Substrate processing method, program, substrate processing apparatus, and semiconductor device manufacturing method

Abstract

To provide a technique capable of improving the film characteristics.SOLUTION: A manufacturing method includes the steps of: (a) preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metal element, and a film formed on the film containing the first metal element and containing boron, aluminum, gallium, or indium as a group 13 element or silicon or germanium as a group 14 element; (b) supplying a gas containing tungsten as a second metal element and halogen to the substrate; (c) supplying a first reaction gas to the substrate; and (d) forming a film containing the second metal element by removing at least a part of the film containing the group 13 element or the group 14 element by performing (b) and (c).SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method, a program, a substrate processing apparatus, and a method for manufacturing a semiconductor device.

Background Art

[0002] In recent years, with the high integration and high performance of semiconductor devices, various types of metal films have been used, and semiconductor devices with a three-dimensional structure have been manufactured. For example, a tungsten film (W film) or the like is used for a control gate of a NAND-type flash memory, which is an example of a semiconductor device with a three-dimensional structure. Further, for example, a titanium nitride (TiN) film may be used as a barrier film between this W film and an insulating film (see, for example, Patent Document 1 and Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when another metal film such as a W film is formed on the surface of a metal film such as a TiN film, the surface of the metal film may be etched by the film-forming gas used to form the other metal film. Then, when the surface of the metal film is etched, the film characteristics may deteriorate.

[0005] An object of the present disclosure is to provide a technology capable of improving film characteristics.

Means for Solving the Problems

[0006] According to one aspect of the present disclosure, (a) A step of preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metallic element, and a film formed on the film containing the first metallic element containing boron, aluminum, gallium, or indium as a Group 13 element, or silicon or germanium as a Group 14 element, (b) A step of supplying the substrate with a gas containing tungsten as a second metallic element and a halogen, (c) A step of supplying a first reaction gas to the substrate, It has, (d)(b) and (c) are performed to remove at least a portion of the film containing the group 13 element or the group 14 element and to form a film containing the second metal element, A technology possessing this feature is provided. [Effects of the Invention]

[0007] According to this disclosure, membrane identification can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a longitudinal cross-sectional view illustrating the configuration of the processing furnace 202a of a substrate processing apparatus 10 according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a cross-sectional view of the processing furnace 202a along line AA. [Figure 3] This is a longitudinal cross-sectional view illustrating the configuration of the processing furnace 202b of a substrate processing apparatus 10 according to one embodiment of the present disclosure. [Figure 4] Figure 3 is a cross-sectional view of the processing furnace 202b along line AA. [Figure 5] This is a block diagram illustrating the configuration of the control unit of a substrate processing apparatus 10 according to one embodiment of the present disclosure. [Figure 6] This figure shows the substrate processing sequence in the processing furnace 202a of the substrate processing apparatus 10 according to one embodiment of the present disclosure. [Figure 7]This figure shows the substrate processing sequence in the processing furnace 202b of the substrate processing apparatus 10 according to one embodiment of the present disclosure. [Figure 8] Figures 8(A) and 8(B) illustrate the film formed on the substrate by processing in furnace 202a, and Figure 8(C) illustrates the film formed on the substrate by processing in furnace 202b. [Figure 9] This figure shows a modified example of the substrate processing sequence in the processing furnace 202b of the substrate processing apparatus 10 according to one embodiment of the present disclosure. [Figure 10] Figure 10(A) shows the structures of Sample 1 and Sample 2 used in this embodiment, and Figures 10(B) and 10(C) show the XPS analysis results of Sample 1 and Sample 2 shown in Figure 10(A). [Figure 11] Figure 11(A) shows the structures of Sample 1 and Sample 2 used in this embodiment, and Figures 11(B) and 11(C) show the XPS analysis results of Sample 1 and Sample 2 shown in Figure 11(A). [Modes for carrying out the invention]

[0009] <One Embodiment of the Present Disclosure> Hereinafter, one embodiment of the present disclosure will be described with reference to Figures 1 to 7 and Figures 8(A) to 8(C). The substrate processing apparatus 10 is configured as an example of equipment used in the manufacturing process of semiconductor devices. Note that the drawings used in the following description are all schematic, and the dimensional relationships and ratios of each element shown in the drawings do not necessarily correspond to those of reality. Furthermore, the dimensional relationships and ratios of each element do not necessarily correspond between multiple drawings.

[0010] (1) Configuration of substrate processing apparatus Figure 1 is a longitudinal cross-sectional view of a processing furnace 202a, which is a first process unit of a substrate processing apparatus (hereinafter simply referred to as the substrate processing apparatus 10) capable of carrying out a semiconductor device manufacturing method, and Figure 2 is a cross-sectional view of the processing furnace 202a along line AA. In this embodiment, after forming a first metal-containing film on the wafer 200 and a cap film on the first metal-containing film in the processing furnace 202a as the first process unit, an example of forming a second metal-containing film in the processing furnace 202b as the second process unit described later while removing at least a part of the cap film formed on the first metal-containing film will be described.

[0011] The processing furnace 202a includes a heater 207 as a heating means (heating mechanism, heating system, heating unit). The heater 207 has a cylindrical shape and is vertically installed by being supported by a heater base (not shown) as a holding plate.

[0012] An outer tube 203 that forms a reaction vessel (processing vessel) concentrically with the heater 207 is disposed inside the heater 207. The outer tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), and is formed in a cylindrical shape with the upper end closed and the lower end open. A manifold (inlet flange) 209 is disposed concentrically with the outer tube 203 below the outer tube 203. The manifold 209 is made of a metal such as stainless steel (SUS), and is formed in a cylindrical shape with the upper and lower ends open. An O-ring 220a as a seal member is provided between the upper end portion of the manifold 209 and the outer tube 203. By supporting the manifold 209 on the heater base, the outer tube 203 is in a vertically installed state.

[0013] Inside the outer tube 203, an inner tube 204 that constitutes a reaction vessel is disposed. The inner tube 204 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), and is formed in a cylindrical shape with the upper end closed and the lower end open. The processing vessel (reaction vessel) is mainly composed of the outer tube 203, the inner tube 204, and the manifold 209. A processing chamber 201a is formed in the cylindrical hollow portion (inside the inner tube 204) of the processing vessel. Here, although the inner tube 204 is included in the configuration of the processing vessel (reaction vessel) and the processing chamber 201a, a configuration without the inner tube 204 may also be possible.

[0014] The processing chamber 201a is configured to be able to accommodate the wafer 200 as a substrate in a state where it is arranged in multiple stages in the vertical direction in a horizontal posture by a boat 217 described later.

[0015] In the processing chamber 201a, nozzles 410, 420, and 430 are provided so as to penetrate the side wall of the manifold 209 and the inner tube 204. Gas supply pipes 310, 320, and 330 as gas supply lines are respectively connected to the nozzles 410, 420, and 430. Thus, the substrate processing apparatus 10 is provided with three nozzles 410, 420, and 430 and three gas supply pipes 310, 320, and 330, and is configured to be able to supply a plurality of types of gases into the processing chamber 201a. However, the processing furnace 202a of the present embodiment is not limited to the above-described form.

[0016] Gas supply pipes 310, 320, and 330 are equipped with flow controllers (flow control units), namely mass flow controllers (MFCs) 312, 322, and 332, respectively, from upstream to downstream. Gas supply pipes 310, 320, and 330 are also equipped with on-off valves, namely valves 314, 324, and 334, respectively. Downstream from the valves 314, 324, and 334 on gas supply pipes 310, 320, and 330 are connected to gas supply pipes 510, 520, and 530, respectively, which supply inert gas. Gas supply pipes 510, 520, and 530 are equipped with MFCs 512, 522, and 532 and valves 514, 524, and 534, respectively, from upstream to downstream.

[0017] Nozzles 410, 420, and 430 are connected to the ends of the gas supply pipes 310, 320, and 330, respectively. The nozzles 410, 420, and 430 are configured as L-shaped nozzles, with their horizontal portions penetrating the side wall of the manifold 209 and the inner tube 204. The vertical portions of the nozzles 410, 420, and 430 are located inside a channel-shaped (groove-shaped) spare chamber 205a that protrudes radially outward from the inner tube 204 and extends vertically. Within the spare chamber 205a, the nozzles are positioned upward (upward in the direction of wafer 200 arrangement) along the inner wall of the inner tube 204.

[0018] The nozzles 410, 420, and 430 are provided to extend from the lower region to the upper region of the processing chamber 201a, and each nozzle has multiple gas supply holes 410a, 420a, and 430a located opposite the wafer 200. This allows processing gas to be supplied to the wafer 200 from the gas supply holes 410a, 420a, and 430a of the nozzles 410, 420, and 430, respectively. These gas supply holes 410a, 420a, and 430a are provided in multiple locations extending from the lower to the upper part of the inner tube 204, each having the same opening area and the same opening pitch. However, the gas supply holes 410a, 420a, and 430a are not limited to the above configuration. For example, the opening area may be gradually increased from the lower to the upper part of the inner tube 204. This makes it possible to more uniformly distribute the flow rate of the gas supplied from the gas supply holes 410a, 420a, and 430a.

[0019] The gas supply holes 410a, 420a, and 430a of nozzles 410, 420, and 430 are provided in multiple locations at a height from the bottom to the top of the boat 217, which will be described later. Therefore, the processing gas supplied into the processing chamber 201a from the gas supply holes 410a, 420a, and 430a of nozzles 410, 420, and 430 is supplied to the wafers 200 housed from the bottom to the top of the boat 217, that is, to the entire area of ​​the wafers 200 housed in the boat 217. The nozzles 410, 420, and 430 only need to be provided so as to extend from the lower region to the upper region of the processing chamber 201a, but it is preferable that they extend to near the ceiling of the boat 217.

[0020] From the gas supply pipe 310, a gas containing a first metal element (hereinafter also referred to as the "first metal-containing gas") is supplied into the processing chamber 201a as a processing gas via the MFC 312, valve 314, and nozzle 410.

[0021] From the gas supply pipe 320, a third reaction gas, which reacts with the first metal-containing gas, is supplied into the processing chamber 201a as a processing gas via the MFC 322, valve 324, and nozzle 420. In this disclosure, an example is given in which the third reaction gas is also used as a reaction gas that reacts with a gas containing a group 13 or group 14 element, as described later.

[0022] From the gas supply pipe 330, a gas containing a group 13 or group 14 element, as a processing gas, is supplied into the processing chamber 201a via the MFC 332, valve 334, and nozzle 430.

[0023] From the gas supply pipes 510, 520, and 530, nitrogen (N2) gas, for example, is supplied as an inert gas into the processing chamber 201a via MFCs 512, 522, and 532, valves 514, 524, and 534, and nozzles 410, 420, and 430, respectively. The following describes an example in which N2 gas is used as the inert gas, but other noble gases such as argon (Ar), helium (He), neon (Ne), and xenon (Xe) gas may also be used as the inert gas.

[0024] The processing gas supply system mainly consists of gas supply pipes 310, 320, 330, MFCs 312, 322, 332, valves 314, 324, 334, and nozzles 410, 420, 430, but nozzles 410, 420, 430 alone may be considered as the processing gas supply system. The processing gas supply system may simply be called the gas supply system. When the first metal-containing gas is supplied from gas supply pipe 310, the first metal-containing gas supply system mainly consists of gas supply pipe 310, MFC 312, and valve 314, but nozzle 410 may also be considered as part of the first metal-containing gas supply system. Similarly, when the third reaction gas is supplied from gas supply pipe 320, the third reaction gas supply system mainly consists of gas supply pipe 320, MFC 322, and valve 324, but nozzle 420 may also be considered as part of the third reaction gas supply system. When a nitrogen-containing gas is supplied as a third reaction gas from the gas supply pipe 320, the third reaction gas supply system can also be referred to as the nitrogen-containing gas supply system. Furthermore, when a gas containing a group 13 or group 14 element flows from the gas supply pipe 330, the group 13 or group 14 element-containing gas supply system is mainly composed of the gas supply pipe 330, MFC 332, and valve 334, although the nozzle 430 may also be considered as part of the group 13 or group 14 element-containing gas supply system. Additionally, the inert gas supply system is mainly composed of gas supply pipes 510, 520, 530, MFC 512, 522, 532, and valves 514, 524, 534.

[0025] In this embodiment, the gas supply method involves transporting gas through nozzles 410, 420, and 430 located within a cylindrical space defined by the inner wall of the inner tube 204 and the edges of the multiple wafers 200, i.e., within a preliminary chamber 205a. The gas is then ejected into the inner tube 204 from multiple gas supply holes 410a, 420a, and 430a located on the nozzles 410, 420, and 430, facing the wafer. More specifically, the gas supply holes 410a of nozzle 410, 420a of nozzle 420, and 430a of nozzle 430 eject the processing gas in a direction parallel to the surface of the wafer 200, i.e., horizontally.

[0026] The exhaust port (exhaust vent) 204a is a through-hole formed on the side wall of the inner tube 204, opposite the nozzles 410, 420, and 430, that is, 180 degrees opposite to the spare chamber 205a. For example, it is a slit-shaped through-hole that is elongated vertically. Therefore, the gas supplied into the processing chamber 201a from the gas supply holes 410a, 420a, and 430a of the nozzles 410, 420, and 430, and the gas that has flowed over the surface of the wafer 200, i.e., the residual gas, flows through the exhaust port 204a into the exhaust passage 206, which is formed by the gap between the inner tube 204 and the outer tube 203. The gas that has flowed into the exhaust passage 206 then flows into the exhaust pipe 231 and is discharged outside the processing furnace 202a.

[0027] The exhaust vent 204a is located opposite the multiple wafers 200 (preferably from the top to the bottom of the boat 217), and the gas supplied from the gas supply holes 410a, 420a, and 430a to the vicinity of the wafers 200 in the processing chamber 201a flows horizontally, i.e., parallel to the surface of the wafers 200, and then flows into the exhaust passage 206 through the exhaust vent 204a. In other words, the gas remaining in the processing chamber 201a is exhausted through the exhaust vent 204a parallel to the main surface of the wafers 200. Note that the exhaust vent 204a is not limited to being a slit-shaped through-hole, but may be composed of multiple holes.

[0028] The manifold 209 is provided with an exhaust pipe 231 for exhausting the atmosphere inside the processing chamber 201a. Connected to the exhaust pipe 231, in order from upstream, are a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201a, an APC (Auto Pressure Controller) valve 243, and a vacuum pump 246 as a vacuum evacuation device. The APC valve 243 can be opened and closed while the vacuum pump 246 is operating to evacuate and stop the vacuum evacuation inside the processing chamber 201a. Furthermore, the pressure inside the processing chamber 201a can be adjusted by adjusting the valve opening while the vacuum pump 246 is operating. The exhaust system, or exhaust line, is mainly composed of the exhaust port 204a, exhaust passage 206, exhaust pipe 231, APC valve 243, and pressure sensor 245. The vacuum pump 246 may also be considered as part of the exhaust system.

[0029] Below the manifold 209, a seal cap 219 is provided as a furnace opening cover capable of hermetically closing the lower end opening of the manifold 209. The seal cap 219 is configured to abut the lower end of the manifold 209 from the vertically downward side. The seal cap 219 is made of a metal such as SUS and is formed in a disc shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a sealing member that abuts the lower end of the manifold 209. On the opposite side of the processing chamber 201a in the seal cap 219, a rotating mechanism 267 is installed to rotate a boat 217 that houses the wafers 200. The rotation shaft 255 of the rotating mechanism 267 passes through the seal cap 219 and is connected to the boat 217. The rotating mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered vertically by a boat elevator 115, which is installed vertically outside the outer tube 203 as a lifting mechanism. The boat elevator 115 is configured to allow the boat 217 to be moved in and out of the processing chamber 201a by raising and lowering the seal cap 219. The boat elevator 115 is configured as a transport device (transport mechanism) for transporting the boat 217 and the wafers 200 contained in the boat 217 to the inside and outside of the processing chamber 201a.

[0030] The boat 217, which serves as a substrate support, is configured to support multiple wafers 200, for example 25 to 200 wafers 200, in a horizontal position and aligned vertically with their centers aligned, in multiple stages, that is, arranged with spacing between them. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, a heat-insulating plate 218, also made of a heat-resistant material such as quartz or SiC, is supported in a horizontal position in multiple stages (not shown). This configuration makes it difficult for heat from the heater 207 to be transferred to the seal cap 219 side. However, this embodiment is not limited to the above configuration. For example, instead of providing a heat-insulating plate 218 at the bottom of the boat 217, a heat-insulating cylinder, which is a cylindrical member made of a heat-resistant material such as quartz or SiC, may be provided.

[0031] As shown in Figure 2, a temperature sensor 263 is installed inside the inner tube 204 as a temperature detector. The amount of current supplied to the heater 207 is adjusted based on the temperature information detected by the temperature sensor 263 so that the temperature inside the processing chamber 201a reaches a desired temperature distribution. The temperature sensor 263 is configured in an L-shape, similar to the nozzles 410, 420, and 430, and is installed along the inner wall of the inner tube 204.

[0032] Figure 3 is a longitudinal cross-sectional view of the processing furnace 202b, which is a second process unit of the substrate processing apparatus 10, and Figure 4 is a cross-sectional view of the processing furnace 202b along line AA. The processing furnace 202b in this embodiment differs from the processing furnace 202a described above in the configuration of the processing chamber 201a. In the processing furnace 202b, only the parts that differ from the processing furnace 202a described above will be explained below, and the parts that are the same will not be explained. The processing furnace 202b is equipped with a processing chamber 201b as a second processing chamber.

[0033] Within the processing chamber 201b, nozzles 440 and 450 are provided so as to penetrate the side wall of the manifold 209 and the inner tube 204. Gas supply pipes 340 and 350 are connected to the nozzles 440 and 450, respectively. However, the processing furnace 202b of this embodiment is not limited to the above configuration.

[0034] Gas supply pipes 340 and 350 are equipped with MFCs 342 and 352, respectively, from the upstream side. Additionally, gas supply pipes 340 and 350 are equipped with valves 344 and 354, respectively. Downstream of valves 344 and 354 on gas supply pipes 340 and 350, gas supply pipes 540 and 550, which supply inert gas, are connected, respectively. Gas supply pipes 540 and 550 are equipped with MFCs 542 and 552 and valves 544 and 554, respectively, from the upstream side.

[0035] Nozzles 440 and 450 are connected to the ends of the gas supply pipes 340 and 350, respectively. The nozzles 440 and 450 are configured as L-shaped nozzles, with their horizontal portions penetrating the side wall of the manifold 209 and the inner tube 204. The vertical portions of the nozzles 440 and 450 are located inside a channel-shaped (groove-shaped) spare chamber 205b that protrudes radially outward from the inner tube 204 and extends vertically. Within the spare chamber 205b, the nozzles are positioned upward (upward in the direction of wafer 200 arrangement) along the inner wall of the inner tube 204.

[0036] The nozzles 440 and 450 are provided to extend from the lower region of the processing chamber 201b to the upper region of the processing chamber 201b, and each has a plurality of gas supply holes 440a and 450a at positions facing the wafer 200.

[0037] Multiple gas supply holes 440a and 450a of nozzles 440 and 450 are provided at a height from the bottom to the top of the boat 217, which will be described later. Therefore, the processing gas supplied into the processing chamber 201b from the gas supply holes 440a and 450a of nozzles 440 and 450 is supplied to the entire area of ​​the wafer 200 housed from the bottom to the top of the boat 217.

[0038] From the gas supply pipe 340, a gas containing a second metal element (hereinafter also referred to as "second metal-containing gas") is supplied to the processing chamber 201b as a processing gas via the MFC 342, valve 344, and nozzle 440.

[0039] From the gas supply pipe 350, a first reaction gas, which reacts with the second metal-containing gas, is supplied into the processing chamber 201b as a processing gas via the MFC 352, valve 354, and nozzle 450.

[0040] From the gas supply pipes 540 and 550, an inert gas, such as N2 gas, is supplied into the processing chamber 201b via MFCs 542 and 552, valves 544 and 554, and nozzles 440 and 450, respectively. While the following description will focus on the use of N2 gas as the inert gas, other noble gases such as argon (Ar), helium (He), neon (Ne), and xenon (Xe) gas may also be used as the inert gas.

[0041] The processing gas supply system (processing gas supply section) is mainly composed of gas supply pipes 340, 350, MFCs 342, 352, valves 344, 354, and nozzles 440, 450, but nozzles 440, 450 alone may be considered as the processing gas supply system. The processing gas supply system can also be simply called the gas supply system. When a second metal-containing gas is supplied from gas supply pipe 340, the second metal-containing gas supply system is mainly composed of gas supply pipe 340, MFC 342, and valve 344, but nozzle 440 may also be considered as part of the second metal-containing gas supply system. Similarly, when a first reaction gas is supplied from gas supply pipe 350, the first reaction gas supply system is mainly composed of gas supply pipe 350, MFC 352, and valve 354, but nozzle 450 may also be considered as part of the first reaction gas supply system. The first reaction gas supply system can also be called the reducing gas supply system. Furthermore, when hydrogen-containing gas is supplied as the first reaction gas from the gas supply pipe 350, the first reaction gas supply system can also be called the hydrogen-containing gas supply system. In addition, the inert gas supply system is mainly composed of gas supply pipes 540, 550, MFCs 542, 552, and valves 544, 554. The inert gas supply system can also be called the purge gas supply system, dilution gas supply system, or carrier gas supply system.

[0042] (Configuration of the control unit) As shown in Figure 5, the controller 121, which is the control unit (control means), is configured as a computer equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, storage device 121c, and I / O port 121d. The RAM 121b, storage device 121c, and I / O port 121d are configured to exchange data with the CPU 121a via an internal bus. An input / output device 122, configured as, for example, a touch panel, is connected to the controller 121.

[0043] The storage device 121c is composed of, for example, flash memory, an HDD (Hard Disk Drive), etc. The storage device 121c contains, in a readable format, a control program that controls the operation of the substrate processing device, and a process recipe that describes the procedures and conditions for the semiconductor device manufacturing method, which will be described later. The process recipe is a combination of steps that cause the controller 121 to execute each step in the semiconductor device manufacturing method, which will be described later, and to obtain a predetermined result; it functions as a program. Hereinafter, this process recipe, control program, etc., will be collectively referred to simply as a program. In this specification, the term "program" may include only the process recipe, only the control program, or a combination of the process recipe and the control program. The RAM 121b is configured as a memory area (work area) where programs and data read by the CPU 121a are temporarily held.

[0044] The I / O port 121d is connected to the MFCs 312, 322, 332, 342, 352, 512, 522, 532, 542, 552, valves 314, 324, 334, 344, 354, 514, 524, 534, 544, 554, pressure sensor 245, APC valve 243, vacuum pump 246, heater 207, temperature sensor 263, rotating mechanism 267, boat elevator 115, gate valves 70a to 70d, first substrate transfer machine 112, etc., which are provided in the aforementioned processing furnaces 202a and 202b, respectively.

[0045] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read recipes and other data from the storage device 121c in response to input of operation commands from the input / output device 122. The CPU 121a is configured to control the flow rate adjustment operations of various gases by MFCs 312, 322, 332, 342, 352, 512, 522, 532, 542, and 552, the opening and closing operations of valves 314, 324, 334, 344, 354, 514, 524, 534, 544, and 554, the opening and closing operations of the APC valve 243 and the pressure adjustment operations of the APC valve 243 based on the pressure sensor 245, the temperature adjustment operations of the heater 207 based on the temperature sensor 263, the starting and stopping of the vacuum pump 246, the rotation and rotation speed adjustment operations of the boat 217 by the rotating mechanism 267, the raising and lowering operations of the boat 217 by the boat elevator 115, and the loading operations of wafers 200 into the boat 217, etc., in accordance with the contents of the read recipe.

[0046] The controller 121 can be configured by installing the above-mentioned program, stored in an external storage device (for example, magnetic tape, magnetic disks such as flexible disks or hard disks, optical disks such as CDs or DVDs, magneto-optical disks such as MOs, or semiconductor memory such as USB memory or memory cards) 123, into a computer. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to simply as recording media. In this specification, a recording media may include only the storage device 121c, only the external storage device 123, or both. Note that the program may be provided to the computer using communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0047] (2) Substrate processing process (film formation process) An example of a process in which, as one step in the manufacturing process of a semiconductor device, a first metal-containing film containing a first metal element and a cap film are formed on a wafer 200 in a processing furnace 202a, and a second metal-containing film containing a second metal element is formed on the wafer 200 in a processing furnace 202b while removing at least a portion of the cap film formed on the first metal-containing film, will be explained using Figures 6, 7, and 8(A) to 8(C). In the following explanation, the operation of each part constituting the substrate processing apparatus 10 is controlled by the controller 121.

[0048] In the substrate processing process (semiconductor manufacturing process) according to this embodiment, (a) A step of preparing a substrate having a film containing a first metal element and a film containing a group 13 or group 14 element formed on the film containing the first metal element, (b) A step of supplying a gas containing a second metal element to the substrate, (c) A step of supplying a first reaction gas to the substrate, It has, (d)(b) and (c) are performed to remove at least a portion of the film containing the Group 13 or Group 14 element formed on the film containing the first metal element, while forming a film containing the second metal element on the substrate. It holds.

[0049] In this specification, the term "wafer" may refer to "the wafer itself" or to "a laminate (assembly) of a wafer and a predetermined layer or film formed on its surface" (i.e., the term "wafer" may include the predetermined layer or film formed on the surface). Similarly, the term "surface of the wafer" may refer to "the surface (exposed surface) of the wafer itself" or to "the surface of a predetermined layer or film formed on the wafer, i.e., the outermost surface of the wafer as a laminate." In this specification, the term "substrate" is used interchangeably with the term "wafer."

[0050] A. Formation of the first metal-containing film First, a wafer 200 is brought into a processing furnace 202a, which serves as the first process unit, and a first metal-containing film containing a first metal element and a cap film containing a group 13 or group 14 element are formed on the wafer 200.

[0051] (Wafer delivery) Once multiple wafers 200 are loaded into the boat 217 (wafer charging), the boat 217 supporting the multiple wafers 200 is lifted by the boat elevator 115 and transported into the processing chamber 201a (boat loading), as shown in Figure 1. In this state, the seal cap 219 closes the lower end opening of the outer tube 203 via the O-ring 220b.

[0052] (Pressure adjustment and temperature adjustment) The processing chamber 201a, i.e., the space where the wafer 200 is located, is evacuated by a vacuum pump 246 to a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201a is measured by a pressure sensor 245, and the APC valve 243 is feedback-controlled based on this measured pressure information (pressure adjustment). The processing chamber 201a is also heated by a heater 207 to a desired temperature. At this time, the amount of power supplied to the heater 207 is feedback-controlled based on the temperature information detected by a temperature sensor 263 to ensure a desired temperature distribution inside the processing chamber 201a (temperature adjustment). The rotation of the wafer 200 is also started by a rotation mechanism 267. The evacuation of the processing chamber 201a, the heating of the wafer 200, and the rotation are all continued at least until the processing of the wafer 200 is completed.

[0053] [First metal-containing film formation process] Next, the step of forming a first metal-containing film on the wafer 200 is performed.

[0054] (First metal-containing gas supply step S10) Valve 314 is opened, and the first metal-containing gas flows into the gas supply pipe 310. The flow rate of the first metal-containing gas is regulated by MFC 312 and supplied into the processing chamber 201a from the gas supply hole 410a of the nozzle 410, and exhausted from the exhaust pipe 231. At the same time, valve 514 is opened, and an inert gas such as N2 gas flows into the gas supply pipe 510. The inert gas that has flowed through the gas supply pipe 510 is regulated by MFC 512 and supplied into the processing chamber 201a together with the first metal-containing gas, and exhausted from the exhaust pipe 231. At this time, in order to prevent the first metal-containing gas from entering the nozzles 420 and 430, valves 524 and 534 are opened, and inert gas flows into the gas supply pipes 520 and 530. The inert gas is supplied into the processing chamber 201a via gas supply pipes 320, 330 and nozzles 420, 430, and exhausted through exhaust pipe 231.

[0055] At this time, the APC valve 243 is adjusted to set the pressure in the processing chamber 201 to a pressure within the range of, for example, 1 to 3990 Pa. The supply flow rate of the first metal-containing gas controlled by the MFC 312 is set to a flow rate within the range of, for example, 0.1 to 2.0 slm. The supply flow rates of the inert gas controlled by the MFCs 512, 522, and 532 are each set to a flow rate within the range of, for example, 0.1 to 20 slm. In the following steps, the temperature of the heater 207 is set to a temperature such that the temperature of the wafer 200 is within the range of, for example, 300 to 650°C. The time for supplying the first metal-containing gas to the wafer 200 is set to a time within the range of, for example, 0.01 to 30 seconds. In this disclosure, numerical range notations such as "1 to 3990 Pa" mean that the lower limit and upper limit are included in that range. Therefore, for example, "1 to 3990 Pa" means "1 Pa or more and 3990 Pa or less". The same applies to other numerical ranges.

[0056] At this time, a first metal-containing gas is supplied to the wafer 200. Here, the first metal-containing gas can be, for example, a gas containing titanium (Ti) as the first metal element, and as an example, titanium tetrachloride (TiCl4) gas containing halogen elements can be used.

[0057] (Purge Step S11) After a predetermined time has elapsed since the start of supplying the first metal-containing gas, valve 314 is closed to stop the supply of the first metal-containing gas. At this time, the APC valve 243 of the exhaust pipe 231 is left open, and the processing chamber 201a is evacuated using the vacuum pump 246 to remove any unreacted or metal-containing gas that has contributed to the formation of the first metal-containing film remaining in the processing chamber 201a. At this time, valves 514, 524, and 534 are left open to maintain the supply of inert gas to the processing chamber 201a. The inert gas acts as a purge gas, enhancing the effect of removing any unreacted or metal-containing gas that has contributed to the formation of the first metal-containing film remaining in the processing chamber 201a.

[0058] (Third reaction gas supply step S12) After a predetermined time has elapsed since the start of purging, valve 324 is opened to allow the third reaction gas to flow into the gas supply pipe 320. The flow rate of the third reaction gas is regulated by MFC 322 and supplied into the processing chamber 201a from the gas supply hole 420a of nozzle 420, and exhausted from exhaust pipe 231. At the same time, valve 524 is opened to allow inert gas to flow into the gas supply pipe 520. In addition, to prevent the third reaction gas from entering nozzles 410 and 430, valves 514 and 534 are opened to allow inert gas to flow into gas supply pipes 510 and 530.

[0059] At this time, the APC valve 243 is adjusted to set the pressure in the processing chamber 201a to a pressure within the range of, for example, 1 to 3990 Pa. The supply flow rate of the third reaction gas controlled by MFC 322 is set to a flow rate within the range of, for example, 0.1 to 30 slm. The supply flow rates of the inert gas controlled by MFC 512, 522, and 532 are each set to a flow rate within the range of, for example, 0.1 to 20 slm. The time for supplying the third reaction gas to the wafer 200 is set to a time within the range of, for example, 0.01 to 30 seconds.

[0060] At this time, a third reaction gas is supplied to the wafer 200. Here, the third reaction gas can be, for example, a nitrogen-containing gas containing nitrogen (N). As the nitrogen-containing gas, ammonia (NH3) gas can be used.

[0061] (Purge Step S13) After a predetermined time has elapsed since the start of supplying the third reaction gas, valve 324 is closed to stop the supply of the third reaction gas. Then, using the same processing procedure as in step S11, any unreacted or third reaction gas that has contributed to the formation of the first metal-containing film remaining in the processing chamber 201a is removed from the processing chamber 201a.

[0062] (Performed the prescribed number of times) By performing the above steps S10 to S13 in order one or more times (a predetermined number of times (p times)), a first metal-containing film containing a first metal element of a predetermined thickness is formed on the wafer 200, as shown in Figure 8(A). It is preferable to repeat the above cycle multiple times. Here, for example, a TiN film is formed on the wafer 200 as the first metal-containing film.

[0063] [Cap film formation process] Next, a step is performed to form a cap film on the wafer 200 on which the first metal-containing film has been formed on its surface. The cap film is a group 13 or group 14 element-containing film containing a group 13 or group 14 element, and functions as an antioxidant film that prevents oxidation of the outermost surface of the first metal-containing film described above.

[0064] (Supplying gas containing Group 13 or Group 14 elements - Step S20) Valve 334 is opened, and a gas containing a group 13 or group 14 element flows into the gas supply pipe 330. The gas containing a group 13 or group 14 element has its flow rate regulated by MFC 332 and is supplied into the processing chamber 201a from the gas supply hole 430a of the nozzle 430, and exhausted from the exhaust pipe 231. At the same time, valve 534 is opened, and an inert gas flows into the gas supply pipe 530. In addition, to prevent the gas containing a group 13 or group 14 element from entering the nozzles 410 and 420, valves 514 and 524 are opened, and an inert gas flows into the gas supply pipes 510 and 520.

[0065] At this time, the APC valve 243 is adjusted to set the pressure in the processing chamber 201 to a pressure within the range of, for example, 1 to 3990 Pa. The supply flow rate of the Group 13 or Group 14 element-containing gas controlled by the MFC 332 is set to a flow rate within the range of, for example, 0.1 to 30 slm. The supply flow rates of the inert gas controlled by the MFCs 512, 522, and 532 are each set to a flow rate within the range of, for example, 0.1 to 20 slm. The time for supplying the Group 13 or Group 14 element-containing gas to the wafer 200 is set to a time within the range of, for example, 0.01 to 30 seconds.

[0066] At this time, a gas containing a group 13 or group 14 element is supplied to the wafer 200 on which the first metal-containing film has been formed on its surface. Here, as the group 13 or group 14 element-containing gas, for example, a Si-containing gas containing silicon (Si) can be used, and as an example, dichlorosilane (SiH2Cl2, abbreviated as DCS) gas can be used. By using a group 13 or group 14 element-containing gas, the cap film can be easily sublimated and removed when forming the second metal-containing film, which will be described later.

[0067] Group 14 elements include, for example, silicon (Si) and germanium (Ge), and at least one other element. Group 14 element-containing gases include, for example, these elements along with at least one hydrogen (H), halogen elements (fluorine (F), chlorine (Cl)), and alkyl groups (e.g., methyl group CH3). Examples of Si-containing gases include silane gases and halosilane gases. Examples of silane gases include monosilane (SiH4), disilane (Si2H6), and trisilane (Si3H8). Examples of halosilane gases include dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), tetrachlorosilane (SiCl4), and hexachlorodisilane (Si2Cl6).

[0068] (Purge Step S21) After a predetermined time has elapsed since the start of supplying the gas containing the Group 13 or Group 14 element, the valve 334 is closed to stop the supply of the gas containing the Group 13 or Group 14 element. Then, using the same processing procedure as in step S11, any unreacted or Group 13 or Group 14 element-containing gas remaining in the processing chamber 201a that has contributed to the formation of the cap film is removed from the processing chamber 201a.

[0069] (Third reaction gas supply step S22) After a predetermined time has elapsed since the start of purging, valve 324 is opened to allow the third reaction gas to flow into the gas supply pipe 320. The flow rate of the third reaction gas is regulated by MFC 322 and supplied into the processing chamber 201a from the gas supply hole 420a of nozzle 420, and exhausted from exhaust pipe 231. At the same time, valve 524 is opened to allow inert gas to flow into the gas supply pipe 520. In addition, to prevent the third reaction gas from entering nozzles 410 and 430, valves 514 and 534 are opened to allow inert gas to flow into gas supply pipes 510 and 530.

[0070] At this time, the APC valve 243 is adjusted to set the pressure in the processing chamber 201a to a pressure within the range of, for example, 1 to 3990 Pa. The supply flow rate of the third reaction gas controlled by MFC 322 is set to a flow rate within the range of, for example, 0.1 to 30 slm. The supply flow rates of the inert gas controlled by MFC 512, 522, and 532 are each set to a flow rate within the range of, for example, 0.1 to 20 slm. The time for supplying the third reaction gas to the wafer 200 is set to a time within the range of, for example, 0.01 to 30 seconds.

[0071] At this time, a third reaction gas is supplied to the wafer 200. Here, as the third reaction gas, for example, NH3 gas, which is an N-containing gas containing N, can be used.

[0072] (Purge Step S23) After a predetermined time has elapsed since the start of supplying the third reaction gas, valve 324 is closed to stop the supply of the third reaction gas. Then, using the same processing procedure as in step S11, any unreacted or partially formed third reaction gas remaining in the processing chamber 201a is removed from the processing chamber 201a.

[0073] (Performed the prescribed number of times) By repeating the cycle of steps S20 to S23 described above one or more times (a predetermined number of times (n)), a cap film of a predetermined thickness is formed on the wafer 200 on which the first metal-containing film is formed on the surface, as shown in Figure 8(B). It is preferable to perform the above cycle multiple times, and it is preferable to use cyclic supply. The thickness of the cap film formed here is preferably 0.2 to 3 nm. If the thickness of the cap film is greater than 3 nm, the cap film may remain even after the second metal-containing film formation step described later. Also, if it is thinner than 0.2 nm, the underlying first metal-containing film may be oxidized. That is, during the second metal-containing film formation step, the oxidized first metal-containing film is etched, and a decrease in the properties of the first metal-containing film occurs. Here, a decrease in the properties of the first metal-containing film means that if the first metal-containing film is a barrier film, the barrier performance decreases. For this reason, it is preferable to form the cap film to be 0.2 nm or more in thickness, which can suppress the oxidation of the first metal-containing film. While increasing the thickness of the cap film enhances the oxidation suppression effect of the first metal-containing film, it may not be removed during the formation of the second metal-containing film. Therefore, in this process, a cap film with a thickness of 0.2 to 3 nm, preferably 0.2 to 2 nm, is formed on the wafer 200 on which the first metal-containing film is formed on the surface. By setting the thickness to 2 nm or less, it becomes possible to remove the cap film during the second metal-containing film formation process. Here, for example, a silicon nitride (SiN) film, which is a Si-containing film of group 14 elements, is formed as the cap film. Here, 0.2 nm is the thickness of one atomic layer when the cap film is composed of SiN. Since the thickness of one atomic layer varies depending on the type of cap film, the film thickness (number of layers) may be changed depending on the type of cap film. By forming a film with a thickness of one atomic layer, the oxidation suppression effect of the first metal-containing film can be obtained. If the thickness is less than one atomic layer, holes will be formed, and the oxidation suppression effect of the first metal-containing film will be insufficient. Furthermore, by making the cap film only a few atomic layers thick, the oxidation suppression effect can be further enhanced. However, with a layer of only one atomic layer thickness, pinholes may form, and the first metal-containing film may oxidize through these pinholes.Therefore, the cap film is preferably made of two or more atomic layers and a few atomic layers or less. Forming two or more atomic layers can suppress the formation of pinholes. Pinholes can occur due to steric hindrance caused by the molecular size of the raw material gas used in the formation of the cap film, as well as due to the reaction characteristics of the raw material gas and the reaction characteristics of the reaction gas. Furthermore, by making the thickness of the cap film a few atomic layers, it is possible to form the second metal-containing film while removing at least a portion of the cap film formed on the first metal-containing film during the formation process of the second metal-containing film. Here, if the cap film is SiN, the thickness of two to a few atomic layers is 0.4 to 1.8 nm. By making it 1.8 nm or less, it becomes possible to remove the cap film in the initial stage of the second metal-containing film formation process, and the layer in which the second metal-containing film and the cap film are mixed can be reduced. In the layer in which the second metal-containing film and the cap film are mixed, the electrical properties of the second metal-containing film may deteriorate.

[0074] (After-purge and return to atmospheric pressure) Inert gas is supplied into the processing chamber 201a from gas supply pipes 510, 520, and 530, and exhausted from exhaust pipe 231. The inert gas acts as a purge gas, purging the processing chamber 201a and removing any remaining gases and by-products (after-purging). Subsequently, the atmosphere inside the processing chamber 201a is replaced with inert gas (inert gas replacement), and the pressure inside the processing chamber 201a is returned to atmospheric pressure (restoration to atmospheric pressure).

[0075] (Wafer removal) Subsequently, the seal cap 219 is lowered by the boat elevator 115, opening the lower end of the outer tube 203. Then, the processed wafer 200, with the first metal-containing film formed on the wafer 200 and the cap film formed on the first metal-containing film, is unloaded from the lower end of the outer tube 203 (boat unloading) while supported by the boat 217. After that, the processed wafer 200 is removed from the boat 217 (wafer discharge).

[0076] B. Formation of a second metal-containing film Next, the wafer 200 processed in the processing furnace 202a is brought into the processing furnace 202b, which serves as the second process unit. That is, the wafer 200 having a first metal-containing film and a cap film formed on the first metal-containing film is prepared in the processing furnace 202b. Then, the pressure and temperature inside the processing chamber 201b are adjusted to the desired pressure and temperature distribution. This process differs from the process in the processing furnace 202a described above only in the gas supply process. Therefore, only the parts that differ from the process in the processing furnace 202a described above will be explained below, and the parts that are the same will be omitted from the explanation.

[0077] [Second metal-containing film formation process] Next, the wafer 200 on which a cap film has been formed on its surface is subjected to the step of forming a second metal-containing film containing a second metal element while removing at least a portion of the cap film formed on the first metal-containing film.

[0078] (Second metal-containing gas supply step S30) Valve 344 is opened, and a second metal-containing gas flows into the gas supply pipe 340. The flow rate of the second metal-containing gas is regulated by MFC 342 and supplied into the processing chamber 201b from the gas supply hole 440a of the nozzle 440, and exhausted from the exhaust pipe 231. At the same time, valve 544 is opened, and an inert gas such as N2 gas flows into the gas supply pipe 540. The inert gas that has flowed through the gas supply pipe 540 is regulated by MFC 542 and supplied into the processing chamber 201b together with the second metal-containing gas, and exhausted from the exhaust pipe 231. At this time, in order to prevent the second metal-containing gas from entering the nozzle 450, valve 554 is opened, and inert gas flows into the gas supply pipe 550. The inert gas is supplied into the processing chamber 201b via the gas supply pipe 350 and nozzle 450, and exhausted from the exhaust pipe 231.

[0079] At this time, the APC valve 243 is adjusted to set the pressure in the processing chamber 201 to a range of, for example, 0.1 to 6650 Pa. The supply flow rate of the second metal-containing gas controlled by the MFC 342 is set to a flow rate of, for example, 0.01 to 10 slm. The supply flow rates of the inert gas controlled by the MFCs 542 and 552 are set to a flow rate of, for example, 0.1 to 20 slm, respectively. The time for supplying the second metal-containing gas to the wafer 200 is set to a time of, for example, 0.01 to 30 seconds. At this time, the temperature of the heater 207 is set to a temperature such that the temperature of the wafer 200 is in the range of, for example, 250 to 550°C. The only gases flowing in the processing chamber 201b are the second metal-containing gas and the inert gas. By supplying the second metal-containing gas, the cap film on the wafer 200 is removed, and a second metal-containing film with a thickness of, for example, less than one atomic layer to several atomic layers is formed on the wafer 200 (surface underlayer).

[0080] At this time, a second metal-containing gas is supplied to the wafer 200 on which a cap film has been formed on its surface. Here, as the second metal-containing gas, for example, tungsten hexafluoride (WF6) gas can be used, which contains tungsten (W) as the second metal element and fluorine (F) as the halogen element.

[0081] At this time, the cap film is sublimated by the supply of a second metal-containing gas. That is, the cap film reacts with the halogen elements contained in the second metal-containing gas, and the cap film is removed (etched). Specifically, by supplying WF6 gas, an example of a second metal-containing gas, to a SiN film, an example of a cap film, SiN and WF6 react, W is adsorbed onto the wafer 200 surface, and silicon tetrafluoride (SiF4) and N2 are produced. Because SiF4 is easily sublimated, the SiF4 is sublimated, and the N2 is removed by purging in the next step S31. That is, the cap film is removed.

[0082] Here, the removal of the cap film may include a state where a portion of the cap film remains. In other words, a portion of the cap film may remain in the second metal-containing film. In device structures, for example, a TiN film may be formed on an aluminum oxide (AlO) film, and a W film may be formed on top of that. In this case, the W film functions as an electrode, while the TiN film does not. Therefore, even if an insulating film exists between the W film and the TiN film, it has little effect on their respective electrical properties.

[0083] (Purge Step S31) After a predetermined time has elapsed since the start of supplying the second metal-containing gas, valve 344 is closed to stop the supply of the second metal-containing gas. At this time, the APC valve 243 of the exhaust pipe 231 is left open, and the processing chamber 201b is evacuated using the vacuum pump 246 to remove any unreacted material or cap film remaining in the processing chamber 201b and to remove the second metal-containing gas that has contributed to the formation of the second metal-containing film. At this time, valves 544 and 554 are left open to maintain the supply of inert gas to the processing chamber 201b. The inert gas acts as a purge gas, enhancing the effect of removing any unreacted material or cap film remaining in the processing chamber 201b and to remove the second metal-containing gas that has contributed to the formation of the second metal-containing film.

[0084] (First reaction gas supply step S32) After a predetermined time has elapsed since the start of purging, valve 354 is opened to allow the first reaction gas to flow into the gas supply pipe 350. The flow rate of the first reaction gas is regulated by MFC 352 and supplied to the processing chamber 201b from the gas supply hole 450a of the nozzle 450, and exhausted from the exhaust pipe 231. At the same time, valve 554 is opened to allow inert gas to flow into the gas supply pipe 550. The flow rate of the inert gas that has flowed through the gas supply pipe 550 is regulated by MFC 552 and supplied to the processing chamber 201b together with the first reaction gas, and exhausted from the exhaust pipe 231. At this time, in order to prevent the first reaction gas from entering the nozzle 440, valve 544 is opened and inert gas is allowed to flow into the gas supply pipe 540. The inert gas is supplied to the processing chamber 201b via the gas supply pipe 340 and nozzle 440, and exhausted from the exhaust pipe 231.

[0085] At this time, the APC valve 243 is adjusted to set the pressure in the processing chamber 201b to a pressure within the range of, for example, 1 to 3990 Pa. The supply flow rate of the first reaction gas controlled by the MFC 352 is set to a flow rate within the range of, for example, 0.1 to 50 slm. The supply flow rates of the inert gas controlled by the MFCs 542 and 552 are set to flow rates within the range of, for example, 0.1 to 20 slm, respectively. The time for supplying the first reaction gas to the wafer 200 is set to a time within the range of, for example, 0.1 to 20 seconds. At this time, the temperature of the heater 207 is set to a temperature such that the temperature of the wafer 200 is within the range of, for example, 200 to 600°C. The only gases flowing in the processing chamber 201b are the first reaction gas and the inert gas. As the first reaction gas is supplied, the cap film on the wafer 200 is removed, and a second metal-containing film with a thickness of, for example, less than one atomic layer to several atomic layers is formed on the wafer 200 (surface underlayer).

[0086] At this time, a first reaction gas is supplied to the cap film formed on the surface of the wafer 200. As the first reaction gas, for example, hydrogen (H2) gas, which is a reducing gas and contains hydrogen (H) (hereinafter also referred to as "hydrogen-containing gas"), can be used.

[0087] The supply of the first reaction gas removes halogen elements from the film, further removing the cap film. Specifically, when WF6 gas, an example of a second metal-containing gas, and H2 gas, an example of a first reaction gas, are supplied to the wafer 200 on which a cap film has been formed on its surface, WF6 and H2 react to produce hydrogen fluoride (HF), forming a W film from which F has been removed. Furthermore, the SiN film acting as a cap film is removed by the HF produced by this reaction. In other words, the cap film is removed by halogen elements contained in the second metal-containing gas, and then further removed by the HF produced by the supply of the second metal-containing gas and the first reaction gas.

[0088] In other words, by forming a cap film on the first metal-containing film, oxidation of the first metal-containing film is suppressed, and when forming the second metal-containing film on the cap film, the cap film can be sublimated and eliminated. That is, a second metal-containing film can be formed that has a low content of Group 13 or Group 14 elements contained in the cap film.

[0089] Here, the supply flow rate of the first reaction gas is set to be less than the supply flow rate of the second metal-containing gas described above, and after a predetermined period (after a predetermined number of cycles), it is changed to approximately the same flow rate as the supply flow rate of the second metal-containing gas. Here, approximately the same flow rate includes an error of about 10%. In this way, by initially supplying a larger flow rate of the second metal-containing gas compared to the supply flow rate of the first reaction gas, the reaction between the halogen elements contained in the second metal-containing gas and the cap film is promoted, and the cap film is removed. Then, after the cap film has been removed after a predetermined period, by setting the supply flow rate of the first reaction gas to approximately the same as the supply flow rate of the second metal-containing gas, the reaction between the first reaction gas and the second metal-containing gas is promoted, and a second metal-containing film with fewer halogen elements is formed. In other words, it is possible to form a second metal-containing film with fewer halogen elements on top of the first metal-containing film while suppressing etching of the first metal-containing film by the formation of the second metal-containing film.

[0090] Furthermore, the supply flow rate of the first reaction gas may initially be higher than the supply flow rate of the inert gas used as a carrier gas, and then changed to a flow rate lower than that of the inert gas after a predetermined period (after a predetermined number of cycles). In this way, by initially supplying a flow rate of the first reaction gas that is higher than that of the carrier gas, the reaction between the second metal-containing gas and the first reaction gas is promoted, increasing the amount of HF produced and removing the cap film. After the cap film has been removed after a predetermined period, the supply flow rate of the first reaction gas can be reduced compared to that of the inert gas to suppress the formation of reaction byproducts.

[0091] (Purge Step S33) After a predetermined time has elapsed since the start of supplying the first reaction gas, valve 354 is closed to stop the supply of the first reaction gas. Then, using the same processing procedure as in step S11, the unreacted material or cap film remaining in the processing chamber 201b is removed, and the first reaction gas, which has contributed to the formation of the second metal-containing film, is removed from the processing chamber 201.

[0092] (Performed the prescribed number of times) By repeating the cycle of steps S30 to S33 described above one or more times (a predetermined number of times (m times)), it is possible to form a second metal-containing film containing a second metal element of a predetermined thickness on the wafer 200 while sublimating the cap film formed on the wafer 200. That is, as shown in Figure 8(C), it is possible to form a second metal-containing film of a predetermined thickness on the wafer 200 while removing at least a portion of the cap film formed on the first metal-containing film. It is preferable to perform the above cycle multiple times, and the number of cycles in the second metal-containing film formation step (m times) is greater than the number of cycles in the cap film formation step (n times) described above. That is, m > n (where m and n are positive integers). This makes it possible to form a second metal-containing film of a predetermined thickness on the wafer 200 while sublimating the cap film formed on the wafer 200.

[0093] (After-purge and return to atmospheric pressure) Inert gas is supplied into the processing chamber 201b from gas supply pipes 540 and 550, respectively, and exhausted from exhaust pipe 231. The inert gas acts as a purge gas, purging the processing chamber 201b and removing any remaining gases and by-products (after-purging). Subsequently, the atmosphere inside the processing chamber 201b is replaced with inert gas (inert gas replacement), and the pressure inside the processing chamber 201b is returned to atmospheric pressure (restoration to atmospheric pressure).

[0094] (Wafer removal) Subsequently, the seal cap 219 is lowered by the boat elevator 115, opening the lower end of the outer tube 203. Then, the processed wafer 200, supported by the boat 217, is unloaded from the lower end of the outer tube 203 to the outside of the outer tube 203 (boat unloading). After that, the processed wafer 200 is removed from the boat 217 (wafer discharge).

[0095] (3) Effects of this embodiment According to this embodiment, one or more of the following effects can be obtained. (a) Film properties can be improved. (b) In particular, oxidation of the surface of the barrier film (first metal-containing film) can be suppressed. (c) Furthermore, etching of the barrier film can be suppressed, and the barrier properties of the barrier film can be improved. (d) The resistivity of the metal-containing film (second metal-containing film) formed on the barrier film can be reduced. (e) The properties of the metal-containing film formed on the barrier film can be improved.

[0096] <Other Embodiments> The embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the embodiments described above, and can be modified in various ways without departing from its essence.

[0097] (modified version) Figure 9 shows a modified example of the substrate processing sequence in one embodiment of the present disclosure. This modified example differs from the embodiment described above in the second metal-containing film formation step. Specifically, in the second metal-containing film formation step, a second metal-containing gas supply and a first reaction gas supply are performed to form a second metal-containing film of a predetermined thickness on the wafer 200 while removing at least a portion of the cap film. Then, a second metal-containing gas supply and a second reaction gas supply, which supplies a second reaction gas different from the first reaction gas, are performed to form another film containing a second metal element on the second metal-containing film. Here, the other film containing a second metal element formed on the second metal-containing film contains the second metal element contained in the second metal-containing film and has a lower resistivity compared to the second metal-containing film. This modified example makes it possible to form a second metal-containing film with low resistivity while removing at least a portion of the cap film.

[0098] Here, when WF6 gas is used as the second metal-containing gas, H2 gas (the first hydrogen-containing gas) as the first reaction gas, and B2H6 gas (the second hydrogen-containing gas) as the second reaction gas, by supplying WF6 gas and H2 gas a predetermined number of times (m times), a W film with little SiN and F residue is formed on the wafer 200 while removing at least a portion of the SiN film, which is an example of a cap film formed on the first metal-containing film. Then, by supplying WF6 gas and B2H6 gas a predetermined number of times (q times), a W film with low resistivity is formed. In other words, it is possible to form a second metal-containing film with low resistivity on the first metal-containing film while suppressing etching of the first metal-containing film by the formation of the second metal-containing film.

[0099] In the above embodiment, an example was described in which DCS gas is used as the Group 13 or Group 14 element-containing gas in the cap film formation process. However, the method is not limited to this and can be applied to cases where different gases are used. For example, it can be applied when hexachlorodisilane (Si2Cl6, abbreviated as HCDS) gas is used as the Group 13 or Group 14 element-containing gas. When HCDS gas is supplied as the Group 13 or Group 14 element-containing gas and NH3 gas is supplied as the third reaction gas, Si2Cl6 and NH3 react, and Si x N y Chlorine (Cl2) and hydrochloric acid (HCl) are generated, and a SiN film can be formed as a cap film on the wafer 200 on which a first metal-containing film has been formed on its surface.

[0100] Furthermore, although the above embodiment described an example in which H2 gas is used as the first reaction gas in the second metal-containing film formation step, the method is not limited to this and can be applied to cases where different gases are used. For example, it can be applied when monosilane (SiH4) gas or disilane (Si2H6) gas, which are gases containing silicon (Si) and hydrogen (H), are used as the first reaction gas. By using a gas containing Si and H, such as SiH4 gas, as the first reaction gas, the reaction is accelerated compared to the case in which H2 gas is used as described above, the amount of HF produced increases, and the etching (removal) of the SiN film by HF can be accelerated.

[0101] Furthermore, the above embodiment can also be applied when diborane (B2H6) gas or monoborane (BH3) gas, which are gases containing boron (B) and hydrogen (H), are used as the first reaction gas in the second metal-containing film formation step. By using a gas containing B and H, such as B2H6 gas, as the first reaction gas, the reaction is accelerated compared to the case where H2 gas is used as described above, increasing the amount of HF produced and promoting the etching (removal) of the SiN film by HF. In addition, it is possible to reduce the resistivity of the second metal-containing film, such as a W film, formed on the first metal-containing film, such as a TiN film.

[0102] Here, SiH4 and B2H6 react more readily with WF6 than H2. Therefore, by using SiH4 or B2H6 gas as the first reaction gas, the reaction with WF6 is promoted, increasing the amount of HF produced and thus accelerating the removal of the SiN film by HF. However, in the reaction between WF6 and SiH4 (or B2H6), a W film may form before the SiN film is removed, and the SiN film may remain beneath the W film. Also, when H2 gas is used as the first reaction gas, the reaction with WF6 is slower and the amount of residual SiN film is less compared to when SiH4 or B2H6 gas is used.

[0103] Furthermore, in the above embodiment, the first metal-containing film formation step and the cap film formation step are performed in the same processing furnace 202a (in situ), and then the second metal-containing film formation step is performed in the processing furnace 202b (ex-situ) to suppress oxidation of the surface of the first metal-containing film and to form the second metal-containing film on top of the first metal-containing film. However, the invention is not limited to this configuration, and the second metal-containing film formation step may be performed continuously in the same processing furnace as the first metal-containing film formation step and the cap film formation step. That is, the process may be carried out continuously while the wafer 200 with the cap film formed on its surface is housed in the processing chamber 201a without being removed from the processing chamber 201a. In other words, the process may be carried out continuously in the same processing chamber (in situ).

[0104] Furthermore, although the above embodiment described an example in which a TiN film is used as the first metal-containing film, the method is not limited to this and can also be applied to metal-containing films such as molybdenum (Mo) film, ruthenium (Ru) film, and copper (Cu) film.

[0105] Furthermore, in the above embodiment, an example was described in which a SiN film is used as the cap film containing a Group 13 or Group 14 element. However, the invention is not limited to this, and can also be applied to films containing Group 13 elements such as boron (B), aluminum (Al), gallium (Ga), and indium (In), or films containing Group 14 elements such as Si and germanium (Ge). For example, in addition to a SiN film, a nitride film such as an aluminum nitride (AlN) film can be used as the cap film. These films suppress the oxidation of the underlying metal-containing film and can be sublimated and destroyed when a metal-containing film different from the underlying metal-containing film is formed on the cap film. Note that SiN films are more easily sublimated and destroyed compared to AlN films.

[0106] Examples of Group 13 element-containing gases include those containing these elements along with at least one hydrogen (H), halogen elements (fluorine (F), chlorine (Cl)), and alkyl groups (e.g., methyl group CH3). Examples of Al-containing gases include trimethylaluminum (Al(CH3)3) gas and aluminum trichloride (AlCl3) gas. By using such gases, AlN films can be formed.

[0107] Furthermore, although the above embodiment describes an example in which purging is performed between each step in the second metal-containing film formation process, the invention is not limited to this, and purging is not required between each step in the second metal-containing film formation process. The second metal-containing gas and the first reaction gas, or the second metal-containing gas and the second reaction gas, may be supplied simultaneously.

[0108] Examples are described below, but this disclosure is not limited to these examples. [Examples]

[0109] First, as shown in Figure 10(A), using the processing furnace 202a of the substrate processing apparatus 10 described above, Sample 1 was prepared by performing the first metal-containing film formation step and the cap film formation step in the substrate processing sequence shown in Figure 6 above to form a TiN film and a SiN film as a cap film on a wafer 200. Sample 2 was prepared by performing only the first metal-containing film formation step in the substrate processing sequence shown in Figure 6 above to form a TiN film on a wafer. X-ray photoelectron spectroscopy (XPS) analysis was performed on the surfaces of Sample 1 and Sample 2.

[0110] As shown in Figures 10(B) and 10(C), the peak values ​​for Sample 1 and Sample 2 were different, confirming that the formation of a cap film on the TiN film suppresses the TiO component and inhibits oxidation of the TiN film.

[0111] Next, as shown in Figure 11(A), the substrate processing sequence shown in Figure 7 was performed using the processing furnace 202b of the substrate processing apparatus 10 described above to form W films on the surfaces of sample 1 and sample 2, respectively, and XPS analysis was performed on the surfaces of sample 1 and sample 2.

[0112] As shown in Figure 11(B), the Ti2p intensity of Sample 1 was higher than that of Sample 2, confirming that a larger amount of TiN film remained. In other words, it was confirmed that the formation of a cap film suppressed the etching of the TiN film during W film deposition. Furthermore, as shown in Figures 10(C) and 11(C), the peak value of the cap film disappeared, confirming that the cap film was removed by forming a W film on top of it.

[0113] Although various typical embodiments and examples of the present disclosure have been described above, the present disclosure is not limited to these embodiments and examples, and they can be used in combination as appropriate. [Explanation of Symbols]

[0114] 10 Substrate Processing Equipment 121 Controller 200 wafers (substrates) 201a, 201b Processing Rooms 202a, 202b processing reactors

Claims

1. (a) A step of preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metallic element, and a film formed on the film containing the first metallic element containing boron, aluminum, gallium, or indium as a group 13 element, or silicon or germanium as a group 14 element, (b) A step of supplying the substrate with a gas containing tungsten as a second metallic element and fluorine, (c) A step of supplying a first reaction gas to the substrate, It has, (d)(b) and (c) are performed to remove at least a portion of the film containing the Group 13 or Group 14 element which suppresses oxidation of the surface of the film containing the first metal element, thereby forming a film containing the second metal element which has a low content of the Group 13 or Group 14 element, or does not contain the Group 13 or Group 14 element. A substrate processing method having the following characteristics.

2. The substrate processing method according to claim 1, wherein the first reaction gas is a reducing gas.

3. The substrate processing method according to claim 1, wherein the first reaction gas is a hydrogen-containing gas.

4. The substrate processing method according to claim 3, wherein the hydrogen-containing gas is hydrogen gas.

5. The substrate processing method according to claim 1, wherein the first reaction gas is a gas containing silicon and hydrogen.

6. The substrate processing method according to claim 1, wherein the first reaction gas is a gas containing boron and hydrogen.

7. (e) The process further comprises supplying a second reaction gas different from the first reaction gas to the substrate, The substrate processing method according to claim 1, wherein after (f) and (d), (b) and (e) are performed to form another film containing the second metal element on the film containing the second metal element.

8. The substrate processing method according to claim 7, wherein the first reaction gas is a first hydrogen-containing gas, and the second reaction gas is a second hydrogen-containing gas.

9. (d) The substrate processing method according to claim 1, wherein a film containing the second metal element is formed on a film containing the group 13 element or the group 14 element from which at least a portion has been removed.

10. (d) The substrate processing method according to claim 1, wherein a film containing the second metal element is formed on the substrate.

11. (d) The substrate processing method according to claim 1, wherein a film containing the second metal element is formed on the film containing the first metal element.

12. (d) The substrate processing method according to claim 1, wherein the film containing the group 13 element or the group 14 element is removed and a film containing the second metal element is formed.

13. The substrate processing method according to claim 1, wherein the thickness of the film containing the group 13 element or the group 14 element in (a) is one atomic layer or more and several atomic layers or less.

14. (a) A procedure for preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metallic element, and a film formed on the film containing the first metallic element containing boron, aluminum, gallium, or indium as a group 13 element, or silicon or germanium as a group 14 element, (b) A procedure for supplying a gas containing tungsten as a second metallic element and fluorine to the substrate, (c) A procedure for supplying a first reaction gas to the substrate, A procedure to remove at least a portion of the film containing the Group 13 or Group 14 element, which suppresses oxidation of the surface of the film containing the first metal element, by performing (d), (b) and (c), to form a film containing the second metal element, which has a low content of the Group 13 or Group 14 element, or does not contain the Group 13 or Group 14 element; A program that causes a circuit board processing unit to execute commands via a computer.

15. A gas supply system provides a gas containing tungsten and fluorine as second metallic elements and a first reaction gas to a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metallic element, and a film formed on the film containing the first metallic element containing boron, aluminum, gallium, or indium as a group 13 element, or silicon or germanium as a group 14 element. (a) A process for preparing the substrate, (b) A process of supplying the substrate with a gas containing the second metal element and fluorine, (c) A process of supplying the first reaction gas to the substrate, It has, A control unit is configured to control the gas supply system so as to perform the process of (d), (b) and (c) to remove at least a portion of the film containing the Group 13 or Group 14 element, which suppresses oxidation of the surface of the film containing the first metal element, and to form a film containing the second metal element, which has a low content of the Group 13 or Group 14 element, or does not contain the Group 13 or Group 14 element. A substrate processing apparatus having

16. (a) A step of preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metallic element, and a film formed on the film containing the first metallic element containing boron, aluminum, gallium, or indium as a group 13 element, or silicon or germanium as a group 14 element, (b) A step of supplying the substrate with a gas containing tungsten as a second metallic element and fluorine, (c) A step of supplying a first reaction gas to the substrate, It has, (d)(b) and (c) are performed to remove at least a portion of the film containing the Group 13 or Group 14 element which suppresses oxidation of the surface of the film containing the first metal element, thereby forming a film containing the second metal element which has a low content of the Group 13 or Group 14 element, or does not contain the Group 13 or Group 14 element. A method for manufacturing a semiconductor device having [a certain feature].

17. (c) The substrate processing method according to claim 1, wherein the flow rate of the first reaction gas is supplied at a rate less than that of the gas containing the second metal element, and after a predetermined period of time, the flow rate of the first reaction gas is changed to a flow rate that is approximately the same as that of the gas containing the second metal element.

18. (c) The substrate processing method according to claim 1, wherein the flow rate of the first reaction gas is set to a flow rate greater than the supply flow rate of the inert gas, and after a predetermined period of time, the flow rate of the first reaction gas is changed to a flow rate less than the supply flow rate of the inert gas.

19. The substrate processing method according to claim 1, wherein the film containing the group 13 element or the group 14 element is a nitride film.

20. The substrate processing method according to claim 1, wherein the film containing the group 13 element or the group 14 element is formed with a thickness of two atomic layers or more and several atomic layers or less.

21. The substrate processing method according to claim 1, wherein in (a), the substrate is a substrate removed from a processing chamber in which a film containing the group 13 element or the group 14 element has been formed, and the substrate is brought into a processing chamber in which (d) is performed.

22. The substrate processing method according to claim 21, wherein in (a), the film containing the group 13 element or the group 14 element is transported from the processing chamber to the outside of the processing chamber where it is oxidized.

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