W-plug deposition process method, semiconductor apparatus and semiconductor process device

Abstract

The present application relates to the technical field of semiconductors, and provides a W-plug deposition process method, a semiconductor apparatus and a semiconductor process device. The W-plug deposition process method comprises: alternately introducing a fluorine-containing tungsten gas and a hydrogen-containing gas into a reaction chamber to perform an atomic layer deposition reaction, so as to form a fluorine-containing tungsten film; and introducing the fluorine-containing tungsten gas and the hydrogen-containing gas into the reaction chamber at the same time to perform a vapor deposition reaction, so as to form a block tungsten layer, wherein the fluorine content of the fluorine-containing tungsten film is less than that of the block tungsten layer. The fluorine-containing tungsten film of the present application can prevent a large number of by-product fluorine atoms generated during the stage of forming the block tungsten layer from attacking a substrate, thereby avoiding the electrical failure of the semiconductor apparatus caused by fluorine attack points appearing inside the substrate, and improving the yield of the semiconductor apparatus.

Description

Process method for depositing tungsten plug, semiconductor device and semiconductor process equipment Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a process method for depositing tungsten plugs, a semiconductor device, and semiconductor process equipment. Background Art

[0002] With the gradual development of integrated circuit technology, feature sizes are getting smaller and smaller. Traditional aluminum interconnection processes are limited by signal delays under small line widths. To solve this problem, copper interconnection has been used instead of aluminum interconnection technology. The emergence of copper interconnection technology has effectively solved the problem of signal delay, and the integration of chips and the density of devices have also been greatly improved. However, due to the diffusion problem of copper, the contact hole process connecting the front-end device and the back-end interconnection line can use chemically and electrically stable metals to fill the holes (Via) or trenches (Trench), such as tungsten plug (W-plug) technology.

[0003] Tungsten has stable chemical and electrical properties. Tungsten plug (W-plug) is a process widely used in the contemporary semiconductor industry. It uses a unique method to fill metal tungsten into vias or trenches, and utilizes the good conductivity and anti-electromigration properties of metal tungsten to ultimately achieve the process requirements of reliable electrical conduction between front-end devices and back-end metal interconnections. In the related tungsten plug process, a barrier layer with the function of protecting the substrate is usually set between the substrate and the bulk tungsten layer. As the feature size becomes smaller and smaller, the barrier layer has an increasingly greater impact on the resistivity of the tungsten plug. The related tungsten plug process usually adopts the method of thinning the thickness of the barrier layer and the nucleation layer to reduce the impact on the resistivity. However, the barrier performance of the thinned barrier layer to fluorine atoms is greatly weakened, and the problem of fluorine atoms penetrating the barrier to attack the bottom substrate is prone to occur, causing electrical failure of the semiconductor device and reduced yield.

[0004] Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a process method for depositing tungsten plugs, a semiconductor device and semiconductor process equipment, which can alleviate the problem of fluorine atoms penetrating the bottom substrate, avoid the occurrence of fluorine attack points inside the substrate that cause electrical failure of the semiconductor device, and improve the yield of the semiconductor device.

[0006] In order to achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0007] In a first aspect, an embodiment of the present application provides a process method for depositing a tungsten plug, which is used to process a preset substrate, wherein the preset substrate includes a substrate and a protective layer located above the substrate, and the process method for depositing the tungsten plug includes: alternately introducing fluorine-containing tungsten gas and hydrogen-containing gas into a reaction chamber to perform an atomic layer deposition reaction to form a fluorine-containing tungsten film; simultaneously introducing the fluorine-containing tungsten gas and the hydrogen-containing gas into the reaction chamber to perform a vapor deposition reaction to form a bulk tungsten layer; wherein the fluorine content of the fluorine-containing tungsten film is less than the fluorine content of the bulk tungsten layer.

[0008] Furthermore, an embodiment of the present application provides a first possible implementation of the first aspect, wherein, before forming the fluorine-containing tungsten film, the process method for depositing the tungsten plug also includes: introducing a hydrogen-containing gas into the reaction chamber to allow the hydrogen-containing gas to be adsorbed on the surface of the protective layer to form a wetting layer; wherein the wetting layer produces a reduction reaction with fluorine, a by-product produced during the formation of the fluorine-containing tungsten film.

[0009] Furthermore, the embodiment of the present application provides a second possible implementation of the first aspect, wherein the introducing of hydrogen-containing gas into the reaction chamber so that the hydrogen-containing gas is adsorbed on 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 value into the reaction chamber so that hydrogen atoms are adsorbed on the surface of the protective layer to form the wetting layer.

[0010] Furthermore, an embodiment of the present application provides a third possible implementation of the first aspect, wherein the range of the first preset flow 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 are all 5 Torr-300 Torr.

[0011] Furthermore, the embodiment of the present application provides a fourth possible implementation of the first aspect, wherein the alternate introduction of fluorine-containing tungsten gas and hydrogen-containing gas into the reaction chamber to perform an atomic layer deposition reaction to form a fluorine-containing tungsten film comprises: 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 fluorine-containing tungsten gas into the reaction chamber, and setting the flow rate of the fluorine-containing tungsten gas to a second preset flow value, and setting the introduction time of the fluorine-containing tungsten gas to a first preset time length, so that the fluorine-containing metal molecules are adsorbed on the wetted substrate. layer surface; S504, performing a purge process, and the time of the purge process is set to a second preset time length to remove the fluorine-containing tungsten gas floating in the reaction chamber; S506, introducing 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 time length, so that the hydrogen-containing gas and the fluorine-containing metal molecules undergo a reduction reaction to generate a fluorine-containing tungsten film; S508, performing a purge process, and the time of the purge process is set to a fourth preset time length to remove the hydrogen-containing gas in the reaction chamber and the hydrogen fluoride gas generated by the reduction reaction.

[0012] Furthermore, the embodiment of the present application provides a fifth possible implementation of the first aspect, wherein the process method for depositing the tungsten plug further includes: cyclically executing S500 to S508 a preset number of times to form the fluorine-containing tungsten film of a preset thickness.

[0013] Further, the embodiment of the present application provides a sixth possible implementation of the first aspect, wherein the first preset temperature range is 250°C-400°C; and / or, the fourth preset pressure range is 3Torr-100Torr; and / or, the second preset flow value range is 10sccm-500sccm; and / or, the third preset flow value range is 100sccm-10000sccm.

[0014] Furthermore, an embodiment of the present application provides a seventh possible implementation of the first aspect, wherein the range of the first preset time length, the second preset time length, the third preset time length and the fourth preset time length are all 0.1s-5s; and / or the range of the preset thickness is greater than 1nm.

[0015] In the second aspect, an embodiment of the present application further provides a semiconductor device, comprising: a contact hole, a fluorine-containing tungsten film and a bulk tungsten layer deposited on the protective layer of the contact hole substrate, the fluorine-containing tungsten film and the bulk tungsten layer being deposited based on the process method for depositing tungsten plugs described in the first aspect, and the fluorine-containing tungsten film being located between the protective layer and the bulk tungsten layer.

[0016] Furthermore, an embodiment of the present application provides a first possible implementation of the second aspect, wherein the protective layer includes a barrier layer and a nucleation layer, and the barrier layer is located between the substrate and the nucleation layer.

[0017] In a third aspect, an embodiment of the present application further provides a semiconductor process device, comprising a reaction chamber, an air intake assembly, and a controller, wherein the controller comprises at least one processor and at least one memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the process method for depositing a tungsten plug as described in the first aspect is implemented.

[0018] The embodiments of the present application provide a tungsten plug deposition process method, a semiconductor device, and a semiconductor process equipment for processing a preset substrate, wherein the preset substrate includes a substrate and a protective layer located above the substrate. The tungsten plug deposition process method includes: alternately introducing a fluorine-containing tungsten gas and a hydrogen-containing gas into a reaction chamber to perform an atomic layer deposition reaction to form a fluorine-containing tungsten film; simultaneously introducing a fluorine-containing tungsten gas and a hydrogen-containing gas into the reaction chamber to perform a vapor deposition reaction to form a bulk tungsten layer; wherein the fluorine content of the fluorine-containing tungsten film is less than the fluorine content of the bulk tungsten layer. The present application deposits a layer of fluorine-containing tungsten film before depositing the bulk tungsten layer, thereby preventing a large amount of byproduct fluorine atoms generated during the bulk tungsten layer formation stage from attacking the substrate. In addition, the fluorine impurity content in the fluorine-containing tungsten film is low, and the probability of attacking the substrate is low, thereby alleviating the problem of fluorine atoms penetrating the bottom substrate, avoiding the occurrence of fluorine attack points inside the substrate that cause electrical failure of the semiconductor device, and improving the yield of the semiconductor device.

[0019] Other features and advantages of the embodiments of the present application will be described in the subsequent description, or some features and advantages can be inferred or determined without doubt from the description, or can be learned by implementing the above-mentioned technologies of the embodiments of the present application.

[0020] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] FIG1 shows a process flow chart of depositing tungsten plugs in the related art;

[0023] FIG2 shows a ventilation timing diagram of a tungsten plug deposition process in the related art;

[0024] FIG3 shows a schematic diagram of a hole filling process of a tungsten plug in the related art;

[0025] FIG4 shows a flow chart of a process for depositing a tungsten plug provided in an embodiment of the present application;

[0026] FIG5 shows a process flow chart of depositing a tungsten plug according to an embodiment of the present application;

[0027] FIG6 shows a process flow chart of another method for depositing a tungsten plug according to an embodiment of the present application;

[0028] FIG7 shows a ventilation timing diagram of a process for depositing a tungsten plug provided in an embodiment of the present application;

[0029] FIG8 shows a schematic diagram of hole filling provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0031] In the related art tungsten plug deposition process, an adhesion barrier layer (Ti / TiN) is grown before the tungsten plug is grown. The TiN mainly serves to prevent fluorine atoms from attacking the underlying substrate. The growth of the tungsten plug is divided into two processes: the growth of the nucleation layer and the growth of the bulk tungsten layer. Referring to the related art tungsten plug deposition process flow chart shown in Figure 1, the related tungsten plug deposition process mainly includes the following steps:

[0032] Step S101 : heating a wafer to a temperature required for the process, wherein the wafer includes a substrate 11 and a TiN barrier layer 12 .

[0033] Step S102 : generating a nucleation layer 13 on the surface of the TiN barrier layer 12 . The generation of the nucleation layer 13 can reduce the growth incubation period of the bulk tungsten layer.

[0034] In step S103 , a bulk tungsten layer 14 is formed on the surface of the nucleation layer 13 .

[0035] Referring to the ventilation timing diagram of the tungsten plug deposition process as shown in FIG2 , the ventilation timing of the tungsten plug deposition process can be performed according to the following steps:

[0036] S20: After the wafer is heated to the required temperature, the growth of the nucleation layer begins.

[0037] The growth of the nucleation layer is carried out by atomic layer deposition. B2H6 and WF6 are alternately introduced into the reaction chamber for atomic layer deposition (ALD) reaction. The steps of B2H6 and WF6 performing the atomic layer deposition reaction are cyclically performed. Each cycle includes the following four steps:

[0038] S21: B2H6 pulse of set duration is introduced into the reaction chamber;

[0039] S22: introducing an inert gas into the reaction chamber to purge the reaction chamber;

[0040] S23: introducing a WF6 pulse of a set duration into the reaction chamber;

[0041] S24: Introducing an inert gas into the reaction chamber to purge the reaction chamber.

[0042] The number of cycles of executing steps S21 to S24 can be determined according to the required thickness of the nucleation layer.

[0043] S25: After the nucleation layer is grown, WF6 pulses and H2 pulses are simultaneously introduced into the reaction chamber to perform a chemical vapor deposition (CVD) reaction to generate a bulk tungsten layer. The process of generating the bulk tungsten layer is accompanied by the generation of fluorine atoms as a by-product.

[0044] The nucleation layer is amorphous tungsten with a high resistivity, while the bulk tungsten layer is crystalline tungsten with a low resistivity. The TiN barrier layer and tungsten nucleation layer have high resistivity. However, as process technology advances and feature sizes become smaller and smaller, the barrier layer and tungsten nucleation layer have an increasingly greater impact on the resistivity of the tungsten plug. Tungsten plug processes in related art typically employ a method of thinning the thickness of the barrier layer and nucleation layer to reduce the impact on the resistivity of the tungsten plug. Referring to the schematic diagram of the tungsten plug filling process in related art shown in FIG3 , reducing the thickness of the barrier layer 12 and nucleation layer 13 can easily weaken the barrier layer 12's ability to block fluorine attack. Fluorine atoms are generated as a byproduct during the chemical vapor deposition reaction of WF6 and H2 to form the bulk tungsten layer 14. Fluorine (F) can easily penetrate the reduced-thickness barrier layer 12 and attack the substrate 11, resulting in fluorine attack points 30, i.e., voids, within the substrate 11. The appearance of fluorine attack points 30 can easily cause the barrier layer 12 to break, which in turn can lead to electrical failure of the semiconductor device and reduced yield.

[0045] In order to improve the above problems, the embodiments of the present application provide a tungsten plug deposition process method and a semiconductor device, which are described in detail below.

[0046] This embodiment provides a process method for depositing a tungsten plug. The process method can be used to process a predetermined substrate. Referring to the flow chart of the process method for depositing a tungsten plug shown in FIG4 , the method includes the following steps:

[0047] In step S402 , a fluorine-containing tungsten gas and a hydrogen-containing gas are alternately introduced into the reaction chamber to perform an atomic layer deposition reaction to form a fluorine-containing tungsten film.

[0048] Referring to the process flow diagram for depositing a tungsten plug, shown in Figure 5, the aforementioned substrate comprises a substrate 51 and a protective layer 52 positioned above the substrate. Protective layer 52 protects substrate 51 and may include, for example, 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 perform an atomic layer deposition reaction, depositing a fluorine-containing tungsten film 54 on protective layer 52.

[0049] The fluorine-containing tungsten gas can undergo a reduction reaction with the hydrogen-containing gas to generate hydrogen fluoride and a fluorine-containing tungsten compound. The metallic tungsten in the compound has good electrical conductivity and anti-electromigration properties. The fluorine-containing tungsten gas in this embodiment is preferably tungsten hexafluoride WF6.

[0050] Under certain process temperature and process pressure, fluorine-containing tungsten gas is first introduced into the reaction chamber for a certain period of time to allow 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 to allow 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 then pumped away, and the resulting metal film contains lower fluorine impurities, which is called a fluorine-containing tungsten film.

[0051] By alternately introducing fluorine-containing tungsten gas and hydrogen-containing gas into the reaction chamber multiple times, a fluorine-containing tungsten film of a certain thickness can be generated. The number of times the fluorine-containing tungsten gas and hydrogen-containing gas are alternately introduced can be determined according to the required thickness of the fluorine-containing tungsten film. The thicker the film, the more times required.

[0052] In step S404 , a fluorine-containing tungsten gas and a hydrogen-containing gas are simultaneously introduced into the reaction chamber to perform a vapor deposition reaction to form a bulk tungsten layer.

[0053] After a fluorine-containing tungsten film of a certain thickness is grown, the growth of the bulk tungsten layer begins. Fluorine-containing tungsten gas and hydrogen-containing gas are simultaneously introduced into the reaction chamber to perform a chemical vapor deposition reaction to generate the bulk tungsten layer.

[0054] The fluorine content of the above-mentioned fluorine-containing tungsten film is lower than that of the bulk tungsten layer. The fluorine-containing tungsten film is the first line of defense to prevent fluorine from attacking the substrate, and can prevent the penetration of byproduct fluorine (i.e., fluorine atoms) generated during the formation of the bulk tungsten layer.

[0055] The above-mentioned tungsten plug deposition process method provided in this embodiment can block a large number of by-product fluorine atoms generated in the bulk tungsten layer formation stage from attacking the substrate by depositing a layer of fluorine-containing tungsten film before depositing the bulk tungsten layer. In addition, the fluorine impurity content in the fluorine-containing tungsten film is low, and the probability of attacking the substrate is small, which alleviates the problem of fluorine atoms penetrating the bottom substrate, avoids the occurrence of fluorine attack points inside the substrate that cause electrical failure of semiconductor devices, and improves the yield of semiconductor devices.

[0056] In one embodiment, in order to prevent fluorine atoms from attacking the substrate during the deposition of the fluorine-containing tungsten film, before forming the fluorine-containing tungsten film, the process for depositing a tungsten plug provided by this embodiment further includes the following steps S400:

[0057] In step S400 , hydrogen-containing gas is introduced into the reaction chamber to be adsorbed on the surface of the protective layer to form a wetting layer. The wetting layer reacts with fluorine, a byproduct produced during the formation of the fluorine-containing tungsten film, to generate a reduction reaction.

[0058] A certain flow of hydrogen-containing gas is continuously introduced into the reaction chamber to immerse the above-mentioned predetermined substrate in the reaction chamber filled with hydrogen-containing gas. As shown in FIG5 , a layer of hydrogen-containing molecules is adsorbed on the surface of the protective layer above the substrate to form a wetting layer 53 .

[0059] The hydrogen-containing gas may be any gas that can undergo a reduction reaction with the fluorine-containing tungsten gas to generate hydrogen fluoride, such as hydrogen, borane, or silane. In this embodiment, hydrogen is preferred.

[0060] After the wetting layer is formed, the fluorine-containing tungsten film begins to grow. During the growth process of the fluorine-containing tungsten film, by-product fluorine (i.e., fluorine atoms) will be produced. When the fluorine atoms attack the underlying substrate, the hydrogen-containing molecules in the wetting layer react with the fluorine atoms to generate hydrogen fluoride gas, which is pumped away, thereby alleviating the fluorine attack. As the fluorine-containing tungsten film grows, the hydrogen-containing molecules in the wetting layer will gradually decrease. After the growth of the fluorine-containing tungsten film is completed, the wetting layer disappears.

[0061] The wetting layer is the second line of defense to prevent fluorine from attacking the substrate. The hydrogen-containing gas molecules in the wetting layer can react with the fluorine atoms produced during the formation of the fluorine-containing tungsten film to generate gaseous hydrogen fluoride which is then pumped away, thereby alleviating the fluorine attack during the formation of the fluorine-containing tungsten film.

[0062] By generating a wetting layer formed by hydrogen-containing gas on the protective layer of the substrate, the wetting hydrogen-containing gas can react with the by-product fluorine atoms produced during the formation of the fluorine-containing tungsten film to generate gaseous hydrogen fluoride which is pumped away, thereby alleviating the fluorine attack during the formation of the fluorine-containing tungsten film.

[0063] In one embodiment, a specific implementation of 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; and continuously introducing a 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.

[0064] The butterfly valve controller controls the reaction chamber to maintain a certain pressure value (i.e., a first preset pressure value), or controls the pressure in the reaction chamber to gradually increase within a certain range (i.e., from a second preset pressure value to a third preset pressure value) based on the butterfly valve controller. Hydrogen-containing gas is introduced into the reaction chamber for a certain period of time in a pulsed manner, and the hydrogen-containing gas is adsorbed on the surface of the protective layer to form a wetting layer.

[0065] The second preset pressure value may be the same as or different from the first preset pressure value, the third preset pressure value may be the same as or different from the first preset pressure value, and the third preset pressure value is greater than the second preset pressure value.

[0066] In one embodiment, the process conditions for forming the wetting layer are:

[0067] The pressure of the reaction chamber is maintained at a first preset pressure value, and the flow rate of the hydrogen-containing gas is maintained at a first preset flow rate value. The duration of the hydrogen-containing gas introduction is 3 seconds to 100 seconds, preferably 10 to 20 seconds in this embodiment. The first preset pressure value ranges from 5 Torr to 300 Torr, preferably 40 Torr in this embodiment; the first preset flow rate ranges from 1000 sccm to 10,000 sccm.

[0068] In another embodiment, the process conditions for forming the wetting layer are:

[0069] The pressure in the reaction chamber increases from the second preset pressure value to the third preset pressure value. The flow rate of the hydrogen-containing gas is maintained at the first preset flow rate. The hydrogen-containing gas is introduced for a duration of 3 seconds to 100 seconds, preferably 10 to 20 seconds in this embodiment. The second preset pressure value ranges from 5 Torr to 300 Torr, and the third preset pressure value ranges from 5 Torr to 300 Torr. The first preset flow rate ranges from 1000 sccm to 10,000 sccm.

[0070] In one embodiment, a specific embodiment of forming a fluorine-containing tungsten film includes the following steps:

[0071] S500 , heating the substrate to maintain 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.

[0072] The substrate is heated to stabilize the process temperature of the reaction chamber within a first preset temperature range of 250° C. to 400° C. The process pressure within the reaction chamber is controlled to stabilize within a fourth preset pressure range of 3 Torr to 100 Torr, preferably 3 Torr to 90 Torr.

[0073] S502, introducing fluorine-containing tungsten gas into the reaction chamber, and the flow rate of the fluorine-containing tungsten gas is set to a second preset flow value, and the introduction time of the fluorine-containing tungsten gas is set to a first preset time length, so that the fluorine-containing metal molecules are adsorbed on the surface of the wetting layer.

[0074] Fluorine-containing tungsten gas is introduced into the reaction chamber in a pulsed manner, causing a uniform layer of fluorine-containing metal molecules to adsorb on 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 introduction time of the fluorine-containing tungsten gas is set to a first preset duration, which ranges from 0.1 second to 5 seconds.

[0075] S504 , performing a purge process, wherein the purge process duration is set to a second preset duration to remove the fluorine-containing tungsten gas floating in the reaction chamber.

[0076] The reaction chamber is purged to remove excess fluorine-containing tungsten gas from the reaction chamber, leaving only fluorine-containing metal molecules adsorbed on the wafer surface. The purge process is set to a second preset duration, which ranges from 0.1s to 5s.

[0077] S506, introducing hydrogen-containing gas into the reaction chamber, and the flow rate of the hydrogen-containing gas is set to a third preset flow 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 fluorine-containing metal molecules undergo a reduction reaction to form a fluorine-containing tungsten film.

[0078] Hydrogen-containing gas is introduced into the reaction chamber in a pulsed manner, and the hydrogen-containing gas undergoes a reduction reaction with the fluorine-containing metal molecules adsorbed on the wafer to generate a fluorine-containing tungsten film of a certain thickness (such as 0.02nm to 0.04nm, preferably 0.03nm) and hydrogen fluoride gas.

[0079] In one embodiment, the third preset flow rate value ranges from 100 sccm to 10,000 sccm, and the third preset time length ranges from 0.1 s to 5 s.

[0080] In the process of forming the fluorine-containing tungsten film, the fluorine-containing tungsten gas and the hydrogen-containing gas are introduced alternately. The content of fluorine atoms in the fluorine-containing tungsten film is lower than that in the bulk tungsten layer. The content of fluorine atoms in the fluorine-containing tungsten film can be e per cubic centimeter. +19 Fluorine atoms. The content of fluorine atoms in the bulk tungsten layer can be e per cubic centimeter. +20Fluorine atom.

[0081] S508 , performing a purge process, wherein the purge process duration is set to a fourth preset duration to remove the hydrogen-containing gas and the hydrogen fluoride gas generated by the reduction reaction in the reaction chamber.

[0082] The reaction chamber is purged to remove excess hydrogen-containing gas and hydrogen fluoride gas generated by the reaction of the hydrogen-containing gas with the fluorine-containing metal molecules. The fourth preset duration ranges from 0.1s to 5s. The first, second, third, and fourth preset durations may be the same or different.

[0083] In one embodiment, the above steps S500 to S508 are executed cyclically for a predetermined number of times to form a fluorine-containing tungsten film having a predetermined thickness. The predetermined number of times is related to the desired predetermined thickness of the fluorine-containing tungsten film.

[0084] In one embodiment, the predetermined thickness of the fluorine-containing tungsten film may be greater than 1 nm.

[0085] The above-mentioned tungsten plug deposition process method provided in this embodiment, by growing a fluorine-containing tungsten film between the nucleation layer and the bulk tungsten layer, plays a role in blocking fluorine atoms from penetrating the substrate, thereby solving the problem of fluorine atoms attacking the bottom 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 fluorine-containing tungsten film to generate gaseous hydrogen fluoride which is extracted away, thereby alleviating the fluorine attack.

[0086] Based on the above embodiment, this embodiment provides a process method for depositing a tungsten plug. Referring to another process flow chart of depositing a tungsten plug as shown in FIG6 , the process can be specifically performed according to the following steps:

[0087] In step S601 , a substrate 51 is provided, and a Ti / TiN barrier layer 61 is formed on the substrate 51 .

[0088] Step S602 , heating the substrate 51 to a preset process temperature.

[0089] A nucleation layer 62 is generated on the surface of the Ti / TiN barrier layer 61. As shown in the process venting timing diagram of depositing the tungsten plug in FIG7 , in the process of heating the substrate 51 to generate the nucleation layer 62, the following steps S71 to S74 are cyclically executed to generate the nucleation layer of a set thickness:

[0090] S71: continuously introducing a B2H6 pulse into the reaction chamber for a predetermined time;

[0091] S72: Introducing an inert gas into the reaction chamber to purge the reaction chamber to remove excess B2H6 gas in the reaction chamber;

[0092] S73: continuously introducing WF6 pulses into the reaction chamber for a predetermined time;

[0093] S74: Inert gas is introduced into the reaction chamber to purge the reaction chamber to remove excess WF6 gas in the reaction chamber.

[0094] The number of times steps S71 to S74 are cyclically executed can be determined according to the required thickness of the nucleation layer. The more times steps S71 to S74 are executed, the thicker the nucleation layer formed will be.

[0095] In step S603 , a H 2 pulse with a duration of 3 s to 100 s is introduced into the reaction chamber to allow H 2 molecules to be adsorbed on the surface of the nucleation layer 62 to form a wetting layer 53 .

[0096] The flow rate of the H2 pulse can range from 1000 sccm to 10000 sccm. The reaction chamber is controlled to maintain a certain pressure, or the pressure of the reaction chamber is controlled to increase. The pressure range of the reaction chamber needs to be maintained at 5 Torr-300 Torr, preferably 40 Torr.

[0097] In step S604 , WF6 pulses and H2 pulses are alternately introduced into the reaction chamber to form a fluorine-containing tungsten film 54 .

[0098] The WF6 molecules adsorbed on the wafer surface react with H2 through atomic layer deposition to generate a tungsten film containing fewer fluorine atoms, which is called a fluorine-containing tungsten film.

[0099] 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 extracted, thereby alleviating the fluorine attack. As the fluorine-containing tungsten film grows, the hydrogen molecules in the wetting layer 53 gradually decrease. After the growth of the fluorine-containing tungsten film 54 is completed, the wetting layer 53 disappears.

[0100] The process conditions for generating a fluorine-containing tungsten film are as follows: a process temperature between 250-400° C., a process pressure between 3 Torr-100 Torr, preferably between 3 Torr-90 Torr; a flow rate of a WF6 pulse between 10 sccm-500 sccm, and a flow rate of an H2 pulse between 100 sccm-10000 sccm.

[0101] As shown in FIG7 , the following steps S75 to S78 are executed cyclically to generate a nucleation layer of a certain thickness:

[0102] S75, introducing a WF6 pulse with a duration of 0.1s-5s into the reaction chamber, and the flow rate of the WF6 gas is in the range of 10sccm-500sccm;

[0103] S76, introducing an inert gas into the reaction chamber to perform a purge process to remove excess WF6 gas in the reaction chamber except for a layer of WF6 molecules adsorbed on the surface of the wafer. The purge process time ranges from 0.1s to 5s.

[0104] S77, introducing a H2 pulse of 0.1s-5s duration into the reaction chamber to cause the H2 molecules to react with a layer of WF6 molecules adsorbed on the surface of the wafer to generate a fluorine-containing tungsten film 54, with the flow rate of the H2 gas ranging from 100 sccm to 10,000 sccm;

[0105] S78, introducing an inert gas into the reaction chamber to perform a purge process to remove excess H2 gas and hydrogen fluoride gas generated by the reduction reaction in the reaction chamber. The purge process time ranges from 0.1s to 5s.

[0106] The number of times steps S75 to S78 are cyclically executed can be determined according to the required thickness of the fluorine-containing tungsten film.

[0107] In step S605 , WF6 pulses and H2 pulses are simultaneously introduced into the reaction chamber to perform a vapor deposition reaction, thereby forming a bulk tungsten layer 55 .

[0108] The tungsten plug deposition process provided in this embodiment solves the problem of fluorine attacking the substrate. The fluorine-containing tungsten film itself has the characteristics of low fluorine content and low probability of fluorine attacking the substrate. The formation of the fluorine-containing tungsten film can also block the large amount of fluorine atoms generated during the formation of the bulk tungsten layer from attacking the substrate, thereby avoiding fluorine atoms attacking the substrate and causing electrical failure of the semiconductor device, thereby improving the yield of the semiconductor device.

[0109] Corresponding to the process method for depositing tungsten plugs provided in the above-mentioned embodiments, an embodiment of the present application provides a semiconductor device, including: a contact hole, referring to the hole filling schematic diagram shown in Figure 8, a fluorine-containing tungsten film 54 and a bulk tungsten layer 55 are deposited on the protective layer of the contact hole substrate 51, and the fluorine-containing tungsten film 54 and the bulk tungsten layer 55 are deposited based on the process method for depositing tungsten plugs provided in the above-mentioned embodiments, and the fluorine-containing tungsten film 54 is located between the protective layer and the bulk tungsten layer 55.

[0110] In one embodiment, the protective layer includes a barrier layer 61 and a nucleation layer 62 , and the barrier layer 61 is located between the substrate 51 and the nucleation layer 62 .

[0111] The contact hole process provided in this embodiment can adopt the tungsten plug deposition process method provided in the above embodiment. In one embodiment, a wetting layer can also be included between the nucleation layer 62 and the fluorine-containing 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 fluorine-containing tungsten film 54 react with the hydrogen molecules in the wetting layer to generate hydrogen fluoride gas, which is extracted. The wetting layer gradually disappears during the formation of the fluorine-containing tungsten film 54.

[0112] The semiconductor device provided in this embodiment has the same implementation principle and technical effects as those of the aforementioned embodiments. For the sake of brief description, for matters not mentioned in the semiconductor device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0113] Corresponding to the tungsten plug deposition process method provided in the above-mentioned embodiment, an embodiment of the present application provides a semiconductor process equipment, including a reaction chamber, an air intake component and a controller, the controller including at least one processor and at least one memory, the memory storing a computer program, and when the computer program is executed by the processor, the tungsten plug deposition process method provided in the above-mentioned embodiment is implemented.

[0114] Among them, a heating base is provided in the reaction chamber, which supports the wafer and heats the wafer so that the wafer can be heated to the temperature required for the process. The air intake assembly is used to introduce corresponding reaction gases into the reaction chamber, for example, alternately introducing B2H6 and WF6 into the reaction chamber for atomic layer deposition (ALD) reaction, or simultaneously introducing fluorine-containing tungsten gas and hydrogen-containing gas into the reaction chamber for vapor deposition reaction. The air intake assembly is also used to introduce purge gas into the reaction chamber.

[0115] In some embodiments, the reaction chamber is further provided with an exhaust port, a butterfly valve for controlling the flow rate of the exhaust port, and a butterfly valve controller. Based on the butterfly valve controller, the pressure of the reaction chamber, the exhaust of the gas in the reaction chamber, etc. can be controlled.

[0116] For example, the controller can be either a host computer or a slave computer. The controller can control the opening of a valve in an air inlet assembly to introduce the corresponding gas into the reaction chamber. The controller can also control the opening and closing of the valve in the air inlet assembly to control the flow rate of the process gas. The controller can also control the pressure in the reaction chamber, the exhaust of gas from the reaction chamber, and so on by controlling a butterfly valve controller.

[0117] An embodiment of the present application provides a computer-readable medium, wherein the computer-readable medium stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the method described in the above embodiment.

[0118] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process of the system described above can refer to the corresponding process in the aforementioned embodiment and will not be repeated here.

[0119] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0120] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0121] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be based on the scope of protection of the claims.

Claims

1. A process for depositing a tungsten plug, for processing a preset substrate, wherein the preset substrate comprises a substrate and a protective layer located above the substrate, characterized in that: The process for depositing the tungsten plug comprises: Alternately introducing fluorine-containing tungsten gas and hydrogen-containing gas into the reaction chamber to perform atomic layer deposition reaction to form a fluorine-containing tungsten film; The fluorine-containing tungsten gas and the hydrogen-containing gas are simultaneously introduced into the reaction chamber to perform a vapor deposition reaction to form a bulk tungsten layer; wherein the fluorine content of the fluorine-containing tungsten film is less than the fluorine content of the bulk tungsten layer.

2. The process for depositing a tungsten plug according to claim 1, characterized in that: Before forming the fluorine-containing tungsten film, the process for depositing a tungsten plug further includes: A hydrogen-containing gas is introduced into the reaction chamber to adsorb the hydrogen-containing gas on the surface of the protective layer to form a wetting layer; wherein the wetting layer produces a reduction reaction with fluorine, a byproduct produced during the formation of the fluorine-containing tungsten film.

3. The process for depositing a tungsten plug according to claim 2, characterized in that: The step of introducing hydrogen-containing gas into the reaction chamber so that the hydrogen-containing gas is adsorbed on the surface of the protective layer to form a wetting layer comprises: Stabilize the pressure of the reaction chamber at a first preset pressure value, or increase the pressure of the reaction chamber from a second preset pressure value to a third preset pressure value; A hydrogen-containing gas at a first preset flow rate is continuously introduced into the reaction chamber so that hydrogen atoms are adsorbed on the surface of the protective layer to form the wetting layer.

4. The process for depositing a tungsten plug according to claim 3, characterized in that: The first preset flow rate value ranges from 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-300 Torr.

5. The process for depositing a tungsten plug according to claim 2, characterized in that: The step of alternately introducing a fluorine-containing tungsten gas and a hydrogen-containing gas into the reaction chamber to perform an atomic layer deposition reaction to form a fluorine-containing tungsten film comprises: S500, heating the substrate to maintain 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 fluorine-containing tungsten gas 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 time length, so that the fluorine-containing metal molecules are adsorbed on the surface of the wetting layer; S504, performing a purge process, wherein the duration of the purge process is set to a second preset duration, so as to remove the fluorine-containing tungsten gas floating in the reaction chamber; S506, introducing 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 fluorine-containing metal molecules undergo a reduction reaction to generate a fluorine-containing tungsten film; S508 , performing a purge process, wherein the duration of the purge process is set to a fourth preset duration, so as to remove the hydrogen-containing gas in the reaction chamber and the hydrogen fluoride gas generated by the reduction reaction.

6. The process for depositing a tungsten plug according to claim 5, characterized in that: Also includes: The steps S500 to S508 are executed cyclically for a preset number of times to form the fluorine-containing tungsten film with a preset thickness.

7. The process for depositing a tungsten plug according to claim 5, characterized in that: 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 value ranges from 10 sccm to 500 sccm; and / or, The third preset flow rate value ranges from 100 sccm to 10000 sccm.

8. The process for depositing a tungsten plug according to claim 6, characterized in that: The range of the first preset time length, the second preset time length, the third preset time length and the fourth preset time length are all 0.1s-5s; and / or, The range of the preset thickness is greater than 1 nm.

9. A semiconductor device comprising: A contact hole, characterized in that a fluorine-containing tungsten film and a bulk tungsten layer are deposited on the protective layer of the contact hole substrate, the fluorine-containing tungsten film and the bulk tungsten layer are deposited based on the process method for depositing tungsten plugs according to any one of claims 1 to 8, and the fluorine-containing tungsten film is located between the protective layer and the bulk tungsten layer.

10. The semiconductor device according to claim 9, characterized in that The protective layer includes a barrier layer and a nucleation layer, and the barrier layer is located between the substrate and the nucleation layer.

11. A semiconductor process equipment, comprising a reaction chamber, an air intake assembly and a controller, characterized in that: The controller includes at least one processor and at least one memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the process method for depositing a tungsten plug according to any one of claims 1 to 8 is implemented.

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