon reactants on a substrate surface to form silicon nitride (SiN) ). In block 706, the substrate may be exposed to one or more gas phase boron reactants (e.g., one or more boron and / or carbon precursors). The one or more boron reactants can react with silicon nitride on the surface of the substrate, so the boron and carbon components are introduced into the film to form a silicon nitride film including the boron and carbon components. In certain embodiments, the one or more boron reactants are decomposed on the substrate surface.

In certain embodiments, one or more of the reactants may be at least partially decomposed on the substrate surface. For example, one or more of a silicon reactant, a nitrogen reactant, or a boron reactant are provided under chemical vapor deposition (CVD) conditions.

In some embodiments, the process for exposing the substrate to a silicon reactant, a nitrogen reactant, and / or a boron reactant may include a chemical vapor deposition (CVD) process. In some embodiments, each of the substrate being exposed to a silicon reactant, the substrate being exposed to a nitrogen reactant, and the substrate being exposed to a boron reactant can include a CVD process, including, for example, a pulsed CVD process.

In some embodiments, exposing the substrate to a silicon reactant, a nitrogen reactant, and / or a boron reactant may include vapor deposition in which one or more reactants are decomposed to facilitate formation of a SiN (B, C) film Process.

In some embodiments, the ALD and / or CVD process may be a plasma enhanced process (eg, a direct plasma process and / or a remote plasma process). In some embodiments, the ALD and / or CVD process does not include a plasma enhanced process. For example, ALD The process may be a thermal ALD process.

In some embodiments, the processes for exposing the substrate to a silicon reactant, a nitrogen reactant, and / or a boron reactant may be overlapped or combined. For example, one or more of a silicon reactant, a nitrogen reactant, and / or a boron reactant may be provided with partially or fully overlapping pulses.

In some embodiments, a nitrogen-containing gas (eg, nitrogen (N ₂ ) and / or ammonia (NH ₃ )) may be continuously fed through a process for depositing a SiN (B, C) film (eg, Nitrogen-containing gases can be used as carrier gases and / or reactants). For example, a nitrogen-containing gas can be used as a carrier gas for reactants in a plasma process (eg, for producing a nitrogen-containing plasma). In some embodiments, the nitrogen-containing gas is continuously or substantially continuously fed into the reaction chamber throughout the deposition process, for example, including reactant pulses simultaneously introducing the silicon reactant and / or the boron reactant into the reactor chamber. in. The nitrogen-containing gas flow rate and / or the concentration of the nitrogen stream can be adjusted during the deposition process (eg, during the pulsed supply of silicon reactants and / or boron and / or carbon reactants).

Various silicon reactants may be suitable. In some embodiments, suitable silicon reactants in a process for depositing a silicon nitride film may include silicon halides, silylamines, silamines, and / or silanes (e.g., including one or more alkyl groups) Of silane). For example, a suitable silicon reactant may include silicon chloride. In some embodiments, the silicon reactant may include a halosilane. In some embodiments, the silicon reactant may include a halide-containing alkyl silicon compound. In some embodiments, the silicon reactant may be an alkylsilane. In certain embodiments, the reaction product may comprise silicon octachlorotrisilane Silane _{(Si 3 Cl 8, octachlorotrisilane,} OCTS). In some embodiments, the silicon reactant may include hexachlorodisilane (Si ₂ Cl ₆ , hexachlorodisilane, HCDS).

Suitable nitrogen reactants can include various nitrogen-containing reactants. In certain embodiments, the nitrogen reactant may include hydrogen (NH) bonded to nitrogen. In certain embodiments, suitable nitrogen reactant may be ammonia (NH _3). In certain embodiments, a suitable nitrogen reactant may be hydrazine (N ₂ H ₄ ). In certain embodiments, a suitable nitrogen reactant may include one or more reactive species produced by a nitrogen-containing plasma, including, for example, nitrogen-containing free radicals. In certain embodiments, a suitable nitrogen reactant may include a nitrogen atom.

In certain embodiments, a suitable boron reactant may include a boron compound having at least one organic ligand. In some embodiments, the organic ligand may have a double bond and / or a triple bond. In certain embodiments, the organic ligand may be a cyclic ligand. In certain embodiments, the organic ligands may include unlocalized electrons. In certain embodiments, a suitable boron reactant may comprise a trialkylboron compound. In certain embodiments, a suitable boron reactant may include triethylboron (B (C ₂ H ₅ ) ₃ , TEB). In certain embodiments, a suitable reactant may comprise boron trimethyl boron _{(B (CH 3) 3,} TMB). In certain embodiments, a suitable boron reactant may comprise a linear or branched alkyl group (including, for example, linear or branched C ₈ -C ₈ and more preferably linear or branched C ₃ -C ₅ ) Trialkyl boron compound. Suitable boron reactants may include various other boron-containing reactants. In certain embodiments, the boron reactant may include boron halide, alkylboron, and / or borane. In certain embodiments, the boron reactant may include boron halide, borane halide, and complexes thereof. By way of example, a suitable boron halide may have a boron to halide ratio of about 0.5 to about 1.

Suitable boranes may include compounds according to Formula I or Formula II.

B _n H _{n + x} (Chemical Formula I)

Wherein n is an integer from 1 to 10, preferably from 2 to 6, and x is an even number, and is preferably 4, 6, or 8.

B _n H _m (Chemical Formula II)

Wherein n is an integer of 1 to 10, preferably 2 to 6, and m is an integer of 1 to 10, preferably 2 to 6, different from n.

Examples of the above-mentioned borane according to Chemical Formula I include nested-borane (B _n H _{n + 4} ), cobweb-borane (B _n H _{n + 6} ), and open-net-borane (B _n H _{n + 8} ). Examples of the borane according to Chemical Formula II include a fused-borane (B _n H _m ). In addition, a borane complex such as (CH ₃ CH ₂ ) ₃ N--BH ₃ can be used.

In certain embodiments, suitable boron reactants may include borane halides, specifically fluoride, bromide, and chloride. An example of a suitable compound is B ₂ H ₅ Br. Other examples include boron halides with high boron / halide ratios, such as B ₂ F ₄ , B ₂ C ₁₄ and B ₂ Br ₄ . Boron halide complexes can also be used.

In certain embodiments, halogenogenoborane according to Formula III may be a suitable boron reactant.

B _n X _n (Chemical Formula III)

Wherein X is chlorine (Cl) or bromine (Br), and n is an integer of 4 or 8 to 12 when X is chlorine, or n is an integer of 7 to 10 when X is bromine.

In certain embodiments, a carborane according to Formula IV may be a suitable boron reactant.

C ₂ B _n H _{n + x} (Chemical Formula IV)

Examples of carborane according to Chemical Formula IV include closed-carborane (C ₂ B _n H _{n + 2} ), nested-carborane (C ₂ B _n H _{n + 4} ), and cobweb-carbon Borane (C ₂ B _n H _{n + 6} ).

In certain embodiments, the amine-borane adduct according to Chemical Formula V may be a suitable boron reactant.

R ₃ NBX ₃ (chemical formula V)

Wherein R is a straight or branched C1 to C10, preferably C1 to C4 alkyl or H, and X is a straight or branched C1 to C10, preferably C1 to C4 alkyl, H or halo.

In certain embodiments, an aminoborane according to formula VI where one or more of the substituents on the boron is an amine group may be a suitable boron reactant.

R ₂ N (chemical formula VI)

Wherein R is a linear or branched C1 to C10, preferably C1 to C4 alkyl group or a substituted or unsubstituted aryl group.

An example of a suitable aminoborane is (CH ₃ ) ₂ NB (CH ₃ ) ₂ .

In certain embodiments, a suitable boron reactant may include borazine (--BH--NH--) ₃ and / or a volatile derivative thereof.

In certain embodiments, an alkylboron or alkylborane may be a suitable boron reactant, where the alkyl group is typically a straight or branched C1 to C10 alkyl group, preferably a C2 to C4 alkyl group.

In some embodiments, a substrate, such as a semiconductor workpiece, on which a silicon nitride film containing boron and carbon is desired to be deposited is loaded into a reactor chamber. The reactor chamber can be part of a cluster tool in which various processes in the formation of integrated circuits are performed Minute. In certain embodiments, batch processing reactors (including, for example, mini-batch processing reactors (e.g., reactors with a capacity of 8 substrates or less) and / or furnace batches A processing reactor (eg, a reactor having a capacity of 50 or more substrates) performs one or more deposition processes described herein. In some embodiments, one or more of the deposition processes described herein can be performed in a single wafer reactor. In certain embodiments, a space reactor chamber (eg, a space ALD reactor chamber) may be suitable. In certain embodiments, a reactor chamber having a cross-flow configuration may be suitable. In certain embodiments, a reactor chamber having a showerhead configuration may be suitable.

Exemplary single wafer reactors are commercially available under the tradenames Pulsar® 2000 and Pulsar® 3000 from ASM USA, Inc. of Phoenix, Arizona, and from ASM, Tokyo, Japan under the tradenames Eagle® XP and Eagle® XP8. Japan Co., Ltd. Exemplary batch ALD reactors are commercially available under the trade names A400 ^(TM) and A412 ^(TM) from ASM Europe GmbH, Almere, The Netherlands.

FIG. 14 is a flowchart illustrating another example of a process 800 for forming a silicon nitride film (eg, a SiN (B, C) film) containing boron and carbon components. The process 800 may include a sequence 802 having a process 804 for forming silicon nitride on a substrate surface and a process 812 for introducing boron and carbon components into the silicon nitride. In some embodiments, the sequencing 802 may be repeated multiple times to form a SiN (B, C) film having a desired composition and / or thickness. The ratio of the number of times the process 804 is performed to the number of times the process 812 is performed can be varied to fine-tune the concentration of the boron and carbon components in the film and thus to achieve a film with the desired characteristics. For example, the number of times the process 804 is repeated can be selected The ratio of the number of times the process 812 is repeated to provide a film having the desired boron and carbon component content.

A process 804 for forming silicon nitride on a substrate surface may include blocks 806, 808, and 810. At block 806, the substrate may be exposed to one or more silicon reactants. At a block 808, the substrate may be exposed to one or more nitrogen reactants. In block 810, blocks 806 and 808 may be repeated multiple times (eg, the number of cycles of process 804). In some embodiments, exposing the substrate to the one or more silicon reactants in block 806 may include exposing the substrate to a silicon reactant pulse, and exposing the substrate to the one or more nitrogen reactions in block 808. The object may include exposing the substrate to a nitrogen reactant pulse. In some embodiments, the silicon reactant pulses of block 806 and the nitrogen reactant pulses of block 808 are by a purge step to remove excess silicon reactants and / or reaction byproducts from the reactor chamber (Figure Not shown). The purge step may include flowing a purge gas and / or evacuating the reactor chamber (e.g., by evacuating the reactor chamber) to remove or substantially remove excess reactants and / or reaction byproducts. product. In some embodiments, for example, by performing a purge step (not shown) after exposing the substrate to the one or more nitrogen reactants in block 808, before performing the repeat process in block 810 Remove excess nitrogen reactants and / or reaction byproducts. In some embodiments, the process 804 is an ALD process. In some embodiments, the process 804 is a CVD process in which one or more of the reactants are at least partially decomposed on the substrate surface. In some embodiments, the pulses of the silicon reactant and the pulses of the nitrogen reactant may at least partially overlap.

Process 812 for introducing boron and carbon components into silicon nitride may include blocks 814 and 816. At a block 814, the substrate may be exposed to one or more boron reactants. In block 816, block 814 may be repeated multiple times (e.g., the number of cycles of process 812). In some embodiments, exposing the substrate to the one or more boron reactants includes exposing the substrate to a boron reactant pulse. For example, in block 816, the boron reactant pulse of block 814 may be repeated multiple times. In certain embodiments, each boron reactant pulse may be separated by a purge step (not shown) to remove excess boron reactants and / or reaction byproducts. In some embodiments, a single boron reactant pulse is provided (eg, no repeat of process 814 is performed). In some embodiments, the one or more boron reactants are provided under CVD conditions such that the one or more boron reactants are decomposed on a substrate surface.

In some embodiments, the process for forming the SiN (B, C) film (for example, the process 800 shown in FIG. 14) may be a hybrid process including both an ALD process and a CVD process. For example, a process for forming a silicon nitride (SiN) film (for example, process 804 shown in FIG. 14) may include an ALD process, and is used to introduce boron and carbon components to the silicon nitride (SiN) film. The process (eg, process 812 shown in FIG. 14 to form a SiN (B, C) film) may include a CVD process.

In some embodiments, no plasma is used in either of process 804 or process 812. For example, the process 804 and / or the process 812 may include a thermal process, such as a thermal ALD process and / or a thermal CVD process.

The silicon reactant used in the ALD process to provide a silicon nitride film (SiN) may include octachlorotrisilane (Si ₃ Cl ₈ , octachlorotrisilame, OCTS) and / or hexachlorodisilane (Si ₂ Cl ₆ , hexachlorodisilane, HCDS). The nitrogen reactant in the ALD process may include ammonia (NH ₃ ). Exposing the substrate to silicon reactant (e.g., block 806 shown in FIG. 14) may include exposing the substrate to a Si ₃ Cl ₈ and / or Si ₂ Cl _6. For example, including, for example, by means of a nitrogen carrier gas, Si ₃ Cl ₈ and / or Si ₂ Cl _{6 can be} fed into a reactor chamber (eg, a silicon reactant pulse) for a certain duration. Exposing the substrate to a nitrogen reactant (e.g., a block 808 shown in FIG. 14) may include exposing the substrate to NH _3. For example, including, for example, with the aid of a nitrogen carrier gas, NH ₃ may be fed into the reactor chamber (eg, a nitrogen reactant pulse) for a certain duration. The pulse length of the silicon reactant pulse and / or the nitrogen reactant pulse may be about 0.05 seconds to about 5.0 seconds, about 0.1 seconds to about 3 seconds, or about 0.2 seconds to about 1.0 seconds. For example, the nitrogen reactant pulse and / or the silicon reactant pulse may be about 1 second.

As described herein, a purge step may be performed in the ALD process after a pulse of reactants used to deliver one or more reactants into the reactor chamber, such as to remove excess reactants from near the substrate surface and / or Reaction by-products. Gases such as nitrogen (N ₂ ), argon (Ar), and / or helium (He) can be used as the purge gas to help remove excess reactants and / or reaction byproducts. In some embodiments, the purge step of the ALD process may be about 1 second to about 20 seconds, about 1 second to about 15 seconds, or about 1 second to about 10 seconds, including about 5 seconds. For example, one cycle of an ALD process for exposing a substrate to a silicon reactant and / or a nitrogen reactant may include a reactant pulse of about 0.5 seconds, followed by a purge step of about 5 seconds. In some embodiments, one cycle of the ALD process may include a silicon reactant pulse of about 0.5 seconds, followed by a purge step of about 5 seconds, followed by a nitrogen reactant pulse of about 0.5 seconds, and then about 5 seconds. Purge step in seconds.

The cycle of the ALD process can be repeated multiple times until a film having the desired thickness and / or composition is obtained. In some embodiments, the deposition parameters such as the reactant flow rate, the duration of reactant flow, the duration of the purge step, and / or the reactants themselves may vary during one or more deposition cycles during the ALD process, To obtain a film having the desired characteristics. For example, one or more deposition parameters of an ALD process cycle may be different from one or more deposition parameters of another ALD process cycle.

As described herein, in some embodiments, a process for depositing a silicon nitride film (eg, a SiN (B, C) film) including a boron and carbon component may include a chemical vapor deposition (CVD) process. A CVD process for introducing boron and carbon components into a silicon nitride film may include decomposition of one or more reactants and / or chemical interactions between the plurality of reactants on the silicon nitride film. For example, reactants can be fed into a reactor chamber, and the decomposition of the reactants facilitates the formation of a desired film. In certain embodiments, a suitable boron reactant may include triethylboron (B (C ₂ H ₅ ) ₃ , TEB) and / or trimethylboron (B (CH ₃ ) ₃ , TMB). For example, the TEB fed into the reactor chamber can be decomposed on the silicon nitride film to facilitate the introduction of boron and carbon components into the silicon nitride film.

In some embodiments, a pulsed CVD process may be used. In some embodiments, the process for depositing a SiN (B, C) film includes an ALD process to provide a silicon nitride SiN film on a substrate surface, and a CVD process performed after at least one cycle of the ALD process, The CVD process is used to introduce boron and carbon components into a silicon nitride film to form a SiN (B, C) film (e.g., a pulse for delivering a pulse of one or more boron reactants to a reactor chamber). CVD process). In some embodiments, the CVD process can be repeated multiple times to provide a SiN (B, C) film with the desired composition (e.g., The cycle of the CVD process including the pulse of the reactant and the subsequent purging process is repeated multiple times). In some embodiments, the CVD process used to introduce the boron and carbon components is not a pulsed CVD process so that the boron reactant is fed into the reactor chamber in a continuous or substantially continuous flow to achieve the desired boron And carbon component SiN (B, C) film.

The pulsed CVD process may include feeding a reactant gas (eg, a reactant pulse) into the reactor chamber for a certain duration. In certain embodiments, the reactant pulse of the CVD process may have a duration of about 0.05 seconds to about 5.0 seconds, about 0.1 seconds to about 3 seconds, or about 0.2 seconds to about 1.0 seconds. For example, the reactant pulse may be about 0.5 seconds.

In some embodiments, the interval between two reactant pulses may include stopping the flow of the one or more reactants of the reactant pulse. The interval between the reactant pulses may have a duration in the range of 1 second to about 20 seconds (including about 1 second to about 15 seconds, or about 1 second to about 10 seconds). For example, the interval may be about 5 seconds. In some embodiments, the spacing includes transporting the substrate to a space that is non-reactive or substantially non-reactive. In some embodiments, the interval includes a purge step. For example, the interval may include a step of transporting the substrate to a space where there is no reactant or substantially no reactant, and a purge step. For example, a purge step may be performed after a pulse for delivering one or more reactants to a reactor chamber for a pulsed CVD process, such as to remove excess reactants from near the surface of the substrate and / or Reaction by-products. Purge step may include contacting one or more inert gases (e.g., argon (Ar), helium (He), and / or nitrogen (N ₂₎ flow through the reactor chamber. In certain embodiments, each may be A purge step is performed after a reactant pulse. The purge step may include removing excess reactants and / or by-products from the vicinity of the substrate. In some embodiments, the purge step of the CVD process may have about 1 second to about 20 seconds, about 1 second to about 15 seconds, or about 1 second to about 10 seconds in duration. For example, the purge process may be about 5 seconds. The reactant pulse and / or other durations of the purge process are also It may be appropriate, and this may be determined by a person skilled in the art according to a specific situation.

A suitable duration in which the reactant gas is provided into the reactor chamber and / or a duration of the purge step, a reactant pulse and / or a gas flow rate in the purge step may depend on one or more of the reaction processes Parameters, such as adjusting the reactant pulse duration and / or the reactant pulse gas flow rate, and / or the purge step duration and / or the purge step gas flow rate to provide the desired reactants near the substrate surface and / Or remove desired reactants from near the surface of the substrate.

As described herein, the process for depositing a SiN (B, C) film may include multiple iterations of the process for providing a silicon nitride film, and subsequent introduction of boron and carbon components to the nitride Repeated sequencing of the process in the silicon film (eg, sequencing 802 shown in FIG. 14). In some embodiments, the ordering may be repeated multiple times (eg, the ordering is repeated Z times) to provide a SiN (B, C) film having a desired composition and / or thickness. For example, a process for forming a SiN (B, C) film may include multiple cycles of an ALD process for depositing a silicon nitride SiN film, and thereafter for introducing boron and carbon components to the nitride The sequencing of multiple cycles of a CVD process in a silicon SiN film is repeated multiple times to provide a SiN (B, C) film with a desired composition and / or thickness.

In some embodiments, multiple cycles including an ALD process for depositing a silicon nitride film and subsequent CVD for introducing boron and carbon components into the silicon nitride film may be performed. The sequencing of multiple cycles of the process is repeated from about 1 to about 150 times, including about 25 to about 75 times. For example, the ordering can be repeated about 75 times. For example, the ordering can be repeated 100 times.

Multiple cycles of a process for providing a silicon nitride (SiN) film in a sequence may be selected (for example, X cycles of the ALD process, such as repeating the process 804 shown in FIG. 14 multiple times or performing multiple cycles) and / Or multiple cycles of a process for introducing boron and carbon components into silicon nitride (eg, Y cycles of a CVD process, such as repeating the process 812 shown in FIG. 14 multiple times or performing multiple cycles), To achieve the desired film characteristics. For example, sequencing may include multiple cycles of an ALD process, followed by multiple cycles of a CVD process. The number of ALD cycles and / or CVD cycles may be varied to provide a SiN (B, C) film containing a desired composition and / or thickness. For example, the number of cycles for a process for introducing boron and carbon components can be selected to provide a SiN (B, C) film with a desired boron and carbon component content (e.g., to exhibit a desired etch rate , Conformality performance, and / or other film properties).

In some embodiments, the number of cycles of the process for providing the boron and carbon components of the silicon nitride film in the sequence may be about 1 cycle to about 20 cycles, including about 1 cycle to about 10 cycles. In some embodiments, the process for providing boron and carbon components can be repeated five times. For example, a pulsed CVD process for introducing boron and carbon components into a silicon nitride film can be repeated three times within a sequence. The process cycle for providing the boron and carbon components may be performed before the process for depositing the silicon nitride SiN film is additionally cycled. For example, the sequencing of the SiN (B, C) film deposition process may include: firstly, the process for depositing the silicon nitride SiN film is cycled multiple times, and secondly for the boron and carbon groups The process of adding to the SiN film is repeated several times.

In some embodiments, the ratio of the number of cycles of a process for depositing a silicon nitride film to the number of cycles of a process for introducing boron and carbon components within a sequence (eg, a ratio of Y: X) may be about 1 : 1 to about 100: 1, including about 3: 1 to about 50: 1. In some embodiments, the ratio of the number of cycles of the process for depositing the silicon nitride film to the number of cycles of the process for introducing the boron and carbon components may be about 5: 1 to about 20: 1. The ratio can be expressed as a percentage or a boron-carbon process fraction, for example, as a percentage of the total number of cycles in a sequence that is a process for introducing boron and carbon components. For example, the boron-carbon process fraction or the percentage of the total number of cycles in the sequencing for a process for introducing boron and carbon components can be adjusted to provide a SiN (B, C) film with the desired composition. The percentage or boron-carbon process fraction can be calculated by the following equation: X / (X + Y) * 100%. In certain embodiments, the boron-carbon process fraction or the percentage of the total number of cycles in the sequencing for a process for introducing boron and carbon components may be from about 0.01% to about 50%, including about 5% to about 20% . For example, the boron-carbon process fraction may be about 10%. For example, a process having a boron-carbon process fraction of about 5.0% to about 10% can form a SiN _x (B _y , C _z ) film, where x can be about 1.3 to about 1.8, and y can be about 0.5 to about 1.5. And z may be about 0.3 to about 1.3.

The first stage and / or the second stage of the ALD process and / or the CVD process may be performed at a process temperature of about 25 ° C to about 800 ° C (including about 100 ° C to about 600 ° C). Process temperatures as mentioned herein may include the temperature of the reactor chamber base, the temperature of the reactor chamber wall, and / or the temperature of the substrate itself. In some embodiments, the first step of the ALD process and / or the CVD process may be performed at a process temperature of about 150 ° C to about 500 ° C. Phase and / or Phase 2. For example, one or both of the first and second stages of the ALD process and / or the CVD process may be performed at a process temperature of about 200 ° C to about 400 ° C. For example, a reactor chamber described herein can be performed in a reactor chamber having a base, a substrate, and / or a reactor chamber wall and heated to a temperature of about 200 ° C to about 400 ° C (eg, a temperature of about 400 ° C). The first and / or second stage in one or more cycles of the ALD process. For example, a CVD process may be performed in a reactor chamber having a base, a substrate, and / or a reactor chamber wall and heated to a temperature of about 400 ° C. In certain embodiments, the introduction of boron and carbon components into silicon nitride can be performed at process temperatures of less than 400 ° C (including, for example, about 325 ° C to about 400 ° C and about 350 ° C to about 400 ° C). CVD process.

In some embodiments, the temperature of the process for depositing the silicon nitride SiN film and / or the process for introducing the boron and carbon components may be high enough to facilitate a process with a reduced thermal budget while facilitating Decomposition of one or more reactants (for example, silicon reactants and / or nitrogen reactants in ALD processes, and / or boron reactants in CVD processes), and / or between reactants and / or between reactants and the substrate surface Between reactions. In some embodiments, a process temperature for depositing a silicon nitride SiN film and / or introducing boron and carbon components may be about 325 ° C to about 800 ° C, including about 350 ° C to about 600 ° C, and about 400 ° C to About 600 ° C, or about 375 ° C to about 450 ° C. For example, a CVD process for introducing boron and carbon components into silicon nitride can be performed at a process temperature of about 400 ° C (e.g., including decomposing the boron reactant TEB to introduce boron and carbon components to CVD process of silicon nitride film). In some embodiments, an ALD process for depositing a silicon nitride (SiN) film may be performed at a process temperature of about 400 ° C (e.g., one or more of the reactants may be ALD process that decomposes when forming a SiN film). In some embodiments, the temperature of the ALD process may be different from the temperature of the CVD process. In some embodiments, the same temperature is used for an ALD process for forming a silicon nitride SiN film and a CVD process for adding boron and carbon components to the SiN film.

A thermal ALD process for forming a silicon nitride SiN film (e.g., in a Pulsar® 3000 chamber of ASM USA, Inc., commercially available from Phoenix, Arizona) can be used to perform the ) An example of a film deposition process. The thermal ALD process can be performed on a 300 millimeter (mm) wafer at a process temperature of about 400 ° C, the wafer containing octachlorotrisilane (Si) that is fed into the reactor chamber with a carrier gas (e.g., nitrogen). ₃ Cl ₈ , octachlorotrisilane, OCTS), such that the silicon reactant pulse has a duration of about 1 second and then a purge process with a duration of about 5 seconds (for example, using a purge gas containing nitrogen) . OCTS can be stored in a bubbler at about 40 ° C and provided from the bubbler into the reactor chamber (e.g., can be kept open by controlling the valve used to deliver OCTS into the reactor chamber To control the mass flow rate of OCTS). The thermal ALD process may include a nitrogen reactant containing ammonia (NH ₃ ) that is fed into the reactor chamber such that the nitrogen reactant pulse has a duration of about 1 second and is performed after the nitrogen reactant pulse for about 5 seconds The duration of the purge process (for example, using a purge gas containing nitrogen). May be maintained at a pressure from about 1.5 bar to provide a gas source to the reactor chamber NH ₃ (e.g., can be used by controlling the NH ₃ delivered to the reactor chamber holding a valve opening degree controlled NH ₃ Mass flow rate). The ALD process can be cycled multiple times. Multiple cycles of the thermal CVD process for introducing boron and carbon components into the SiN film can be performed after multiple cycles of the ALD process. The thermal CVD process may be performed at a temperature of about 400 ° C and may include a boron reactant for supplying a boron reactant containing triethylboron (B (C ₂ H ₅ ) ₃ , TEB) to the reactor chamber. A pulse, wherein the boron reactant pulse may have a duration of about 0.5 seconds. A purge step with a duration of about 5 seconds may be performed after the boron reactant pulse (eg, using a purge gas containing nitrogen). For example, the SiN (B, C) deposition process may include sequencing of 19 cycles including an ALD process and 2 cycles of a subsequent CVD process (eg, providing a boron-carbon process score of about 10%), where the sequencing Was repeated 75 times.

The composition of the film can be adjusted, for example, by increasing or decreasing the boron-carbon process fraction of a process for depositing a silicon nitride film containing boron and carbon components. For example, the boron and carbon content of the film can be adjusted by adjusting the boron-carbon process fraction of the film manufacturing process. In some embodiments, the silicon nitride film including the boron and carbon components may have about 0.1 atomic% to about 50 atomic% boron, including about 1 atomic% to about 35 atomic% boron. For example, a silicon nitride film including a boron and a carbon component may have about 5 atomic% to about 30 atomic% boron. In some embodiments, the silicon nitride film including the boron and carbon components may have about 0.1 atomic% to about 50 atomic% carbon, including about 1 atomic% to about 35 atomic% carbon. For example, a silicon nitride film including a boron and a carbon component may have about 5 atomic% to about 30 atomic% carbon. In some embodiments, the silicon and / or nitrogen content can be adjusted by adjusting the boron-carbon process fraction of the film manufacturing process.

In some embodiments, a SiN (B, C) film formed according to one or more processes described herein may have a desired dielectric constant (κ-value). The dielectric constant of the SiN (B, C) film can be lower than that of the conventional silicon nitride film. In some embodiments, SiN (B, C) The film may have a dielectric constant of less than about 7, including less than about 6. For example, a SiN (B, C) film may have a dielectric constant between about 4.8 and about 7 (including between about 4.8 and 6 and between about 4.8 and about 5.5). In some embodiments, the dielectric constant of the SiN (B, C) film can be adjusted by adjusting the boron carbon process of the SiN (B, C) film manufacturing process. In some embodiments, a SiN (B, C) film having a dielectric constant of about 5.5 can be formed using a deposition process having a boron-carbon process fraction of about 10% or higher. For certain applications of semiconductor devices (e.g., bulkhead materials that are characteristic of transistor gates) having a reduced dielectric constant (e.g., a dielectric constant smaller than that of a conventional silicon nitride film) The SiN (B, C) film can help improve one or more device electrical parameters, including reduction of device parasitic capacitance.

As described herein, the SiN (B, C) film can be a sacrificial film in a semiconductor device manufacturing process. For example, the SiN (B, C) film can be selectively removed during the etching process. In some embodiments, the sacrificial SiN (B, C) film can be fabricated in a semiconductor device using an etching process including chlorine (C1) and / or fluorine (F) (such as a plasma process containing chlorine and / or fluorine). It was selectively removed during the period. In some embodiments, a SiN (B, C) film may form part of a fabricated semiconductor device. For example, a SiN (B, C) film may be more resistant to etching than one or more other materials used in the fabrication of semiconductor devices.

The SiN (B, C) film may have a desired etch selectivity to another material in the device. For example, the etching selectivity of the SiN (B, C) film can be fine-tuned by adjusting the boron and carbon component content of the film (for example, by adjusting the boron-carbon process fraction of the film manufacturing process). In some embodiments, the SiN (B, C) film can be etched by a dry etching process and / or a wet etching process. For example, the plasma etching process (including Fluorine-containing plasma) to etch SiN (B, C) film. In some embodiments, the SiN (B, C) film may have an etch selectivity (eg, dry etch and / or wet etch selectivity) of about 5 or more to another material of the device, including about 10 Or greater than 10, about 20 or greater than 20, or about 50 or greater selectivity.

In some embodiments, the SiN (B, C) film may exhibit a desired wet etch selectivity, such as a wet etch selectivity to a thermal silicon oxide (TOX) layer. For example, the SiN (B, C) film can be more resistant to wet etching than the thermal silicon oxide layer, so that the ratio of the wet etching rate of the SiN (B, C) film to the wet etching rate of the thermal silicon oxide layer is less than About 1, less than about 0.5, or less than about 0.3. In some embodiments, the ratio of the wet etch rate of the SiN (B, C) film to the wet etch rate of the thermal silicon oxide layer may be less than about 0.1.

In some embodiments, one or more silicon nitride films (SiN (B, C)) containing boron and carbon components formed according to one or more processes described herein may have a variety of etching solutions. Desired etch rate. In some embodiments, a silicon nitride film (eg, a SiN (B, C) film) comprising a boron and carbon component may be resistant or substantially resistant to one or more wet etchant. For example, a SiN (B, C) film may have less than about 1 nanometer / minute (nm / min) (including less than about 0.5 nanometer / minute) in one or more of the following etching solutions at the provided temperature. Minutes, including less than about 0.2 nm / minute, and including less than about 0.1 nm / minute): Nitric acid (HNO ₃ ) solution (eg, having about 65% to about 75% by weight) concentrated at about 80 ° C % HNO ₃ concentration solution), 5.5% by weight hydrofluoric acid (HF) at room temperature (for example, a temperature of about 25 ° C), nitric acid: hydrogen at about room temperature (for example, a temperature of about 25 ° C) A solution having a ratio of hydrofluoric acid: water (HNO ₃ : HF: H ₂ O) of about 1: 1: 5, having about 10% by weight of sodium hydroxide (about NaOH) solution in NaOH concentration, a hydrochloric acid (HCl) solution (e.g., a solution having a HCl concentration of about 35% to about 40% by weight) concentrated at about room temperature (e.g., a temperature of about 25 ° C), and at A sulfuric acid solution (H ₂ SO ₄ ) concentrated at about room temperature (eg, a temperature of about 25 ° C.) (eg, a solution having a H ₂ SO ₄ concentration greater than about 90% by weight).

In some embodiments, a silicon nitride film (e.g., a SiN (B, C) film) comprising a boron and carbon component may be resistant or substantially resistant to about room temperature (e.g., a temperature of about 25 ° C) A wet etchant containing phosphoric acid (H ₃ PO ₄ ) at a concentration of about 85% by weight. In some embodiments, a silicon nitride film (e.g., a SiN (B, C) film) comprising a boron and carbon component can or is substantially resistant to one or more of the following wet etchant (e.g., , An etching rate of less than about 3 nanometers per minute (nm / min), and after immersion in 1% by weight of hydrofluoric acid (HF) for about 2 minutes): at about room temperature (eg, a temperature of about 25 ° C) Phosphoric acid (H ₃ PO ₄ ) at a concentration of about 85% by weight, an aqueous sodium hydroxide (NaOH) solution having a concentration of about 10% by weight at about room temperature (eg, a temperature of about 25 ° C.), at about room temperature (For example, a temperature of about 25 ° C), a hydrochloric acid (HCl) solution having a concentration of about 35% to about 40% by weight (for example, about 37% by weight), and a temperature at about room temperature (for example, about 25 ° C) ) Solution with sulfuric acid (H ₂ SO ₄ ) at a concentration greater than about 90% by weight (eg, 98% by weight).

In some embodiments, the SiN (B, C) film may have a ratio of hydrogen peroxide: hydrofluoric acid: water (H ₂ O ₂ : HF: H ₂ O) of about 5: 5: 90 by volume. The solution has an etch rate greater than about 1.0 nanometers per minute (nm / min) at about room temperature (eg, at a temperature of about 25 ° C). In certain embodiments, the SiN (B, C) film can be used in an oxygen-containing environment (including, for example, ozone and / or oxygen-containing plasmas (for example, plasmas containing oxygen atoms and / or other oxygen-containing free radicals) )) Is etched after being exposed to the treatment agent.

As described herein, a SiN (B, C) film can be deposited on and / or over a three-dimensional (3-D) structure while exhibiting the desired conformality or step coverage. In some embodiments, the SiN (B, C) film may have a thickness of about 2: 1 or higher than 2: 1 (including about 3: 1 or higher than 3: 1, about 5: 1, or higher than 5: 1). , Or a ratio of about 8: 1 or higher than 8: 1) on the three-dimensional structure exhibiting the desired conformality or step coverage. In some embodiments, the SiN (B, C) film may have a thickness of about 10: 1 or higher than 10: 1, about 25: 1 or higher than 25: 1, or about 50: 1 or higher than 50: 1 The three-dimensional structure of the aspect ratio exhibits the desired conformality or step coverage. In certain embodiments, a SiN (B, C) film can exhibit a desired step coverage on one or more features as described herein, including about 80% or higher (including about 90% or Higher than 90%, about 95%, or higher than 95%, or about 100%). In some embodiments, a SiN (B, C) film can exhibit when formed on a three-dimensional structure having an aspect ratio of up to about 250: 1 (including up to about 150: 1 and up to about 100: 1). A step coverage of about 80% or higher (including about 90% or higher, or about 95% or higher than 95%, or about 100%).

In some embodiments, a portion of the SiN (B, C) film deposited on the sidewalls of the three-dimensional structure may exhibit a desired etch rate compared to an etching rate of a portion of the film deposited on the top surface of the three-dimensional feature. Etching rate. In some embodiments, a portion of the SiN (B, C) film deposited on the sidewall of the three-dimensional structure may exhibit a SiN (B, C) film as a portion of the SiN (B, C) film deposited on the top surface of the structure ( B, C) Uniform or substantially uniform etch rate of the film. For example, the etch rate of the sidewall portion of the SiN (B, C) film The ratio of the etch rate of the top surface portion of the SiN (B, C) film may be less than about 4, including less than about 2, and about 1.5. In some examples, the ratio is about one.

In some embodiments, a silicon nitride film (eg, a SiN (B, C) film) containing boron and carbon components may be subjected to an annealing process after its formation. In some embodiments, the SiN (B, C) film may be annealed in an inert gas environment (eg, an environment containing nitrogen and / or one or more inert gases). For example, the annealing process may be performed in a nitrogen environment at a temperature of about 600 ° C or higher, about 800 ° C or higher, or 1000 ° C or higher. In some embodiments, the SiN (B, C) film can be annealed at temperatures up to about 900 ° C. In some embodiments, the SiN (B, C) film can be in a hydrogen environment, for example, at a temperature of about 600 ° C or higher, about 800 ° C or higher, or 1000 ° C or higher ( Including up to about 900 ° C). In certain embodiments, the boron and carbon components of the SiN (B, C) film do not diffuse out of the film when annealed at a temperature up to about 900 ° C in a nitrogen environment. In certain embodiments, the annealing may be performed in a hydrogen or inert gas environment, for example, at a temperature of about 600 ° C or higher, about 800 ° C or higher, or 1000 ° C or higher.

Examples of SiN (B, C) film

FIG. 15A graphically represents a fraction of a boron-carbon process having a fraction of about 0% to about 15% (e.g., a percentage of the total number of cycles of a process for introducing boron and carbon content into a silicon nitride SiN film) ) Of the four films (eg, as measured by Rutherford backscattering spectrometry (RBS)). Shows the atomic percentages of silicon, nitrogen, boron, carbon, and chlorine for each of the four films, where the atomic percentages of silicon, nitrogen, boron, and carbon are shown with reference to the left vertical axis, and the atomic percentage of chlorine with reference to the right vertical The axis is shown. Each of the four films may be formed according to one or more processes as described herein. For example, SiN films and SiN (B, C) films with varying compositions can utilize depositions performed in a Pulsar® 3000 chamber (e.g., commercially available from ASM America, Inc., of Phoenix, Arizona). The process is deposited by a thermal ALD process for forming a silicon nitride SiN film. The thermal ALD process can be performed on a 300 millimeter (mm) wafer at a temperature of about 400 ° C and a pressure of about 0.1 to about 10 torr, the wafer containing a feed gas containing a carrier gas (eg, nitrogen). To the silicon reactant of octachlorotrisilane (Si ₃ Cl ₈ , OCTS) in the reactor chamber such that the silicon reactant pulse has a duration of about 1 second and then a purge step with a duration of about 5 seconds ( (For example, using a purge gas containing nitrogen). OCTS can be stored in a bubbler at about 40 ° C and provided from the bubbler into the reactor chamber (e.g., can be kept open by controlling the valve used to deliver OCTS into the reactor chamber The degree of control of the mass flow rate of OCTS). The thermal ALD process may include a nitrogen reactant containing ammonia (NH ₃ ) that is fed into the reactor chamber such that the nitrogen reactant pulse has a duration of about 1 second and is performed after the reactant pulse with a duration of about 5 seconds. A duration purge step (for example, using a purge gas containing nitrogen). May be maintained at a pressure from about 1.5 bar to provide a gas source to the reactor chamber NH ₃ (e.g., can be used by controlling the NH ₃ delivered to the reactor chamber holding a valve opening degree controlled NH ₃ Mass flow rate). The ALD process can be cycled multiple times. Multiple cycles of a pulsed thermal CVD process for introducing boron and carbon components into the SiN film can be performed after multiple cycles of the ALD process. The thermal CVD process may be performed at a temperature of about 400 ° C. and a pressure of about 0.1 torr to about 10 torr, and may contain triethylboron (B (C ₂ H ₅ ) ₃ , TEB) that is fed into the reactor chamber. ) A boron reactant, wherein the boron reactant pulse may have a duration of about 0.5 seconds, and a purge step having a duration of about 5 seconds is performed after the reactant pulse (eg, using a purge gas containing nitrogen) . For example, the SiN (B, C) deposition process may include multiple cycles including an ALD process and a sequence of one to three cycles of a subsequent CVD process (e.g., to provide a boron-carbon process of about 0% to about 15%). Score), wherein the ranking can be repeated multiple times (eg, about 50 to about 100 times). For example, the ordering can be repeated 75 times.

The curve shown in FIG. 15A shows that the boron and carbon content of the film can increase as the boron-carbon process fraction increases. For example, the boron and carbon component content may increase linearly or substantially linearly as the boron-carbon process fraction increases. FIG. 15A shows that the silicon content and nitrogen content can decrease as the fraction of the boron-carbon process increases. For example, the silicon and / or nitrogen content may decrease linearly or substantially linearly as the boron-carbon process fraction increases. FIG. 15A further illustrates that the chlorine content may decrease as the fraction of the boron-carbon process increases.

FIG. 15B is a graph showing the film growth rate in Å / cycle of four films formed by a manufacturing process having a boron-carbon process fraction of about 0% to about 15%. The cycle as shown in FIG. 15B may correspond to the sequencing of multiple cycles including a process for providing a silicon nitride (SiN) film, and multiple processes for introducing boron and carbon into a SiN film. (For example, ranking 802 shown in FIG. 14). Each of the four films may be formed according to one or more processes as described herein (eg, a process as described with reference to FIG. 15A). FIG. 15B shows that the film growth rate can be divided with the boron-carbon process. The number increases and decreases. Without being limited by any particular theory or mode of operation, boron reactants adsorbed on the surface of the substrate can reduce silicon reactants and / or nitrogen reactants (e.g., silicon reactants from subsequent silicon nitride deposition processes and / or The ability of nitrogen reactants) to properly adsorb onto the surface of a substrate. Increasing the boron-carbon process fraction (e.g., when an increased amount of boron reactant is provided in the SiN (B, C) film fabrication process) can further reduce silicon and / or nitrogen reactants from subsequent silicon nitride deposition processes The ability to adsorb onto the surface of a substrate. In addition, without being limited by any particular theory or mode of operation, the reduced ability of silicon and / or nitrogen reactants from subsequent silicon nitride deposition processes to be adsorbed onto the substrate surface can also be generated based on the boron-carbon process fraction. Films with higher contents of boron and carbon components were originally desired.

In some embodiments, the film thickness non-uniformity (eg, 1 sigma (1σ) thickness non-uniformity) may not be negatively affected by the increased boron-carbon process fraction. In some embodiments, the film thickness non-uniformity remains the same or substantially the same as the increased boron-carbon process fraction. For example, the film thickness unevenness of a process for depositing a silicon nitride film having a boron and carbon component may be less than about 20%, including less than about 10% and about 5%. In some embodiments, the film thickness non-uniformity can be improved as the boron-carbon process fraction is reduced to a specific value. For example, a boron-carbon process fraction of less than about 10% can provide improved film thickness non-uniformity.

Referring to FIG. 16, a Fourier transform infrared spectroscopy (FTIR) analysis of four films having a boron-carbon process fraction of about 0% to about 15% is shown. Each of the four films may be formed according to one or more processes as described herein (eg, a process as described with reference to FIG. 15A). FTIR indicates the presence of various features within each membrane, including, for example, the presence of various chemical bonds. For example, FTIR analysis may show the addition of features and / or changes in features of the film after it is subjected to a film manufacturing process. The peaks corresponding to the various features of each film in FIG. 16 are labeled "O" or "*" to indicate the origin of the labeled features. For example, the peaks labeled "O" in the graph indicate characteristics (e.g., hydrogen (NH) bonded to nitrogen, hydrogen (OH) bonded to oxygen, hydrogen (Si) bonded to silicon (Si -H), nitrogen bonded to silicon (Si-N)) is contributed by a process for depositing a silicon nitride SiN film. For example, peaks marked with "*" indicate characteristics (e.g., hydrogen bonded to carbon, hydrogen bonded to boron, carbon bonded to boron, carbon bonded to another carbon, bonded Boron to another boron) is contributed by a process for introducing boron and carbon components into a silicon nitride SiN film. FIG. 16 illustrates that a process for introducing boron and carbon into a silicon nitride film can provide features such as hydrogen (CH) bonded to carbon and / or hydrogen (BH) bonded to boron (e.g., as in mediation shown in FIG. 16 and about 2500 cm ^-1 between 3000cm ^-1), such as boron and carbon bonded to boron (BC), boron is bonded to another (BB), and / or bonded to another carbon Carbon (CC) and the like (for example, as shown in FIG. 16 between 1000 cm ^-1 and about 1500 cm ^-1 (for example, at about 1200 cm ^-1 )). FIG. 16 shows that the Si-H bonding characteristics decrease as the boron-carbon process fraction increases. The reduction in Si-H bonding characteristics can be beneficial to improve the performance of SiN (B, C) films, such as the improvement of the electrical properties of the films. Figure 16 also shows that the peaks corresponding to nitrogen (Si-N) bonded to silicon can shift to higher wavenumbers as the fraction of the boron-carbon process increases, such as indicating changes in the bond between silicon and nitrogen .

FIG. 17 shows an analysis based on X-ray reflectance (XRR) measurements of four films having a boron-carbon process fraction of about 0% to about 15%. The film thickness in nanometers, the film density in grams / cubic centimeters (g / cm ³ ), and the film roughness in nanometers (nm) are shown. Each of the four films may be formed according to one or more processes as described herein (eg, a process as described with reference to FIG. 15A). FIG. 17 shows that the film density decreases as the boron-carbon process fraction increases and the film roughness increases slightly as the boron-carbon process fraction increases.

FIG. 18 is a graph showing corresponding films formed by processes having various boron-carbon process fractions in nanometers per minute (nm / min) in a diluted HF solution (for example, 0.5% by weight HF solution) Out of the wet etch rate. The film may be formed according to one or more processes as described herein (eg, a process as described with reference to FIG. 9A). As shown in FIG. 18, the wet etch rate of a silicon nitride film (eg, a SiN (B, C) film) containing boron and carbon components may decrease significantly as the boron-carbon process fraction increases. FIG. 18 shows that a film deposition process having a boron-carbon process fraction greater than about 5% can produce a SiN (B, C) film with a significantly reduced wet etch rate. For example, a SiN (B, C) film (e.g., a SiN (B, C) film suitable for partition wall applications) with a desired wet etch rate in diluted HF can be obtained by having a higher than about 10 % Boron-Carbon Process Fraction Process.

19A to 19D illustrate the wet etching performance of a silicon nitride film (eg, a SiN (B, C) film) containing boron and carbon components deposited on the trench structure 1300 of the substrate. The film may be formed according to one or more processes as described herein (eg, a process as described with reference to FIG. 15A). 19A and 19C illustrate scanning electron microscope (SEM) images of the trench structure 1300 having the film 1302 on one or more surfaces of the trench structure 1300 before the film 1302 is exposed to a wet etchant. For example, using A wet etchant containing a dilute hydrofluoric acid (HF) solution (eg, a 0.5% by weight HF solution) for a period of time (eg, up to about 2 minutes). 19B and 19D illustrate the film 1302 after exposure to a wet etchant. 19B and 19D illustrate that the film 1302 is not or substantially not affected by the wet etchant. For example, the ratio of the wet etch rate of the film 1302 to the etch rate of the underlying thermal oxide layer (eg, thermal silicon dioxide, TOX) may be less than about 3:10. FIGS. 19B and 19D also show a film 1302 that provides conformal coverage of the trench structure 1300 after wet etching. For example, the film 1302 does not delaminate from the underlying trench structure and / or does not exhibit other disadvantages.

20A to 20D show that a SiN (B, C) film on the surface of the high-aspect-ratio trench structure 1400 is exposed to a wet etchant for about 4 minutes (for example, after being immersed in a diluted hydrofluoric acid (HF or dHF) solution (for example, 0.5% by weight HF solution) after scanning electron microscope (SEM) image. The film may be formed according to one or more processes as described herein (eg, a process as described with reference to FIG. 15A). FIG. 20A is a lower magnification image of the trench structure 1400 at 13k × magnification, showing an upper portion 1402 of the trench, a middle section 1404 of the trench, and a lower portion 1406 of the trench. The upper portion 1402 is shown at a higher magnification at 250k × magnification in FIG. 20B, the middle section 1404 is shown at a higher magnification at 250k × magnification in FIG. 20C, and the lower portion 1406 is shown in FIG. 20D at It is shown at a higher magnification at 250k × magnification. As shown in FIGS. 20A to 20D, the SiN (B, C) film may exhibit excellent conformality or step coverage for the high aspect ratio trench structure 1400 after being exposed to a wet etchant. For example, FIGS. 20A to 20D show a thickness of about 20 nanometers formed on the upper portion 1402 of the trench structure 1400 and a thickness of about 20 nanometers. A thickness of about 20 nm on the middle section 1404 and a thickness of about 19 nm on the lower portion 1406 of the trench structure 1400, such as a SiN (B, C) film (e.g., about 95% or more Shape). The ratio of the wet etching rate of the SiN (B, C) film to the etching rate of the underlying thermal oxide (eg, thermal silicon dioxide, TOX) as shown in FIGS. 20A to 20D may be less than about 1: 2. .

21A to 21D show scanning electrons of a silicon nitride film (eg, a SiN (B, C) film) containing boron and carbon on the surface of the high-aspect-ratio trench structure 1500 before being exposed to a wet etchant Microscope (SEM) image. The film may be formed according to one or more processes as described herein (eg, a process as described with reference to FIG. 15A). FIG. 21A is a lower magnification image of the trench structure 1500 at 11k × magnification, FIG. 21B shows an upper portion 1502 of the trench structure 1500 at a higher magnification of 200k ×, and FIG. 21C is at 200k × The middle section 1504 of the trench structure 1500 is shown at a higher magnification, and FIG. 21D shows the lower portion 1506 of the trench structure 1500 at a high magnification of 200k ×. 21A to 21D illustrate that a SiN (B, C) film can exhibit excellent step coverage or conformality. For example, FIG. 21B to FIG. 21D show a thickness of about 23 nm formed on the upper portion 1502 of the trench structure 1500, a thickness of about 23 nm formed on the middle section 1504 of the trench structure 1500, and formation A SiN (B, C) film (eg, about 95% or greater than 95% conformality) on the lower portion 1506 of the trench structure 1500 with a thickness of about 24 nm.

The etching rate of the SiN (B, C) film in a wet etchant (for example, a wet etchant in which the ratio of H ₂ O ₂ : HF: H ₂ O by volume is about 5: 5: 90) may be about 1.1 nm / min (nm / min) ± about 0.3 nm / min. In some embodiments, the SiN (B, C) film may be immersed in ozone (O ₃ ) before being exposed to a wet etchant, for example to increase the film's etch rate. The etch rate of the SiN (B, C) film immersed in ozone before being exposed to the wet etchant may have a film etch rate of about 2.2 nm / minute ± about 0.5 nm / minute. In some embodiments, the etch rate may vary depending on the film composition.

The SiN (B, C) film deposited on a blanket wafer and analyzed by Raffford backscattering spectroscopy (RBS) shows the just-deposited film before immersion in a 0.5% by weight HF solution and after immersion for about 2 minutes The composition of the film is: 20 atomic% silicon (Si), 35 atomic% nitrogen (N), 20 atomic% boron (B), 18 atomic% carbon (C), 6 atomic% oxygen (O), 1 atomic% of chlorine (Cl). The composition of the film after immersion in the HF solution was: 19 atomic% of Si, 30 atomic% of N, 25 atomic% of B, 19 atomic% of C, 7 atomic% of O, and 1 atomic% of Cl. RBS analysis shows that the composition of the film may not be significantly affected by the HF immersion process.

Although the present invention is provided in the context of certain embodiments and examples, those skilled in the art will understand that the present invention extends to other alternative embodiments and / or uses of the described embodiments and / or their uses, and Obvious retouching form and equivalent. In addition, although several variations of the embodiments of the present invention have been shown and explained in detail, other retouches within the scope of the present invention will be readily apparent to those skilled in the art based on this disclosure. It is also envisaged that various combinations or sub-combinations can be made to the specific features and aspects of the embodiments, and that the various combinations or sub-combinations still fall within the scope of the invention. It should be understood that various features and aspects of the disclosed embodiments may be combined with each other or replaced with each other to form a changed mode of the embodiments of the present invention. Therefore, it is intended that the scope of the invention should not be limited to the specific features described above. 定 实施 例。 Example.

The headings (if any) provided herein are for convenience only and do not necessarily affect the scope or meaning of the devices and methods disclosed herein.

Claims (26)

A method for doping a semiconductor substrate includes depositing boron and a carbon film on the semiconductor substrate in a reaction space by exposing the semiconductor substrate to a vapor-phase boron precursor at a process temperature of 300 ° C to 450 ° C. Wherein the gas phase boron precursor includes boron, carbon, and hydrogen; and annealing the boron and carbon film at a temperature of 800 ° C to 1200 ° C. The method for doping a semiconductor substrate according to item 1 of the scope of patent application, wherein the vapor phase boron precursor is decomposed on the semiconductor substrate. The method for doping a semiconductor substrate according to item 1 of the patent application scope, wherein the gas phase boron precursor comprises triethylboron or trimethylboron. The method for doping a semiconductor substrate according to item 1 of the scope of patent application, wherein the gas phase boron precursor is supplied to the reaction space together with a carrier gas containing argon. The method for doping a semiconductor substrate according to item 1 of the patent application scope further comprises depositing a silicon oxide film on the semiconductor substrate before depositing the boron and carbon films. The method for doping a semiconductor substrate according to item 1 of the scope of patent application, wherein the boron and carbon films are directly deposited on the semiconductor substrate. The method for doping a semiconductor substrate according to item 1 of the scope of patent application, further comprising depositing a boron dopant film on the semiconductor substrate before depositing the boron and carbon films, wherein the boron dopant films are different On the boron and carbon film, and wherein the boron dopant film and the boron and carbon film are sequentially deposited and deposited on the boron and carbon film The semiconductor substrate is not exposed to ambient air from the deposited boron dopant film. The method for doping a semiconductor substrate according to item 1 of the scope of patent application, further comprising maintaining a pressure of 0.5 to 10 torr in the reaction space during exposing the semiconductor substrate to the vapor phase boron precursor. . The method for doping a semiconductor substrate according to item 1 of the scope of the patent application, wherein the boron and carbon films have a maximum thickness of 5 nm. A method for doping a semiconductor substrate includes: depositing a boron and carbon film on the semiconductor substrate in a reaction space by a chemical vapor deposition process, wherein depositing the boron and carbon film includes: at a process temperature greater than 300 ° C Exposing the three-dimensional structure on the semiconductor substrate to a vapor phase boron precursor in an inert gas environment; and after exposing the three-dimensional structure on the semiconductor substrate to the vapor phase boron precursor, purging the A reaction space; and annealing the boron and carbon films in a nitrogen environment, wherein a cover layer is not formed on the boron and carbon films before annealing. The method for doping a semiconductor substrate according to item 10 of the scope of patent application, wherein depositing comprises: depositing the boron and carbon film on the three-dimensional structure on the semiconductor substrate. The method for doping a semiconductor substrate according to item 11 of the scope of patent application, wherein the three-dimensional structure has an aspect ratio greater than 8: 1, and wherein the boron and carbon films have a step coverage of greater than 80%. The method for doping a semiconductor substrate according to item 10 of the application, wherein the boron and carbon films have a thickness of up to 5 nm. The method for doping a semiconductor substrate according to item 10 of the patent application scope further comprises: before depositing the boron and carbon film, depositing a silicon oxide film on the semiconductor substrate. The method for doping a semiconductor substrate according to item 10 of the scope of patent application, wherein the gas phase boron precursor is supplied to the reaction space together with a carrier gas containing argon. The method for doping a semiconductor substrate according to item 10 of the patent application scope, further comprising performing the annealing at a temperature of 800 ° C to 1200 ° C. A method for depositing a film containing boron and carbon, wherein the film containing boron and carbon is deposited on a substrate in a reaction space, and the method for depositing the film containing boron and carbon includes a cycle process, and the cycle process includes The substrate is brought into contact with the vapor-phase boron precursor in at least two deposition cycles at a process temperature of 250 ° C to up to 400 ° C, and the deposition cycles are separated by a purge step to form the substrate on the substrate. A film containing boron and carbon, wherein the vapor phase boron precursor is decomposed on the substrate, and wherein the film has a thickness of less than 30 Angstroms. The method for depositing a film containing boron and carbon as described in item 17 of the scope of patent application, wherein the film containing boron and carbon has a thickness of less than 15 Angstroms. The method for depositing a film containing boron and carbon as described in item 18 of the scope of patent application, wherein the film containing boron and carbon has a thickness of less than 5 Angstroms. The method for depositing a film containing boron and carbon as described in item 17 of the scope of the patent application, wherein the film containing boron and carbon is substantially resistant to a diluted hydrofluoric acid solution. The method for depositing a film containing boron and carbon as described in item 17 of the patent application scope further comprises: depositing the film containing boron and carbon in a batch processing reactor. The method for depositing a film containing boron and carbon according to item 17 of the scope of patent application, further comprising forming silicon oxide, aluminum nitride, aluminum oxide, and nitrogen on the film containing boron and carbon in the reaction space. At least one of silicon compounds. The method for depositing a film containing boron and carbon according to item 17 of the scope of patent application, further comprising: depositing the boron and carbon on at least one of silicon oxide, aluminum nitride, aluminum oxide, and silicon nitride. Of the film. The method for depositing a film containing boron and carbon according to item 23 of the scope of patent application, further comprising: forming the silicon oxide, the aluminum nitride, the aluminum oxide, and the nitride in the reaction space. The at least one of silicon. The method for depositing a film containing boron and carbon according to item 17 of the scope of the patent application, wherein the cycle process includes less than 100 deposition cycles. The method for depositing a film containing boron and carbon as described in item 17 of the scope of patent application, wherein the film containing boron and carbon has a 1σ unevenness of less than 5%.