TWI902316B - Process methods, semiconductor devices, and semiconductor process equipment for depositing tungsten plugs - Google Patents

Abstract

This application provides a process method, semiconductor device, and semiconductor process equipment for W-plug deposition, which relates to the field of semiconductor technology. The process method for W-plug deposition comprises: alternately introducing fluorine tungsten gas and hydrogen gas into the reaction chamber for atomic layer deposition reaction, forming a fluorine tungsten film; simultaneously introducing fluorine tungsten gas and hydrogen gas into the reaction chamber for gas-phase deposition reaction, forming a block tungsten layer; wherein the fluorine content of the fluorine containing tungsten film is lower than that of the block tungsten layer.

Description

Manufacturing process of tungsten plugs, semiconductor devices and semiconductor manufacturing equipment

This application relates to the field of semiconductor technology, and in particular to a process method for depositing tungsten plugs, semiconductor devices, and semiconductor process equipment.

As integrated circuit manufacturing processes have gradually developed, feature sizes have become smaller and smaller. Traditional aluminum interconnect processes are limited by signal delay under small linewidths. To solve this problem, copper interconnects have been used to replace aluminum interconnect technology. The emergence of copper interconnect technology has effectively solved the signal delay problem, and the integration of chips and the density of devices have been greatly improved. However, due to the diffusion problem of copper, the contact via process connecting front-end devices and back-end interconnects can use chemically and electrically stable metals to fill the vias or trenches, such as tungsten plug (W-plug) technology.

Tungsten has stable chemical and electrical properties, and tungsten plugging (W-plug) is a widely used process in the modern semiconductor industry. It uses a unique method to fill tungsten metal into a via or trench, taking advantage of tungsten's good conductivity and anti-electromigration properties, ultimately achieving the process requirement of reliable electrical conduction between front-end devices and back-end metal interconnects. In the manufacturing process of tungsten plugs, a barrier layer is typically placed between the substrate and the bulk tungsten layer to protect the substrate. As feature sizes become smaller, the barrier layer has a greater impact on the resistivity of the tungsten plug. The manufacturing process usually involves thinning the barrier layer and nucleation layer to reduce their impact on resistivity. However, the thinned barrier layer significantly weakens its ability to block fluorine atoms, making it easier for fluorine atoms to penetrate the barrier and attack the substrate, leading to electrical failure of the semiconductor device and reduced yield.

In view of this, the purpose of this application is to provide a process method for depositing tungsten plugs, a semiconductor device, and a semiconductor process equipment that can alleviate the problem of fluorine atoms penetrating the bottom liner, avoid fluorine attack points inside the liner that lead to electrical failure of the semiconductor device, and improve the yield of the semiconductor device.

To achieve the above objectives, the technical solution adopted in this application embodiment is as follows:

In a first aspect, this application provides a method for manufacturing a deposited tungsten plug, used to process a predetermined substrate, the predetermined substrate including a substrate and a protective layer located above the substrate, the method comprising: alternately introducing a fluorinated tungsten gas and a hydrogen-containing gas into a reaction chamber to perform an atomic layer deposition reaction to form a fluorinated tungsten film; and simultaneously introducing the fluorinated tungsten gas and the hydrogen-containing gas into the reaction chamber to perform a gas phase deposition reaction to form a bulk tungsten layer; wherein the fluorine content of the fluorinated tungsten film is less than the fluorine content of the bulk tungsten layer.

Furthermore, this application embodiment provides a first possible embodiment of the first aspect, wherein, prior to forming the fluorinated tungsten film, the process of manufacturing the deposited tungsten plug further includes: introducing a hydrogen-containing gas into a reaction chamber, causing the hydrogen-containing gas to adsorb onto the surface of the protective layer to form a wetting layer; wherein the wetting layer undergoes a reduction reaction with fluorine, a byproduct generated during the formation of the fluorinated tungsten film.

Furthermore, this application embodiment provides a second possible implementation of the first aspect, wherein the process of introducing hydrogen-containing gas into the reaction chamber to cause the hydrogen-containing gas to adsorb onto the surface of the protective layer to form a wetting layer includes: stabilizing the pressure of the reaction chamber at a first preset pressure value, or increasing the pressure of the reaction chamber from a second preset pressure value to a third preset pressure value; and continuously introducing hydrogen-containing gas at a first preset flow rate into the reaction chamber to cause hydrogen atoms to adsorb onto the surface of the protective layer to form the wetting layer.

Furthermore, this application embodiment provides a third possible embodiment of the first aspect, wherein the range of the first preset flow rate value is 1000 sccm to 10000 sccm; and/or, the range of the first preset pressure value, the second preset pressure value, and the third preset pressure value is 5 Torr to 300 Torr.

Furthermore, this application embodiment provides a fourth possible implementation of the first aspect, wherein the alternating introduction of fluorinated tungsten gas and hydrogen-containing gas into the reaction chamber for atomic layer deposition reaction to form a fluorinated tungsten film includes: S500, heating the substrate to maintain its temperature within a first preset temperature range and stabilizing the pressure of the reaction chamber within a fourth preset pressure range; S502, introducing the fluorinated tungsten gas into the reaction chamber, wherein the flow rate of the fluorinated tungsten gas is set to a second preset flow rate value, and the introduction time of the fluorinated tungsten gas is set to a first preset duration, so that fluorinated metal molecules are adsorbed onto the immersion film. S504, Perform a purging process, and the purging process time is set to a second preset duration to remove the fluorinated tungsten gas floating in the reaction chamber; S506, Introduce the hydrogen-containing gas into the reaction chamber, and the flow rate of the hydrogen-containing gas is set to a third preset flow rate value, and the introduction time of the hydrogen-containing gas is set to a third preset duration, so that the hydrogen-containing gas and the fluorinated metal molecules can undergo a reduction reaction to generate a fluorinated tungsten film; S508, Perform a purging process, and the purging process time is set to a fourth preset duration to remove the hydrogen-containing gas and the hydrogen fluoride gas generated by the reduction reaction from the reaction chamber.

Furthermore, this application embodiment provides a fifth possible embodiment of the first aspect, wherein the process method for manufacturing the deposited tungsten plug further includes: performing S500~S508 a preset number of times to form the fluorinated tungsten film of a preset thickness.

Furthermore, this application embodiment provides a sixth possible embodiment of the first aspect, wherein the first preset temperature range is 250℃-400℃; and/or, the fourth preset pressure range is 3Torr-100Torr; and/or, the second preset flow rate range is 10sccm-500sccm; and/or, the third preset flow rate range is 100sccm-10000sccm.

Furthermore, this application embodiment provides a seventh possible embodiment of the first aspect, wherein the first preset duration, the second preset duration, the third preset duration and the fourth preset duration are all in the range of 0.1s-5s; and/or, the preset thickness is in the range of greater than 1nm.

Secondly, this application embodiment also provides a semiconductor device, comprising: a contact hole on which a fluorinated tungsten film and a bulk tungsten layer are deposited, the fluorinated tungsten film and the bulk tungsten layer being deposited based on the process method for depositing tungsten plugs described in the first aspect, the fluorinated tungsten film being located between the protective layer and the bulk tungsten layer.

Furthermore, this application embodiment provides a first possible embodiment of the second aspect, wherein the protective layer includes a barrier layer and a nucleation layer, the barrier layer being located between the substrate and the nucleation layer.

Thirdly, this application embodiment also provides a semiconductor manufacturing apparatus, including a reaction chamber, an intake assembly, and a controller, the controller including at least one processor and at least one memory storing a computer program that, when executed by the processor, implements the process method for depositing tungsten plugs as described in the first aspect.

This application provides a method for depositing tungsten plugs, a semiconductor device, and semiconductor process equipment for processing a predetermined substrate. The predetermined substrate includes a substrate and a protective layer located above the substrate. The method for depositing tungsten plugs includes: alternately introducing fluorinated tungsten gas and hydrogen-containing gas into a reaction chamber to perform an atomic layer deposition reaction to form a fluorinated tungsten film; and simultaneously introducing fluorinated tungsten gas and hydrogen-containing gas into the reaction chamber to perform a gas phase deposition reaction to form a bulk tungsten layer; wherein the fluorine content of the fluorinated tungsten film is less than the fluorine content of the bulk tungsten layer. This application utilizes a fluorinated tungsten film deposited before the bulk tungsten layer is deposited. This prevents a large number of fluorine atoms, a byproduct generated during the bulk tungsten layer formation, from attacking the substrate. Furthermore, the fluorinated tungsten film has a low fluorine impurity content, resulting in a lower probability of substrate attack. This alleviates the problem of fluorine atoms penetrating the bottom substrate, avoids fluorine attack points inside the substrate that could lead to electrical failure of semiconductor devices, and improves the yield of semiconductor devices.

Other features and advantages of the embodiments of this application will be set forth in the following description, or some features and advantages may be inferred or unambiguously determined from the description, or may be learned by practicing the above-described techniques of the embodiments of this application.

To make the above-mentioned objectives, features and advantages of this application more apparent, preferred embodiments are described below in detail with reference to the accompanying figures.

To make the purpose, technical solution and advantages of the embodiments of this application clearer, the technical solution of this application will be described below with reference to the accompanying drawings. Obviously, the embodiments described are some of the embodiments of this application, not all of them.

In the tungsten plug deposition process of related technologies, an adhesion barrier layer (Ti/TiN) is grown before the tungsten plug itself. TiN primarily serves to block fluorine atoms from attacking the substrate. The growth of the tungsten plug consists of two processes: the growth of the nucleation layer and the growth of the bulk tungsten layer. Referring to Figure 1, the tungsten plug deposition process of related technologies mainly includes the following steps:

Step S101: Heat the wafer to the temperature required for the process. The wafer includes a substrate 11 and a TiN barrier layer 12.

Step S102: A nucleation layer 13 is generated on the surface of the TiN barrier layer 12. By generating the nucleation layer 13, the growth and incubation period of the bulk tungsten layer can be reduced.

In step S103, a bulk tungsten layer 14 is formed on the surface of the nucleation layer 13.

Referring to Figure 2, which shows the relevant venting sequence diagram for the tungsten plug deposition process, the venting sequence for the tungsten plug deposition process can be performed according to the following steps:

S20: After the wafer is heated to the required temperature, it enters the growth of the nucleation layer.

Nucleation layer growth occurs via atomic layer deposition (ALD). _B₂H₆ and _WF₆ are alternately introduced into the reaction chamber to initiate ALD. The _{ALD reaction is performed cyclically using B₂H₆ and WF₆ ,} with each cycle consisting of the following four steps:

S21: Introduce _{a B2H6 pulse} of a set duration into the reaction chamber;

S22: Inert gas is introduced into the reaction chamber to purge the reaction chamber;

S23: Inject a WF ₆ pulse of a set duration into the reaction chamber;

S24: Purge the reaction chamber with inert gas.

The number of cycles for steps S21 to S24 can be determined based on the required nucleation layer thickness.

S25: After the nucleation layer has grown, WF ₆ pulses and H ₂ pulses are simultaneously introduced into the reaction chamber to carry out chemical vapor deposition (CVD) to generate a bulk tungsten layer. The process of generating the bulk tungsten layer is accompanied by the generation of fluorine atoms as a byproduct.

The aforementioned nucleation layer is an amorphous tungsten with high resistivity, while the bulk tungsten layer is a crystalline tungsten with low resistivity. Both the TiN blocking layer and the tungsten nucleation layer have high resistivity. However, as manufacturing processes advance and feature sizes become smaller, the blocking layer and nucleation layer have an increasingly significant impact on the resistivity of tungsten plugs. Related tungsten plug manufacturing processes typically employ methods to reduce the thickness of the blocking layer and nucleation layer to minimize their influence on the tungsten plug's resistivity. Referring to Figure 3, a schematic diagram of the tungsten plug process for filling vias, a reduction in the thickness of the stop layer 12 and nucleation layer 13 can weaken the stop layer 12's ability to block fluorine attacks. During the chemical vapor deposition reaction of _WF6 and _H2 to form the bulk tungsten layer 14, fluorine atoms, a byproduct, are generated. This byproduct, fluorine (F), easily penetrates the reduced-thickness stop layer 12 and attacks the substrate 11, resulting in fluorine attack points 30, or voids, within the substrate 11. The appearance of fluorine attack points 30 can easily cause the stop layer 12 to fracture, leading to electrical failure of the semiconductor device and reduced yield.

To address the aforementioned issues, this application provides a method for depositing tungsten plugs and a semiconductor device, which will be described in detail below.

This embodiment provides a process method for depositing tungsten plugs, which can be used to process a predetermined substrate. Referring to the flowchart of the process method for depositing tungsten plugs shown in Figure 4, the method includes the following steps:

In step S402, fluorine-containing tungsten gas and hydrogen-containing gas are alternately introduced into the reaction chamber to carry out atomic layer deposition reaction and form a fluorine-containing tungsten film.

Referring to the process flow diagram of the deposited tungsten plug shown in Figure 5, the aforementioned pre-designed substrate includes a substrate 51 and a protective layer 52 located above the substrate. The protective layer 52 can protect the substrate 51, and may include a TiN barrier layer, or a TiN barrier layer and a nucleation layer. Fluorine-containing tungsten gas and hydrogen-containing gas are alternately introduced into the reaction chamber to carry out an atomic layer deposition reaction, and a fluorine-containing tungsten film 54 is deposited on the protective layer 52.

The aforementioned fluorinated tungsten gas can undergo a reduction reaction with a hydrogen-containing gas to generate hydrogen fluoride and fluorinated tungsten compounds. The metallic tungsten in these compounds has good electrical conductivity and anti-electromigration properties. In this embodiment, tungsten hexafluoride _WF6 is preferred as the fluorinated tungsten gas.

Under certain process temperature and pressure, fluorine-containing tungsten gas is first introduced into the reaction chamber for a certain period of time, causing a uniform layer of fluorine-containing metal molecules to be adsorbed on the wafer surface. Then, hydrogen-containing gas is introduced into the reaction chamber for a certain period of time, causing the hydrogen-containing gas to undergo a reduction reaction with the fluorine-containing tungsten molecules on the wafer surface to form a metal film. The generated hydrogen fluoride gas is removed, and the generated metal film contains relatively low levels of fluorine impurities, and is called a fluorine-containing tungsten film.

By repeatedly and alternately introducing fluorinated tungsten gas and hydrogen gas into the reaction chamber, a fluorinated tungsten film of a certain thickness can be generated. The number of times the fluorinated tungsten gas and hydrogen gas are alternately introduced can be determined according to the required thickness of the fluorinated tungsten film; the greater the thickness, the more times it needs to be introduced.

In step S404, fluorine-containing tungsten gas and hydrogen-containing gas are simultaneously introduced into the reaction chamber to carry out a gas-phase deposition reaction and form a bulk tungsten layer.

After a fluorinated tungsten film of a certain thickness is grown, the growth of a bulk tungsten layer begins. Fluorinated tungsten gas and hydrogen gas are simultaneously introduced into the reaction chamber to carry out a chemical vapor deposition reaction and generate a bulk tungsten layer.

The fluorine content of the aforementioned fluorine-containing tungsten film is less than that of the bulk tungsten layer. The fluorine-containing tungsten film is the first line of defense against fluorine attack on the substrate and can block the penetration of fluorine (i.e., fluorine atoms), a byproduct generated during the formation of the bulk tungsten layer.

The tungsten plug deposition process provided in this embodiment deposits a fluorinated tungsten film before the bulk tungsten layer is deposited. This prevents a large number of fluorine atoms, a byproduct generated during the bulk tungsten layer formation stage, from attacking the substrate. Furthermore, the fluorinated tungsten film has a low fluorine impurity content, resulting in a low probability of attacking the substrate. This alleviates the problem of fluorine atoms penetrating the bottom substrate, avoids fluorine attack points inside the substrate that could lead to electrical failure of the semiconductor device, and improves the yield of the semiconductor device.

In one embodiment, to prevent fluorine atoms from attacking the substrate during the deposition of the fluorinated tungsten film, the manufacturing method of the deposited tungsten plug provided in this embodiment further includes the following step S400 before forming the fluorinated tungsten film:

In step S400, hydrogen-containing gas is introduced into the reaction chamber, causing the hydrogen-containing gas to be adsorbed on the surface of the protective layer to form a wetted layer; wherein, the wetted layer undergoes a reduction reaction with fluorine, a byproduct generated during the formation of the fluorine-containing tungsten film.

A certain flow rate of hydrogen-containing gas is continuously introduced into the reaction chamber, so that the aforementioned pre-set substrate is immersed in the reaction chamber filled with hydrogen-containing gas. As shown in Figure 5, a layer of hydrogen-containing molecules will be adsorbed on the surface of the protective layer above the substrate, forming an impregnation layer 53.

The hydrogen-containing gas can be any gas that can undergo a reduction reaction with the fluorinated tungsten gas to produce hydrogen fluoride, such as hydrogen, borane or silane. In this embodiment, hydrogen is preferred.

After the wetting layer is formed, the fluorine-containing tungsten film begins to grow. During the growth of the fluorine-containing tungsten film, fluorine (i.e., fluorine atoms) is produced as a byproduct. When fluorine atoms attack the bottom substrate, the hydrogen molecules in the wetting layer react with the fluorine atoms to generate hydrogen fluoride gas, which is then removed, thus mitigating the fluorine attack. As the fluorine-containing tungsten film grows, the number of hydrogen molecules in the wetting layer gradually decreases, and the wetting layer disappears after the fluorine-containing tungsten film has finished growing.

The wetting layer is the second line of defense against fluorine attack on the substrate. The wetting hydrogen-containing gas molecules can react with the fluorine atoms generated during the formation of the fluorine-containing tungsten film to generate gaseous hydrogen fluoride, which is then removed, thereby mitigating the fluorine attack during the formation of the fluorine-containing tungsten film.

By generating a hydrogen-containing gas-impregnated layer on the protective layer of the substrate, the impregnated hydrogen-containing gas can react with fluorine atoms, a byproduct produced during the formation of the fluorine-containing tungsten film, to generate gaseous hydrogen fluoride, which is then removed, thus mitigating the fluorine attack during the formation of the fluorine-containing tungsten film.

In one embodiment, the specific method for forming the wetting layer includes: stabilizing the pressure of the reaction chamber at a first preset pressure value, or increasing the pressure of the reaction chamber from a second preset pressure value to a third preset pressure value; continuously introducing hydrogen-containing gas at a first preset flow rate into the reaction chamber, so that hydrogen atoms are adsorbed on the surface of the protective layer to form the wetting layer.

Based on the butterfly valve controller controlling the reaction chamber to maintain a certain pressure value (i.e., the first preset pressure value), or based on the butterfly valve controller controlling the pressure in the reaction chamber to gradually increase within a certain range (i.e., from the second preset pressure value to the third preset pressure value), hydrogen-containing gas is introduced into the reaction chamber for a certain period of time through pulses, and the hydrogen-containing gas will be adsorbed on the surface of the protective layer to form a wetting layer.

The second preset pressure value may be the same as or different from the first preset pressure value, and the third preset pressure value may be the same as or different from the first preset pressure value. The third preset pressure value is greater than the second preset pressure value.

In one embodiment, the process conditions for forming the wetted layer are:

The pressure in the reaction chamber is maintained at a first preset pressure value, the flow rate of the hydrogen-containing gas is maintained at a first preset flow rate value, and the introduction time of the hydrogen-containing gas is 3s-100s, preferably 10-20s in this embodiment. The range of the first preset pressure value is 5Torr-300Torr, preferably 40Torr in this embodiment; the range of the first preset flow rate value is 1000sccm-10000sccm.

In another embodiment, the process conditions for forming the wetted layer are:

The pressure in the reaction chamber is increasing from a second preset pressure value to a third preset pressure value. The flow rate of the hydrogen-containing gas is maintained at a first preset flow rate value. The duration of hydrogen-containing gas introduction is 3s-100s, preferably 10-20s in this embodiment. The range of the second preset pressure value is 5Torr-300Torr, and the range of the third preset pressure value is 5Torr-300Torr; the range of the first preset flow rate value is 1000sccm-10000sccm.

In one embodiment, the specific method for generating a fluorinated tungsten film includes the following steps:

S500 heats the substrate, maintaining its temperature within a first preset temperature range, and stabilizes the pressure in the reaction chamber within a fourth preset pressure range.

The substrate is heated to stabilize the process temperature of the reaction chamber within a first preset temperature range, which is 250℃-400℃. The process pressure within the reaction chamber is controlled to stabilize within a fourth preset pressure range, which is 3 Torr-100 Torr, preferably 3 Torr-90 Torr.

S502, fluorine-containing tungsten gas is introduced into the reaction chamber, and the flow rate of the fluorine-containing tungsten gas is set to a second preset flow rate value, and the introduction time of the fluorine-containing tungsten gas is set to a first preset duration, so that fluorine-containing metal molecules are adsorbed on the surface of the wetted layer.

Fluorine-containing tungsten gas is introduced into the reaction chamber via pulses, causing a uniform layer of fluorine-containing metal molecules to be adsorbed onto the wafer surface. The flow rate of the fluorine-containing tungsten gas is set to a second preset flow rate value, which ranges from 10 sccm to 500 sccm, and the gas introduction time is set to a first preset duration, which ranges from 0.1 s to 5 s.

S504, a purging process is performed, and the purging process time is set to a second preset duration to remove fluorinated tungsten gas floating in the reaction chamber.

The reaction chamber is purged to remove excess fluorinated tungsten gas, retaining only the fluorinated metal molecules adsorbed on the wafer surface. The purging process time is set to a second preset duration, ranging from 0.1s to 5s.

S506, a hydrogen-containing gas is introduced into the reaction chamber, and the flow rate of the hydrogen-containing gas is set to a third preset flow rate value, and the introduction time of the hydrogen-containing gas is set to a third preset duration, so that the hydrogen-containing gas and fluorine-containing metal molecules can undergo a reduction reaction to generate a fluorine-containing tungsten film.

Hydrogen-containing gas is introduced into the reaction chamber via pulses. The hydrogen-containing gas undergoes a reduction reaction with fluorine-containing metal molecules adsorbed on the wafer to generate a fluorine-containing tungsten film and hydrogen fluoride gas of a certain thickness (e.g., 0.02nm~0.04nm, preferably 0.03nm).

In one implementation, the third preset flow rate ranges from 100 sccm to 10000 sccm, and the third preset duration ranges from 0.1 s to 5 s.

As mentioned above, during the formation of the fluorinated tungsten film, fluorinated tungsten gas and hydrogen gas are alternately introduced. The fluorine atom content in the fluorinated tungsten film is lower than that in the bulk tungsten layer. The fluorine atom content in the fluorinated tungsten film can be e ⁺¹⁹ fluorine atoms per cubic centimeter, while the fluorine atom content in the bulk tungsten layer can be e ⁺²⁰ fluorine atoms per cubic centimeter.

S508, a purging process is performed, and the purging process time is set to the fourth preset duration to remove hydrogen-containing gas and hydrogen fluoride gas generated by the reduction reaction from the reaction chamber.

The reaction chamber is purged to remove excess hydrogen-containing gas and hydrogen fluoride gas generated from the reaction of hydrogen-containing gas with fluorine-containing metal molecules. The fourth preset time ranges from 0.1s to 5s, and the first, second, third, and fourth preset times can be the same or different.

In one embodiment, S500 to S508 are repeated a preset number of times to form a fluorinated tungsten film of a preset thickness. The preset number of times is related to the desired preset thickness of the fluorinated tungsten film.

In one embodiment, the default thickness of the fluorinated tungsten film can be a thickness value greater than 1 nm.

The above-described tungsten plug deposition process provided in this embodiment grows a fluorinated tungsten film between the nucleation layer and the bulk tungsten layer, which blocks fluorine atoms from penetrating the substrate, thus solving the problem of fluorine atoms attacking the substrate. By adsorbing a wetting layer on the surface of the nucleation layer, the wetting hydrogen-containing gas can react with the fluorine atoms generated during the formation of the fluorinated tungsten film, generating gaseous hydrogen fluoride which is then removed, thus mitigating the fluorine attack.

Based on the aforementioned embodiments, this embodiment provides a process method for manufacturing deposited tungsten plugs. Referring to another process flow diagram for deposited tungsten plugs shown in Figure 6, the specific steps are as follows:

Step S601, a substrate 51 is provided, and a Ti/TiN barrier layer 61 is formed on the substrate 51.

Step S602: Heat the substrate 51 to the preset process temperature.

A nucleation layer 62 is formed on the surface of the Ti/TiN barrier layer 61. As shown in the process flow diagram of the deposited tungsten plug in Figure 7, during the process of generating the nucleation layer 62 after heating the substrate 51, the following steps S71~S74 are performed cyclically to generate a nucleation layer of a set thickness:

S71: Continuously introduce _{B2H6 pulses} of predetermined duration into the reaction chamber;

S72: Inert gas is introduced into the reaction chamber to purge the reaction chamber and remove excess _B2H6 gas from the reaction chamber _;

S73: Continuously introduce WF ₆ pulses of a predetermined duration into the reaction chamber;

S74: Inert gas is introduced into the reaction chamber to purge the reaction chamber and remove excess WF ₆ gas from the reaction chamber.

The number of times steps S71 to S74 are executed can be determined based on the required nucleation layer thickness. The more times steps S71 to S74 are executed, the thicker the nucleation layer will be.

In step S603, a pulse of _H2 lasting 3s-100s is introduced into the reaction chamber, causing _H2 molecules to adsorb onto the surface of the nucleation layer 62 to form a wetting layer 53.

The flow rate of the _H2 pulse can range from 1000 sccm to 10000 sccm; the reaction chamber should be kept at a certain pressure, or the pressure of the reaction chamber should be controlled to increase. The pressure range of the reaction chamber needs to be maintained between 5 Torr and 300 Torr, preferably 40 Torr.

In step S604, WF ₆ pulses and H ₂ pulses are alternately introduced into the reaction chamber to generate a fluorinated tungsten membrane 54.

_WF6 molecules adsorbed on the wafer surface undergo an atomic layer deposition reaction with _H2 to generate a tungsten film containing fewer fluorine atoms, known as a fluorinated tungsten film.

During the growth of the fluorine-containing tungsten film, fluorine (i.e., fluorine atoms) is produced as a byproduct. The hydrogen molecules in the wetting layer 53 react with the fluorine atoms to generate hydrogen fluoride gas, which is then removed, thus mitigating the fluorine attack. As the fluorine-containing tungsten film grows, the number of hydrogen molecules in the wetting layer 53 gradually decreases. After the fluorine-containing tungsten film 54 has grown completely, the wetting layer 53 disappears.

The process conditions for generating fluorinated tungsten films are as follows: process temperature between 250-400℃, process pressure between 3 Torr-100 Torr, preferably 3 Torr-90 Torr; WF6 pulse flow rate between 10 sccm-500 sccm, and H2 pulse flow rate between 100 sccm-10000 sccm.

As shown in Figure 7, the following steps S75~S78 are repeated to generate a nucleation layer of a certain thickness:

S75, introduce a WF ₆ pulse with a duration of 0.1s-5s into the reaction chamber, and the flow rate of the WF ₆ gas is in the range of 10sccm-500sccm;

S76, Inert gas is introduced into the reaction chamber for a purging process to remove excess _WF6 gas in the reaction chamber except for a layer of _WF6 molecules adsorbed on the wafer surface. The purging process time ranges from 0.1s to 5s.

S77, introduce _H2 pulses with a duration of 0.1s-5s into the reaction chamber so that _H2 molecules react with a layer of _WF6 molecules adsorbed on the wafer surface to generate a fluorinated tungsten film 54. The flow rate of _H2 gas is in the range of 100sccm-10000sccm.

S78, an inert gas is introduced into the reaction chamber to perform a purging process to remove excess _H2 gas and hydrogen fluoride gas generated by the reduction reaction. The purging process time ranges from 0.1s to 5s.

The number of times steps S75 to S78 are executed can be determined based on the required thickness of the fluorinated tungsten film.

In step S605, WF ₆ pulse and H ₂ pulse are simultaneously introduced into the reaction chamber to carry out a gas-phase deposition reaction, forming a bulk tungsten layer 55.

The tungsten plug deposition process provided in this embodiment solves the problem of fluorine attack on the substrate. The fluorine-containing tungsten film itself has the characteristics of low fluorine content and low probability of fluorine attack on the substrate. The formation of the fluorine-containing tungsten film can also block a large number of fluorine atoms generated during the formation of the bulk tungsten layer from attacking the substrate, avoiding the electrical failure of semiconductor devices caused by fluorine atom attack on the substrate, and improving the yield of semiconductor devices.

Corresponding to the tungsten plug deposition process method provided in the above embodiments, this application embodiment provides a semiconductor device, including: a contact hole, as shown in the via filling schematic diagram in FIG8, wherein a fluorinated tungsten film 54 and a bulk tungsten layer 55 are deposited on the protective layer of the contact hole substrate 51, the fluorinated tungsten film 54 and the bulk tungsten layer 55 are deposited based on the tungsten plug deposition process method provided in the above embodiments, and the fluorinated tungsten film 54 is located between the protective layer and the bulk tungsten layer 55.

In one embodiment, the protective layer includes a barrier layer 61 and a nucleation layer 62, with the barrier layer 61 located between the substrate 51 and the nucleation layer 62.

The contact hole manufacturing process provided in this embodiment can adopt the tungsten plug deposition process method provided in the above embodiment. In one embodiment, a wetting layer may be included between the nucleation layer 62 and the fluorinated tungsten film 54. The wetting layer is a layer of hydrogen molecules uniformly adsorbed on the surface of the nucleation layer. The by-product fluorine atoms generated during the formation of the fluorinated tungsten film 54 react with the hydrogen molecules in the wetting layer to generate hydrogen fluoride gas, which is then removed. The wetting layer gradually disappears during the formation of the fluorinated tungsten film 54.

The semiconductor device provided in this embodiment has the same implementation principle and technical effect as the aforementioned embodiments. For the sake of brevity, any parts not mentioned in the semiconductor device embodiments can be referred to the corresponding content in the aforementioned method embodiments.

Corresponding to the tungsten plug deposition process method provided in the above embodiments, this application provides a semiconductor process apparatus, including a reaction chamber, an air intake assembly, and a controller. The controller includes at least one processor and at least one memory, in which a computer program is stored. When the computer program is executed by the processor, the tungsten plug deposition process method provided in the above embodiments is implemented.

The reaction chamber includes a heating base that supports and heats the wafer to the required process temperature. An inlet gas system is used to introduce appropriate reaction gases into the reaction chamber. For example, alternating introduction _{of B₂H₆} and _WF₆ gases can be used for atomic layer deposition (ALD) reactions, or simultaneous introduction of fluorine-containing tungsten gas and hydrogen-containing gas can be used for gas phase deposition reactions. The inlet gas system also introduces purge gas into the reaction chamber.

In some embodiments, the reaction chamber is also equipped with an exhaust port and a butterfly valve and a butterfly valve controller for controlling the flow rate of the exhaust port. Based on the butterfly valve controller, the pressure of the reaction chamber and the discharge of gas from the reaction chamber can be controlled.

For example, the controller can be a host computer or a slave computer. The controller can open and close the valve of the air intake component to introduce the corresponding gas into the reaction chamber; the controller can also control the flow rate of the process gas by controlling the opening and closing degree of the air intake valve. The controller can also control the pressure in the reaction chamber and the discharge of gas from the reaction chamber by controlling the butterfly valve controller.

This application embodiment provides a computer-readable medium storing computer-executable instructions that, when invoked and executed by a processor, cause the processor to implement the method described in the above embodiment.

Those skilled in the field will understand that, for the sake of convenience and brevity, the specific working process of the system described above can be found in the corresponding process in the aforementioned embodiments, and will not be repeated here.

If this function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method of each embodiment of this application. The aforementioned storage media include: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs, and other media that can store program code.

In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Finally, it should be noted that the above embodiments are merely specific implementations of this application, used to illustrate the technical solution of this application, and not to limit it. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solution recorded in the foregoing embodiments within the scope of the technology disclosed in this application, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solution to deviate from the spirit and scope of the technical solution of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application shall be determined by the scope of protection of the claim.

11: Substrate 12: TiN Barrier Layer 13: Nucleation Layer 14: Bulk Tungsten Layer 30: Fluorine Attack Point 51: Substrate 52: Protective Layer 53: Wetting Layer 54: Fluorine-Containing Tungsten Film 55: Bulk Tungsten Layer 61: Barrier Layer 62: Nucleation Layer S101-S103, S20-S25, S400-S404, S601-S605, S71-S78: Steps

When reading in conjunction with the accompanying figures, the following detailed description is the best way to understand this disclosure. It should be noted that, according to standard industry practice, the components are not drawn to scale. In fact, the dimensions of the components may be arbitrarily increased or decreased for clarity of explanation. Figure 1 shows a flow chart of the tungsten plug deposition process in the related technology; Figure 2 shows a venting timing diagram of the tungsten plug deposition process in the related technology; Figure 3 shows a schematic diagram of the tungsten plug filling process in the related technology; Figure 4 shows a flow chart of a tungsten plug deposition process method provided by this embodiment; Figure 5 shows a flow chart of a tungsten plug deposition process provided by this embodiment; Figure 6 shows a flow chart of another tungsten plug deposition process provided by this embodiment; Figure 7 shows a venting timing diagram of a tungsten plug deposition process provided by this embodiment; Figure 8 shows a schematic diagram of a pore filling process provided by this embodiment.

S402, S404: Steps

Claims (11)

A method for manufacturing a deposited tungsten plug is used to process a predetermined substrate, the predetermined substrate including a substrate and a protective layer located above the substrate, wherein the method for manufacturing the deposited tungsten plug includes: introducing a hydrogen-containing gas into a reaction chamber, causing the hydrogen-containing gas to be adsorbed onto the surface of the protective layer to form a wetting layer; alternately introducing a fluorinated tungsten gas and a hydrogen-containing gas into the reaction chamber to perform an atomic layer deposition reaction to form a fluorinated tungsten film; and simultaneously introducing the fluorinated tungsten gas and the hydrogen-containing gas into the reaction chamber to perform a gas phase deposition reaction to form a tungsten layer; wherein the fluorine content of the fluorinated tungsten film is less than the fluorine content of the tungsten layer. The method for manufacturing a deposited tungsten plug as described in claim 1, wherein the wetting layer undergoes a reduction reaction with fluorine, a byproduct generated during the formation of the fluorine-containing tungsten film. The manufacturing method of the deposited tungsten plug as described in claim 2, wherein the process of introducing the hydrogen-containing gas into the reaction chamber to allow the hydrogen-containing gas to adsorb onto the surface of the protective layer to form the wetting layer includes: stabilizing the pressure of the reaction chamber at a first preset pressure value, or increasing the pressure of the reaction chamber from a second preset pressure value to a third preset pressure value; and continuously introducing the hydrogen-containing gas at a first preset flow rate value into the reaction chamber to allow hydrogen atoms to adsorb onto the surface of the protective layer to form the wetting layer. The manufacturing method of the deposited tungsten plug as described in claim 3, wherein the first preset flow rate value is in the range of 1000 sccm to 10000 sccm; and/or, the first preset pressure value, the second preset pressure value and the third preset pressure value are all in the range of 5 Torr to 300 Torr. The manufacturing method of the deposited tungsten plug as described in claim 2, wherein the alternating introduction of the fluorinated tungsten gas and the hydrogen-containing gas into the reaction chamber to perform an atomic layer deposition reaction to form the fluorinated tungsten film, includes: S500, heating the substrate, maintaining the temperature of the substrate within a first preset temperature range, and stabilizing the pressure of the reaction chamber within a fourth preset pressure range; S502, introducing the fluorinated tungsten gas into the reaction chamber, wherein the flow rate of the fluorinated tungsten gas is set to a second preset flow rate value, and the introduction time of the fluorinated tungsten gas is set to a first preset duration, so that fluorinated metal molecules are adsorbed on the surface of the wetting layer; S504, A purging process is performed, and the purging process time is set to a second preset duration to remove the fluorinated tungsten gas floating in the reaction chamber; S506, The hydrogen-containing gas is introduced into the reaction chamber, and the flow rate of the hydrogen-containing gas is set to a third preset flow rate value, and the introduction time of the hydrogen-containing gas is set to a third preset duration, so that the hydrogen-containing gas and the fluorinated metal molecules undergo a reduction reaction to generate a fluorinated tungsten film; S508, A purging process is performed, and the purging process time is set to a fourth preset duration to remove the hydrogen-containing gas and the hydrogen fluoride gas generated by the reduction reaction from the reaction chamber. The manufacturing method of the deposited tungsten plug as described in claim 5 further includes: performing S500 to S508 a preset number of times to form the fluorinated tungsten film of a preset thickness. The manufacturing method of the deposited tungsten plug as described in claim 5, wherein the first preset temperature range is 250°C-400°C; and/or, the fourth preset pressure range is 3 Torr-100 Torr; and/or, the second preset flow rate range is 10 sccm-500 sccm; and/or, the third preset flow rate range is 100 sccm-10000 sccm. The process method for depositing tungsten plugs as described in claim 5, wherein the first preset time, the second preset time, the third preset time and the fourth preset time are all in the range of 0.1s-5s; and/or, the fluorinated tungsten film is formed with a preset thickness greater than 1nm. A semiconductor device includes: a contact hole, wherein a fluorinated tungsten film and a tungsten layer are deposited on a protective layer under the contact hole, the fluorinated tungsten film and the tungsten layer being deposited based on a process method for depositing tungsten plugs as described in any one of claims 1-8, the fluorinated tungsten film being located between the protective layer and the tungsten layer. The semiconductor device as claimed in claim 9, wherein the protective layer includes a blocking layer and a nucleation layer, the blocking layer being located between the substrate and the nucleation layer. A semiconductor manufacturing apparatus includes a reaction chamber, an intake assembly, and a controller, wherein the controller includes at least one processor and at least one memory storing a computer program that, when executed by the processor, implements a process method for depositing tungsten plugs as described in any one of claims 1-8.