CN119948203A

CN119948203A - Chalcogenide-based thin film modifier, semiconductor substrate and semiconductor device manufactured using the same

Info

Publication number: CN119948203A
Application number: CN202380068082.0A
Authority: CN
Inventors: 郑在善; 李承铉; 金德铉
Original assignee: Soulbrain Co Ltd
Current assignee: Soulbrain Co Ltd
Priority date: 2022-10-07
Filing date: 2023-10-06
Publication date: 2025-05-06
Also published as: CN119948202A; CN119998490A; KR20240049770A; KR20240049197A; KR102758951B1; KR20240049771A; KR102713069B1; KR102700990B1

Abstract

The present invention relates to a chalcogenide film modifier, a semiconductor substrate and a semiconductor device manufactured using the same. The method for manufacturing a metalloid-containing thin film of the present invention uses a precursor compound containing halogen and a specific chalcogenide film modifier capable of filling the position of the halogen separated from the precursor compound, thereby improving the reliability of a high-purity thin film and easily manufacturing it through a simple process.

Description

Chalcogenide thin film modifier, semiconductor substrate manufactured using the same, and semiconductor device

Technical Field

The present invention relates to a chalcogenide (chalcogenide) thin film modifier, a semiconductor substrate and a semiconductor device manufactured using the same, and more particularly, to a chalcogenide thin film modifier, a semiconductor substrate and a semiconductor device manufactured using the same, in which the thin film modifier can be used for a chalcogenide thin film for forming a GST (Ge-Sb-Te) triple film or the like to greatly increase a deposition rate of the thin film and greatly reduce impurities, thereby improving reliability of a phase change device.

Background

Chalcogenides are compounds containing chalcogen of group sixteen and have the property of rapidly undergoing a phase change between crystalline and amorphous states when heated, which can be used to realize phase change memory devices.

In forming data storage materials for phase change memory devices, the content of byproduct carbon compounds in chalcogenide thin films can have an important effect on the quality and performance of the data storage materials in addition to the process conditions such as precursor materials and deposition temperatures.

In general, a substance such as GeTe2 can be formed using a germanium precursor in an oxidation state of tetravalent, but there is a problem in that not only the reliability of the phase change device cannot be ensured due to the poor phase transfer characteristics, but also Te is precipitated during the phase transfer operation.

In addition, deposition is typically performed at low temperatures below 200 ℃, and thus, there is a need to provide techniques for complete removal of ligands from precursors.

Therefore, there is a need to develop a chalcogenide thin film modifier capable of ensuring the reliability of a phase change device, improving the problem of Te precipitation during a phase transfer operation, and having excellent reactivity sufficient to completely remove ligands in a precursor, and a semiconductor substrate and a semiconductor device manufactured thereby, and the like.

Further, it is required to develop a chalcogenide thin film modifier which can be applied to memories such as NAND or DRAM, logic devices, and the like, and semiconductor substrates and semiconductor devices manufactured therefrom, and the like, in addition to the above-described phase change devices.

Prior art literature

Korean patent No. 10-1279925

Disclosure of Invention

Problems to be solved by the invention

In order to solve the problems in the prior art as described above, an object of the present invention is to provide a compound of a predetermined structure as a chalcogenide-based thin film modifier to activate a substrate adsorption precursor to provide an activated substrate adsorption precursor and to have excellent reactivity enough to completely remove a ligand to provide a high quality thin film under low temperature deposition conditions, and further, to provide a semiconductor substrate and a semiconductor device including the thin film.

The above object and other objects of the present invention can be achieved by the present invention as described below.

Means for solving the problems

In order to achieve the above object, the present invention provides a chalcogenide thin film modifier which activates a substrate adsorption precursor having a center metal of Ge, sb, te, se or Sn to provide an activated substrate adsorption precursor, and replaces a first ligand of the substrate adsorption precursor with a second ligand of the chalcogenide thin film modifier.

The chalcogenide thin film may be Ge, geTe, GST (GeSbTe), GSS (GeSbSe), snTe, SST (SnSbTe), or GSST (GeSnSbTe).

The above-described reactive gas can be replaced because the activation energy of the activated substrate adsorption precursor is smaller than that of the above-described substrate adsorption precursor.

The first ligand may contain both silicon and carbon, or both nitrogen and carbon, or both oxygen and carbon.

The second ligand has an activation energy (Activation energy, E _A),(E_{A First ligand}>E_{A Second ligand}) lower than the activation energy of the first ligand of the substrate adsorption precursor, which activation energy is determined upon reaction with a subsequently injected precursor compound.

The substrate adsorption precursor may contain no halogen, and the chalcogenide thin film modifier may contain at least one halogen selected from iodine and bromine.

The chalcogenide thin film modifier may be Hydrogen Iodide (HI), hydrogen bromide (HBr), or a mixed gas obtained by mixing hydrogen iodide or hydrogen bromide in an inert gas at a molar ratio of 1 to 99.

The chalcogenide thin film may be a germanium-tellurium thin film or a germanium support film constituting the germanium-tellurium thin film.

The germanium-tellurium film may comprise an antimony-tellurium film in an upper portion.

The thin film may be a deposited film.

Wherein, the deposition can be Atomic Layer Deposition (ALD), plasma Enhanced Atomic Layer Deposition (PEALD), chemical Vapor Deposition (CVD), plasma Enhanced Chemical Vapor Deposition (PECVD), metal Organic Chemical Vapor Deposition (MOCVD) or Low Pressure Chemical Vapor Deposition (LPCVD).

The chalcogenide thin film modifier can replace a reaction gas.

The above-mentioned chalcogenide thin film modifier can replace the first ligand adsorbed to the precursor of the substrate with the second ligand (for example, halogen) of the chalcogenide thin film modifier to activate the precursor adsorbed to the substrate, thereby easily reacting with the reaction precursor injected later, and thus, a reaction compound which is safe to handle due to a slightly low reactivity can be used.

As an example, there is a problem that the Guan ligand cannot be completely removed even by using a reactive compound (for example, teH ₂) having high reactivity, although the mechanism of implanting TeH ₂ having high reactivity into a precursor (for example, substrate-Ge-Guan) adsorbed on a substrate to form, for example, substrate-Ge-Te-H and releasing it as Guan-H is followed.

The present invention follows the mechanism of injecting a chalcogenide-based thin film modifier (e.g., H-I) into a precursor adsorbed to a substrate (e.g., substrate-Ge-Guan) to form, for example, substrate-Ge-I and detach in the form of Guan-H, and completely removing the ligands of the substrate-adsorbed precursor, i.e., hydrocarbon impurities, by thorough reaction. Thereafter, a plurality of tellurium precursors can be implanted to form a chalcogenide thin film (e.g., substrate-Ge-Te-H).

That is, the second ligand of the chalcogenide thin film modifier has an activation energy (Activation energy, E _A),(E_{A First ligand}>E_{A Second ligand}) lower than that of the first ligand of the substrate adsorption precursor, and the activation energy may be determined at the time of reaction with the precursor compound injected later.

The present invention also provides a semiconductor substrate comprising a substrate and a thin film deposited using the chalcogenide thin film modifier.

The present invention also provides a semiconductor substrate comprising a substrate and a thin film, wherein the thin film comprises a film formed by laminating an antimony-tellurium upper layer film and a germanium-tellurium lower layer film, and the germanium-tellurium lower layer film or a germanium support film constituting the germanium-tellurium lower layer film is a film formed by depositing the above-mentioned chalcogenide thin film modifier in a ligand-substituted manner.

The film may have a multilayer structure of two or more layers.

The carbon-containing compound as a by-product of the thin film as measured by SIMS may be 3,000 counts/sec or less.

The deposition rate of the film can beThe above.

The iodine atoms of the film may be 50 counts/sec or more as measured by SIMS.

In addition, the present invention provides a semiconductor device including the above semiconductor substrate.

The semiconductor device may be a memory including a phase change memory device, NAND, and DRAM, a logic device, or the like.

Effects of the invention

According to the present invention, it is possible to provide a chalcogenide-based thin film modifier which effectively removes a ligand of a precursor compound adsorbed to a substrate to improve a deposition rate and reduce impurities of a thin film, thereby not only improving the thin film productivity, but also replacing a reaction gas.

Further, the characteristics of the phase change device can be improved, and further, there is an effect of providing a thin film manufacturing method using the same, and a semiconductor substrate and a semiconductor device manufactured thereby.

In addition, the above-mentioned chalcogenide thin film modifier can replace the first ligand adsorbed to the precursor of the substrate with the second ligand (for example, halogen) of the chalcogenide thin film modifier to activate the precursor adsorbed to the substrate, thereby allowing easy reaction with the reaction precursor injected later, and therefore, a reaction compound which is safe to handle due to a slightly low reactivity can be used.

In addition, in order to solve the problem that the conventional technique is not able to completely remove the Guan ligand even with a highly reactive reaction compound (for example, teH 2), although the mechanism of injecting TeH2 having high reactivity into a precursor adsorbed to a substrate (for example, substrate-Ge-Guan) to form, for example, substrate-Ge-Te-H and releasing it in the form of Guan-H is followed, the mechanism of injecting a chalcogenide thin film modifier (for example, H-I) into a precursor adsorbed to a substrate (for example, substrate-Ge-Guan) to form, for example, substrate-Ge-I and releasing it in the form of Guan-H can be followed, and after the ligand of the substrate-adsorbed precursor, that is, hydrocarbon impurities, is completely removed by a thorough reaction, various tellurium precursors can be injected to form a chalcogenide thin film (for example, substrate-Ge-Te-H).

Drawings

FIG. 1 is a view showing film deposition of example 1 obtained by using a chalcogenide-based film modifier before and after the addition of a precursor compound and without adding ammonia gas according to an example of the present invention.

Fig. 2 is a view showing film deposition of example 2 obtained by using a chalcogenide-based film modifier before and after the addition of a precursor compound and without adding ammonia gas according to another example of the present invention.

Fig. 3 is a diagram showing thin film deposition of comparative example 1 in which a chalcogenide-based thin film modifier is not used but ammonia gas is charged as a reaction gas according to the prior art.

Detailed Description

Hereinafter, the chalcogenide thin film modifier, the semiconductor substrate and the semiconductor device manufactured by using the same of the present invention will be described in detail.

The inventors of the present invention have confirmed that providing a predetermined compound as a chalcogenide thin film modifier, which allows a ligand to be efficiently released from a precursor compound having a metalloid (metalloid) for forming a chalcogenide thin film as a central metal, can greatly improve the deposition rate of the thin film and significantly reduce Cl, O, si, H, NH, metal oxide, and particularly carbon remaining as a process by-product. Based on this, the present invention has been completed by conducting studies on a chalcogenide low-temperature deposited film.

Hereinafter, a chalcogenide thin film modifier, a semiconductor substrate including a thin film manufactured using the same, and a semiconductor device will be described in detail.

Chalcogenide thin film modifier

The above-mentioned chalcogenide-based thin film modifier may be a substance that activates a substrate adsorption precursor in the present invention to provide an activated substrate adsorption precursor.

As an example, the center metal of the substrate adsorption precursor is Ge, sb, te, se or Sn, and the ligand contains both silicon and carbon, or both nitrogen and carbon, or both oxygen and carbon to be adsorbed on the substrate.

Such a substrate adsorption precursor may be a substance that can be activated not only when activated with a predetermined structure under low-temperature process conditions to modify into an activated substrate adsorption precursor so that the ligand is sufficiently detached, but also to provide reactivity sufficient to replace the reaction gas.

The term "predetermined structure" used in the present invention means that the ligand contained in the substrate adsorption precursor is replaced with halogen unless otherwise specifically defined in the present invention.

As an example, the ligands of the substrate adsorption precursor may contain both silicon and carbon, or both nitrogen and carbon.

Preferably, the substrate adsorption precursor does not contain halogen, and the chalcogenide thin film modifier contains at least one halogen selected from iodine and bromine.

Specifically, the chalcogenide thin film modifier may be Hydrogen Iodide (HI), hydrogen bromide (HBr), or a mixed gas obtained by mixing Hydrogen Iodide (HI), hydrogen bromide (HBr), or a mixed gas of hydrogen bromide and an inert gas at a molar ratio of 1 to 99, and is preferably a substance represented by the above structure or a mixed gas of the above inert gas in view of transporting a gas-phase substance and reaching a reaction surface. At this time, the side reaction is suppressed and the film growth rate is adjusted to significantly reduce by-product carbon-containing compounds in the film, thereby reducing corrosion and deterioration, and also has an effect of achieving a stoichiometric oxidation state when forming the chalcogenide-based film.

Specifically, the chalcogenide thin film modifier is a gas mixture of 3N to 15N pure hydrogen iodide, 1 to 99mol% of 3N to 15N hydrogen iodide and the balance of inert gas making the total amount 100mol%, or a water solution mixture of 0.5 to 70mol% of 3N to 15N hydrogen iodide and the balance of water making the total amount 100mol%, wherein when the inert gas is nitrogen, helium or argon having a purity of 4N to 9N, the process by-product reduction effect is remarkable, the step coverage (step coverage) effect is excellent, and the thin film density improvement effect and the thin film electrical characteristics are more excellent.

Preferably, the chalcogenide thin film modifier may be a gas mixture of pure hydrogen iodide of 5n to 6n, 1 to 99mol% of hydrogen iodide of 5n to 6n and the balance of inert gas making the total amount 100mol%, or an aqueous solution mixture of hydrogen iodide of 5n to 6n and the balance of water making the total amount 100mol%, wherein the inert gas may be nitrogen, helium or argon having a purity of 4n to 9n, and in this case, side reactions can be suppressed when forming a thin film, and the growth rate of the thin film can be adjusted to reduce process byproducts in the thin film, thereby reducing corrosion and degradation, and improving crystallinity of the thin film, and even if the thin film is formed on a substrate having a complicated structure, step coverage and thickness uniformity of the thin film can be greatly improved.

Preferably, the chalcogenide thin film modifier may be a compound having a purity of 99.9% or more, a compound having a purity of 99.95% or more, or a compound having a purity of 99.99% or more, and when a compound having a purity of less than 99% is used as a reference, impurities may remain in the thin film or cause side reactions with precursors or reactants, and therefore, 99% or more of the material should be used as much as possible.

Preferably, the chalcogenide thin film modifier has a vapor pressure of 180 to 240k, which is one atmosphere, and in this range, a substance can be smoothly transported into the chamber, and thus, the chalcogenide thin film modifier has an effect of improving the reactivity of the chalcogenide thin film and improving the continuity and the film quality of the thin film.

The chalcogenide thin film modifier can replace a reaction gas.

In the present invention, the method may include a step of vaporizing and injecting a chalcogenide thin film modifier or a precursor compound described later, and then performing a plasma post-treatment, in which the growth rate of the thin film can be improved and the process by-products can be reduced.

The thin film may be a deposited film.

The deposition may be Atomic Layer Deposition (ALD), plasma Enhanced Atomic Layer Deposition (PEALD), chemical Vapor Deposition (CVD), plasma Enhanced Chemical Vapor Deposition (PECVD), metal Organic Chemical Vapor Deposition (MOCVD), or Low Pressure Chemical Vapor Deposition (LPCVD).

The substrate may be a silicon wafer containing-H, -OH end groups, an insulating film, a dielectric film, or the like.

As an example, the central metal of the substrate adsorption precursor may be a transition metal, and preferably, ge or Te.

A substance having a structure in which these central metals are bonded to the above-described ligands can be used as a substrate adsorption precursor, and can be activated with the above-described chalcogenide-based thin film modifier, thereby obtaining an activated substrate adsorption precursor. In this case, the process by-product reduction effect is remarkable and the phase change property is excellent when the chalcogenide thin film is formed.

When the above substrate adsorption precursor is (N, N' -diisopropyl-dimethylguanidino) (dimethylamino) germanium (II), the substrate adsorption precursor structure activated by the above chalcogenide thin film modifier may be substrate-Ge-I, and when the oxidation number of the central metal is divalent, it is preferable in terms of reduction of reaction energy.

The substrate adsorption precursor may be a germanium compound represented by chemical formula 1 below.

[ Chemical formula 1]

In the above chemical formula 1, Y ¹ and Y ² are independently selected from R ³、NR⁴R⁵ OR ⁶, and the above R ¹～R⁶ is independently an alkyl group of C ₁～C₇.

In the above chemical formula 1, Y ¹ and Y ² may be -N(CH₃)₂、-N(CH₃)(CH₂CH₃)、-CH₃、-CH(CH₃)₂ or-C (CH ₃)₃) independently of each other.

In the chemical formula 1, R ¹～R² may be a germanium compound of methyl, ethyl, propyl or tert-butyl, independently of each other.

The substrate adsorption precursor may be germanium (II) halide, such as Ge (II) Br ₂、Ge(Ⅱ)Cl₂ (dioxane (dioxane)) or Ge (II) F ₂.

For example, when the substrate adsorption precursor is bis (trimethylsilyl) tellurium (Bis (trimethylsilyl) telluride), the substrate adsorption precursor structure activated by the chalcogenide thin film modifier may be-substrate-Ge-Te-I, and when the oxidation number of the central metal is divalent, it is preferable in terms of reduction of reaction energy.

In the present invention, the precursor compound for forming a thin film is a molecule having one or more ligands composed of C, N, si, H, X (halogen) at the central metal atom (M), and when it is a precursor having a vapor pressure of 1 to 100torr at 25 ℃, the effect of filling the ligand-release site (LEAVING SITE) with a chalcogenide-based thin film modifier described later can be maximized.

The central metal may be Ge, sb, te, se or Sn.

As an example, the precursor compound may be a compound represented by the following chemical formula 1.

[ Chemical formula 1]

(In the above chemical formula 1, Y ¹ and Y ² are each independently selected from R ³、NR⁴R⁵ OR OR ⁶, and the above R ¹～R⁶ are each independently C ₁～C₇ alkyl.)

As a specific example, the substrate adsorption precursor may be a germanium compound Ge(Ⅱ)Br₂(dioxane)、Ge(Ⅱ)Br₂、Ge(Ⅱ)Cl₂、Ge(Ⅱ)Cl₂(dioxane)、Ge(Ⅱ)F₂(dioxane)、Ge(Ⅱ)F₂.

As another example, the precursor compound may be a compound represented by the following chemical formula 2.

[ Chemical formula 2]

(In the above chemical formula 2, M ₂ is a metalloid, and R ₅～R₁₀ is hydrogen or an alkyl group having 1 to 6 carbon atoms independently of each other, unlike germanium, tellurium or selenium which is a metal used in chemical formula 1.)

The M ₂ may be tellurium (Te) or selenium (Se).

R ₅～R₁₀ mentioned above can be CH ₃ or C ₂H₅ independently of one another.

As an example, the compound represented by the above chemical formula 2 may be one or more selected from structures represented by chemical formulas 2-1 to 2-7.

[ Chemical formulas 2-1] to [ chemical formulas 2-7]

The above-described precursor compounds are molecules having a metalloid as a central metal atom (M ₁、M₂) and having different ligands, and can maximize the reaction with a chalcogenide thin film modifier described later when they are precursors having a vapor pressure of 1 to 100torr at 25 ℃.

Examples of the tellurium precursor compound and selenium precursor compound include bis (trimethylsilyl) tellurium (Bis (trimethylsilyl) telluride), tellurium tetrachloride (Tellurium tetrachloride), tellurium bromide (Tellurium bromide), biphenylditelluride (Diphenyl ditelluride), tellurium dioxide (Tellurium dioxide), bis (trimethylsilyl) selenide (Bis (trimethylsilyl) seleide), selenium dichloride (Selenium dichloride), selenium tetrachloride (Selenium tetrachloride), selenium dibromide (Selenium dibromide), selenium tetrabromide (Selenium tetrabromide), diphenyl selenoether (DIPHENYL SELENIDE), and selenium dioxide (Selenium dioxide), and in this case, the reaction with a halide to be described later can be maximized.

As a specific example, the tellurium precursor compound may be a compound represented by the following chemical formula 3-1.

[ Chemical formula 3-1]

As an example, the precursor compound may be mixed with a polar solvent and then introduced into a chamber, and in this case, there is an advantage in that the viscosity and vapor pressure of the precursor compound can be easily adjusted.

Preferably, the polar solvent may be an amine solvent, and specific examples thereof include dimethylamine, diethylamine, trimethylamine, and triethylamine. In this case, there is an advantage that the step coverage (step coverage) can be improved even when the deposition temperature is increased during the formation of the thin film, while containing an organic solvent having low reactivity and solubility and being easy to manage moisture.

As an example, the solubility of the polar solvent in water (25 ℃) is 200mg/L or less, preferably 50 to 400mg/L, more preferably 135 to 175mg/L, and within this range, there is an advantage that the reactivity to the precursor compound is low and the water is easy to manage.

In the present invention, the solubility is not particularly limited as long as it is based on a measurement method and a standard conventionally used in the art, and as an example, a saturated solution can be measured by an HPLC method.

Preferably, the content of the polar solvent may be 5 to 95mol%, more preferably 10 to 90mol%, still more preferably 40 to 90mol%, and most preferably 70 to 90mol% based on the total weight of the precursor compound and the polar solvent added.

When the content of the polar solvent to be charged is more than the upper limit value, impurities are induced, resulting in an increase in the resistance and the impurity value in the thin film, and when the content of the organic solvent to be charged is less than the lower limit value, there is a disadvantage in that the effect of improving step coverage and reducing impurities such as chloride (Cl) ions by adding the solvent is not remarkable.

Film and method for producing the same

Including films obtained using the chalcogenide-based film modifiers described above.

The film may have a multilayer structure of two or more layers or a multilayer structure of two or three layers.

The thin film can form a germanium-tellurium thin film or a germanium support film constituting the germanium-tellurium thin film.

As an example, the thin film can be obtained by reacting the activated substrate adsorption precursor represented by the structure of the above chemical formula 1 with a chalcogenide thin film modifier, and in this case, the activated substrate adsorption precursor can be used without considering the reaction energy with the reaction gas, and thus, a high quality thin film can be manufactured.

As an example, the activated substrate adsorption precursor has excellent reactivity that can replace a reaction gas, because the activation energy of the activated substrate adsorption precursor is smaller than that of the substrate adsorption precursor.

As an example, the germanium-tellurium film may include an antimony-tellurium film in an upper portion thereof.

The thin film may be a deposited film.

The carbon-containing compound as a by-product of the thin film measured by SIMS may be 3,000 counts/sec or less, 1,000 counts/sec or less, or 50 to 600 counts/sec.

The deposition rate of the film measured by ellipsometry may beThe above steps,Above or belowWithin the above range, the in-plane direction film continuity and roughness, and the film density can be improved.

The iodine atoms of the film may be 50 counts/sec or more as measured by SIMS.

The one cycle (cycle) may be a unit cycle of adsorbing the chalcogenide thin film modifier to a substrate, purging the non-adsorbed chalcogenide thin film modifier, supplying the precursor compound represented by the chemical formula 2 or the chemical formula 3 to the substrate, purging the precursor compound remaining, modifying the precursor compound with a different chalcogenide thin film modifier, and purging the remaining chalcogenide thin film modifier, and repeating the unit cycle to form a thin film having a desired thickness.

The thin film may be provided on SiO ₂ on a substrate, but is not limited to this and is intended to be limited to, also include-SiH, -SiH ₂、-SiH₃、-SiOH、-Si(OH)₂、-Si(OH)₃ -Si-O-Si-.

The thin film can be used for a semiconductor device, and as an example, can be used for a phase change memory device.

The present invention can also provide a laminated film comprising an antimony-tellurium upper layer film and a germanium-tellurium lower layer film, wherein the germanium-tellurium lower layer film is obtained by activating a precursor compound with a chalcogenide thin film modifier to obtain an activated precursor compound represented by chemical formula 1 or chemical formula 2, and then adding the chalcogenide thin film modifier to modify the ligand of the activated precursor compound.

Method for producing film

The above-described thin film can be manufactured by various methods as long as a step of forming a metalloid thin film including a germanium-tellurium-based material is included.

As an example, the step of forming the metalloid thin film including the germanium-tellurium-based material may be performed by the following method.

As a first step, a chalcogenide thin film modifier and a source gas containing a germanium precursor compound are sequentially injected onto a substrate loaded in a chamber.

As an example, the chalcogenide thin film modifier may contain at least one halogen selected from iodine and bromine, and iodine is preferably used.

In the present invention, the means for supplying the chalcogenide thin film modifier and the source gas containing the germanium precursor compound to the deposition chamber may be a flow control means (Mass Flow Controller; MFC), a means for supplying a Liquid (Liquid DELIVERY SYSTEM; LDS), including a means for supplying a volatile gas by a gas phase flow control (Mass Flow Controller; MFC) method (Vapor Flow Control; VFC), a Liquid phase flow control means (Liquid Mass Flow Controller; LMFC), or the like.

In this case, as a carrier gas or a diluent gas for supplying the chalcogenide thin film modifier and the source gas containing the germanium precursor compound onto the substrate, one or a mixture gas of two or more selected from argon (Ar), nitrogen (N ₂) and helium (He) may be used, but is not limited thereto.

In the present invention, as an example, an inert gas, preferably the carrier gas or the diluent gas, may be used as the purge gas.

The chamber may be an Atomic Layer Deposition (ALD) chamber, a Plasma Enhanced Atomic Layer Deposition (PEALD) chamber, a Chemical Vapor Deposition (CVD) chamber, a Plasma Enhanced Chemical Vapor Deposition (PECVD) chamber, a Metal Organic Chemical Vapor Deposition (MOCVD) chamber, or a Low Pressure Chemical Vapor Deposition (LPCVD) chamber.

The substrate loaded in the chamber may include a semiconductor substrate such as a silicon substrate or a silicon oxide substrate.

The substrate may be further formed with a conductive layer or an insulating layer on an upper portion thereof.

The substrate may be maintained at 50-500 ℃, 80-350 ℃, or 80-200 ℃.

As an example, the substrate may be heated to 50 to 300 ℃, and as a specific example, to 50 to 250 ℃, 50 to 200 ℃, or 70 to 200 ℃, and the chalcogenide thin film modifier and the precursor compound may be sequentially injected.

These chalcogenide thin film modifier and germanium precursor compound may be injected onto the substrate in an unheated or heated state, and then heated during the deposition step in accordance with the deposition efficiency. For example, the substrate may be implanted at 50 to 300 ℃ for 1 to 20 seconds.

As an example, the ratio of the amount (mg/cycle) of the chalcogenide thin film modifier and the amount (mg/cycle) of the precursor compound to be used in the third step may be used.

As an example, the chalcogenide thin film modifier and the germanium precursor compound are in a ratio of 1:1 to 1:20, preferably 1:1 to 1:15, and more preferably 1:1 to 1:10, and in this range, the effect of reducing the carbon-containing compound as a by-product and the effect of satisfying the low-temperature process requirements are remarkable.

As the second step, a step of purging with an inert gas may be included more than once. The inert gas may be the carrier gas or the diluent gas.

In the step of purging the non-adsorbed material, the amount of the purge gas to be introduced into the chamber is not particularly limited, and may be, for example, 10 to 100,000 times, preferably 50 to 50,000 times, more preferably 100 to 10,000 times the volume of the chalcogenide thin film modifier or germanium precursor compound to be introduced into the chamber, and within this range, the chalcogenide thin film modifier and the non-adsorbed germanium precursor compound can be sufficiently removed to form a uniform thin film and prevent deterioration of the film quality. Wherein the purge gas and the germanium precursor compound are added in an amount corresponding to one cycle, and the volumes of the chalcogenide thin film modifier and the germanium precursor compound represent the volume of the vaporized precursor compound vapor.

In the present invention, the purge is preferably 1,000 to 50,000sccm (Standard Cubic CENTIMETER PER minutes; standard square centimeters per Minute), more preferably 2,000 to 30,000sccm, still more preferably 2,500 to 15,000sccm, in which the film growth rate per cycle is properly controlled, and deposition is performed in a single atomic layer (atomic layer) or close thereto, and thus has an advantage in terms of film quality.

As a third step, a chalcogenide thin film modifier is injected into the substrate to fill the detached position with halogen while detaching the ligand of the germanium precursor compound adsorbed on the substrate. At this time, the precursor adsorbed on the substrate is effectively desorbed to improve the reaction rate, to appropriately reduce the film growth rate, and to greatly reduce the carbon-containing compound as a by-product.

As an example, the halide may contain at least one halogen selected from iodine and bromine, and iodine is preferably used.

The time (FEEDING TIME, sec) for supplying the chalcogenide thin film modifier to the surface of the substrate is preferably 0.01 to 10 seconds, more preferably 0.02 to 3 seconds, still more preferably 0.04 to 2 seconds, still more preferably 0.05 to 1 second per one cycle, and within this range, there are advantages that the thin film growth rate is low, the thin film density is improved, and the economy is excellent.

In the present invention, the amount of the chalcogenide thin film modifier to be supplied is based on a flow rate of 1 to 300sccm/cycle based on a volume of 15 to 20L of the chamber, more specifically, based on a flow rate of 10 to 100sccm/cycle based on a volume of 18L of the chamber.

In the present invention, the chalcogenide thin film modifier is supplied to the deposition chamber by, for example, gas supply by a gas phase flow control (Mass Flow Controller; MFC) method.

Preferably, the third step may further include a step of raising the temperature in the chamber to a deposition temperature before the chalcogenide thin film modifier is charged into the chamber, and/or a step of purging the chamber by injecting an inert gas into the chamber before the chalcogenide thin film modifier is charged into the chamber.

As the fourth step, a step of purging with an inert gas may be included more than once. In the present invention, the purge gas may be, for example, the carrier gas or the diluent gas described above.

In the step of purging the non-adsorbed chalcogenide thin film modifier, the amount of the purge gas to be introduced into the chamber may be 10 to 100,000 times, preferably 50 to 50,000 times, more preferably 100 to 10,000 times, as long as the non-adsorbed chalcogenide thin film modifier is sufficiently removed, and within this range, the non-adsorbed chalcogenide thin film modifier can be sufficiently removed to form a uniform thin film and prevent deterioration of the film quality. Wherein the purge gas and the chalcogenide thin film modifier are added in an amount corresponding to one cycle, and the volume of the chalcogenide thin film modifier represents the volume of vaporized chalcogenide thin film modifier vapor.

As a specific example, when the above-mentioned chalcogenide thin film modifier is injected at a flow rate of 100sccm and an injection time of 0.5sec (each cycle), and the purge gas is injected at a flow rate of 3000sccm and an injection time of 5sec (each cycle) in the step of purging the non-adsorbed chalcogenide thin film modifier, the injection amount of the purge gas is 300 times the injection amount of the chalcogenide thin film modifier.

Next, as a fifth step, a tellurium precursor compound may be implanted into the substrate to release the halogen bonded to the germanium central metal and form a tellurium-bonded thin film.

As an example, the tellurium precursor compound may be a compound represented by chemical formula 3.

As an example, the thin film formation method may be performed at a deposition temperature in the range of 50 ℃ to 300 ℃, preferably at a deposition temperature in the range of 50 ℃ to 250 ℃, more preferably at a deposition temperature in the range of 50 ℃ to 200 ℃, and even more preferably at a low deposition temperature in the range of 120 ℃ to 200 ℃, and in this range, the thin film having excellent process characteristics and growing film quality is achieved.

As an example, the thin film formation method may be performed at a deposition pressure in the range of 0.01 to 20torr, preferably 0.1 to 20torr, more preferably 0.1 to 10torr, and most preferably 0.3 to 7torr, and the thin film having a uniform thickness is obtained in this range.

In the present invention, the deposition temperature and the deposition pressure may be measured by the temperature and the pressure formed in the deposition chamber or by the temperature and the pressure applied to the substrate in the deposition chamber.

The sixth step may include a step of purging with an inert gas.

In the purge step performed immediately after the tellurium precursor compound supplying step, the amount of the purge gas to be supplied into the chamber may be 10 to 100,000 times, preferably 50 to 50,000 times, more preferably 100 to 10,000 times, the volume of the tellurium precursor compound to be supplied into the chamber, and within this range, the desired effect can be sufficiently obtained. Wherein the amounts of the purge gas and the tellurium precursor compound are respectively controlled by one cycle.

As an example, in the film forming method, the number of repetitions of the unit cycle to be performed may be 1 to 99,999 times, preferably 10 to 10,000 times, more preferably 50 to 5,000 times, and still more preferably 100 to 2,000 times, as needed, and within this range, a desired film thickness can be obtained, and the effects to be achieved by the present invention can be sufficiently obtained.

As a specific example of the thin film manufacturing method, the chalcogenide thin film modifier and two or more precursor compounds or a mixture thereof with a polar solvent are prepared, respectively, to deposit a thin film on a substrate placed in the chamber.

After the prepared precursor compounds or their mixture with the polar solvent are injected into the vaporizer, they are transferred to the deposition chamber and adsorbed on the substrate after being changed to vapor phase, and the ligand of the tellurium precursor compound is replaced with the chalcogenide thin film modifier, and then the precursor compound that is not adsorbed is purged (purging).

Next, after the prepared tellurium precursor compound is injected into the vaporizer, it is changed to a vapor phase to be transferred to the deposition chamber and adsorbed on the substrate, followed by purging (purging) to remove the unadsorbed tellurium precursor compound.

In the present invention, as an example, a method of supplying a chalcogenide thin film modifier, two or more precursor compounds, or the like to a deposition chamber, a method of supplying a volatile gas by a gas phase flow control (Mass Flow Controller; MFC) method (Vapor Flow Control; VFC) or a method of supplying a Liquid by a Liquid phase flow control (Liquid Mass Flow Controller; LMFC) method (Liquid DELIVERY SYSTEM; LDS) may be used.

In this case, as a carrier gas or a diluent gas for supplying the chalcogenide thin film modifier, the two or more precursor compounds, and the like onto the substrate, one or a mixture gas of two or more selected from argon (Ar), nitrogen (N ₂), and helium (He) may be used, but is not limited thereto.

In the present invention, the unreacted residual object is purged by using an inert gas as a purge gas. This can remove not only the excessive reaction gas but also the by-products generated.

As described above, the thin film formation method may repeat the unit cycle of the step of supplying the chalcogenide thin film modifier to the substrate, the step of purging the non-adsorbed chalcogenide thin film modifier, the step of adsorbing the germanium precursor compound to the substrate, the step of purging the non-adsorbed germanium precursor compound, the step of supplying the chalcogenide thin film modifier to the substrate, the step of purging the non-adsorbed chalcogenide thin film modifier, the step of supplying the tellurium precursor compound, and the step of purging the residual tellurium precursor compound, as a unit cycle, to form a thin film of a desired thickness.

For example, the number of repetitions of the unit cycle may be 1 to 99,999 times, preferably 10 to 10,000 times, more preferably 50 to 5,000 times, still more preferably 100 to 2,000 times, and within this range, the effect of expressing the desired film characteristics is exhibited well.

When the injection time and the purge time of the germanium precursor compound in the first step and the second step are respectively set as a and b, the injection time and the purge time of the halide in the third step and the fourth step are respectively set as c and d, and the injection time and the purge time of the tellurium precursor compound in the fifth step and the sixth step are respectively set as e and f, 0.1-10 a-2 a-4 a, 0.1-10 c-8 c, 2<e-10 and 2 e-8 e are satisfied at the same time.

When the injection and purging of the germanium precursor compound and the halide, and the injection and purging of the tellurium precursor compound are performed as one cycle (cycle), the deposition rate of the germanium thin film can be satisfiedThe above conditions.

When the injection and purging of the germanium precursor compound and the halide, and the injection and purging of the tellurium precursor compound are performed as one cycle (cycle), the following two conditions can be simultaneously satisfied 1) the deposition rate of the thin film is2) The density of the film is 9.8-10.5 g/cm ³.

As an example, the thin film manufacturing apparatus capable of performing the thin film manufacturing method described above includes an ALD chamber, a first vaporizer that vaporizes a chalcogenide thin film modifier, a first transport unit that transports the vaporized chalcogenide thin film modifier into the ALD chamber, a second vaporizer that vaporizes a germanium thin film precursor, and a second transport unit that transports the vaporized thin film precursor into the ALD chamber, a third vaporizer that vaporizes a tellurium thin film precursor, and a third transport unit that transports the vaporized thin film precursor into the ALD chamber. The vaporizer and the transporting unit may be any vaporizer and transporting unit conventionally used in the art.

Semiconductor substrate

The present invention also provides a semiconductor substrate manufactured by the thin film forming method of the present invention or including the thin film, particularly a laminated film, in which the thickness uniformity of the thin film is excellent and the density and reliability of the thin film are excellent.

Preferably, the film is produced at a deposition rate ofIn the above range where the density is 9.8g/cm ³ or more, the diffusion preventing film is excellent in performance, particularly, the phase change reliability is improved, but the present invention is not limited thereto.

Among them, as an example, the halogen remaining in the thin film may be Br ₂、Br、Br^-、Cl₂, cl or Cl ^-, and the lower the halogen remaining amount in the thin film, the more excellent the film quality, so that it is preferable.

The lower the residual carbon content in the thin film, the more excellent the phase transition reliability in the low-temperature deposition step is, and therefore, preferable.

Preferably, the thin film includes a film formed by stacking an antimony-tellurium upper layer film and a germanium-tellurium lower layer film, and the germanium-tellurium lower layer film or a germanium support film constituting the germanium-tellurium lower layer film is a film formed by depositing the above-mentioned chalcogenide thin film modifier in place of a ligand.

As an example, the film may have a multilayer structure of two or more layers, a multilayer structure of three or more layers, or a multilayer structure of two or more layers, as required. As a specific example, the multilayer film having the two-layer structure may be a lower layer film-middle layer film structure, and as a specific example, the multilayer film having the three-layer structure may be a lower layer film-middle layer film-upper layer film structure.

As an example, the lower film may include one or more kinds selected from Si、SiO₂、MgO、Al₂O₃、CaO、ZrSiO₄、ZrO₂、HfSiO₄、Y₂O₃、HfO₂、LaLuO₂、Si₃N₄、SrO、La₂O₃、Ta₂O₅、BaO、TiO₂.

The intermediate layer may be a film containing a metalloid, and preferably may be a germanium-tellurium-based film or a germanium support film constituting a germanium-tellurium-based film.

As an example, the upper layer film may be a film containing a metalloid different from the metalloid, and preferably may be an antimony-tellurium-based film.

Semiconductor device with a semiconductor layer having a plurality of semiconductor layers

According to the present invention, a semiconductor device including the above semiconductor substrate can be provided.

As an example, the semiconductor device may be a phase change memory device or the like.

In the following, preferred embodiments and drawings are presented to aid in understanding the present invention, and are merely for illustrating the present invention, and those skilled in the art may make various changes and modifications within the scope and technical spirit of the present invention, and these changes and modifications fall within the appended claims.

Examples (example)

As precursor compounds, a compound having a structure represented by the following chemical formula 2-8 and a compound having a structure represented by the following chemical formula 3-1 were prepared, respectively.

[ Chemical formulas 2-8]

[ Chemical formula 3-1]

5N HBr and 5N HI were prepared as chalcogenide thin film modifiers, respectively.

The ALD deposition process is performed using the two precursor compounds and the chalcogenide thin film modifier and using the deposition process of the present invention as one cycle.

Specific experimental methods of examples and comparative examples are as follows.

Example 1

As a first step, 5N HI was charged as a chalcogenide-based film modifier to a tank and fed into the chamber at 100sccm/cycle using a mass flow controller (Mass Flow Controller; MFC) at ambient temperature.

The chalcogenide thin film modifier was charged into the deposition chamber loaded with the substrate for 2 seconds, and then argon gas was supplied at 3000sccm for 8 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5Torr.

As a second step, the precursor compound having the structure represented by the above chemical formulas 2 to 8 was charged into a tank maintained at 25℃and supplied to another vaporizer heated to 150℃at a flow rate of 0.05g/min using a liquid mass flow controller (Liquid Mass Flow Controller; LMFC) at ordinary temperature. After the precursor compound vaporized into a vapor phase in the vaporizer was charged into the deposition chamber within 1 second using a mass flow controller (Mass Flow Controller; MFC), argon was supplied at 3000sccm for 5 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5Torr.

As a third step, 5N HI was charged as a chalcogenide-based film modifier to the tank and fed into the chamber at 100sccm/cycle using a mass flow controller (Mass Flow Controller; MFC) at ambient temperature. The chalcogenides film modifier vaporized into vapor phase in the vaporizer was charged into the deposition chamber loaded with the substrate for 2 seconds, and then argon gas was supplied at 3000sccm for 8 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5Torr.

As a fourth step, the precursor compound having the structure represented by the above chemical formula 3-1 was charged into a tank maintained at 25℃and supplied to another vaporizer heated to 150℃at a flow rate of 0.05g/min using a liquid mass flow controller (Liquid Mass Flow Controller; LMFC) at ordinary temperature. After the precursor compound vaporized into a vapor phase in the vaporizer was charged into the deposition chamber within 1 second using a mass flow controller (Mass Flow Controller; MFC), argon was supplied at 3000sccm for 5 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5Torr.

This process was repeated 200 to 400 times at a temperature of 130 ℃ to produce the self-limiting atomic layer film shown in fig. 1.

As shown in FIG. 1, the film is deposited to a thickness of

The deposition rate of the thin film manufactured at the above-mentioned deposition temperature of 130 ℃ is

Further, the impurity content of the above film was measured.

Among them, impurities such as H, C, NH, OSi, cl, ti were measured using a Secondary Ion Mass Spectrometry (SIMS) apparatus.

Specifically, the thin film was dug in the axial direction by ion sputtering, and the impurity value was confirmed in the SIMS chart in consideration of the impurity content (counts) at a sputtering time (sputtering time) of 50 seconds at which contamination at the surface layer of the substrate is less.

In the confirmed SIMS result values, the average impurity content of carbon (C) in the film was calculated to be 151 counts/sec. In addition, it was confirmed that not only carbon but also Cl ^-, O, si, H, NH, metals and metal oxides remained as by-products of the process were reduced.

Example 2

The same procedure as in example 1 above was repeated except that in example 1 above, the temperature condition of 130 ℃ was replaced with the temperature condition of 170 ℃.

As a result, as shown in FIG. 2, the film was deposited to a thickness of

Further, the impurity content of the above film was measured.

Among them, impurities such as H, C, NH, cl, ti were measured using a Secondary Ion Mass Spectrometry (SIMS) apparatus.

Comparative example 1

The same procedure as in example 1 was repeated except that in example 1, the second step was performed without the first step, and then the following fourth' step was performed without the third step.

At this time, the fourth' step is as follows.

As a fourth' step, the precursor compound having the structure represented by the above chemical formula 3-1 was charged into a tank maintained at 25℃and supplied to another vaporizer heated to 150℃at a flow rate of 0.05g/min using a liquid mass flow controller (Liquid Mass Flow Controller; LMFC) at normal temperature. The precursor compound vaporized into a vapor phase in the vaporizer was injected with ammonia gas at 500sccm while being charged into the deposition chamber within 1 second by a mass flow controller (Mass Flow Controller; MFC), and then argon gas was supplied at 3000sccm for 5 seconds to conduct argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5Torr.

This process was repeated 200 to 400 times at a temperature of 130 ℃ to produce the self-limiting atomic layer film shown in fig. 3.

As shown in FIG. 3, the film is deposited to a thickness of

Further, the impurity content of the above film was measured.

Among them, impurities such as H, C, NH, O, cl, ti were measured using a Secondary Ion Mass Spectrometry (SIMS) apparatus.

In the confirmed SIMS result values, the average impurity content of carbon (C) in the film was calculated to be 1806 counts/sec. In addition, it was confirmed that not only carbon but also Cl ^-, O, si, H, NH, metals and metal oxides remained as by-products of the process were reduced.

Comparative example 2

The same procedure as in comparative example 1 was repeated except that the ammonia gas injection and purging steps were omitted in comparative example 1, but deposition did not occur smoothly.

Example 3

An antimony-tellurium-based thin film was laminated on top of the germanium-tellurium-based thin film prepared in example 1. The antimony-tellurium-based thin film is produced using a SbTe ₃ precursor compound.

From the above results, it was confirmed that according to the present invention using a predetermined chalcogenide thin film modifier, not only the deposition rate and deposition thickness were significantly improved, but also the content of by-product carbon compounds was excellent enough to satisfy the low temperature deposition requirement, thereby improving the phase transition reliability, compared with comparative example 1 using ammonia instead of a chalcogenide thin film modifier, and comparative example 2 using neither a chalcogenide thin film modifier nor ammonia.

In particular, it was confirmed that example 1 using the chalcogenide thin film modifier of the present invention improved the deposition rate per cycle by 10% or more and reduced the content of carbon compounds as by-products by 80% or more, as compared with comparative example 1 not using the chalcogenide thin film modifier of the present invention, even when the thin film was produced at a low temperature of 130 ℃.

In addition, by comparing fig. 1 according to example 1 of the present invention, fig. 2 according to example 2 with fig. 3 according to comparative example 1, it was confirmed that hydrocarbon impurities were reduced, and thus a thin film suitable for phase transition was deposited.

Therefore, it was confirmed that when a predetermined compound is used as the chalcogenide thin film modifier of the present invention in the production of a chalcogenide thin film, the thickness and deposition rate increase rate of the thin film are improved, and the impurity reduction characteristics are excellent, so that it is possible to satisfy the low temperature process requirements and form a thin film excellent in phase transition reliability.

Claims

1. A chalcogenide film modifier, wherein:

by activating the substrate adsorbed precursor to provide an activated substrate adsorbed precursor,

The central metal of the substrate adsorption precursor is Ge, Sb, Te, Se or Sn, and the second ligand of the chalcogenide-based film modifier is used to replace the first ligand of the substrate adsorption precursor.

2. The chalcogenide-based thin film modifier according to claim 1, wherein

The chalcogenide thin film is made of Ge, GeTe, GeSbTe, GeSbSe, SnTe, SnSbTe or GeSnSbTe.

3. The chalcogenide-based film modifier according to claim 1, wherein

The second ligand has an activation energy lower than that of the first ligand of the precursor adsorbed on the substrate, and the activation energy is determined when reacting with a subsequently injected precursor compound.

4. The chalcogenide-based thin film modifier according to claim 1, wherein

The substrate adsorption precursor does not contain halogen, and the chalcogenide-based film modifier contains one or more halogens selected from iodine and bromine.

5. The chalcogenide-based thin film modifier according to claim 1, wherein

The chalcogenide-based film modifier is hydrogen iodide, hydrogen bromide, or a mixed gas of hydrogen iodide or hydrogen bromide mixed with an inert gas at a molar fraction of 1 to 99.

6. The chalcogenide-based thin film modifier according to claim 1, wherein

The chalcogenide-based thin film is a germanium-tellurium thin film or a germanium supporting film constituting the germanium-tellurium thin film, and includes an antimony-tellurium thin film on the upper portion thereof.

7. The chalcogenide-based thin film modifier according to claim 1, wherein

The chalcogenide thin film is a deposited film, which is deposited by atomic layer deposition, plasma enhanced atomic layer deposition, chemical vapor deposition, plasma enhanced chemical vapor deposition, organometallic chemical vapor deposition or low pressure chemical vapor deposition.

8. The chalcogenide-based thin film modifier according to claim 1, wherein

The second ligand of the chalcogenide-based thin film modifier has an activation energy lower than that of the first ligand of the precursor adsorbed on the substrate, and the activation energy is determined when reacting with a precursor compound that is subsequently injected.

9. A semiconductor substrate, wherein:

include:

substrate, and

film;

The thin film is a film deposited using the chalcogenide-based thin film modifier according to any one of claims 1 to 8.

10. A semiconductor substrate, wherein:

include:

substrate, and

film;

The thin film includes a film formed by stacking an antimony-tellurium upper film and a germanium-tellurium lower film.

The germanium-tellurium underlayer film or the germanium supporting film constituting the germanium-tellurium underlayer film is a film deposited by using the chalcogenide-based thin film modifier according to any one of claims 1 to 8 in a ligand replacement manner.

11. The semiconductor substrate according to claim 10, wherein

The above-mentioned film is a multi-layer structure of more than two layers.

12. The semiconductor substrate according to claim 10, wherein:

The carbon impurities of the above film measured by secondary ion mass spectrometry were less than 3,000 counts/second, and the deposition rate was / cycle or more, and the iodine atoms measured by SIMS are more than 50 counts/second.

13. A semiconductor device, wherein:

Comprising the semiconductor substrate according to claim 10 or 12.