Substrate processing method, method for manufacturing semiconductor device, program, substrate processing device, and gas supply system

Abstract

The purpose of the present invention is to provide a technique with which it is possible to suppress deterioration of either or both of film characteristic uniformity in a substrate surface and film characteristic uniformity between surfaces due to insufficient supply of raw material gas. This method includes: (a) a step for closing a first valve of a first gas pipe, and supplying a raw material gas from an upstream side of the first gas pipe to store the raw material gas in the first gas pipe; and (b) a step for opening the first valve of the first gas pipe, supplying a first inert gas from the upstream side of the first gas pipe, and supplying the raw material gas and the first inert gas to the substrate from the first gas pipe.

Description

Substrate processing method, semiconductor device manufacturing method, program, substrate processing apparatus, and gas supply system

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

[0002] 2. Description of the Related Art As one step in the manufacturing process of a semiconductor device, a process of forming a metal film on a substrate is sometimes performed (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-120472

[0004] An insufficient supply of source gas may deteriorate either or both of the uniformity of film properties within the substrate surface and the uniformity of film properties between substrates (surfaces).

[0005] The present disclosure provides a technique capable of suppressing deterioration of either or both of the uniformity of film properties within a substrate surface and the uniformity of film properties between surfaces, which deterioration is caused by an insufficient supply of source gas.

[0006] According to one aspect of the present disclosure, there is provided a technique comprising: (a) a step of closing a first valve of a first gas pipe, supplying a source gas from an upstream side of the first gas pipe, and storing the source gas in the first gas pipe; and (b) a step of opening the first valve of the first gas pipe, supplying a first inert gas from an upstream side of the first gas pipe, and supplying the source gas and the first inert gas from the first gas pipe to a substrate.

[0007] According to the present disclosure, it is possible to suppress deterioration of either or both of the uniformity of film characteristics within a substrate surface and the uniformity of film characteristics between surfaces, which is caused by an insufficient supply of source gas.

[0008] Fig. 1 is a longitudinal cross-sectional view showing an outline of a vertical processing furnace of a substrate processing apparatus according to one embodiment. Fig. 2 is a schematic diagram of a controller of the substrate processing apparatus according to one embodiment, and is a block diagram showing a control system of the controller. Fig. 3(A) is a diagram for explaining the flow of exhausting a source gas to the outside of a processing chamber. Fig. 3(B) is a diagram for explaining a case where the source gas is stored in a gas supply pipe. Fig. 3(C) is a diagram for explaining the flow of supplying a source gas to a processing chamber.

[0009] Hereinafter, one embodiment of the present disclosure will be described mainly with reference to Figures 1 to 3. Note that all drawings used in the following description are schematic, and the dimensional relationships, ratios, etc. of elements shown in the drawings do not necessarily match those of reality. Furthermore, the dimensional relationships, ratios, etc. of elements between multiple drawings do not necessarily match.

[0010] (1) Configuration of the Substrate Processing Apparatus As shown in Fig. 1, the processing furnace 202 has a heater 207 as a heating system (temperature adjustment unit). The heater 207 has a cylindrical shape. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas by heat.

[0011] A reaction tube 203 is disposed concentrically inside the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz or silicon carbide and has a cylindrical shape with a closed upper end and an open lower end. A manifold 209 (hereinafter referred to as MF 209) is disposed concentrically below the reaction tube 203. The MF 209 is made of a metal material such as stainless steel and has a cylindrical shape with open upper and lower ends. The upper end of the MF 209 engages with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a is provided between the MF 209 and the reaction tube 203 as a sealing member. The reaction tube 203 is installed vertically, similar to the heater 207. The reaction tube 203 and the MF 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to be able to accommodate a wafer 200 as a substrate.

[0012] Nozzles 249a and 249b are provided in the processing chamber 201 so as to penetrate the sidewall of the MF 209. Gas supply pipes 232a and 232b serving as first gas pipes are connected to the nozzles 249a and 249b, respectively.

[0013] The gas supply pipe 232a is provided with, from upstream to downstream, a vaporizer 300 for vaporizing gas, a valve 302a serving as a fourth valve which is an on-off valve, a valve 302b serving as a third valve, a valve 302c serving as a second valve, and a valve 243a serving as a first valve. A gas supply pipe 232e for supplying an inert gas is connected between the valves 302a and 302b of the gas supply pipe 232a, upstream of the valve 243a of the gas supply pipe 232a. A gas supply pipe 232c for supplying an inert gas is connected downstream of the valve 243a of the gas supply pipe 232a. The gas supply pipes 232c and 232e are provided with, from upstream to downstream, mass flow controllers (MFCs) 241c and 241e serving as flow rate controllers (flow rate control units), and valves 243c and 243e, respectively. An exhaust pipe 232f, which serves as a third gas pipe for exhausting gas from the gas supply pipe 232a, is connected to the gas supply pipe 232a upstream of the valve 243a and between the valve 243a and the valve 302c. The exhaust pipe 232f is provided with a valve 302d. The exhaust pipe 232f is connected to the exhaust pipe 231 upstream of the APC valve 244, which will be described later.

[0014] Gas supply pipe 232b is provided with, in order from the upstream side, an MFC 241b and a valve 243b. A gas supply pipe 232d that supplies an inert gas is connected to gas supply pipe 232b downstream of valve 243b. Gas supply pipe 232d is provided with, in order from the upstream side, an MFC 241d and a valve 243d.

[0015] The nozzles 249a and 249b are respectively provided in the space between the inner wall of the reaction tube 203 and the wafers 200, along the inner wall of the reaction tube 203 from the bottom to the top, so as to rise upward in the stacking direction of the wafers 200. Gas supply holes 250a and 250b for supplying gas are respectively provided on the side surfaces of the nozzles 249a and 249b. The gas supply holes 250a and 250b are each open so as to face the center of the reaction tube 203, so that gas can be supplied toward the wafers 200. A plurality of gas supply holes 250a and 250b are provided from the bottom to the top of the reaction tube 203.

[0016] From the gas supply pipe 232a, the source gas is supplied into the processing chamber 201 via the vaporizer 300, the valves 302a to 302c, 243a, and the nozzle 249a. Furthermore, the source gas is not supplied into the processing chamber 201 via the vaporizer 300, the valves 302a to 302c, the exhaust pipe 232f, and the valve 302d, but is instead exhausted to the exhaust pipe 231. Furthermore, the source gas is stored in the gas supply pipe 232a by switching the valves 302a to 302d, 243a, and 243e.

[0017] A reactive gas that reacts with the source gas is supplied from the gas supply pipe 232b into the processing chamber 201 via an MFC 241b, a valve 243b, and a nozzle 249b.

[0018] Inert gas is supplied from the gas supply pipes 232c and 232d into the processing chamber 201 via MFCs 241c and 241d, valves 243c and 243d, gas supply pipes 232a and 232b, and nozzles 249a and 249b. Inert gas is supplied from the gas supply pipe 232e into the processing chamber 201 via an MFC 241e, a valve 243e, the gas supply pipe 232a, and a nozzle 249a.

[0019] A source gas supply system is mainly composed of the gas supply pipe 232a and the valves 302a-302c and 243a. The vaporizer 300 may be included in the source gas supply system. A source gas exhaust system is mainly composed of the exhaust pipe 232f and the valve 302d. The source gas exhaust system may also be included in the source gas supply system. A reactive gas supply system is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. The source gas supply system and the reactive gas supply system may also be collectively referred to as the gas supply system. An inert gas supply system is mainly composed of the gas supply pipes 232c-232e, the MFCs 241c-241e, and the valves 243c-243e. The inert gas supplied from the gas supply pipe 232e, the MFC 241e, and the valve 243e may also be referred to as the first inert gas. In this case, the gas supply pipe 232e, the MFC 241e, and the valve 243e can be mainly referred to as a first inert gas supply system (also referred to as a first inert gas supply unit). Also, the inert gas supplied from the gas supply pipe 232c, the MFC 241c, and the valve 243c can be mainly referred to as a second inert gas supply system (also referred to as a second inert gas supply unit). The inert gas supply system may be included in the gas supply system.

[0020] Any or all of the various supply systems described above may be configured as a gas supply system 248 that integrates valves 243a to 243e and 302a to 302d, MFCs 241a to 241e, etc. The gas supply system 248 is connected to each of the gas supply pipes 232a to 232e, and is configured so that the supply of various gases into the gas supply pipes 232a to 232e, i.e., the opening and closing of the valves 243a to 243e and 302a to 302d and the flow rate adjustment by the MFCs 241a to 241e, etc., are controlled by a controller 121, which will be described later. The gas supply system 248 is configured as an integrated or separate integrated unit, and can be attached and detached to and from the gas supply pipes 232a to 232e, etc., so that maintenance, replacement, expansion, etc. of the gas supply system 248 can be performed on an integrated unit basis.

[0021] The reaction tube 203 is provided with an exhaust pipe 231 for exhausting the atmosphere inside the processing chamber 201. A vacuum pump 246 (hereinafter referred to as pump 246) serving as an exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 can evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the pump 246 is operating. Furthermore, while the pump 246 is operating, the valve opening degree can be adjusted based on pressure information detected by the pressure sensor 245, thereby adjusting the pressure inside the processing chamber 201. The exhaust pipe 231, the APC valve 244, and the pressure sensor 245 mainly constitute an exhaust system. The pump 246 may be included in the exhaust system.

[0022] A seal cap 219 (hereinafter referred to as the cap 219) serving as a furnace port cover capable of airtightly closing the lower end opening of the MF 209 is provided below the MF 209. An O-ring 220b serving as a sealing member that abuts against the lower end of the MF 209 is provided on the upper surface of the cap 219. A rotation mechanism 267 for rotating a boat 217 (described later) is provided below the cap 219. A rotation shaft 255 of the rotation mechanism 267 passes through the cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The cap 219 is configured to be raised and lowered vertically by a boat elevator 115 (hereinafter referred to as the elevator 115) serving as an elevating mechanism installed outside the reaction tube 203. The elevator 115 is configured to raise and lower the cap 219 so as to load and unload the boat 217 into and out of the process chamber 201. The elevator 115 is configured as a transfer device (transfer mechanism) that transfers the boat 217 , that is, the wafers 200 , into and out of the processing chamber 201 .

[0023] The boat 217, serving as a substrate support, is configured to support multiple wafers 200, for example, 25 to 200, in a horizontal position, aligned vertically with their centers aligned, in multiple stages, i.e., spaced apart. The boat 217 is made of a heat-resistant material such as quartz or SiC. A heat insulating plate 218, also made of a heat-resistant material such as quartz or SiC, is supported in multiple stages below the boat 217. Note that in this specification, a numerical range such as "25 to 200 wafers" means that the lower and upper limits are included in the range. Thus, for example, "25 to 200 wafers" means "25 to 200 wafers." The same applies to other numerical ranges.

[0024] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supply to the heater 207 based on temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 can have a desired temperature distribution.

[0025] As shown in FIG. 2 , the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, such as a touch panel, is connected to the controller 121. The substrate processing apparatus 100 may be configured to include one or more control units. That is, control for performing the processing sequence described below may be performed using one control unit or multiple control units. Furthermore, the multiple control units may be configured as a control system connected to each other via a wired or wireless communication network, and control for performing the processing sequence described below may be performed by the entire control system. In this specification, the term "controller" may refer to one controller, multiple controllers, or a control system configured by multiple controllers. The controller may be a physical controller or a software program residing in the memory of a controller.

[0026] The storage device 121c includes, for example, a flash memory, an HDD (Hard Disk Drive), etc. The storage device 121c readably stores a control program for controlling the operation of the substrate processing apparatus 100, a process recipe describing the procedures and conditions of the substrate processing described below, and the like. The process recipe is a combination of procedures for the substrate processing described below that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. The process recipe is also simply referred to as a recipe. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (work area) for temporarily storing programs, data, etc. read by the CPU 121a.

[0027] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241e, valves 243a to 243e, 302a to 302d, pressure sensor 245, APC valve 244, pump 246, heater 207, temperature sensor 263, rotation mechanism 267, elevator 115, and the like.

[0028] The CPU 121a is configured to read and execute a control program from the storage device 121c, and also to read a recipe from the storage device 121c in response to input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 241a to 241e, the opening and closing operations of the valves 243a to 243e and 302a to 302d, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the elevator 115, and the like.

[0029] The controller 121 can be configured by installing the above-mentioned program stored in an external storage device (e.g., a magnetic disk such as a hard disk, an optical disk such as a CD, or a semiconductor memory such as a USB memory) 123 into a computer. The storage device 121c and the external storage device 123 are configured as computer-readable recording media on which the program is recorded. Hereinafter, these will be collectively referred to simply as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0030] (2) Substrate Processing Step An example of a processing sequence for forming a predetermined film on a wafer 200 using the above-described substrate processing apparatus 100 will be described as one substrate processing step in the manufacturing process of a semiconductor device. In the following description, the operation of each part of the substrate processing apparatus 100 is controlled by a controller 121.

[0031] The term "wafer" used in this specification may refer to the wafer itself or to a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may refer to the surface of the wafer itself or to the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0032] 1, the boat 217 supporting the wafers 200 is lifted by the elevator 115, carried into the processing chamber 201, and accommodated in the processing vessel. In this state, the cap 219 closes the lower end opening of the MF 209 via the O-ring 220b.

[0033] (Pressure Regulation and Temperature Regulation) The inside of the processing chamber 201, i.e., the space in which the wafers 200 are present, is evacuated by the pump 246 to a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on this measured pressure information (pressure regulation). The pump 246 is kept in a constantly operating state at least until processing of the wafers 200 is completed. In addition, the inside of the processing chamber 201 is heated by the heater 207 to a desired temperature. At this time, the amount of power supplied to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the inside of the processing chamber 201 has a desired temperature distribution (temperature regulation). Heating of the inside of the processing chamber 201 by the heater 207 continues at least until processing of the wafers 200 is completed.

[0034] The source gas used here has a vapor pressure of, for example, 100 Torr or less, which is lower than the vapor pressure of other gases supplied to the wafer 200 and cannot be supplied by an MFC. When a gas with a low vapor pressure of, for example, 100 Torr or less is used as the source gas, the supply amount of the source gas at the top of the nozzle 249a in the processing chamber 201 is reduced compared to the bottom of the nozzle 249a, which may result in poor inter-surface film property uniformity across the wafer 200. Furthermore, because gas is supplied from the side of the wafer 200, the supply amount of the source gas at the center of the wafer 200 is reduced compared to the lateral sides of the wafer 200, which may result in poor inter-surface film property uniformity across the wafer 200. Furthermore, when a gas with a low vapor pressure of, for example, 100 Torr or less is used as the source gas, the source gas may backflow out of the processing chamber 201 without being supplied to the wafer 200. In the present disclosure, a source gas with a low vapor pressure of, for example, 100 Torr or less is supplied by a source gas supply process described below. Here, the film characteristics include, for example, the film thickness, electrical characteristics, composition, etc. of the film formed on the wafer 200 .

[0035] (Source Gas Supply Process, Step S1) In this process, a cycle of sequentially performing the following Steps A to D is performed a predetermined number of times (m times, where m is an integer of 1 or greater). [Step A] In this step, the atmosphere in the gas supply pipe 232a is exhausted through the exhaust pipe 232f to exhaust any gas remaining in the gas supply pipe 232a. Specifically, with the valves 302a, 243a, and 243e closed, the valves 302b to 302d are opened, and the atmosphere in the gas supply pipe 232a is evacuated to a vacuum via the gas supply pipe 232a and the exhaust pipe 232f by the APC valve 244 and the pump 246 of the exhaust pipe 231. At this time, the valve 243c may be opened simultaneously to allow an inert gas to flow into the gas supply pipe 232c. The inert gas has a flow rate adjusted by the MFC 241c, is supplied into the processing chamber 201 through the nozzle 249a, and is exhausted through the exhaust pipe 231. At this time, the valve 243d may be opened to allow an inert gas to flow into the gas supply pipes 232b and 232d.

[0036] By exhausting the atmosphere inside the gas supply pipe 232a, the amount of gas remaining inside the gas supply pipe 232a can be reduced. Furthermore, it is possible to prevent the remaining gas from diluting the source gas stored in step C, which will be described later. Furthermore, it is possible to increase the amount of source gas stored in step C. Furthermore, in particular, by exhausting the gas supply pipe 232a so as to create a vacuum atmosphere, it is possible to improve the storage efficiency of the source gas. Furthermore, it is possible to keep the stored amount of source gas and the source gas concentration constant for each cycle.

[0037] [Step B] Next, in this step, as shown in FIG. 3A, a source gas is flowed from the upstream side of the gas supply pipe 232a to the exhaust pipe 232f. Specifically, with the valves 243a and 243e closed, the valves 302a to 302d are opened to flow the source gas from the upstream side of the gas supply pipe 232a to the exhaust pipe 232f. At this time, the valve 243c is simultaneously opened to flow an inert gas into the gas supply pipe 232c. This prevents the atmosphere in the processing chamber 201 from backflowing into the gas supply pipe 232a. The inert gas has a flow rate adjusted by the MFC 241c, is supplied into the processing chamber 201 via the nozzle 249a, and is exhausted from the exhaust pipe 231. At this time, the valve 243d may be opened to flow the inert gas into the gas supply pipes 232b and 232d.

[0038] By flowing the source gas from the upstream side of the gas supply pipe 232a to the exhaust pipe 232f, the gas remaining in the gas supply pipe 232a is pushed out by the source gas and exhausted. This prevents the source gas from being diluted by the remaining gas in the next step, which would otherwise cause a change in the source gas concentration, and makes it possible to keep the concentration of the stored source gas constant for each cycle.

[0039] [Step C] Next, in this step, as shown in FIG. 3B, the source gas is stored in the gas supply pipe 232a. Specifically, while the valves 243a and 243e are closed, the valves 302a and 302d are closed to store the source gas in the gas supply pipe 232a. At this time, the valve 243c is opened to allow an inert gas to flow into the gas supply pipe 232c. That is, while the source gas is stored in the gas supply pipe 232a, the inert gas is supplied from the gas supply pipe 232c through the gas supply pipe 232a to the space where the wafer 200 is present. This prevents the atmosphere in the process chamber 201 from backflowing into the gas supply pipe 232a. The inert gas has a flow rate adjusted by the MFC 241c, is supplied into the process chamber 201 through the nozzle 249a, and is exhausted from the exhaust pipe 231. At this time, the valve 243d may be opened to allow an inert gas to flow into the gas supply pipes 232b and 232d.

[0040] Here, the length of the gas supply pipe 232a between the valve 243a and the valve 302a is configured to be longer than the length of the gas supply pipe 232a between the valve 243a and the reaction tube 203, which is a processing vessel that accommodates the wafers 200. This increases the amount of source gas stored, while reducing the amount of gas remaining when gas backflows from the processing chamber 201 to the gas supply pipe 232a. In addition, the amount of inert gas supplied into the processing chamber 201 simultaneously with the source gas from the gas supply pipe 232e can be reduced.

[0041] In this step, instead of valve 302a, valve 302c or valve 302b may be closed to store the source gas downstream of valve 302c or valve 302b. Alternatively, based on predetermined data, either valve 302c or valve 302b may be closed to store the source gas downstream of the closed valve. Note that the predetermined data includes data on the storage amount based on the diameter of gas supply pipe 232a, the piping length between each valve, and the like when each of valves 302a to 302c is closed, and is stored in storage device 121c or the like.

[0042] That is, by closing the valve 243a and any one of the valves 302a, 302b, and 302c, the gas supply pipe 232a can use the space between the valve 243a and the valve 302a, 302b, and 302c as a storage section for storing gas. This makes it possible to adjust the amount of source gas stored in the gas supply pipe 232a while suppressing backflow from the reaction tube 203.

[0043] Specifically, for example, by closing the valves 243a and 302a, the amount of gas stored in the gas supply pipe 232a can be increased compared to the valves 302b and 302c, and the amount of gas remaining when gas backflows from the processing chamber 201 to the gas supply pipe 232a can be reduced. Furthermore, the amount of inert gas supplied from the gas supply pipe 232e into the processing chamber 201 can be reduced. Furthermore, for example, by closing the valves 243a and 302b, the amount of gas stored in the gas supply pipe 232a can be reduced compared to the valve 302a. Furthermore, for example, by closing the valves 243a and 302c, the amount of gas stored in the gas supply pipe 232a can be reduced compared to the valves 302a and 302b.

[0044] [Step D] Next, in this step, as shown in FIG. 3C , a source gas is flowed into the processing chamber 201. Specifically, with the valves 302a and 302d closed, the valves 243a and 243e are opened to allow the source gas stored in the gas supply pipe 232a to flow into the processing chamber 201. At this time, the source gas stored in the gas supply pipe 232a is pushed out by the inert gas supplied from the gas supply pipe 232e, supplied into the processing chamber 201 via the nozzle 249a, and exhausted from the exhaust pipe 231. At this time, with the valve 243c open, the flow rate of the inert gas supplied to the gas supply pipe 232c by the MFC 241c is set to be greater than the flow rate of the inert gas supplied to the gas supply pipe 232c in the above-described steps A to C. The flow-rate-adjusted inert gas is supplied into the processing chamber 201 together with the source gas and exhausted from the exhaust pipe 231. That is, the source gas and the inert gas are supplied through the gas supply pipe 232a to the space where the wafer 200 is present. Also, to prevent the source gas from entering the nozzle 249b, the valve 243d is opened to allow the inert gas to flow into the gas supply pipe 232d. The inert gas is supplied into the processing chamber 201 through the gas supply pipe 232d and the nozzle 249b, and is exhausted through the exhaust pipe 231.

[0045] As described above, after step C, the valve 243a is opened to supply inert gas from the upstream side of the gas supply pipe 232a, and the source gas and inert gas stored in the gas supply pipe 232a are supplied to the wafers 200. At this time, by simultaneously setting the flow rate of the inert gas supplied from the gas supply pipe 232c to be larger than the flow rate of the inert gas supplied from the gas supply pipe 232c in the above-described steps A to C, the inert gas supplied from the gas supply pipe 232c suppresses backflow of the atmosphere in the processing chamber 201 in steps A to C, and acts to dilute the source gas in step D. Note that the flow rate of the inert gas supplied from the gas supply pipe 232c is adjusted in step D according to the concentration at which the source gas is diluted.

[0046] By opening the valve 243a and simultaneously increasing the flow rate of the inert gas supplied from the gas supply pipe 232c, the concentration of the source gas supplied from the nozzle 249a can be kept constant. Alternatively, the valve 243a may be opened after increasing the flow rate of the inert gas supplied from the gas supply pipe 232c. In this case, the concentration of the source gas supplied from the nozzle 249a can be reduced. Alternatively, the flow rate of the inert gas supplied from the gas supply pipe 232c may be increased after opening the valve 243a. In this case, the concentration of the source gas supplied from the nozzle 249a can be increased. That is, the opening / closing timing of the valve 243a and the flow rate of the inert gas by the MFC 241c are controlled according to the concentration of the source gas to be diluted.

[0047] Furthermore, in this step, the flow rate of the inert gas supplied from the gas supply pipe 232e is made greater than the flow rate of the inert gas supplied from the gas supply pipe 232c by adjusting the MFCs 241e and 241c. By supplying the inert gas in this manner, even when a source gas with a low vapor pressure is used, the source gas can be pushed out by the inert gas, thereby making the supply amount of the source gas between the wafers 200 and the supply amount within the wafer 200 uniform. Therefore, it is possible to prevent a shortage of source gas supply from deteriorating either or both of the uniformity of film characteristics within the wafer 200 and the uniformity of film characteristics between the wafers 200. In particular, it is possible to prevent a deterioration in the uniformity of film characteristics between the wafers 200.

[0048] At this time, the main gas flowing in the processing chamber 201 is the source gas. That is, the source gas is supplied to the wafer 200.

[0049] The source gas may be a gas containing a metal element and a halogen element, and the metal element may be a transition metal from Group 3 to Group 12, or an element containing a Group 13 element.

[0050] As the gas containing a metal element and a halogen element, for example, a gas containing at least one element such as molybdenum (Mo), zirconium (Zr), hafnium (Hf), aluminum (Al), indium (In), gallium (Ga), etc., and a halogen element can be used. Furthermore, as the gas containing a metal element and a halogen element, a gas containing a metal element and at least one element such as fluorine (F), chlorine (Cl), bromine (Br), iodine (I), etc., can be used. As the gas containing a metal element and a halogen element, a gas containing a metal element and Cl is preferably used. One or more of these can be used as the source gas.

[0051] That is, the gas containing a metal element and a halogen element is zirconium chloride (ZrCl ４ ) gas, hafnium chloride (HfCl ４ ) gas, aluminum chloride (AlCl ３ ) gas, gallium chloride (GaCl ３ ) gas, indium chloride (InCl ３ ) gas, molybdenum pentachloride (MoCl ５ ) gas, molybdenum dichloride dioxide (MoO ２ Cl ２ ) gas, molybdenum oxide tetrachloride (MoOCl ４ ) gas, etc. As the source gas, one or more of these can be used.

[0052] The inert gas may be, for example, nitrogen (N ２ In addition to the inert gas, rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas can be used. It is preferable to use Ar gas as the inert gas. Furthermore, one or more of these gases can be used as the inert gas.

[0053] (Removal of residual gas, step S2) After a first layer containing a metal element and a halogen element is formed on at least a portion of the wafer 200, the valves 243a and 243b are closed, and the valves 243c and 243d are opened to supply an inert gas as a purge gas into the gas supply pipes 232a and 232b via the gas supply pipes 232c and 232d. At the same time, the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated to a vacuum by the pump 246, and the processing chamber 201 is purged.

[0054] (Reactive Gas Supply Process, Step S3) Next, a reactive gas is supplied to the wafers 200 in the processing chamber 201 and then exhausted. Specifically, the valve 243b is opened to allow the reactive gas to flow into the gas supply pipe 232b. The flow rate of the reactive gas is adjusted by the MFC 241b, and the reactive gas is supplied into the processing chamber 201 via the nozzle 249b and exhausted from the exhaust pipe 231. At the same time, the valve 243d is opened to allow an inert gas to flow into the gas supply pipe 232d. The flow rate of the inert gas is adjusted by the MFC 241d, and the inert gas is supplied into the processing chamber 201 together with the reactive gas and exhausted from the exhaust pipe 231. Furthermore, to prevent the reactive gas from entering the nozzle 249a, the valve 243c is opened to allow the inert gas to flow into the gas supply pipe 232c. The inert gas is supplied into the processing chamber 201 via the gas supply pipe 232c and the nozzle 249a and then exhausted from the exhaust pipe 231.

[0055] At this time, the main gas flowing in the processing chamber 201 is a reactive gas. That is, the reactive gas is supplied to the wafer 200 .

[0056] A reducing gas can be used as the reactive gas. For example, a gas containing hydrogen (H) can be used as the reducing gas. For example, a gas containing H can be used. ２ ) gas, monosilane (SiH ４ ) gas, disilane (Si ２ H ６ ) gas, trisilane (Si ３ H ８ ) gas, ammonia (NH ３ ) gas, hydrazine (N ２ H ４ ) gas, phosphine (PH３ ) gas, etc. As the reactive gas, one or more of these gases can be used.

[0057] Specifically, for example, MoCl is used as the source gas. ５ The gas is, for example, H ２ When gas was used, MoCl ５ Gas and H ２ The gas reacts to form MoCl ５ Cl in the gas becomes H ２ The first layer containing metal elements and halogen elements on the wafer 200 is reduced by the gas, and is modified into a second layer containing metal elements.

[0058] (Removal of residual gas, step S4) After a second layer containing a metal element is formed on the wafer 200, an inert gas is supplied as a purge gas using a processing procedure similar to that of step S2 described above, and the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated to a vacuum by the pump 246, thereby purging the processing chamber 201.

[0059] (Performed a Predetermined Number of Times, Step S5) By performing the cycle of sequentially performing the above-described steps S1 to S4 a predetermined number of times (n times, where n is an integer of 1 or 2 or more), a predetermined film of a predetermined thickness is formed on the wafer 200. Specifically, for example, a molybdenum (Mo)-containing film, which is a metal-containing film, is formed. If the number of cycles of sequentially performing steps S1 to S4 is less than the predetermined number, the process returns to step S1.

[0060] (After-purging and returning to atmospheric pressure) An inert gas is supplied into the processing chamber 201 from each of the gas supply pipes 232c and 232d, and is exhausted from the exhaust pipe 231. The inert gas acts as a purge gas. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201. Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas, and the pressure in the processing chamber 201 is returned to atmospheric pressure.

[0061] (Wafer Unloading) The elevator 115 lowers the cap 219 to open the bottom end of the MF 209. Then, the processed wafers 200, supported by the boat 217, are unloaded from the bottom end of the MF 209 to the outside of the reaction tube 203. The processed wafers 200 are removed from the boat 217.

[0062] (3) Other Aspects Next, modified examples of the substrate processing apparatus 100 in the above-described aspects will be described in detail. In the following modified examples, only the differences from the above-described aspects will be described in detail.

[0063] 1, a gas supply pipe 232c for supplying an inert gas is provided upstream of a valve 243a of the gas supply pipe 232a. Even when the gas supply pipe 232c is provided upstream of the valve 243a of the gas supply pipe 232a, the source gas can be diluted before being supplied to the wafers 200, thereby increasing the amount of source gas supplied. In other words, the present modification also provides the same effects as those of the above-described embodiment.

[0064] In the above-described embodiment, a case has been described in which a cycle of sequentially performing steps A to D is performed a predetermined number of times (m times, where m is an integer of 1 or 2 or more) as the source gas supply step (step S1). The present disclosure is not limited to the above-described embodiment, and a cycle of sequentially performing steps B to D may be performed a predetermined number of times (m times, where m is an integer of 1 or 2 or more) without performing step A. In this embodiment, the same effects as in the above-described embodiment can be obtained, and in this modified embodiment, the processing time can be further shortened.

[0065] In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple wafers at a time has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several wafers at a time. In the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace.

[0066] When using these substrate processing apparatuses, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0067] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and processing conditions in such a case may be the same as those of the above-described embodiments and modifications, for example.

[0068] Although the embodiments and modifications of the present disclosure have been specifically described above, the embodiments and modifications of the present disclosure are not limited to the above-described embodiments and modifications, and various modifications are possible without departing from the spirit of the present disclosure.

[0069] 200: wafer (substrate), 232a: gas supply pipe (first gas pipe), 243a: valve (first valve)

Claims

1. (a) Closing the first valve of the first gas pipe, supplying a raw material gas from the upstream side of the first gas pipe, and storing the raw material gas in the first gas pipe; and (b) opening the first valve of the first gas pipe, supplying a first inert gas from the upstream side of the first gas pipe, and supplying the raw material gas and the first inert gas from the first gas pipe to a substrate. A substrate processing method comprising the steps of.

2. In (b), the substrate processing method according to claim 1, wherein a second inert gas is supplied from a second gas pipe connected to the first gas pipe to the first gas pipe.

3. The substrate processing method according to claim 2, wherein the second gas pipe is provided on the downstream side of the first valve.

4. The substrate processing method according to claim 2, wherein the second gas pipe is provided on the upstream side of the first valve.

5. The substrate processing method according to claim 3, further comprising (c) a step of supplying the second inert gas from the second gas pipe through the first gas pipe to the space where the substrate is present during (a).

6. The substrate processing method according to claim 5, wherein the flow rate of the second inert gas in (b) is made larger than the flow rate of the second inert gas in (c).

7. The substrate processing method according to claim 2, wherein in (b), the flow rate of the first inert gas is made larger than the flow rate of the second inert gas.

8. Having a third gas pipe connected to the upstream side of the first valve of the first gas pipe, (d) having a step of flowing the raw material gas from the upstream side of the first gas pipe to the third gas pipe, and (a) is performed after (d). The substrate processing method according to claim 1.

9. Having a third gas pipe connected to the upstream side of the first valve of the first gas pipe, (e) having a step of exhausting the atmosphere in the first gas pipe from the third gas pipe before (a). The substrate processing method according to claim 1.

10. The substrate processing method according to claim 8, further comprising (f) a step of exhausting the atmosphere in the first gas pipe from the third gas pipe before (d).

11. Having a second valve provided on the upstream side of the first valve of the first gas pipe, and in (a), closing the second valve and storing the raw material gas on the downstream side of the second valve. The substrate processing method according to claim 1.

12. The substrate processing method according to claim 11, further comprising a third valve provided upstream of the second valve in the first gas pipe, wherein in (a), based on predetermined data, either the second valve or the third valve is closed, and the source gas is stored downstream of the closed valve.

13. The substrate processing method according to claim 1, further comprising a fourth valve provided upstream of the first valve in the first gas pipe, wherein the length of the first gas pipe between the first valve and the fourth valve is longer than the length of the first gas pipe between the first valve and the processing chamber that houses the substrate. The substrate processing method according to claim 1, wherein the vapor pressure of the source gas is lower than the vapor pressure of other gases supplied to the substrate.

15. The substrate processing method according to claim 1, wherein the source gas is a gas containing at least one element selected from Mo, Zr, Hf, Al, In, Ga and a halogen element.

16. A method for manufacturing a semiconductor device, comprising: (a) closing the first valve of the first gas pipe, supplying a source gas from the upstream side of the first gas pipe, and storing the source gas in the first gas pipe; and (b) opening the first valve of the first gas pipe, supplying a first inert gas from the upstream side of the first gas pipe, and supplying the source gas and the first inert gas from the first gas pipe to the substrate.

17. A program for causing a computer to execute the following steps in a substrate processing apparatus: (a) closing the first valve of the first gas pipe, supplying a source gas from the upstream side of the first gas pipe, and causing the source gas to be stored in the first gas pipe; and (b) opening the first valve of the first gas pipe, supplying a first inert gas from the upstream side of the first gas pipe, and causing the source gas and the first inert gas to be supplied from the first gas pipe to the substrate.

18. A substrate processing apparatus having: a first gas pipe for supplying a source gas to a substrate; a first valve provided in the first gas pipe; a first inert gas supply unit for supplying a first inert gas from an upstream side of the first gas pipe; and a control unit configured to be able to control the first valve and the first inert gas supply unit so as to perform: (a) a process of closing the first valve of the first gas pipe, supplying the source gas from the upstream side of the first gas pipe, and storing the source gas in the first gas pipe; and (b) a process of opening the first valve of the first gas pipe, supplying the first inert gas from the upstream side of the first gas pipe, and supplying the source gas and the first inert gas from the first gas pipe to the substrate.

19. A gas supply system having: a first gas pipe for supplying a source gas to a substrate; a first valve provided in the first gas pipe; a first inert gas supply unit for supplying a first inert gas from an upstream side of the first gas pipe, and configured to be able to control the first valve and the first inert gas supply unit so as to perform: (a) a process of closing the first valve of the first gas pipe, supplying the source gas from the upstream side of the first gas pipe, and storing the source gas in the first gas pipe; and (b) a process of opening the first valve of the first gas pipe, supplying the first inert gas from the upstream side of the first gas pipe, and supplying the source gas and the first inert gas from the first gas pipe to the substrate.

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