Substrate processing method and substrate processing apparatus

Abstract

To suppress the silicide formation of the Si-containing layer when a first metal film made of a metal other than Ru, which is deposited on a Si-containing layer exposed on the surface of a substrate, is silicided. [Solution] The substrate processing method of the present disclosure includes the steps of forming a first metal film made of a metal other than Ru on a Si-containing layer exposed on the surface of a substrate, and supplying Si elements to the substrate and forming a metal silicide film from the Si elements and the first metal film.

Description

【Technical Field】 【0001】 The present disclosure relates to a substrate processing method and a substrate processing apparatus. 【Background Art】 【0002】 In manufacturing a semiconductor device, on the surface of a semiconductor wafer (hereinafter referred to as a substrate) which is a substrate, after forming a concave portion in order to provide a wiring layer, various metal films are formed. In order to reduce the contact resistance between the wiring layer and the Si (silicon) - containing layer of the substrate, it is known to form a metal film such as a Ti (titanium) film at the bottom of the concave portion to form a silicide. 【0003】 Patent Document 1 describes depositing Ti by sputtering at the bottom of a connection hole provided on the surface of a substrate, then depositing Ti in the connection hole by plasma CVD, and further performing embedding of Al (aluminum) to form a wiring. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Unexamined Patent Application Publication No. 10 - 223570 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 The present disclosure provides a technique capable of suppressing silicidation of a Si - containing layer when siliciding a first metal film made of a metal other than Ru formed on a Si - containing layer exposed on the surface of a substrate. 【Means for Solving the Problems】 [[ID=৪৪]] 【0006】 The substrate processing method of the present disclosure includes a step of forming a first metal film made of a metal other than Ru on a Si - containing layer exposed on the surface of a substrate, and a step of supplying Si element to the substrate and forming a metal silicide film from the Si element and the first metal film. [Effects of the Invention] 【0007】 This disclosure makes it possible to suppress the silicide formation of the Si-containing layer when a first metal film made of a metal other than Ru, which is deposited on a Si-containing layer exposed on the surface of a substrate, is silicided. [Brief explanation of the drawing] 【0008】 [Figure 1] This is a longitudinal cross-sectional side view showing the surface layer of the substrate before processing in the embodiment and comparative form. [Figure 2A] This is a partial cross-sectional view of the substrate surface layer, showing how it changes depending on the processing method used for comparison. [Figure 2B] This is a partial cross-sectional view of the substrate surface layer, showing how it changes depending on the processing method used for comparison. [Figure 2C] This is a partial cross-sectional view of the substrate surface layer, showing how it changes depending on the processing method used for comparison. [Figure 3] This is a longitudinal cross-sectional side view showing the surface layer of the substrate after processing for comparison. [Figure 4A] This is a partial cross-sectional view of the substrate W, which changes depending on the processing of the embodiment. [Figure 4B] This is a partial cross-sectional view of the substrate W, which changes depending on the processing of the embodiment. [Figure 5A] This is a partial cross-sectional view of the substrate W, which changes depending on the processing of the embodiment. [Figure 5B] This is a partial cross-sectional view of the substrate W, which changes depending on the processing of the embodiment. [Figure 5C] This is a partial cross-sectional view of the substrate W, which changes depending on the processing of the embodiment. [Figure 6] This is a longitudinal cross-sectional side view showing the surface layer of the substrate after processing according to the embodiment. [Figure 7] This is a plan view showing a substrate processing apparatus that performs the processing according to the embodiment. [Figure 8] A longitudinal cross-sectional side view showing a processing module within the aforementioned substrate processing apparatus. [Figure 9] This is a time chart showing the supply and interruption of each gas in the aforementioned processing module. [Figure 10]It is the first SEM image showing the surface layer of the bare wafer after Evaluation Test 1. [Figure 11] It is the second SEM image showing the surface layer of the bare wafer after Evaluation Test 1. [Figure 12] It is a longitudinal sectional view showing the surface layer change of the substrate before and after Evaluation Test 2. [Figure 13] It is a graph showing the results of Evaluation Test 2. 【Mode for Carrying Out the Invention】 【0009】 <Formation of Metal Silicide Film According to Comparative Form> Before explaining the method for forming the metal silicide film according to the present disclosure, the treatment of the comparative form related to the problems of the present disclosure will be explained. FIG. 1 is a diagram showing the surface layer of the substrate before the treatment of the present disclosure and the comparative form. On the surface layer of the substrate W on which the treatment according to the present disclosure and the comparative form are performed, a Si layer 11 as a Si-containing layer and a SiN (silicon nitride) layer 12 laminated on the Si layer 11 are provided. Then, through holes such as holes and trenches are formed in the SiN layer 12, so that for the substrate W, a recess 13 opening on the surface is formed, and the Si layer 11 is exposed on the bottom surface of the recess 13. The side wall of the recess 13 is formed by the SiN layer 12. And as the treatment of the present disclosure and the comparative form, a Ti film (first metal film) 14 is formed on the bottom of the recess 13, and a series of treatments of siliciding the Ti film 14 by heating are performed. Note that the substrate W is, for example, a semiconductor wafer. 【0010】 FIGS. 2A to 2C are partial cross-sectional views of the substrate surface layer changed by the treatment of the comparative form, and the black solid arrows in these figures indicate the diffusion of Ti (titanium), and the white solid arrows indicate the diffusion of Si. The dotted lines in FIGS. 2B and 2C indicate the surface position of the Si layer 11 before the formation of the Ti film 14, that is, the interface position between the Ti film 14 and the Si layer 11 at the beginning of Ti film formation. The same applies to FIGS. 4A to 5C showing the present disclosure described later. And the interface between the Ti film 14 and the Si layer 11 at the beginning of Ti film formation indicated by this dotted line is sometimes simply referred to as the initial interface. 【0011】 First, Ti that forms a Ti film 14 is gradually deposited on the bottom of the recess 13 of the substrate W by plasma CVD (FIG. 2A). At this time, between the Ti film 14 and the Si layer 11 in contact with the Ti film 14, due to the heating of the substrate W during the Ti film formation, Ti and Si that constitute them diffuse mutually through the initial interface according to the concentration gradients of the respective Ti and Si (FIG. 2B). That is, Ti that constitutes the Ti film 14 diffuses into the Si layer 11, and Si that constitutes the Si layer 11 diffuses into the Ti film 14. Since the deposition amount of Ti is large (that is, the Ti film 14 is relatively thick), the amount of Ti diffusing into the Si layer 11 becomes relatively large, and the Ti moves relatively greatly downward and laterally below the Si layer 11. Therefore, as shown in FIG. 2C, the TiSi film 15 is formed so as to erode the Si layer 11 relatively greatly. Specifically described, for the TiSi film 15, its lower end is separated relatively greatly downward from the initial interface, and the side edge is positioned below the SiN layer 12. Therefore, it can be said that the consumption amount of the Si layer 11 is relatively large when forming the TiSi film 15. 【0012】 FIG. 3 is a diagram showing the surface layer of the substrate after the process of the comparative form. The completed TiSi film 15 has relatively high conductivity and constitutes a contact portion between the wiring layer 19 formed later and the Si layer 11. Since the TiSi film 15 is formed so that the Si layer 11 is eroded relatively greatly by the formation of the TiSi film 15, there is a possibility of causing electrical performance defects of the semiconductor device manufactured from the substrate W such as an increase in leakage current (FIG. 3). 【0013】 <Film formation of metal silicide film according to the present disclosure> FIGS. 4A to 5C are partial cross-sectional views of the substrate W that change by the process of the present disclosure (the process of the embodiment). In the process of the embodiment, erosion of the TiSi film 15 in the Si layer 11 as described above is suppressed. Each of the following processes is performed by storing the substrate W in a processing container whose inside is evacuated to a vacuum pressure and supplying each gas into the processing container. The substrate W is heated to a predetermined temperature suitable for the process. 【0014】 A Ti film 14 is deposited on the Si layer 11 at the bottom of the recess 13 by plasma CVD, which is performed by supplying, for example, TiCl4 (titanium tetrachloride) gas, H2 (hydrogen) gas, and Ar (argon) gas to the substrate W shown in Figure 1 inside the processing vessel and generating plasma from these gases (Figure 4A). The deposition time for this Ti film 14 is set to be relatively short, depending on the equipment configuration and other processing conditions used for deposition, so that the thickness of the Ti film 14 is relatively small. For example, the Ti film 14 is deposited so that the thickness L relative to the initial interface is 5 nm or less. Because the thickness of the Ti film 14 is small, the concentration of Ti on the Si layer 11 is low. Therefore, diffusion of Si and Ti due to a concentration gradient between the Ti film 14 and the Si layer 11 is unlikely to occur. Consequently, even if such a Ti film 14 is formed, the formation of a TiSi film 15 and, consequently, the erosion of the TiSi film 15 into the Si layer 11 are suppressed. Although it was stated that the thickness L of the Ti film 14 relative to the initial interface is, for example, 5 nm or less, it is also possible that a portion of the Ti film 14 may change into the TiSi film 15. More specifically, the thickness L of the Ti film 14 or TiSi film 15 relative to the initial interface is 5 nm or less. 【0015】 Next, as shown in Figure 4B, for example, SiH4 (monosilane) gas is supplied into the processing vessel as a gas for supplying Si, and CVD is performed, so that a Si film 16 is deposited on the Ti film 14. Due to the heating of the substrate W for this film formation, mutual diffusion occurs between the Ti film 14 and the Si film 16 according to the concentration gradient of Ti and Si. In other words, the Ti contained in the Ti film 14 diffuses into the Si film 16, and the Si contained in the Si film 16 diffuses into the Ti film 14, and a TiSi film 15 is formed from the Ti film 14 and the Si film 16, respectively. In other words, the Ti film 14 is silicided by the Si in the Si film 16 (Figure 5A). 【0016】 It should be noted that the Si film 16 is not limited to being deposited so as to completely cover the Ti film 14. Alternatively, a small amount of Si that does not form a film may be deposited on the Ti film 14. However, in this explanation, the process will proceed with the Si film 16 formed so as to completely cover the Ti film 14, as shown in Figure 4B. 【0017】 In this embodiment, the source of Si for forming the TiSi film 15 is Si derived from a Si-supplying gas containing Si elements. When interdiffusion of Ti and Si occurs between the Si film 16 formed by the gas and the Ti film 14, interdiffusion of Ti and Si may also occur between the Ti film 14 and the Si layer 11. In other words, even in this embodiment, the Si layer 11 can serve as a source of Si for forming the TiSi film 15. However, as Si is supplied from the Si film 16 to the Ti film 14 and the concentration of Si in the Ti film 14 increases, the interdiffusion of Ti and Si between the Ti film 14 and the Si layer 11 caused by the aforementioned concentration gradient is suppressed. Therefore, in this embodiment, the TiSi film 15 is formed on the initial interface in such a way that erosion of the Si layer 11 is suppressed. 【0018】 Subsequently, TiCl4 gas, H2 gas, and Ar gas are supplied into the processing vessel, and these gases are converted into plasma to deposit a Ti film 17 on top of the TiSi film 15 (Figure 5B). During this deposition, heating of the substrate W by the heating mechanism of the processing apparatus and heating by the plasma causes the Ti constituting the Ti film 17 to diffuse into the TiSi film 15, and the Si constituting the TiSi film 15 to diffuse into the Ti film 17, and the Ti film 17 is also silicided to become the TiSi film 15. In other words, the thickness of the TiSi film 15 increases (Figure 5C). 【0019】 As mentioned above, the thickness L of the Ti film 14 is kept small to suppress erosion of the TiSi film 15 into the Si layer 11. Therefore, the thickness L1 of the Ti film 17 shown in Figure 5B is, for example, larger than the thickness L of the Ti film 14. Since the Ti film 17 changes into a TiSi film 15, the thickness L1 of this Ti film 17 is, more specifically, the increased thickness of the TiSi film 15 from the end of the formation of the Si film 16 to the end of the formation of the Ti film 17. 【0020】 As shown in Figure 5C, after a TiSi film 15 of sufficient thickness is formed, a film-forming gas for metal embedding is supplied into the processing vessel. As a result, a wiring layer 19, which is a second metal film composed of, for example, Ru (ruthenium), is formed on the TiSi film 15 so as to be embedded in the recesses 13 (Figure 6). 【0021】 By the processing described above, a TiSi film 15 of sufficient thickness can be formed on the substrate W while suppressing the erosion of the TiSi film 15 into the Si layer 11. Since the TiSi film 15, which is the contact portion, has sufficient thickness, the electrical connection between the wiring layer 19 and the Si layer 11 is improved, and the electrical performance defects described above can be suppressed. 【0022】 The processing of the embodiment described in Figures 4 and 5 above will be explained in more detail. As previously stated, in this embodiment, the processing uses Si which constitutes the silane gas when forming the TiSi film 15, thereby suppressing the consumption of Si in the Si layer 11 as part of the TiSi film 15. The timing for supplying this Si-supplying gas is set to be after the Ti film 14 has been formed. This is because, as shown in the evaluation test described later, even if silane gas is supplied onto the Si layer 11, the Si in the gas does not easily adsorb onto the Si layer 11. However, if the Ti film 14 has been formed on the Si layer 11, the adsorption of Si onto the Ti film 14 can proceed relatively efficiently, making it a material for forming the TiSi film 15. However, if an excessive amount of Ti is deposited on the Si layer 11 (the Ti film 14 becomes thicker), the erosion of the Si layer 11 by the TiSi film 15 becomes relatively large, as explained in the processing of the comparative example. Therefore, in the processing of this embodiment, silane gas is supplied to the substrate W while a thin Ti film 14 has been formed, so that the Si contained in this gas becomes the material for forming the TiSi film 15. 【0023】 Incidentally, if the formation of the Si film 16 as described in Figure 4(C), and the heating of the substrate W accompanying the formation, allow sufficient diffusion of Ti from the Ti film 14 into the Si film 16, and if the thickness of the TiSi film 15 formed by the formation of the Si film 16 is sufficient, then the formation of the Ti film 17 shown in Figures 5B and 5C may not be necessary. However, if the Si film 16 is made to a thickness that allows sufficient diffusion of Ti, its thickness will be relatively small. Therefore, at the point when the formation of the Si film 16 is completed and the TiSi film 15 is formed from the Si film 16 (the point shown in Figure 5A), there is a risk that the TiSi film 15 may not have sufficient thickness. Forming the Ti film 17 is preferable in order to ensure that the TiSi film 15 has sufficient thickness. In other words, it is preferable to perform the deposition of the first metal film (Ti film) multiple times, and after deposition of the first metal film, supply a gas for Si supply between depositions of the first metal film and the next deposition of the first metal film to deposit the Si film 16, thereby forming a metal silicide film from each first metal film. 【0024】 Furthermore, after the formation of the Ti film 17, the Si film 16 may be formed again to diffuse the Ti constituting the Ti film 17 into the Si film 16, thereby forming a TiSi film 15 that is even thicker. That is, the formation of the Ti film and the Si film may be performed alternately, and the formation of the Ti film and the Si film may be performed multiple times each. When forming the Ti film and the Si film alternately in this way, the formation of the Ti film may be performed last, or the formation of the Si film may be performed last. 【0025】 Incidentally, when supplying Si to the substrate W for adsorption, it was stated that SiH4 (monosilane), a compound containing the Si element, is used as the gas for supplying Si. However, it is not limited to using SiH4 gas; for example, Si2H6 (disilane) may also be used. However, when using Si2H6 gas, unwanted Si films are easily formed on the SiN layer 12 that constitutes the sidewall of the recess 13. In other words, the selectivity for Si film formation between the Ti film 14 and the SiN layer 12 is low. On the other hand, when using SiH4 gas, as shown in the evaluation test described later, the Si film is selectively formed on the Ti film 14 rather than the SiN layer 12. 【0026】 This is because, at relatively high temperatures, SiH4 is adsorbed onto the metal film and then decomposes to produce SiH2, which is the raw material for forming the Si film. In the state of SiH4, it has low adsorption to silicon-containing compounds (meaning it contains silicon as a constituent component, not as an impurity), such as the Si layer 11 and the SiN layer 12. In contrast, Si2H6 decomposes to produce SiH2 before adsorption to each film, and it is thought that this is due to the relatively high adsorption of SiH2 to metals such as Ti and silicon-containing compounds. Therefore, it is preferable to use SiH4 as the gas for supplying Si, which allows for selective adsorption of SiH2 onto the Ti film 14 and prevents film formation on the SiN layer 12. 【0027】 As mentioned above, when supplying SiH4 gas to the substrate W, the presence of the Ti film 14 allows for efficient adsorption of Si. Therefore, when supplying SiH4 gas to the substrate W, the temperature of the substrate W can be, for example, 450°C or less, and the pressure inside the processing container containing the substrate can be, for example, 1 Torr or less. In the evaluation tests described later, it has been confirmed that Si can be adsorbed onto the substrate W at such temperatures and pressures. Furthermore, it has been confirmed that adsorption was possible even at a substrate W temperature of 400°C. 【0028】 <Substrate processing apparatus according to an embodiment> The substrate processing apparatus 1 that performs the processing described above will be described below. Figure 7 is a plan view of the substrate processing apparatus. The substrate processing apparatus 1 comprises a processing module 5a that performs the series of processing described in Figures 4A to 5C, and a processing module 5b for forming the wiring layer 19. Processing module 5a corresponds to the Ti film deposition section and the metal silicide film formation section. 【0029】 The substrate processing apparatus 1 is configured with an atmospheric transport module 2, two load lock modules 3, a vacuum transport module 4, and processing modules 5a and 5b arranged from front to back. The load lock module may be referred to as LLM below. The atmospheric transport module 2 has a housing 21, and the inside of the housing 21 is kept at atmospheric pressure. A transport mechanism 22 is provided inside the housing 21, and this transport mechanism 22 is configured as, for example, a multi-jointed arm that can move left and right. The atmospheric transport module 2 also has, for example, three load ports 23 for transferring substrates W between the transport container C and the LLM 3, and these three load ports 23 are arranged side by side on the left and right. 【0030】 Each load port 23 consists of a stage 24 for a transport container C provided on the front side of the housing 21, a transport opening provided on the side wall of the housing 21 facing the transport container C on the stage 24, and a door 25 for opening and closing the transport opening. The transport container C is configured to store a large number of substrates W and is, for example, called a FOUP (Front Opening Unified Pod), and the transport mechanism 22 transports the substrates W between this transport container C and the LLM3. 【0031】 LLM3 comprises a housing 31, which is configured to appropriately change the pressure inside the housing 31 between atmospheric pressure and a predetermined vacuum pressure. The housing 31 is provided with two transport ports each for transporting substrates W into the atmospheric transport module 2 and the vacuum transport module 4, and each transport port is provided with a gate valve G. Inside the housing 31 is a stage 33 on which substrates W are placed, and substrates W are transferred between the transport mechanism 22 of the atmospheric transport module 2 and the transport mechanism 43 of the vacuum transport module 4 (described later) and the stage 33. 【0032】 The vacuum transport module 4 comprises a housing 41, to which the LLM3, processing modules 5a and 5b are connected via gate valves G. The inside of the housing 41 is evacuated by an exhaust mechanism (not shown), maintaining a vacuum atmosphere at a predetermined pressure while the substrate processing apparatus 1 is in operation. A transport mechanism 43, which is a multi-jointed arm, is provided inside the housing 41. The transport mechanism 43 transports the substrate W between the processing modules 5a and 5b and the LLM3. 【0033】 Of the two processing modules 5a and 5b, processing module 5a will be described as a representative example. Figure 8 is a longitudinal cross-sectional side view of processing module 5a. Processing module 5a is configured to deposit Ti films 14 and 17 by plasma CVD by continuously supplying TiCl4 gas, H2 gas, and argon (Ar) gas to the surface of the substrate W. TiCl4 gas is the raw material gas for film formation, H2 gas is used to eliminate the effects of chlorine, and Ar gas is used for plasma formation. Processing module 5a also deposits a Si film 16 by supplying SiH4 gas to the surface of the substrate W. 【0034】 The processing module 5a includes a metal processing container 51, which is grounded. An exhaust mechanism 52 is connected to the processing container 51, and exhaust is performed from an exhaust port 53 formed in the bottom wall of the processing container 51. This maintains a predetermined vacuum pressure inside the processing container 51. Specifically, for example, during film deposition (during the processing shown in Figures 4A to 5C), the pressure is maintained at 133.3 Pa (1 Torr) or less. The exhaust mechanism 52, similar to the exhaust mechanism of LLM3, is configured to adjust the amount of exhaust inside the processing container 51 by including valves and a vacuum pump, thereby creating a vacuum atmosphere at the desired pressure inside the processing container 51. The processing container 51 also has a substrate W transport port 54 which is opened and closed by the gate valve G. 【0035】 Inside the processing container 51 is a circular stage 55 on which the substrate W is placed in plan view. A heater 56, for example, made of an electric heating wire, is embedded in the stage 55 to adjust the temperature of the stage 55 to, for example, 400°C to 450°C. Similar to the stage 33 of the LLM3, the stage 55 is also provided with three retractable pins on its upper surface, which allow the substrate W to be transferred between the transport mechanism 43 of the vacuum transport module 4 and the stage 55. The stage 55 is grounded and is positioned inside the processing container 51 by a support provided at the bottom of the processing container 51. The support includes an insulating member (not shown) for insulating the stage 55 from the processing container 51. 【0036】 The upper part of the processing container 51 has an opening facing upward, and a shower head 58 is attached via an annular insulating member 57. The shower head 58 is connected to a gas supply mechanism, described later, via a supply channel, and contains a gas diffusion space from which various gases are supplied. The shower head 58 has multiple through holes at its lower part, which release the various gases in the gas diffusion space into the processing container 51. The gas supply mechanism 59 is configured to supply TiCl4 gas, H2 gas, Ar gas, and SiH4 gas. Specifically, the gas supply mechanism 59 includes a supply source for each of these gases, a valve for switching between supplying and stopping the supply of each gas into the processing container 51, and a flow rate adjustment unit such as a mass flow controller for adjusting the supply flow rate of each gas downstream of the supply channel described above. 【0037】 Furthermore, a high-frequency power supply 62, which supplies high-frequency power for plasma formation, is connected to the shower head 58 via a matching unit 61. The processing module 5a is a parallel-plate type plasma processing apparatus consisting of a shower head 58 which forms the upper electrode and a stage 55 which forms the lower electrode. The substrate W is placed on the stage 55 to be positioned in the space between the shower head 58 and the stage 55, and plasma is generated by supplying TiCl4 gas, H2 gas, and Ar gas from the above gases and applying high-frequency power, thereby decomposing the TiCl4 and forming Ti films 14 and 17. In the processing module 5a, as shown in the test results described later, it is preferable to form the Ti film 14 by exposing it to the plasma atmosphere as described above for, for example, 30 seconds or less, and more preferably for 20 seconds. The Si film 16 is formed by the non-plasma-generated SiH4 gas supplied from the shower head 58. Therefore, the deposition of the Ti films 14 and 17 by supplying TiCl4 gas, H2 gas, and Ar gas, and the deposition of the Si film 14 by supplying SiH4 gas, are performed at different timings. 【0038】 The processing module 5b that forms the wiring layer 19 is configured to supply various gases using a CVD method without plasma, and does not have a matching unit 61 or a high-frequency power supply 62, and the stage 55 is not grounded. The gas supply mechanism of processing module 5b has the same configuration as processing module 5a, but uses Ru3(CO) as the film deposition gas. 12 The system is configured to supply Ru-containing gases, such as gases, to the substrate W. 【0039】 Returning to Figure 7, the substrate processing apparatus 1 includes a control unit 10, which is a computer. The control unit 10 includes a program, memory, and a CPU. The program contains instructions (each step) for processing and transporting the substrate W. This program is stored in a storage medium, such as a compact disk, hard disk, magneto-optical disk, DVD, etc., and installed in the control unit 10. The control unit 10 outputs control signals to each part of the substrate processing apparatus 1 using this program, thereby controlling the operation of each part. 【0040】 The operation of the substrate processing apparatus 1 controlled by the control signal includes the movement of each transport mechanism and the raising and lowering of the stage pins to transport the substrate W between modules, opening and closing of the gate valve G, pressure adjustment inside the housing 31 by supplying and exhausting gas in the LLM 3, gas supply from the shower head 58 in each processing module 5a and 5b, pressure adjustment inside the processing container 51, and switching between executing and stopping plasma processing by turning the high-frequency power supply 62 on and off. 【0041】 Next, the transport of the substrate W in the substrate processing apparatus 1 and the processing performed by the processing method in this disclosure will be explained using the timing charts shown in Figures 4A to 5C and Figure 9. The timing charts show the supply and interruption of each gas into the processing container 51 in the processing module 5a. 【0042】 First, the substrate W, which has the recess 13 formed in the transport container C, is transported to the load port 23 of the substrate processing apparatus 1, in the order of load lock module 3 → vacuum transport module 4 → processing module 5a. Then, the pressure in the processing container 51 is adjusted to the pressure described above, and the temperature of the substrate W is adjusted to the temperature described above. After that, TiCl4 gas, H2 gas, and Ar gas are supplied, and these gases are plasma-generated by supplying high-frequency power (time t1), and the first Ti film (Ti film 14) is deposited on the surface of the substrate W (Figure 4A). 【0043】 Subsequently, the supply of TiCl4 gas, H2 gas, Ar gas, and high-frequency power is stopped, and the supply of SiH4 gas is started (time t2, Figure 4B), thereby silicideizing the Ti film 14 (Figure 5A). Next, the supply of SiH4 gas is stopped, and the supply of TiCl4 gas, H2 gas, and Ar gas is started, along with the supply of high-frequency power to create plasma from these gases (time t3), and a second Ti film (Ti film 17) is deposited on the substrate W on which the TiSi film 15 has been deposited (Figure 5B), thereby increasing the thickness of the TiSi film 15. Subsequently, the supply of TiCl4 gas, H2 gas, Ar gas, and high-frequency power is stopped (time t4). As described above, the film thickness L of the Ti film 14 is smaller than the film thickness L1 of the Ti film 17, so for example, the deposition time of the first Ti film (time at times t1 to t2) is shorter than the deposition time of the second Ti film (time at times t3 to t4). 【0044】 The substrate W on which the TiSi film 15 is formed is then transported to the processing module 5b to form the wiring layer 19 (Figure 6). The substrate W on which the wiring layer 19 is formed is then transported to the LLM3 and returned to the transport container C of the load port 23, and transported to a substrate processing device for subsequent processing such as chemical mechanical polishing (CMP). After the formation of the TiSi film 15 in processing module 5a and before the formation of the wiring layer 19 in processing module 5b, any necessary processing may be performed as appropriate. If such processing is to be performed, for example, the processing module performing the processing should be connected to the vacuum transport module 4. 【0045】 (modified version) In this embodiment, an example was described in which the deposition of Ti films 14 and 17 and the deposition of Si film 16 are performed in the same processing module 5a (i.e., within the same processing container). In this case, undesirable chemical reactions may occur between the gases supplied for each deposition, or in the components of the processing module 5a due to these gases. If such concerns exist, the deposition of Ti films 14 and 17 and the deposition of Si film 16 may be performed in different processing modules (i.e., in different processing containers). Even if such concerns do not exist, they may be performed in different processing modules. In this case, the processing module for deposition of Ti films 14 and 17 corresponds to the metal film deposition section, and the processing module for deposition of Si film 16 corresponds to the metal silicide film formation section. The processing module 5a in this embodiment corresponds to a unit in which the metal film deposition section and the metal silicide film formation section are integrally formed. 【0046】 In the above embodiment, Si was supplied to the Ti film 14 by supplying a gas which is a compound containing the element Si, but the method is not limited to this. For example, Si may be supplied to the Ti film 14 by other manufacturing methods such as sputtering, but it is preferable to do so by supplying SiH4 gas, which can effectively perform selective film formation on the Ti film 14. 【0047】 The Ti film 14 deposited in the first Ti film deposition process and the Ti film 17 deposited in the second Ti film deposition process do not have to be the same. In other words, the processing conditions such as the pressure inside the processing container 51 and the flow rates of each gas supplied into the processing container 51 may be different. 【0048】 The metal film to be silicided (first metal film) and deposited on the substrate W is a metal film other than Ru. Examples other than the Ti film illustrated in Figures 4A to 5C include films composed of tungsten (W), molybdenum (Mo), zirconium (Zr), etc. Thus, this technology can also be applied to the formation of metal silicides other than TiSi. The formation of the first metal film on the substrate W is carried out by supplying a gas containing the metal to the substrate, and any method suitable for film deposition can be used. Specifically, the formation of the first metal film is not limited to forming a plasma in the processing chamber. Furthermore, film deposition is not limited to CVD; other deposition methods such as ALD or PVD may be used. 【0049】 In the above embodiment, in order to suppress the decomposition of SiH4 gas into SiH2 and subsequent adsorption to the SiN layer 12 before adsorption to the Ti film 14, the SiH4 gas is supplied to the substrate W without being plasmaized. While it is preferable not to plasmaize the SiH4 gas, it may also be plasmaized and supplied to the substrate W. When using a gas other than SiH4 gas as the Si supply gas, it may also be plasmaized and supplied to the substrate W, or supplied without being plasmaized. 【0050】 The wiring layer 19 embedded in the recess 13 of the substrate W is not limited to Ru, but may be made of a metal such as W, Mo, or Cr (chromium). 【0051】 It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The above embodiments may be omitted, substituted, modified, and combined in various ways without departing from the scope and spirit of the appended claims. 【0052】 (Evaluation test) The following describes the evaluation tests conducted on the series of processes described in this disclosure. 【0053】 (Evaluation Test 1) As part of evaluation test 1, the difference in the adsorption properties of SiH4 gas to Ti and SiN films was confirmed. Two bare silicon wafers were used, one on which a Ti film was deposited and the other on which a SiN film was deposited. Each wafer was heated to 400°C in a processing container, and then exposed to a vacuum atmosphere of 133 Pa (1 torr) for 150 seconds by supplying SiH4 gas at a flow rate of 500 sccm. Each bare wafer after SiH4 gas supply was analyzed by SEM to confirm the presence or absence of the Si film. 【0054】 Figures 10 and 11 are SEM images showing the surface layers of each bare wafer after this evaluation test. Figure 10 is an SEM image of a bare wafer with a Ti film deposited before the supply of SiH4 gas, and Figure 11 is an SEM image of a bare wafer with a SiN film deposited. As shown in these images, the Ti film became a TiSi film through the above test, and a Si film was deposited on the TiSi film. However, no Si film was deposited on the SiN film. From this, it was confirmed that SiH4 gas is not easily adsorbed onto SiN films, but is easily adsorbed onto Ti-containing films such as Ti films, and that Si films are easily deposited on them. 【0055】 <Evaluation Test 2> As part of Evaluation Test 2, we confirmed the difference in expansion of the TiSi film 15 due to erosion into the Si layer depending on the timing of supplying SiH4 gas to the Ti film 14. Figure 12 is a longitudinal cross-sectional view showing the surface layer changes of the substrate before and after Evaluation Test 2. First, multiple bare wafers, which are silicon substrates, were prepared. For each bare wafer, a SiGe (germanium) layer and a Si layer were deposited on the surface by CVD, and the thickness of the Si layer exposed on the surface was measured for each. Next, these bare wafers were subjected to gas treatment as shown in Figures 4A to 5C and Figure 9. The temperature of the bare wafers during treatment was set to 450°C. The supply of SiH4 gas to each bare wafer was started at different timings as shown in Figure 13. More specifically, the times t1 to t4 in the chart shown in Figure 9 are the same for each bare wafer, but the timing of the start of SiH4 gas supply at time t2 was staggered among the bare wafers so that the length of time t1 to t2 differed from one another. 【0056】 After the above series of processes, the length of each interface between the TiSi film and the SiGe layer formed on each bare wafer was measured to determine the thickness of the remaining Si layer on each bare wafer. The difference between the thickness of the remaining Si layer on each bare wafer and the thickness of the Si layer measured before the series of processes was calculated as the Si layer consumption. 【0057】 Figure 13 is a graph showing the results of Evaluation Test 2, with the horizontal axis representing the SiH4 gas supply start time (= length of time t1 to t2) and the vertical axis representing the Si layer consumption. As shown in the figure, the Si consumption was highest at 4.7 nm among the bare wafers when the SiH4 gas supply start time was 0 seconds. As the SiH4 gas supply start time increased, the Si consumption gradually decreased before increasing, and then remained roughly constant after this increase. The Si consumption was lowest at 15 seconds when the SiH4 gas supply start time was 15 seconds, resulting in zero Si consumption. 【0058】 When the SiH4 gas supply start time is zero or close to zero, Si consumption is relatively high. This suggests that the amount of SiH4 gas adsorbed onto the Si layer of the bare wafer is low, and that a large amount of Si originating from the Si layer was used to form the TiSi film 15. The decrease in Si consumption as the SiH4 gas supply start time increases within the range of 15 seconds or less is presumed to be due to the increased adsorption of SiH4 to the bare wafer as a result of the formation of a Ti film by increasing the amount of Ti deposited on the Si layer, and the Si derived from said SiH4 being used in the formation of the TiSi film 15. 【0059】 Furthermore, in the range where the SiH4 gas supply start time is longer than 15 seconds, the Si consumption increases with increasing SiH4 gas supply start time and then remains roughly constant, indicating that the Si layer of the bare wafer is used for the formation of the TiSi film 15 before the SiH4 gas is supplied. It was also shown that the diffusion of Ti onto the Si layer increases as the amount of Ti increases, up to a certain amount. Thus, if the SiH4 gas supply start time is too long, the Si consumption increases, but as shown in the graph, in the range where the SiH4 gas supply start time is 30 seconds or less, the Si consumption is relatively suppressed. Therefore, it is preferable that the SiH4 gas supply start time be 30 seconds or less. 【0060】 The same changes in Si layer consumption were observed even when testing with other processing modules and different processing conditions. From this, it was found that by supplying the deposition gas slightly later than the start of Ti film deposition, SiH4 gas can be adsorbed onto the growing Ti film, thereby supplying Si to the Ti film. [Explanation of Symbols] 【0061】 W board 11 Si layer 14, 17 Ti film 15 TiSi film

Claims

[Claim 1] A step of forming a first metal film made of a metal other than Ru on a Si-containing layer exposed on the surface of a substrate, A step of supplying Si elements to the substrate and forming a metal silicide film from the Si elements and the first metal film, A substrate processing method. [Claim 2] The Si-containing layer is a Si layer that forms the bottom surface of a recess formed in the substrate. The Si element is supplied to the first metal film as a gas which is a compound containing the Si element. The side walls of the recess are composed of a Si-containing compound. The substrate processing method according to claim 1, comprising an embedding step of embedding a second metal film in the recess so as to be laminated on the metal silicide film. [Claim 3] The substrate processing method according to claim 2, wherein the metal other than Ru constituting the first metal film is one of Ti, W, Mo, and Zr. [Claim 4] The substrate processing method according to claim 3, wherein the metal other than Ru constituting the first metal film is Ti. [Claim 5] The substrate processing method according to claim 2, wherein the side wall of the recess is made of a silicon nitride film. [Claim 6] The gas which is a compound containing the aforementioned Si element is SiH ４ The substrate processing method according to claim 5, wherein the gas is used. [Claim 7] The process of forming the first metal film is performed multiple times. The substrate processing method according to claim 2, wherein a step of supplying the Si element to the substrate is performed between the step of forming the first metal film and the next step of forming the first metal film, and the metal silicide film is formed from each of the first metal films. [Claim 8] A metal film deposition section for forming a first metal film made of a metal other than Ru on a Si-containing layer exposed on the surface of the substrate, A metal silicide film forming unit that supplies Si elements to the first metal film and forms a metal silicide film from the Si elements and the first metal film, A substrate processing apparatus equipped with the following:

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