Substrate processing method and substrate processing apparatus

Abstract

To suppress film deposition defects when forming a metal film that will serve as wiring on a metal silicide in a recess of the substrate. [Solution] The substrate processing method of the present disclosure comprises a plasma processing step of performing at least one of the following: a step of supplying a first processing gas containing a first metal to a substrate having a recess in which a semiconductor layer containing silicon is exposed at the bottom surface and the side walls are formed by an insulating film to form a metal silicide film that forms the bottom wall of the recess; a plasma etching step of supplying a plasma-generated etching gas to the substrate to remove the film of the first metal on the side walls of the recess; and a side wall processing step of supplying a plasma-generated second processing gas to the substrate to form a metal-containing film on the side walls of the recess in which the first metal and elements constituting the insulating film are mixed; and a film deposition step of supplying a first film deposition gas containing a second metal to the substrate after the plasma processing step has been performed to form a laminated metal film that is laminated on the metal silicide film.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method and a substrate processing apparatus.

Background Art

[0002] In the manufacturing process of semiconductor devices, recesses such as via holes and trenches are formed in an insulator film formed on a semiconductor wafer (hereinafter referred to as "wafer") which is a substrate. Then, a process of embedding a metal film, which is a wiring material, in the recess so as to be electrically conductive with a semiconductor layer containing silicon exposed on the bottom surface of the recess is performed. Before this embedding is performed, in some cases, the silicon on the bottom surface of the recess is made into a metal silicide to reduce the resistance (contact resistance) at the contact portion between the metal film and the semiconductor layer.

[0003] Patent Document 1 describes that after forming a TiSi film on the bottom of a recess of a substrate, the Ti film formed on the side wall of the recess for forming this titanium silicide film is etched and removed by supplying TiCl4 gas that is not made into plasma. Further, Patent Document 2 describes that while forming a Ti film on the bottom of a recess, a Ti film is not formed on the side wall of the recess by performing a process of making each gas containing TiCl4 gas and H2 gas into plasma in a state where the SiN film forming the side wall of the recess of the substrate is covered with a SiO2 film.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] This disclosure provides a technology that can suppress film deposition defects when forming a metal film that will serve as wiring on a metal silicide in a recess of a substrate. [Means for solving the problem]

[0006] The substrate processing method of the present disclosure includes the steps of supplying a first processing gas containing a first metal to a substrate having a recess in which a semiconductor layer containing silicon is exposed at the bottom surface and the side walls are formed by an insulating film, thereby forming a metal silicide film that forms the bottom wall of the recess, A plasma treatment step comprising: a plasma etching step of supplying a plasma-generated etching gas to the substrate to remove the film of the first metal on the side wall of the recess; and a side wall treatment step of supplying a plasma-generated second treatment gas to the substrate to form a metal-containing film on the side wall of the recess in which the first metal and the elements constituting the insulating film are mixed; and at least one of these steps. A film deposition step is performed in which a first film deposition gas containing a second metal is supplied to the substrate after the plasma treatment step is performed to form a laminated metal film to be laminated on the metal silicide film, It is equipped with. [Effects of the Invention]

[0007] This disclosure makes it possible to suppress film deposition defects when forming a metal film that will serve as wiring on a metal silicide in a recess of a substrate. [Brief explanation of the drawing]

[0008] [Figure 1] This is a longitudinal cross-sectional side view of the wafer before processing according to the embodiment. [Figure 2A] This is a longitudinal cross-sectional side view of a wafer processed according to the first embodiment. [Figure 2B] This is a longitudinal cross-sectional side view of a wafer processed according to the first embodiment. [Figure 3A] This is a longitudinal cross-sectional side view of a wafer processed according to the first embodiment. [Figure 3B] This is a longitudinal cross-sectional side view of a wafer processed according to the first embodiment. [Figure 4] A longitudinal side view of a wafer processed according to the second embodiment. [Figure 5A] A longitudinal side view of a wafer processed according to the second embodiment. [Figure 5B] A longitudinal side view of a wafer processed according to the second embodiment. [Figure 6] A plan view of a substrate processing apparatus that performs the processes of the first and second embodiments. [Figure 7] A longitudinal side view of a processing module provided in the substrate processing apparatus. [Figure 8] A graph showing the results of evaluation test 2. [Figure 9] A graph showing the results of evaluation test 3. [Figure 10] A graph showing the results of evaluation test 4. [Figure 11] A graph showing the results of evaluation test 4. [Figure 12] A graph showing the results of evaluation test 5. [Figure 13] A graph showing the results of evaluation test 5. [Figure 14] A graph showing the results of evaluation test 6.

Best Mode for Carrying Out the Invention

[0009] 〔First Embodiment〕 Fig. 1 shows a longitudinal side view illustrating an example of the wafer A to be processed in the first and second embodiments. In the following description of the wafer A, the thickness direction of the wafer A is taken as the vertical direction. The wafer A includes a Si (silicon) layer 11 which is a semiconductor layer, and a SiN (silicon nitride) film 12 which is an insulator film is laminated on the Si layer 11. Holes are formed in the SiN film 12 in the vertical direction, and the lower ends of these holes reach the Si layer 11. By providing such a SiN film 12 and holes, recesses 13 in the form of trenches or holes are formed in the wafer A, and the side walls of the recesses 13 are formed by the SiN film 12 which is an insulator film. And the bottom wall of the recess 13 is formed by the Si layer 11, that is, a semiconductor layer containing silicon, and the Si layer 11 is exposed on the surface of the wafer A as the bottom surface of the recess 13.

[0010] The processing of the wafer A in the first embodiment will be described. Note that each of the following processes is performed by supplying a gas into a processing vessel in which the wafer A is stored and the inside of which is evacuated to a predetermined vacuum pressure. Note that each process is not limited to being performed in the same processing vessel, and may be performed in separate processing vessels. Also, the wafer A is heated to a predetermined temperature in the processing vessel so that each process proceeds.

[0011] First, TiCl4 (titanium tetrachloride) gas, H2 (hydrogen) gas, and Ar (argon) gas are supplied into the processing vessel in which the wafer A shown in Fig. 1 is stored, and plasma CVD is performed by plasmaizing these gases (Fig. 2A, step S1). The TiCl4 gas is the first processing gas for forming a metal silicide film. Also, the H2 gas is a gas for reacting with and removing the chlorine constituting TiCl4, and the Ar gas is a gas for plasma formation. By supplying these gases, the portion of the Si layer 11 exposed on the bottom surface of the recess 13 reacts with Ti which is the first metal contained in TiCl4, and a TiSi (titanium silicide) film 14 which is a metal silicide film is formed on the bottom wall of the recess 13. On the other hand, a Ti (titanium) film 15 is formed on the side walls of the recess 13.

[0012] Next, TiCl4 gas and Ar gas are supplied into the processing container, and plasma etching is performed by turning these gases into plasma (Figure 2B, step S2). The Ti film 15 on the side walls of the recess 13 is etched mainly by the action of chlorine and chlorine-reactive species such as ions generated from TiCl4. The TiCl4 gas and Ar gas used in this step S2 are etching gases for plasma etching. Therefore, each of these plasma etching gases and metal silicide formation gases contains TiCl4 gas.

[0013] Subsequently, WCl5 (tungsten pentachloride) gas, Ar gas, and H2 gas are supplied to the processing container and CVD is performed, so that a W (tungsten) film 16 is deposited in the recess 13 so as to be layered on the TiSi film 14 (Figure 3A, step S3). WCl5 gas is the first deposition gas for film formation, H2 gas is used to remove chlorine by reacting with it, and Ar gas is a carrier gas. The W contained in WCl5 is the second metal. As will be shown in the evaluation test described later, when each gas, including WCl5 gas, is supplied to the substrate in this way, the W film is deposited on the Ti film, while the deposition of the W film on the SiN film is suppressed. As described above, the Ti film 15 is etched in step S2, so the deposition of the W film 16 on the side walls of the recess 13, which is the SiN film 12, is suppressed by the process in step S3, and the W film 16 is selectively formed at the bottom of the recess 13.

[0014] The supply of WCl5 gas, Ar gas, and H2 gas is stopped before the W film 16, which is a multilayer metal film laminated on the TiSi film 14, is filled into the recess 13 (i.e., before the upper surface of the W film 16, whose thickness increases within the recess 13, reaches the upper end of the recess 13), and step S3 is completed. Therefore, the W film 16 is formed in the recess 13 as a thin film with a relatively small thickness.

[0015] Subsequently, a gas containing, for example, WF6 (tungsten hexafluoride) gas is supplied to the processing container as a second film-forming gas, and a metal film, the W film, is filled into the recess 13 as shown in Figure 3B (step S4). Thus, step S4 is a step in which the W film is formed, just like step S3, but the compounds constituting the gas used for film formation are different from those in step S3. For the sake of illustration, the W film formed by WF6 gas is shown as W film 17, distinguishing it from the W film 16 formed by WCl5 gas. The W film 17, together with the W film 16, forms the wiring of the semiconductor device manufactured from wafer A. The portion of the W film 17 formed above the recess 13 is later removed by CMP.

[0016] The reason why the W film 16 is formed in step S3 before the W film 17 is formed in step S4 will be explained. From the viewpoint of increasing the film deposition efficiency, it is preferable to use WF6 gas rather than WCl5 gas to fill the recess 13 with the W film 17. For this reason, WF6 gas is used in step S4, where this filling is performed. However, the fluorine that makes up WF6 has a relatively high etching effect on the TiSi film 14. For this reason, the W film 16 is formed with WCl5 gas in step S3, and the W film 16 covers the TiSi film 14, protecting it from etching when the W film 17 is filled.

[0017] Furthermore, if wafer A is exposed to the atmosphere between the formation of the TiSi film 14 and the filling of the recess 13 with the W film 17, the W film 16 also plays a role in preventing oxidation of the surface of the TiSi film 14 by the atmosphere, thereby preventing an increase in contact resistance. One example of a case in which wafer A is exposed to the atmosphere is when wafer A is moved through an atmospheric environment from the apparatus for forming the TiSi film 14 to the apparatus for filling the W film 17.

[0018] As described above, according to the first embodiment, the Ti film 15 on the side wall of the recess 13 is etched. Therefore, the volume of the W film 17 embedded in the recess 13 is larger compared to the case where the Ti film 15 is not etched. Ti has a higher electrical resistance than W. For this reason, the first embodiment can suppress the increase in the resistance of the wiring formed in the recess 13. Furthermore, by suppressing the etching of the Ti film 15 on the side wall of the recess 13, the formation of the W film 16 on the side wall of the recess 13 in step S3 is suppressed. By suppressing the formation of the W film 16 on the side wall in this way, it is prevented that the W film 17 will grow laterally from the W film 16 on the side wall when step S4 is performed. If the W film 17 were to grow laterally, the opening of the recess 13 would be closed before the W film 17 filled the recess 13, and there is a risk that a void would be formed in the W film 17. Thus, according to the first embodiment, the formation of the W film 16 on the side wall of the recess 13 is suppressed, thereby preventing defects in the embedding of the W film 17 into the recess 13. In other words, defects in film formation are suppressed for each of the W films 16 and 17.

[0019] Furthermore, in the first embodiment, the Ti film 15 is etched by plasma-forming the TiCl4 gas. As will be shown in the evaluation tests described later, etching of the Ti film 15 can be completed more quickly than when etching is performed without plasma-forming the TiCl4 gas. Therefore, according to the first embodiment, the throughput of the apparatus and system that performs processing from the formation of the TiSi film 14 to the embedding of the W film 17 in the recess 13 can be increased.

[0020] [Second Embodiment] The processing of the second embodiment will be explained, focusing on the differences from the first embodiment. First, step S1 is performed on wafer A shown in Figure 1, forming a TiSi film 14 on the bottom wall of the recess 13 and a Ti film 15 on the side wall. Then, step S2 is performed, and the Ti film 15 is etched and thinned (Figure 4, left side). After that, H2 gas, which is the second processing gas, is supplied into the processing container in which wafer A is stored, and the H2 gas is turned into plasma (Figure 4, right side, step 2A). Due to the action of the plasma-turned H2 gas, the Ti, which is the element constituting the Ti film 15, and the Si and N, which are the elements constituting the side wall of the recess 13, are mixed, and a TiSiN (titanium nitride silicide) film 21, which is a metal nitride silicide film, is formed on the surface layer of the side wall of the recess 13.

[0021] After the process in step S2A is performed, the process in step 2 is performed again, and then the process in step S2A is performed again. That is, step S2 and step S2A, which is performed after step S2, constitute one cycle, and this cycle is repeated. Through the repetition of the cycle, etching of the Ti film 15 and formation of the TiSiN layer 21 proceed.

[0022] After this cycle has been performed a predetermined number of times, the process in step S3 is carried out in the same manner as in the first embodiment. As will be shown in the evaluation test described later, the W film 16 is less likely to form on the TiSiN film 21 than on the Ti film 15. In other words, the process in step S2A can be said to be a process that modifies the side walls of the recess 13. Then, by modifying the side walls and etching the Ti film 15 in this way, the W film 16 is selectively formed at the bottom of the recess 13 in this second embodiment as well, in the same manner as in the first embodiment (Figure 5A). After that, the process in step S4 is carried out, and the W film 17 is filled into the recess 13 (Figure 5B).

[0023] In the second embodiment described above, the formation of the W film 16 on the side wall of the recess 13 is more reliably suppressed, which is preferable. In this second embodiment, steps S2 and S2A may be performed only once each without being repeated. In other words, the process may be carried out in the order of steps S1, S2, S2A, S3, and S4.

[0024] Furthermore, the order in which steps S2 and S2A are performed may be reversed from the example explained in Figure 4. In other words, the process may be performed in the order of steps S1, S2A, S2, S3, and S4. Even when S2A is performed first among steps S2 and S2A, S2A and S2 may be treated as one cycle, and this cycle may be repeated. That is, after performing step S1, the process may be performed in the order of steps S2A, S2, S2A, S2..., and the modification of the sidewall of the recess 13 and etching of the Ti film 15 on the sidewall may be repeated. However, if the thickness of the Ti film 15 is too large when step S2A is performed, the H2 gas plasma may not act sufficiently on the SiN film 12, or the mixing of Ti, Si, and N in the TiSiN film 21 may not be sufficient, which may reduce the sidewall modification effect. From the viewpoint of preventing this, it is preferable to perform S2 first and S2A later in steps S2 and S2A.

[0025] [Example of a substrate processing apparatus configuration] Next, a substrate processing apparatus 3, which is an example of a configuration capable of performing steps S1 to S3 of the first and second embodiments described above, will be explained with reference to the plan view in Figure 6. The substrate processing apparatus 3 includes a loader module 31, a load lock module 35, a first vacuum transport module 41, a second vacuum transport module 42, a connection module 43, and processing modules 51 and 52. Processing module 51 performs the processes of steps S1, S2, and S2A, and processing module 52 performs the process of step S3. In the following explanation, the first vacuum transport module 41 and the second vacuum transport module 42 may be referred to collectively as vacuum transport modules 41 and 42.

[0026] The loader module 31, load lock module 35, first vacuum transport module 41, connection module 43, and second vacuum transport module 42 are arranged in a linear, lateral manner in this order. In the following description of the substrate processing apparatus 3, the side where the loader module 31 is located will be referred to as the front side, and the side where the second vacuum transport module 42 is located will be referred to as the rear side. The load lock module 35 will be referred to as LLM35 below.

[0027] The loader module 31 comprises a housing that maintains atmospheric pressure internally, a wafer A transport mechanism 32 provided within the housing, and load ports 33. In this example, there are four load ports 33, arranged side by side on the front side of the housing. A transport container 34 for storing wafers A, called a FOUP (Front Opening Unified Pod), is placed on each load port 33. The transport mechanism 32 is composed of, for example, a multi-jointed arm that can move left and right, and can transport wafers A between the transport container 34 on each load port 33 and each load lock module 35.

[0028] In this example, three LLM35 units are arranged side by side. Each LLM35 has a housing, which is connected to the loader module 31 and the first vacuum transport module 41 via gate valves G located on its front and rear sides, respectively. With the front and rear gate valves G of the housing closed, the pressure inside the housing can be freely changed between atmospheric pressure and vacuum pressure. Inside the housing of the LLM35 is a stage (not shown) on which the wafer A is placed, and this stage is configured to be able to transfer the wafer A to the transport mechanism 32 and the transport mechanism 44 (described later), which access the LLM35, respectively.

[0029] The first vacuum transport module 41 and the second vacuum transport module 42 are configured similarly to each other and each comprises a housing 41A and 42A, respectively. The insides of housings 41A and 42A are evacuated by an exhaust mechanism (not shown). In this example, two connection modules 43 are provided side by side. Each connection module 43 comprises a housing 43A, which is connected to the housings 41A and 42A of the vacuum transport modules 41 and 42, respectively.

[0030] The exhaust mechanism described above creates a vacuum atmosphere inside the housing 43A of the connection module 43, with the same pressure as inside the housings 41A and 42A. A wafer A is placed inside housing 43A, and a stage (not shown) is provided that is configured to allow the transfer of the wafer A to and from the transfer mechanism 44, which will be described later. Hereafter, the insides of housings 41A, 42A, and 43A, which are in a vacuum atmosphere, will be collectively referred to as the vacuum transfer path 40. An inert gas supply mechanism is also provided to supply an inert gas to the vacuum transfer path 40, and the pressure in the vacuum transfer path 40 is adjusted to a desired vacuum pressure by supplying and exhausting this inert gas.

[0031] Two processing modules are arranged front to back on the left and right sides of the housings 41A of the first vacuum transport module 41 and 42A of the second vacuum transport module 42, respectively, and each processing module is connected to the housing 41A or 42A via a gate valve G1. In this example, processing module 51 is connected to housing 41A, and processing module 52 is connected to housing 42A.

[0032] Each housing 41A and 42A is provided with a transport mechanism 44, each transport mechanism 44 consisting of, for example, a multi-jointed arm that can move back and forth. The transport mechanism 44 in housing 41A transfers wafer A between the LLM 35, the connection module 43, and each processing module connected to housing 41A via a gate valve G1. The transport mechanism 44 in housing 42A transfers wafer A between the connection module 43 and each processing module connected to housing 42A via a gate valve G1. The gate valves G and G1 are closed except when necessary for the transfer of wafer A between modules, separating the atmosphere between modules. Each stage of the load lock module 35 and the connection module 43 is provided with, for example, pins that can be extended or retracted onto the stage to allow for the transfer of wafer A to and from the transport mechanism.

[0033] The substrate processing apparatus 3 is equipped with a control unit 30, which is a computer, and this control unit 30 is equipped with a program. The program incorporates instructions (each step) for processing wafer A in each processing module 51, 52 and for transporting wafer A in the substrate processing apparatus 3. This program is stored in a storage medium, such as a compact disk, hard disk, DVD, etc., and installed in the control unit 30. The control unit 30 outputs control signals to each part of the substrate processing apparatus 3 using this program, and controls the operation of each part. Specifically, it controls the operation of processing modules 51, 52, the opening and closing of gate valves G, G1, the operation of transport mechanisms 32, 44, the operation of the exhaust mechanism, the operation of the inert gas supply mechanism, and the switching of pressure in LLM 35. The control of the operation of processing modules 51, 52 includes temperature control of wafer A on the stage 66 by supplying power to heater 67 (described later), switching control of supply and stop of supply of each gas into the processing container 61 by opening and closing valve V, and switching of high-frequency power supplies 69, 75 on and off.

[0034] <Configuration of processing module 51> The processing module 51 will be described with reference to Figure 7, which is a longitudinal cross-sectional side view. The processing module 51 is a capacitively coupled plasma processing apparatus and is equipped with a metal processing vessel 61, which is grounded. A wafer A transport port 62 is provided in the side wall of the processing vessel 61, and this transport port 62 is opened and closed by the gate valve G1 described above. In the processing vessel 61, a heater 63 for adjusting the temperature inside the processing vessel 61 is embedded in the shower head 71, which will be described later and constitutes the side wall and ceiling wall. One end of an exhaust passage 64 is open at the bottom of the processing vessel 61, and the other end of the exhaust passage 64 is connected to an exhaust mechanism 65 which includes a valve and a vacuum pump. The exhaust mechanism 65 exhausts the inside of the processing vessel 61 to create a vacuum atmosphere at a desired pressure.

[0035] A stage 66 is provided inside the processing container 61, and the wafer A is placed on the stage 66 so that it is horizontal. Above the stage 66 is a processing space 70 to which gas is supplied from a shower head 71, which will be described later. A heater 67 is embedded in the stage 66 as a heating mechanism, and the placed wafer A is heated by the heater 67 to a preset processing temperature. The stage 66 is also configured as a lower electrode, and a high-frequency power supply 69 that supplies high-frequency power for bias application (for plasma ion pull) is connected to the stage 66 via a matching unit 68. Although not shown in the figure, three pins that can be extended and retracted from the upper surface of the stage 66 by a lifting mechanism are provided, and the wafer A can be transferred between the upper surface of the stage 66 and the transport mechanism 44 described above via these pins.

[0036] Furthermore, a shower head 71 is provided so as to form the ceiling wall of the processing container 61 and is attached to the processing container 61 via an insulating member 79. The shower head 71 has a gas diffusion space 72 and a number of discharge ports 73 that open downwards to discharge the gas supplied from the diffusion space 72 toward the processing space 70. The shower head 71 is configured as an upper electrode, and a high-frequency power supply 75 that supplies high-frequency power for plasma formation is connected to the shower head 71 via a matching unit 74.

[0037] High-frequency power of a predetermined frequency is supplied from the high-frequency power supply 75 to the shower head 71, causing the gas supplied from the shower head 71 to the processing space 70 to be turned into plasma. While high-frequency power is supplied from the high-frequency power supply 75, high-frequency power is supplied from the high-frequency power supply 69 to the stage 66, drawing in the ions that make up the plasma toward the stage 66. The frequency of the high-frequency power supplied from the high-frequency power supply 75 to the shower head 71 is higher than the frequency of the high-frequency power supplied from the high-frequency power supply 75 to the stage 66.

[0038] Furthermore, the downstream end of the gas channel 76 is connected to the diffusion space 72 of the showerhead 71. The upstream side of the gas channel 76 branches to form gas channels 81 to 83. The upstream end of gas channel 81 is connected to the TiCl4 gas supply source 81A, the upstream end of gas channel 82 is connected to the Ar (argon) gas supply source 82A, and the upstream end of gas channel 83 is connected to the H2 (hydrogen) gas supply source 83A. For each of the gas channels 81 to 83, a flow rate adjustment unit M, consisting of a valve V, a mass flow controller, etc., is sequentially installed facing upstream. By opening and closing the valve V, the supply and cessation of each gas from each gas supply source 81A to 83A to the processing space 70 via the showerhead 71 is switched. The flow rate adjustment unit M adjusts the flow rate of each gas supplied to the processing space 70 to a preset amount.

[0039] <Configuration of other processing modules> Processing module 52 has a configuration that is generally similar to processing module 51, except that a WCl5 gas supply source is provided instead of the TiCl4 gas supply source 81A. WCl5 gas is supplied from the WCl5 gas supply source to the processing space 70 via a flow path interposed by a valve V and a flow rate adjustment unit M, and processing is performed on wafer A. Furthermore, processing module 52 does not perform plasma processing on wafer A and therefore differs from processing module 51 in that it does not have high-frequency power supplies 75 and 69.

[0040] In processing module 51, the TiCl4 gas supply source 81A, the valve V and flow rate adjustment unit M provided in the gas flow path 81 constitute a first processing gas supply unit for forming the TiSi film 14. Furthermore, the TiCl4 gas supply source 81A, the Ar gas supply source 82A, the valve V and flow rate adjustment unit M provided in the gas flow paths 81 and 82, and the high-frequency power supply 75 for plasmaizing the gas constitute a plasma etching gas supply unit for supplying plasmaized etching gas for etching the Ti film 15. The H2 gas supply source 83A, the valve V and flow rate adjustment unit M provided in the gas flow path 83, and the high-frequency power supply 75 constitute a second processing gas supply unit for modifying the side walls of the recess 13. Each of this second processing gas supply unit and the plasma etching gas supply unit described above corresponds to a plasma processing unit. In addition, the WCl5 gas supply source in processing module 52, the valve V and flow rate adjustment unit M provided in the WCl5 gas flow path constitute a first film deposition gas supply unit. The plasma treatment process in step S2 corresponds to a plasma etching process, and the plasma treatment process in step S2A corresponds to a sidewall treatment process. The process in step S3 corresponds to a film deposition process for forming a multilayer metal film.

[0041] <Operation of the substrate processing device 3> The operation of the substrate processing apparatus 3 will be described assuming that the processing of wafer A according to the second embodiment is performed on wafer A. Wafer A is unloaded from the transport container 34 and transported in the order of loader module 31 → LLM 35 → vacuum transport path 40. After that, wafer A is placed on the stage 66 of the processing module 51 and heated to a predetermined processing temperature, for example, 450°C. TiCl4 gas, H2 gas, and Ar gas are supplied to the processing space 70 of the processing module 51, and the pressure of the processing space 70 is set to, for example, 5 Torr (6.67 × 10⁻⁶). 2 The state is set to Pa). Meanwhile, high-frequency power is supplied from the high-frequency power supplies 75 and 69 to the shower head 71 and stage 66, respectively, causing the gases to be plasma-generated and ions to be drawn into the wafer A in the plasma. As a result, the wafer A described in Figure 1 is subjected to the process of step S1 described in Figure 2A, and a TiSi film 14 is formed on the bottom wall of the recess 13.

[0042] Subsequently, the supply of H2 gas to the processing space 70 is stopped, and the supply of TiCl4 gas and Ar gas, and the supply of high-frequency power from high-frequency power supplies 75 and 69 are continued while the pressure in the processing space 70 is maintained at, for example, 5 Torr, and step S2 is performed instead of step S1. That is, the Ti film 15 formed on the side wall of the recess 13 during the processing of step S1 is etched. Subsequently, the pressure in the processing space 70 is set to, for example, 9 Torr (1.2 × 10⁻⁶). 3 As the temperature reaches Pa, the gas supplied to the processing space 70 changes from TiCl4 gas and Ar gas to H2 gas, and step S2A is performed, forming a TiSiN film 21 on the side wall of the recess 13.

[0043] Subsequently, the cycle consisting of steps S2 and S2A, as described in Figure 4, is repeated by changing the pressure in the processing space 70 and changing the gas supplied to the processing space 70. When this cycle is repeated a predetermined number of times, the supply of each gas to the processing space 70 and the supply of high-frequency power from the high-frequency power supplies 75 and 69 are stopped, and wafer A is transported from processing module 51 to processing module 52 via the vacuum transport path 40. The pressure in the processing space 70 of processing module 52 is, for example, 50 Torr (6.67 × 10⁻¹⁰). 3 With the wafer A heated to, for example, 450°C (Pa), WCl5 gas, H2 gas, and Ar gas are supplied to the processing space 70, and the process shown in step S3 in Figure 5A is carried out to form the W film 16 which is to be laminated on the TiSi film 14. After that, the supply of these gases to the processing space 70 is stopped, and the wafer A is transported in the order of vacuum transport path 40 → LLM 35 → loader module 31 and returned to the transport container 34.

[0044] The transport container 34 is transported through an atmospheric environment by a transport mechanism for transport containers to a substrate processing apparatus (for convenience, referred to as substrate processing apparatus 3A) separate from the substrate processing apparatus 3, where step S4 is performed. Specifically, the W film 17 is filled into the recess 13 as shown in Figure 5B by the supply of WF6 gas. The substrate processing apparatus 3A has the same configuration as the substrate processing apparatus 3, except that it includes a processing module (for convenience, referred to as processing module 53) for performing step S4, and the substrate processing apparatuses 3 and 3A constitute a substrate processing system for processing wafer A. The processing module 53 is configured similarly to processing modules 51 and 52, except that it includes a gas supply source capable of supplying WF6 gas to wafer A.

[0045] When processing wafer A in the first embodiment using the substrate processing apparatus 3, the processing module 51 should perform the same processing and transport as described above for wafer A, except that it performs only step S2 of steps S2 and S2A. The configuration of the substrate processing apparatus 3 can be changed as appropriate. For example, a processing module for removing the native oxide film formed on the surface of the Si layer 11 before the processing of step S1 may be provided in place of some of the multiple processing modules 51 or some of the multiple processing modules 52. In addition, the multiple processing modules connected to the vacuum transport path 40 of the substrate processing apparatus 3 may include a processing module 53 for filling the W film 17 as described above, and by providing the processing module 53 in this way, the series of processes from steps S1 to S4 may be performed within the substrate processing apparatus 3.

[0046] Furthermore, steps S1, S2, and S2A are not limited to being performed in the same processing module 51, but may be performed in separate processing modules. However, since TiCl4 and Ar gas are commonly used in steps S1 and S2, and H2 gas is commonly used in steps S2 and S2A, it is preferable to perform steps S1, S2, and S2A in the same processing module 51 from the viewpoint of preventing an increase in manufacturing costs due to the provision of a mechanism to supply the same type of gas to each processing module. It is also preferable to perform steps S1, S2, and S2A in the same processing module 51 from the viewpoint of reducing the time required to transport wafer A and obtaining high throughput for the substrate processing apparatus 3.

[0047] By the way, in the second embodiment, we have described that both step S2, in which the Ti film 15 is etched, and step S2A, in which the TiSiN film 15 is formed, are performed. However, it is also possible to perform only step S2A. Therefore, it is not limited to etching the Ti film 15 between the formation of the TiSi film 14 in step S1 and the formation of the W film 16 in step S3. However, as mentioned above, if the thickness of the Ti film 15 is large, the modification effect on the side walls of the recess 13 is reduced, so it is preferable to perform both steps S2 and S2A.

[0048] Furthermore, if the formation of the TiSiN film 21 in step S2A and the etching of the Ti film 15 are performed between step S1 and step S3, the etching of the Ti film 15 is not limited to plasma treatment as shown in the second embodiment. In other words, the etching of the Ti film 15 may be performed by supplying each gas, including the etching gas, without plasma formation. Specifically, for example, the etching of the Ti film 15 may be performed by supplying TiCl4 gas and H2 gas to wafer A without plasma formation.

[0049] If the process of supplying non-plasma TiCl4 gas and H2 gas is designated as step S2B, then in the process of performing both steps S2 and S2A as described in the second embodiment, step S2B can be performed instead of step S2. In other words, the order in which step S2A and S2B are performed does not matter, the process may be performed as a cycle in which one of steps S2A and S2B is performed sequentially, or steps S2A and S2B may be performed once each without being repeated as a cycle. However, as mentioned above, from the viewpoint of throughput, it is preferable to perform step S2, which is a plasma process, rather than step S2B, which is a non-plasma process.

[0050] Incidentally, when performing the modification treatment of the side walls of the recesses 13 in step S2A, the use of H2 gas plasma is not limited to that which is used; for example, plasma of an inert gas such as Ar gas or N2 (nitrogen) gas may also be used. However, when a gas with a relatively large molecular weight, such as Ar gas or N2 gas, is plasma-formed and supplied to wafer A, there is a risk that the etching effect on the TiSi film 14 will be relatively large. Also, because of the large molecular weight, the plasma does not easily penetrate into the side walls of the recesses 13, so the modification effect may be relatively small. Therefore, in order to suppress etching of the TiSi film 14 and obtain a high modification effect, it is preferable to perform step S2A by plasma-forming H2 gas, which has a relatively small molecular weight.

[0051] Furthermore, in step S2, as described above, the Ti film 15 is etched by the action of chlorine and chlorine-activated species. Therefore, the Ti film 15 may be etched by supplying a metal chloride gas other than TiCl4 gas to wafer A and plasma-generating the gas. Specifically, for example, gases such as ZrCl4, WCl5, TaCl5, and MoCl5 may be supplied to wafer A and plasma-generating these gases to etch the Ti film 15. Thus, the etching gas is not limited to TiCl4 gas. However, it is preferable to use TiCl4 gas, which is the gas used for forming the TiSi film 14 in step S1, as the etching gas in step S2, from the viewpoint of preventing complexity of the apparatus configuration and preventing an increase in the manufacturing cost of the apparatus. For the same reason, in step 2B, which is a non-plasma etching process as described above, the etching gas is not limited to TiCl4 gas, but it is preferable to use TiCl4 gas as the etching gas.

[0052] Although steps S2 and S2A are shown assuming that the Ti film 15 is deposited on the entire sidewall of the recess 13 in step S1, the Ti film 15 is not limited to covering the entire sidewall in this way, and may be scattered on the sidewall. Also, the silicon layer 11 on which the TiSi film 14 is formed in step S1 may be the wafer A itself, or a film formed on the wafer A. Furthermore, the formation of the TiSi film 14 in step S1 is not limited to plasma treatment, but may also be performed by heat treatment without plasma. However, when forming a metal silicide film such as this TiSi film 14, it is preferable to perform it by plasma treatment from the viewpoint of preventing a decrease in throughput. Regarding the deposition of the W films 16 and 17 in steps S3 and S4, steps S3 and S4 are not limited to non-plasma treatment, but may also be performed by plasma treatment. Furthermore, the W films 16 and 17 are not limited to being deposited by CVD, but may also be deposited by ALD.

[0053] Furthermore, although an example of forming a TiSi film 14 as a metal silicide film in step S1 was shown, the metal silicide film formed in step S1 is not limited to a TiSi film; for example, a ZrSi film may be formed using plasma-induced ZrCl4 gas. Therefore, the metal to be etched from the side wall of the recess 13 in step S2 is the metal used to form this metal silicide, and step S2 is not limited to etching Ti. The formation of the metal nitride silicide in step S2A is also the formation of a metal nitride silicide using the metal (first metal) used to form the metal silicide in step S1, and is not limited to forming a TiSiN film 21.

[0054] Furthermore, although step S3 is shown as forming a W film 16 on the metal silicide film by supplying WCl5 gas, the laminated metal film formed on the metal silicide film is not limited to a W film 16; for example, a Mo (molybdenum) film may also be formed. In the case of forming a Mo film instead of a W film 16, step S3 can be performed by supplying a gas containing Mo, such as MoCl5 (molybdenum pentachloride) gas, MoO2Cl2 gas, or MoOCl4 gas, to wafer A instead of WCl5 gas to perform the film formation. Then, step S4 can be performed as a step of supplying a gas such as MoF6 (molybdenum hexafluoride) to wafer A to form a Mo film and fill the recess 13 with the Mo film.

[0055] Since MoCl5 has the same molecular structure as WCl5 except that its constituent element is Mo instead of W, supplying MoCl5 gas to wafer A will result in the same phenomena as when WCl5 gas is supplied to wafer A. That is, if a Ti film 15 is formed on the side wall of the recess 13 when MoCl5 gas is supplied to wafer A, a Mo film will be formed on this Ti film 15, which may cause problems in subsequent processing. However, even if MoCl5 gas is supplied to the SiN film 12 or TiSiN layer 21, the formation of a Mo film on these SiN films 12 and TiSiN layers 21 is suppressed.

[0056] Therefore, when MoCl5 gas is supplied to wafer A instead of WCl5 gas in step S3, performing steps S2 and S2A before step S3 suppresses the formation of the Mo film on the sidewall of the recess 13, preventing defects in the embedding of the Mo film into the recess 13 during the execution of step S4. For this reason, this technique is particularly effective when forming a Mo film in the recess 13, as well as when forming W films 16 and 17 in the recess 13. Note that the gas used to form the W film 16 or W film 17 is not limited to the gases described above; for example, WCl6 gas, WOCl4 gas, WO2Cl2 gas, etc., may also be used.

[0057] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The above embodiments may be omitted, replaced, modified, and / or combined in various ways without departing from the scope and spirit of the appended claims.

[0058] <Evaluation Test> The evaluation tests related to this technology are described below. In these evaluation tests, regarding the processing of the second embodiment, the order of steps S2 and S2A in one cycle differs from the order described in Figure 4, with S2A being performed first and S2 being performed later.

[0059] • Evaluation Test 1 As evaluation test 1-1, steps S1, S3, and S4 were performed on wafer A shown in Figure 1, and an SEM image of wafer A after processing was acquired to observe the state of the bottom and sides of the recess 13. As evaluation test 1-2, the same processing as in evaluation test 1-1 was performed on wafer A shown in Figure 1, except that step S2 was also performed, and an SEM image was acquired to observe the state of the bottom and sides of the recess 13. Therefore, in evaluation test 1-2, the processing of the first embodiment (i.e., the processing of steps S1 to S4) was performed on wafer A. As evaluation test 1-3, the same processing as in evaluation test 1-1 was performed on wafer A shown in Figure 1, except that steps S2 and S2A were also performed, and an SEM image was acquired to observe the state of the bottom and sides of the recess 13. Therefore, in evaluation test 1-3, the processing of the second embodiment was performed on wafer A.

[0060] In evaluation test 1-2, the etching time in step S2 (the time wafer A is exposed to the TiCl4 gas and Ar gas plasma) was set to 300 seconds. In evaluation test 1-3, the execution time for one cycle (the sum of the execution time for one step S2A and one step S2) was set to 50 seconds. The number of cycles was set to 3. Therefore, steps S2A and S2 were performed alternately three times each.

[0061] Observations revealed that in evaluation test 1-1, the thickness of the W film 16 formed at the bottom of the recess 13 was 3.3 nm, and the thickness of the W film formed on the sidewall of the recess 13 was 2.6 nm. In evaluation test 1-2, the thickness of the W film 16 formed at the bottom of the recess 13 was 3.9 nm, and the thickness of the W film formed on the sidewall of the recess 13 was 1.2 nm. In evaluation test 1-3, the thickness of the W film 16 formed at the bottom of the recess 13 was 7.2 nm, and the thickness of the W film formed on the sidewall of the recess 13 was 1.6 nm. As described above, the ratio of the thickness of the W film 16 at the bottom of the recess 13 to the thickness of the W film on the sidewall of the recess 13 is 1-3 > 1-2 > 1-1. Therefore, in evaluation tests 1-2 and 1-3, the formation of the W film 16 at the bottom of the recess 13 was suppressed while the formation of the W film on the sidewall of the recess 13 was achieved, confirming the effectiveness of this technology. Comparing the results of evaluation tests 1-2 and 1-3, it can be seen that the W film deposition on the sidewalls of the recess 13 was suppressed by the treatment in step S2A.

[0062] • Evaluation Test 2 As part of evaluation test 2-1, multiple substrates with flat Si films formed on their surfaces were prepared, and a Ti film was formed on each substrate by performing the same process as in step S1. Subsequently, each substrate was subjected to the same etching process as in step S2. That is, the Ti film was etched using plasma-induced TiCl4 and Ar gas. This etching of the Ti film was performed with different etching times set for each substrate, and after etching, the amount of etching of the Ti film was measured by X-ray fluorescence analysis (XRF). Furthermore, as part of evaluation test 2-2, the same test as in evaluation test 2-1 was performed, except that a substrate with a flat SiN film formed on its surface was used. Therefore, in evaluation test 2-2, the etching process was performed on the Ti film formed on the SiN film.

[0063] Figure 8 is a graph showing the results of evaluation test 2. As shown in the graph, both evaluation tests 2-1 and 2-2 confirmed that the Ti film could be etched by processing with plasma-induced TiCl4 and Ar gas. In evaluation test 2-1, the amount of etching increased with increasing etching time, whereas in evaluation test 2-2, the amount of etching increased with increasing etching time within a relatively short range, but remained constant within a relatively long range. This is because the thickness of the Ti film formed on the SiN film was smaller than that formed on the Si film, and in evaluation test 2-2, the entire Ti film was etched on substrates where the etching time was set to a relatively long time. From the results of evaluation test 2, it can be confirmed that the Ti film 15 formed on the side walls of the recesses 13 formed by the SiN film 12 can be etched by performing step S2 as described in embodiments 1 and 2.

[0064] • Evaluation Test 3 As Evaluation Test 3, multiple substrates with flat SiN films formed on their surfaces were prepared, and Ti films were formed on these SiN films using the same method as in step S1 of the embodiment. Subsequently, some of the substrates were treated using the same method as in step 2A of the embodiment. That is, they were exposed to an H2 gas plasma. The treatment time for exposure to the H2 gas plasma was set differently for each substrate. Then, each substrate was analyzed by X-ray photoelectric spectroscopy (XPS). Of the above Evaluation Test 3, the test in which the substrates were not exposed to the H2 gas plasma was designated as Evaluation Test 3-1, and the tests in which the H2 plasma treatment time was set to 90 seconds, 180 seconds, and 270 seconds were designated as Evaluation Tests 3-2, 3-3, and 3-4, respectively.

[0065] Figure 9 is a graph showing the results of evaluation test 3, with the horizontal axis representing binding energy (unit: eV) and the vertical axis representing intensity (unitless). The spectral intensity at 460-459 eV indicates the amount of TiOx, and the intensity for evaluation tests 3-1 > 3-2 > 3-3 > 3-4. This TiOx is generated from Ti and TiSi when the substrate is exposed to air during XPS measurement, so it is estimated that the amounts of Ti and TiSi before XPS measurement were in evaluation tests 3-1 > 3-2 > 3-3 > 3-4. Furthermore, the spectral intensity at 456 eV indicates the amount of TiN and TiSiN, and the intensity for evaluation tests 3-2, 3-3, and 3-4 is greater than that for evaluation test 3-1. The difference in intensity among evaluation tests 3-2, 3-3, and 3-4 is slight, but the intensity of evaluation test 3-4 is the highest, followed by evaluation test 3-3.

[0066] The results of this evaluation test 3 showed that exposure of the substrate to an H2 gas plasma resulted in mixing of Ti, an element constituting the Ti film, and Si and N, elements constituting the SiN film. Therefore, it was confirmed that by performing the process in step S2A of the second embodiment, a TiSiN film 21 can be formed from the SiN constituting the side wall of the recess 13 and the Ti film 15 on the side wall.

[0067] • Evaluation Test 4 As part of evaluation test 4-1, multiple substrates with flat SiN films formed on their surfaces were prepared, and Ti films were formed on these SiN films using the same method as in step S1 of the embodiment. Subsequently, the Ti films were etched using the same method as in step S2 of the embodiment, and then a W film was deposited on the substrate using the same method as in step S3 of the embodiment. The deposition time for the W film (the time for supplying WCl5 gas to the substrate) was varied for each substrate. The film thickness of the W film and the Ti film formed on each substrate were then measured using XRF. Furthermore, as evaluation test 4-2, the same test as evaluation test 4-2 was performed, except that the etching of the Ti film was not performed.

[0068] The graphs in Figures 10 and 11 show the results of this evaluation test 4. In the graph in Figure 10, the horizontal axis is set to the deposition time of the W film (in seconds), and the vertical axis is set to the measured thickness of the W film (in nm). In the graph in Figure 11, the horizontal axis is set to the deposition time of the W film (in seconds), and the vertical axis is set to the measured thickness of the Ti film (in nm). From the graph in Figure 11, it can be seen that for each substrate in evaluation test 4-2, the W film was deposited on top of the Ti film that had already been formed. Furthermore, from the graph in Figure 10, it can be seen that in evaluation test 4-2, the thickness of the W film increased as the deposition time increased. On the other hand, from the graph in Figure 11, it can be seen that for each substrate in evaluation test 4-1, the W film deposition process was performed on the substrate when no Ti film had been formed or when only a small amount of Ti film had been formed. Furthermore, from the graph in Figure 10, it can be seen that in evaluation test 4-1, the thickness of the W film was 0 regardless of the deposition time. In other words, no W film was formed on any of the substrates in evaluation test 4-1.

[0069] The results of this evaluation test 4 showed that when a Ti film is formed on a SiN film, a W film is formed on the SiN film, while when a Ti film is not formed on the SiN film, a W film is not formed on the SiN film. Therefore, it was confirmed that etching the Ti film 15 on the side wall of the recess 13 by performing step S2 as described in the first and second embodiments is effective in preventing the W film from forming on the side wall of the recess 13 when step S3 is executed.

[0070] • Evaluation Test 5 As part of evaluation test 5-1, the Ti films on multiple substrates, each with a Ti film formed on it, were etched using the same method as in step S2 of the embodiment. In other words, in evaluation test 5-1, TiCl4 gas and Ar gas were supplied to the substrates, and these gases were converted into plasma to etch the Ti films. The etching time (the time the substrate was exposed to the TiCl4 gas and Ar gas plasma) was varied for each substrate. After etching, the amount of etching of the Ti film on each substrate was measured.

[0071] Furthermore, in evaluation test 5-2, the Ti films on multiple substrates, each with a Ti film formed on it, were etched using the same method as in step S2B of the embodiment. In other words, in evaluation test 5-2, TiCl4 gas and Ar gas were supplied, and the Ti films were etched by heat treatment without plasma generation of these gases. The etching time (the supply time of TiCl4 gas and Ar gas to the substrate) was changed for each substrate. Except for the fact that the gases were not plasma-generated and the etching time for some substrates differed from the etching time for the substrates in evaluation test 5-1, the substrates in evaluation test 5-2 were processed under the same processing conditions as in evaluation test 5-1.

[0072] Furthermore, in evaluation test 5-3, Ar gas alone was supplied to multiple substrates, each with a Ti film formed on it, and the Ar gas was turned into a plasma to etch the Ti film. In this evaluation test 5-3 as well, different etching times (the time the substrate was exposed to the Ar gas plasma) were set for each substrate. Except for the fact that the Ar gas was not turned into a plasma and the etching times for some substrates differed from those for the substrates in evaluation test 5-1, the substrates in evaluation test 5-3 were processed under the same conditions as in evaluation test 5-1.

[0073] Figure 12 is a graph showing the results of evaluation tests 5-1 and 5-2, and Figure 13 is a graph showing the results of evaluation tests 5-2 and 5-3. In these graphs, the horizontal axis is set to etching time (in seconds), and the vertical axis is set to the amount of etching of the Ti film (in nm). As shown in the graph of Figure 12, the amount of etching of the Ti film is greater in evaluation test 5-1 than in evaluation test 5-2 at each etching time. Therefore, it was confirmed that etching the Ti film 15 of the recess 13 by plasma treatment in step S2, as described in the embodiment, can increase the throughput of the apparatus compared to etching the Ti film 15 without performing the plasma treatment described as step S2B.

[0074] Furthermore, as shown in the graph in Figure 13, the amount of etching of the Ti film is greater in evaluation test 5-1 than in evaluation test 5-3 at each etching time. Comparing the results of evaluation tests 5-2 and 5-3 from Figures 12 and 13, there is no significant difference in the amount of etching between evaluation tests 5-2 and 5-3 when the etching time is the same. From these results, it can be seen that the etching effect of the Ti film is largely due to the plasma-generated TiCl4 gas. When TiCl4 gas is plasma-generated, unlike when it is not plasma-generated, chlorine and chlorine-activated species are generated, as described in the embodiment. The generation of chlorine and chlorine-activated species has also been confirmed by simulation.

[0075] Therefore, from the results of these evaluation tests 5-1 to 5-3, it can be inferred that chlorine and chlorine reactive species contribute significantly to the etching of the Ti film. Furthermore, simulations have confirmed that chlorine gas and chlorine reactive species react with Ti within the temperature range of 0°C to 1000°C. In summary, evaluation test 5 demonstrates that in etching the Ti film 15 on the side wall of the recess 13 in the embodiment, treating it by plasma-forming a metal chloride gas such as TiCl4 gas is effective in increasing the etching rate of the Ti film.

[0076] • Evaluation Test 6 As evaluation test 6-1, a Ti film was deposited on a substrate on which a Si film had been formed to form a TiSi film. The same process as in step S3 of the embodiment (i.e., supply of WCl5 gas) was performed, and the thickness of the W film formed on the TiSi film was measured. As evaluation test 6-2, a TiSi film was formed by nitriding the TiSi film formed in the same manner as in evaluation test 6-1 to form a TiSiN film. Thereafter, the same process as in step S3 of the embodiment was performed, and the thickness of the W film formed on the TiSiN film was measured. In both evaluation tests 6-1 and 6-2, the film deposition time for the W film was varied for each substrate.

[0077] Figure 14 is a graph showing the results of evaluation test 6, with the W film deposition time (in seconds) on the horizontal axis and the W film thickness (in nm) on the vertical axis. As shown in this graph, in evaluation test 6-1, the W film thickness increased as the deposition time increased. On the other hand, in evaluation test 6-2, the W film thickness was 0 nm regardless of the deposition time, meaning that no W film was formed. Therefore, from the results of evaluation test 6 and the aforementioned evaluation test 3, it is shown that by performing step S2A as described in the embodiment and forming the TiSiN film 21 on the side wall of the recess 13, it is possible to prevent the formation of the W film on the side wall when performing the subsequent step S3. [Explanation of Symbols]

[0078] A wafer 11 Silicon layer 12. Silicon nitride film (SiN film) 13 recess 14. Titanium silicide film (TiSi film) 16 W membrane 21 Titanium nitride silicide film (TiSiN film)

Claims

1. A step of supplying a first processing gas containing a first metal to a substrate having a recess in which a semiconductor layer containing silicon is exposed at the bottom surface and the side walls are formed by an insulating film, thereby forming a metal silicide film that forms the bottom wall of the recess, A plasma treatment step comprising: a plasma etching step of supplying plasma-generated etching gas to the substrate to remove the film of the first metal on the side wall of the recess; and a side wall treatment step of supplying plasma-generated second treatment gas to the substrate to form a metal-containing film on the side wall of the recess in which the first metal and the elements constituting the insulating film are mixed; and at least one of these steps. A film deposition step is performed in which a first film deposition gas containing a second metal is supplied to the substrate after the plasma treatment step is performed to form a laminated metal film to be laminated on the metal silicide film, A substrate processing method comprising the following:

2. The film formation process is stopped before the laminated metal film is filled into the recess. The substrate processing method according to claim 1, further comprising the step of supplying a second film-forming gas, which is a compound different from the first film-forming gas, to the substrate after the film-forming step to fill the recesses with a metal film.

3. The substrate processing method according to claim 1, wherein the plasma processing step includes the plasma etching step, and the etching gas is a metal chloride gas.

4. The first metal is titanium, The aforementioned metal silicide film is a titanium silicide film. The substrate processing method according to claim 3, wherein the first processing gas and the etching gas contain titanium tetrachloride.

5. The plasma treatment step includes the side wall treatment step, The aforementioned insulating film is a silicon nitride film. The substrate processing method according to claim 1, wherein the metal-containing film is a metal nitride silicide film.

6. The substrate processing method according to claim 5, wherein the second processing gas is hydrogen gas.

7. The substrate processing method according to claim 5, further comprising an etching step of supplying an etching gas that has not been plasma-treated to the substrate after forming a metal silicide film and before forming the laminated metal film, to remove the first metal film on the side walls of the recesses.

8. The first metal is titanium, The aforementioned metal silicide film is a titanium silicide film. The substrate processing method according to claim 7, wherein the first processing gas and the non-plasma-treated etching gas are titanium tetrachloride gas.

9. The substrate processing method according to claim 1, wherein the plasma processing step includes the plasma etching step and the metal-containing film formation step.

10. The substrate processing method according to claim 9, wherein the plasma etching step is performed first, and the metal-containing film formation step is performed later.

11. The substrate processing method according to claim 9, wherein a cycle is repeated in which one of the plasma etching step and the metal-containing film formation step is performed in sequence, and the other is performed in sequence.

12. The substrate processing method according to claim 1, wherein the first metal is tungsten and the laminated metal film is a tungsten film, or the second metal is molybdenum and the laminated metal film is a molybdenum film.

13. A processing container for storing the substrate, A substrate having a recess in which a semiconductor layer containing silicon is exposed at the bottom surface and the side walls are formed by an insulating film, a first processing gas supply unit supplies a first processing gas containing a first metal into the processing container in order to form a metal silicide film that forms the bottom wall of the recess, A plasma processing unit comprising at least one of the following: a plasma etching gas supply unit that supplies plasma-generated etching gas into the processing container to remove the film of the first metal on the side wall of the recess; and a second processing gas supply unit that supplies plasma-generated second processing gas into the processing container to form a metal-containing film on the side wall of the recess in which the first metal and the elements constituting the insulating film are mixed; A film deposition gas supply unit supplies a first film deposition gas containing a second metal into the processing container in order to form a laminated metal film to be laminated on the metal silicide film of the substrate processed by the plasma processing unit, A substrate processing apparatus equipped with the following:

Images