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

Abstract

The present invention provides a technique capable of suppressing deterioration of either or both of in-plane film characteristic uniformity and inter-plane film characteristic uniformity caused by insufficient supply of a raw material gas. A substrate processing method includes: (a) closing a first valve of a first gas tube, supplying a raw material gas from an upstream side of the first gas tube, and storing the raw material gas in the first gas tube; 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 the substrate.

Description

Technical Field

[0001] This disclosure relates to a substrate processing method, a method and process for manufacturing a semiconductor device, a substrate processing apparatus, and a gas supply system. Background Technology

[0002] As a 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] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-120472 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Sometimes, insufficient supply of raw material gas can lead to the deterioration of either or both of the film property uniformity within the substrate surface and the film property uniformity between substrates (surfaces).

[0008] This disclosure provides a technique that can suppress the deterioration of either or both of the uniformity of film properties within the substrate surface and the uniformity of film properties between surfaces caused by insufficient supply of raw material gas.

[0009] Methods for solving problems

[0010] According to one aspect of this disclosure, a technique is provided that includes the following steps:

[0011] (a) Closing the first valve of the first gas pipe, supplying raw material gas from the upstream side of the first gas pipe, and storing the raw material gas in the first gas pipe; and

[0012] (b) Open the first valve of the first gas pipe, supply the first inert gas from the upstream side of the first gas pipe, and supply the raw material gas and the first inert gas from the first gas pipe to the substrate.

[0013] Invention Effects

[0014] According to this disclosure, it is possible to suppress the deterioration of either or both of the film property uniformity within the substrate surface and the film property uniformity between surfaces caused by insufficient supply of raw material gas. Attached Figure Description

[0015] Figure 1 This is a schematic longitudinal sectional view of a vertical processing furnace in a substrate processing apparatus of one type.

[0016] Figure 2This is a schematic structural diagram of the controller of a substrate processing device in one mode, and a diagram of the control system of the controller represented by a block diagram.

[0017] Figure 3 (A) is a diagram illustrating the process of discharging the raw material gas to the outside of the treatment room. Figure 3 (B) is a diagram used to illustrate the situation of storing raw material gas in a gas supply pipe. Figure 3 (C) is a diagram illustrating the process of supplying the feed gas to the processing chamber. Detailed Implementation

[0018] The following is mainly based on Figures 1-3 One aspect of this disclosure will be described. Furthermore, the accompanying drawings used in the following description are schematic, and the dimensional relationships and scales of the elements shown may not necessarily correspond to reality. Additionally, the dimensional relationships and scales of elements may not be consistent across different drawings.

[0019] (1) Structure of the substrate processing device

[0020] like Figure 1 As shown, the processing furnace 202 has a heater 207 as a heating system (temperature adjustment unit). The heater 207 is cylindrical in shape. The heater 207 also functions as an activation mechanism (excitation unit) that uses heat to activate (excite) the gas.

[0021] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz or silicon carbide, and is formed into a cylindrical shape that is closed at the top and open at the bottom. Below the reaction tube 203, a manifold 209 (hereinafter referred to as MF209) is arranged concentrically with the reaction tube 203. The MF209 is made of a metal material such as stainless steel, and is formed into a cylindrical shape that is open at both the top and bottom. The upper end of the MF209 engages with the lower end of the reaction tube 203, thus supporting the reaction tube 203. An O-ring 220a, serving as a sealing component, is provided between the MF209 and the reaction tube 203. The reaction tube 203 is installed vertically, just like the heater 207. The processing container (reaction vessel) is mainly composed of the reaction tube 203 and the MF209. A processing chamber 201 is formed in the hollow part of the processing container. The processing chamber 201 is configured to accommodate a wafer 200, which serves as a substrate.

[0022] Nozzles 249a and 249b are provided inside the processing chamber 201, penetrating the side wall of MF209. Nozzles 249a and 249b are respectively connected to gas supply pipes 232a and 232b, which serve as first gas pipes.

[0023] Starting from the upstream side, gas supply pipe 232a is provided with: a vaporizer 300 for vaporizing gas, an on / off valve 302a (which serves as the fourth valve), a third valve 302b, a second valve 302c, and a first valve 243a. A gas supply pipe 232e for supplying inert gas is connected upstream of valve 243a and between valves 302a and 302b in gas supply pipe 232a. A gas supply pipe 232c for supplying inert gas is connected downstream of valve 243a in gas supply pipe 232a. Starting from the upstream side, gas supply pipes 232c and 232e are provided with: mass flow controllers (MFC) 241c and 241e (which serve as flow controllers, or flow control units), and valves 243c and 243e. An exhaust pipe 232f, serving as a third gas pipe, is connected upstream of valve 243a and between valve 243a and valve 302c in gas supply pipe 232a. A valve 302d is installed in exhaust pipe 232f. Exhaust pipe 232f is connected upstream of APC valve 244 of exhaust pipe 231 (described later).

[0024] An MFC 241b and a valve 243b are sequentially installed on the gas supply pipe 232b from the upstream side. A gas supply pipe 232d for supplying inert gas is connected to the gas supply pipe 232b downstream of the valve 243b. An MFC 241d and a valve 243d are sequentially installed on the gas supply pipe 232d from the upstream side.

[0025] In the space between the inner wall of the reaction tube 203 and the wafer 200, nozzles 249a and 249b are respectively provided, rising from the lower part of the inner wall of the reaction tube 203 along the upper part towards the loading direction of the wafer 200. Gas supply holes 250a and 250b for supplying gas are respectively provided on the side of the nozzles 249a and 249b. The gas supply holes 250a and 250b open towards the center of the reaction tube 203, allowing gas to be supplied to the wafer 200. Multiple gas supply holes 250a and 250b are provided from the lower part to the upper part of the reaction tube 203.

[0026] Raw material gas is supplied to the processing chamber 201 through gas supply pipe 232a, vaporizer 300, valves 302a-302c, 243a, and nozzle 249a. Instead of supplying raw material gas to the processing chamber 201 through gas supply pipe 232a, vaporizer 300, valves 302a-302c, exhaust pipe 232f, and valve 302d, the raw material gas is discharged through exhaust pipe 231. Furthermore, the raw material gas is stored in gas supply pipe 232a by switching between valves 302a-302d, 243a, and 243e.

[0027] The reaction gas that reacts with the raw material gas is supplied from the gas supply pipe 232b through MFC 241b, valve 243b, and nozzle 249b into the processing chamber 201.

[0028] Inert gas is supplied to the processing chamber 201 from gas supply pipes 232c and 232d via MFCs 241c and 241d, valves 243c and 243d, gas supply pipes 232a and 232b, and nozzles 249a and 249b, respectively. Additionally, inert gas is supplied to the processing chamber 201 from gas supply pipe 232e via MFC 241e, valve 243e, gas supply pipe 232a, and nozzle 249a.

[0029] The raw material gas supply system mainly consists of gas supply pipe 232a, valves 302a-302c, and 243a. The vaporizer 300 can also be included in the raw material gas supply system. The raw material gas exhaust system mainly consists of exhaust pipe 232f and valve 302d. The raw material gas exhaust system can also be included in the raw material gas supply system. The reaction gas supply system mainly consists of gas supply pipe 232b, MFC 241b, and valve 243b. The raw material gas supply system and the reaction gas supply system can also be collectively referred to as the gas supply system. Additionally, the inert gas supply system mainly consists of gas supply pipes 232c-232e, MFC 241c-241e, and valves 243c-243e. Furthermore, the inert gas supplied from gas supply pipes 232e, MFC 241e, and valve 243e can be referred to as the first inert gas. In this case, the gas supply pipe 232e, MFC 241e, and valve 243e can also be referred to as the first inert gas supply system (also called the first inert gas supply unit). Alternatively, the inert gas supplied from the gas supply pipe 232c, MFC 241c, and valve 243c can be referred to as the second inert gas. In this case, the gas supply pipe 232c, MFC 241c, and valve 243c can also be referred to as the second inert gas supply system (also called the second inert gas supply unit). The inert gas supply system can also be included within the gas supply system.

[0030] One or all of the aforementioned supply systems can be configured as a gas supply system 248 integrating valves 243a-243e, 302a-302d, and MFCs 241a-241e. The gas supply system 248 is connected to gas supply pipes 232a-232e, and the supply of various gases to the gas supply pipes 232a-232e is controlled by the controller 121 (described later), including the opening and closing of valves 243a-243e and 302a-302d, and the flow adjustment of MFCs 241a-241e. The gas supply system 248 can be configured as an integrated unit or a modular unit, allowing for installation and removal of the gas supply pipes 232a-232e, and enabling maintenance, replacement, and addition of the gas supply system 248 on a unit-by-unit basis.

[0031] An exhaust pipe 231 is provided in the reaction tube 203 to expel the atmosphere from the processing chamber 201. The exhaust pipe 231 is connected to a vacuum pump 246 (hereinafter referred to as pump 246), which is an exhaust device, via a pressure sensor 245 (a pressure detector, or pressure detection unit) that detects the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 (a pressure regulator, or pressure adjustment unit). The APC valve 244 is configured such that by opening and closing the valve while the pump 246 is operating, vacuum exhaust from the processing chamber 201 can be performed and stopped; and by adjusting the valve opening based on the pressure information detected by the pressure sensor 245 while the pump 246 is operating, the pressure inside the processing chamber 201 can be adjusted. The exhaust system mainly consists of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The pump 246 may also be included in the exhaust system.

[0032] A sealing cover 219 (hereinafter referred to as cover 219) is provided below MF209, which can airtightly seal the lower opening of MF209. An O-ring 220b, which serves as a sealing member, is provided on the upper surface of cover 219 and abuts against the lower end of MF209. A rotation mechanism 267, which rotates the crystal boat 217 (described later), is provided below cover 219. The rotation shaft 255 of the rotation mechanism 267 passes through cover 219 and is connected to the crystal boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the crystal boat 217. Cover 219 is configured to be raised and lowered vertically by a crystal boat elevator 115 (hereinafter referred to as elevator 115), which serves as a lifting mechanism and is provided outside the reaction tube 203. Elevator 115 is configured to move the crystal boat 217 in and out of the processing chamber 201 by raising and lowering cover 219. The elevator 115 is configured as a conveying device (conveying mechanism) for transporting the crystal boat 217, i.e. the wafer 200, to and from the processing chamber 201.

[0033] The wafer boat 217, serving as a substrate support, is configured to support multiple wafers 200, for example, 25 to 200 wafers 200 arranged horizontally and aligned with each other in a vertical direction in multiple layers, i.e., arranged at intervals. The wafer 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 layers at the bottom of the wafer boat 217. Furthermore, the numerical range expression "25 to 200 wafers" in this specification refers to the inclusion of both the lower and upper limits within that range. Therefore, for example, "25 to 200 wafers" means "more than 25 wafers and less than 200 wafers." The same applies to other numerical ranges.

[0034] A temperature sensor 263, which functions as a temperature detector, is installed inside the reaction tube 203. The power supply to the heater 207 is adjusted based on the temperature information detected by the temperature sensor 263, thereby achieving the desired temperature distribution within the processing chamber 201.

[0035] like Figure 2 As shown, the controller 121, serving as the control unit (control unit), is configured as a computer having a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, a storage device 121c, and an 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 121e. An input / output device 122, such as a touch panel, is connected to the controller 121. Furthermore, the board processing apparatus 100 may be configured to have one control unit or multiple control units. That is, control for performing the processing sequence described later can be performed using one control unit or multiple control units. Additionally, multiple control units can be configured as a control system interconnected via a wired or wireless communication network, or control for performing the processing sequence described later can be performed as a whole through the control system. In this specification, when the term "control unit" is used, in addition to the case of including one control unit, there are also cases of including multiple control units and cases of including a control system composed of multiple control units. In addition, the control unit can be a physical controller or it can exist in the controller's memory through software programs.

[0036] The storage device 121c is configured such as flash memory or HDD (Hard Disk Drive). The storage device 121c stores, in a readable manner, a control program that controls the operation of the board processing apparatus 100, and a process flow describing the board processing procedures or conditions described later. The process flow is a combination of processes that enable the controller 121 to execute the various processes in the board processing described later to obtain a predetermined result, and functions as a program. Hereinafter, the process flow or control program will be collectively referred to as a program. Furthermore, the process flow will be simply referred to as a process. In this specification, when the term "program" is used, there may be cases where only a process flow unit is included, cases where only a control program unit is included, or cases where both are included. The RAM 121b is configured as a storage area (working area) that temporarily holds the program or data read by the CPU 121a.

[0037] I / O port 121d is connected to the aforementioned MFC241a~241e, valves 243a~243e, 302a~302d, pressure sensor 245, APC valve 244, pump 246, heater 207, temperature sensor 263, rotating mechanism 267, elevator 115, etc.

[0038] CPU 121a is configured to read and execute a control program from storage device 121c, and to read a process from storage device 121c based on input commands from input / output device 122. CPU 121a is configured to control the following actions according to the read process content: flow rate adjustment of various gases performed by MFCs 241a-241e; opening and closing of valves 243a-243e and 302a-302d; opening and closing of APC valve 244 and pressure adjustment based on pressure sensor 245; starting and stopping of pump 246; temperature adjustment based on temperature sensor 263 and heater 207; rotation and speed adjustment of crystal boat 217 performed by rotating mechanism 267; and lifting of crystal boat 217 performed by elevator 115.

[0039] The controller 121 can be configured to install the aforementioned program stored in an external storage device (e.g., a hard disk, a CD, a USB flash drive, or a semiconductor memory) 123 onto a computer. The storage device 121c and the external storage device 123 constitute a computer-readable storage medium on which the program is recorded. Hereinafter, they will also be collectively referred to as storage media. In this specification, the use of the term "storage media" may indicate that only the storage device 121c is included, only the external storage device 123 is included, or both are included. Furthermore, the program may be provided to the computer using a communication unit such as the Internet or a dedicated line, without using the external storage device 123.

[0040] (2) Substrate processing process

[0041] Using the substrate processing apparatus 100 described above, as a step in the substrate processing process of semiconductor device manufacturing, an example of a processing sequence for forming a predetermined film on wafer 200 will be described. In the following description, the operation of each part constituting the substrate processing apparatus 100 is controlled by the controller 121.

[0042] As used in this specification, the term "wafer" sometimes refers to the wafer itself, and sometimes to a laminate of the wafer and a specified layer or film formed on its surface. The term "surface of the wafer" as used in this specification sometimes refers to the surface of the wafer itself, and sometimes to the surface of a specified layer, etc., formed on the wafer. When described in this specification as "forming a specified layer on the wafer," it sometimes means forming the specified layer directly on the surface of the wafer itself, and sometimes it means forming the specified layer on top of layers, etc., formed on the wafer. The use of the term "substrate" in this specification has the same meaning as the use of the term "wafer."

[0043] (Wafer loading)

[0044] When multiple wafers 200 are loaded into the crystal boat 217, such as Figure 1 As shown, the crystal boat 217, supporting multiple wafers 200, is lifted by the elevator 115 and moved into the processing chamber 201, where it is housed in the processing container. In this state, the cover 219 closes the lower opening of the MF209 via the O-ring 220b.

[0045] (Pressure and temperature adjustment)

[0046] Vacuum exhaust is performed by pump 246 to achieve the desired pressure (vacuum level) within the processing chamber 201, i.e., the space where the wafer 200 exists. At this time, the pressure within the processing chamber 201 is measured by pressure sensor 245, and feedback control (pressure adjustment) is applied to APC valve 244 based on this measured pressure information. Pump 246 remains continuously operational at least until the processing of the wafer 200 is complete. Additionally, heating is performed by heater 207 to achieve the desired temperature within the processing chamber 201. At this time, feedback control (temperature adjustment) is applied to the electrical current supplied to heater 207 based on temperature information detected by temperature sensor 263 to achieve the desired temperature distribution within the processing chamber 201. Heating within the processing chamber 201 by heater 207 continues at least until the processing of the wafer 200 is complete.

[0047] The feed gas used here is a gas with a vapor pressure of, for example, 100 Torr or less, which is a gas with a vapor pressure lower than other gases supplied to the wafer 200 and cannot be supplied by the MFC. When using a gas with a low vapor pressure of 100 Torr or less as the feed gas, the supply amount of feed gas to the upper part of the nozzle 249a is reduced compared to the lower part of the nozzle 249a in the processing chamber 201, and sometimes the film characteristic uniformity between the wafer 200 surfaces deteriorates. In addition, the gas is supplied from the side of the wafer 200, therefore, the supply amount of feed gas to the center side of the wafer 200 is reduced compared to the side side of the wafer 200, and sometimes the film characteristic uniformity within the wafer 200 surfaces deteriorates. In addition, when using a gas with a low vapor pressure of 100 Torr or less as the feed gas, sometimes the feed gas is not supplied to the wafer 200 and flows back out of the processing chamber 201. In this disclosure, for example, a feed gas with a low vapor pressure of 100 Torr or less is supplied through the feed gas supply process described later. Here, film characteristics refer to, for example, the film thickness, electrical properties, composition, etc. of the film formed on wafer 200.

[0048] (Raw material gas supply process, step S1)

[0049] In this process, the following steps A to D will be performed in sequence for a specified number of times (m times, where m is an integer of 1 or 2 or higher).

[0050] [Step A]

[0051] In this step, the atmosphere in the gas supply pipe 232a is discharged from the exhaust pipe 232f, and the gas remaining in the gas supply pipe 232a is expelled. Specifically, with valves 302a, 243a, and 243e closed, valves 302b to 302d are opened, and the atmosphere in the gas supply pipe 232a is vacuumed through the gas supply pipe 232a and the exhaust pipe 232f using the APC valve 244 and pump 246 of the exhaust pipe 231. At this time, valve 243c can be opened simultaneously to allow inert gas to flow into the gas supply pipe 232c. The inert gas flow rate is adjusted by MFC 241c and supplied to the processing chamber 201 through nozzle 249a, and discharged from the exhaust pipe 231. Alternatively, valve 243d can also be opened at this time to allow inert gas to flow in the gas supply pipes 232b and 232d.

[0052] By venting the atmosphere from the gas supply pipe 232a, the amount of gas remaining in the gas supply pipe 232a can be reduced. Furthermore, it can prevent the raw material gas stored in step C (described later) from being diluted by residual gas. Additionally, it can increase the amount of raw material gas stored in step C. Moreover, in particular, by creating a vacuum atmosphere within the gas supply pipe 232a through venting, the storage efficiency of the raw material gas can be improved. Furthermore, the storage amount and concentration of the raw material gas can be kept constant through a cycle.

[0053] [Step B]

[0054] Next, in this step, as Figure 3 As shown in (A), the raw material gas flows from the upstream side of the gas supply pipe 232a to the exhaust pipe 232f. Specifically, with valves 243a and 243e closed, valves 302a to 302d are opened, allowing the raw material gas to flow from the upstream side of the gas supply pipe 232a to the exhaust pipe 232f. At the same time, valve 243c is opened, allowing inert gas to flow into the gas supply pipe 232c. This suppresses the backflow of atmosphere from the processing chamber 201 into the gas supply pipe 232a. The inert gas flow rate is adjusted by MFC 241c, supplied to the processing chamber 201 via nozzle 249a, and discharged from the exhaust pipe 231. Alternatively, valve 243d can also be opened at this time, allowing inert gas to flow within the gas supply pipes 232b and 232d.

[0055] By allowing the raw material gas to flow 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 expelled by the raw material gas. Therefore, it is possible to suppress the concentration change of the raw material gas caused by dilution of the raw material gas by the residual gas in subsequent steps, and to maintain a constant concentration of the stored raw material gas in a cyclical manner.

[0056] [Step C]

[0057] Next, in this step, as Figure 3 As shown in (B), the raw material gas is stored in the gas supply pipe 232a. Specifically, with valves 243a and 243e closed, valves 302a and 302d are closed, and the raw material gas is stored in the gas supply pipe 232a. At this time, with valve 243c open, inert gas flows into the gas supply pipe 232c. That is, during the period when the raw material gas is stored in the gas supply pipe 232a, inert gas is supplied from the gas supply pipe 232c to the space where the wafer 200 exists via the gas supply pipe 232a. This suppresses the backflow of the atmosphere in the processing chamber 201 into the gas supply pipe 232a. The inert gas flow rate is adjusted by MFC 241c, supplied into the processing chamber 201 via nozzle 249a, and discharged from the exhaust pipe 231. Alternatively, valve 243d can be opened at this time to allow inert gas to flow in the gas supply pipes 232b and 232d.

[0058] Here, the gas supply pipe 232a between valve 243a and valve 302a is configured such that its length is longer than that between valve 243a and reaction pipe 203, which serves as the processing container for housing wafer 200. This increases the amount of raw material gas stored and reduces the amount of gas remaining when it flows back from the processing chamber 201 to the gas supply pipe 232a. Furthermore, it reduces the amount of inert gas supplied to the processing chamber 201 simultaneously with the raw material gas from the gas supply pipe 232e.

[0059] In this step, valve 302c or valve 302b can be closed instead of valve 302a, and the raw material gas can be stored downstream of valve 302c or valve 302b. Alternatively, one of valves 302c or valve 302b can be closed according to specified data, and the raw material gas can be stored downstream of the closed valve. Furthermore, the storage volume data based on the diameter of the gas supply pipe 232a and the piping length between each valve when valves 302a to 302c are closed is stored in the storage device 121c and the like as specified data.

[0060] That is, by closing one of the valves 243a, 302a, 302b, or 302c, the gas supply pipe 232a can be used as a storage section for storing gas. This allows for adjustment of the amount of raw material gas stored in the gas supply pipe 232a and suppresses backflow from the reaction pipe 203.

[0061] Specifically, for example, by closing valves 243a and 302a, compared to valves 302b and 302c, the amount of gas stored in the gas supply pipe 232a can be increased, and the amount of residual gas when flowing back from the processing chamber 201 to the gas supply pipe 232a can be reduced. Additionally, the amount of inert gas supplied to the processing chamber 201 from the gas supply pipe 232e can be reduced. Furthermore, for example, by closing valves 243a and 302b, compared to valve 302a, the amount of gas stored in the gas supply pipe 232a can be reduced. Furthermore, for example, by closing valves 243a and 302c, compared to valves 302a and 302b, the amount of gas stored in the gas supply pipe 232a can be reduced.

[0062] [Step D]

[0063] Next, in this step, as Figure 3As shown in (C), the raw material gas flows within the processing chamber 201. Specifically, with valves 302a and 302d closed, valves 243a and 243e are opened, allowing the raw material gas stored in the gas supply pipe 232a to flow within the processing chamber 201. At this time, the raw material gas stored in the gas supply pipe 232a is forced out by the inert gas supplied from the gas supply pipe 232e, supplied into the processing chamber 201 via nozzle 249a, and discharged from the exhaust pipe 231. At this time, with valve 243c open, the flow rate of the inert gas supplied from MFC 241c to the gas supply pipe 232c is greater than the flow rate of the inert gas supplied to the gas supply pipe 232c in steps A to C above. The inert gas with adjusted flow rate is supplied into the processing chamber 201 together with the raw material gas and discharged from the exhaust pipe 231. That is, the raw material gas and the inert gas are supplied to the space where the wafer 200 exists via the gas supply pipe 232a. In addition, to prevent the raw material gas from entering the nozzle 249b, valve 243d is opened to allow inert gas to flow into gas supply pipe 232d. The inert gas is supplied into the processing chamber 201 through gas supply pipe 232d and nozzle 249b, and discharged from exhaust pipe 231.

[0064] As described above, after step C, valve 243a is opened, and inert gas is supplied from the upstream side of gas supply pipe 232a, supplying the raw material gas and inert gas stored in gas supply pipe 232a to wafer 200. At this time, the flow rate of inert gas supplied from gas supply pipe 232c is simultaneously made greater than the flow rate of inert gas supplied from gas supply pipe 232c in steps A to C. Therefore, the inert gas supplied from gas supply pipe 232c functions to suppress backflow of the atmosphere in processing chamber 201 in steps A to C, and to dilute the raw material gas in step D. Furthermore, in step D, the flow rate of inert gas supplied from gas supply pipe 232c is adjusted according to the concentration of the diluted raw material gas.

[0065] By increasing the inert gas flow rate supplied from the gas supply pipe 232c while opening valve 243a, the concentration of the raw material gas supplied from nozzle 249a can be kept constant. Alternatively, valve 243a can be opened after increasing the inert gas flow rate supplied from gas supply pipe 232c. In this case, the concentration of the raw material gas supplied from nozzle 249a can be reduced. Furthermore, the inert gas flow rate supplied from gas supply pipe 232c can be increased after opening valve 243a. In this case, the concentration of the raw material gas supplied from nozzle 249a can be increased. That is, the opening and closing timing of valve 243a and the inert gas flow rate control performed by MFC 241c are determined according to the diluted raw material gas concentration.

[0066] Furthermore, in this step, by adjusting MFC241e and 241c, the flow rate of inert gas supplied from gas supply pipe 232e is made greater than the flow rate of inert gas supplied from gas supply pipe 232c. In this way, by supplying inert gas, even when using raw material gas with low vapor pressure, the raw material gas can be squeezed out using inert gas, thus homogenizing the supply amount of raw material gas between wafers 200 and within the wafer 200 planes. Therefore, it is possible to suppress the deterioration of either or both of the film characteristic uniformity within the wafer 200 planes and the film characteristic uniformity between planes due to insufficient supply of raw material gas. In particular, it is possible to suppress the deterioration of film characteristic uniformity between planes.

[0067] At this time, the main gas flowing in the processing chamber 201 is the raw material gas. That is, the raw material gas is supplied to the wafer 200.

[0068] As the feedstock gas, gases containing metallic and halogen elements can be used. Here, in addition to transition metals from Groups 3 to 12, elements containing Group 13 elements can also be used as the metallic element.

[0069] As a gas containing both a metallic element and a halogen element, a gas containing at least one element such as molybdenum (Mo), zirconium (Zr), hafnium (Hf), aluminum (Al), indium (In), or gallium (Ga) and a halogen element can be used. Alternatively, a gas containing a metallic element and at least one element such as fluorine (F), chlorine (Cl), bromine (Br), or iodine (I) can be used. A gas containing both a metallic element and a halogen element is preferred. One or more of these can be used as the feed gas.

[0070] That is, as gases containing metallic and halogen elements, zirconium chloride (ZrCl4), hafnium chloride (HfCl4), aluminum chloride (AlCl3), gallium chloride (GaCl3), indium chloride (InCl3), molybdenum pentachloride (MoCl5), molybdenum dichlorodioxide (MoO2Cl2), and molybdenum tetrachlorodioxide (MoOCl4) can be used. One or more of these can be used as the raw material gas.

[0071] Inert gases, in addition to nitrogen (N2), can also include rare gases such as argon (Ar), helium (He), neon (Ne), and xenon (Xe). Ar is preferred as the inert gas. Furthermore, more than one of these gases can be used.

[0072] (Residual gas removal, step S2)

[0073] After forming a first layer containing metal and halogen elements on at least a portion of the wafer 200, with valves 243a and 243b closed, valves 243c and 243d are opened, and inert gas as purging gas is supplied to gas supply pipes 232a and 232b via gas supply pipes 232c and 232d. With the APC valve 244 of the exhaust pipe 231 open, the processing chamber 201 is purged by vacuum exhaust through pump 246.

[0074] (Reaction gas supply process, step S3)

[0075] Next, reactive gas is supplied to the wafer 200 in the processing chamber 201 for exhaust. Specifically, valve 243b is opened, allowing reactive gas to flow in gas supply pipe 232b. The reactive gas flow rate is adjusted by MFC 241b and supplied to the processing chamber 201 via nozzle 249b, and discharged from exhaust pipe 231. At the same time, valve 243d is opened, allowing inert gas to flow into gas supply pipe 232d. The inert gas flow rate is adjusted by MFC 241d and supplied to the processing chamber 201 together with the reactive gas, and discharged from exhaust pipe 231. In addition, to prevent reactive gas from entering nozzle 249a, valve 243c is opened, allowing inert gas to flow into gas supply pipe 232c. The inert gas is supplied to the processing chamber 201 via gas supply pipe 232c and nozzle 249a, and discharged from exhaust pipe 231.

[0076] At this time, the main gas flowing in the processing chamber 201 is the reactive gas. That is, the reactive gas is supplied to the wafer 200.

[0077] A reducing gas can be used as the reactant gas. For example, a gas containing hydrogen (H) can be used. Gases containing H include hydrogen (H₂), silane (SiH₄), silane (Si₂H), propane (Si₃H₈), ammonia (NH₃), hydrazine (N₂H₄), and phosphine (PH₃). One or more of these can be used as the reactant gas.

[0078] Specifically, when using, for example, MoCl5 gas as the raw material gas and H2 gas as the reaction gas, the Cl in the MoCl5 gas is reduced by the H2 gas through the reaction of MoCl5 gas and H2 gas, and the first layer on wafer 200 containing metal elements and halogen elements is modified into a second layer containing metal elements.

[0079] (Residual gas removal, step S4)

[0080] After forming a second layer containing metal elements on wafer 200, an inert gas is supplied as a purging gas through a process similar to step S2 described above. With the APC valve 244 of exhaust pipe 231 open, the processing chamber 201 is purged by vacuum exhaust through pump 246.

[0081] (Perform the prescribed number of times, step S5)

[0082] By sequentially performing 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 wafer 200. Specifically, for example, a molybdenum (Mo) film is formed as a metal-containing film. If the sequential performance of steps S1 to S4 is less than the predetermined number of times, the process returns to step S1.

[0083] (Post-purge and atmospheric pressure recovery)

[0084] Inert gas is supplied into the processing chamber 201 through gas supply pipes 232c and 232d, and discharged through exhaust pipe 231. The inert gas acts as a purging gas. As a result, the processing chamber 201 is purged, and any residual gases and reaction byproducts within it are removed. Afterwards, the atmosphere within the processing chamber 201 is replaced with inert gas, and the pressure inside the processing chamber 201 returns to atmospheric pressure.

[0085] (Wafer removal)

[0086] The cover 219 is lowered by the elevator 115, opening the lower end of MF209. Then, the processed wafer 200, supported by the crystal boat 217, is moved from the lower end of MF209 to the outside of the reaction tube 203. The processed wafer 200 is removed from the crystal boat 217.

[0087] (3) Other methods

[0088] Next, a modified example of the substrate processing apparatus 100 in the above-described manner will be described in detail. In the following modifications, only the points that differ from the above-described manner will be described in detail.

[0089] (Modified example)

[0090] In this variation, such as Figure 1 As shown by the dashed line, the gas supply pipe 232c for supplying inert gas is positioned upstream of the specific valve 243a of the gas supply pipe 232a. Even when the gas supply pipe 232c is positioned upstream of the specific valve 243a of the gas supply pipe 232a, the raw material gas can be diluted and supplied to the wafer 200, thereby increasing the supply amount of raw material gas. That is, in this modified example, the same effect as described above can be obtained.

[0091] Furthermore, in the above-described method, the raw material gas supply step (step S1) is illustrated by taking the case where steps A through D are performed sequentially a predetermined number of times (m times, where m is an integer of 1 or 2 or more). This disclosure is not limited to the above method; step A may be omitted, and steps B through D may be performed sequentially a predetermined number of times (m times, where m is an integer of 1 or 2 or more). In this method, the same effect as the above method can be obtained, and in this variation, the processing time can be further shortened.

[0092] Furthermore, the above-described method illustrates an example of forming a film using a batch-type substrate processing apparatus that processes multiple wafers at a time. This disclosure is not limited to the above-described method; for example, it can also be suitably applied to cases where a monolithic substrate processing apparatus that processes one or several wafers at a time is used to form a film. Additionally, the above-described method illustrates an example of forming a film using a substrate processing apparatus equipped with a hot-wall type furnace. This disclosure is not limited to the above-described method; it can also be suitably applied to cases where a substrate processing apparatus equipped with a cold-wall type furnace is used to form a film.

[0093] When using these substrate processing apparatuses, each processing can be performed under the same processing procedures and conditions as described above or in the modified examples, and the same effects as described above or in the modified examples can be obtained.

[0094] The above methods or variations can be used in appropriate combinations. In this case, the processing procedures and conditions can be set to be the same as those in the above methods or variations.

[0095] The foregoing has provided a detailed description of the methods and variations of this disclosure. However, the methods and variations of this disclosure are not limited to the above-described methods and variations, and various changes can be made without departing from its core essence.

[0096] Symbol Explanation

[0097] 200… wafer (substrate), 232a… gas supply pipe (first gas pipe), 243a… valve (first valve).

Claims

1. A substrate processing method, characterized in that, It has the following processes: (a) Closing the first valve of the first gas pipe, supplying 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) Open the first valve of the first gas pipe, supply the first inert gas from the upstream side of the first gas pipe, and supply the raw material gas and the first inert gas from the first gas pipe to the substrate.

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

3. The substrate processing method according to claim 2, characterized in that, The second gas pipe is located downstream of the first valve.

4. The substrate processing method according to claim 2, characterized in that, The second gas pipe is located upstream of the first valve.

5. The substrate processing method according to claim 3, characterized in that, The substrate processing method includes the following steps: (c) during (a), the second inert gas is supplied from the second gas pipe through the first gas pipe to the space in which the substrate exists.

6. The substrate processing method according to claim 5, characterized in that, Make the flow rate of the second inert gas in (b) greater than the flow rate of the second inert gas in (c).

7. The substrate processing method according to claim 2, characterized in that, In (b), the flow rate of the first inert gas is greater than the flow rate of the second inert gas.

8. The substrate processing method according to claim 1, characterized in that, It includes: a third gas pipe connected to the first gas pipe at a position upstream of the first valve. The substrate processing method includes the following steps: (d) causing the raw material gas to flow from the upstream side of the first gas pipe to the third gas pipe. (a) follows (d).

9. The substrate processing method according to claim 1, characterized in that, It includes: a third gas pipe connected to the first gas pipe at a position upstream of the first valve. The substrate processing method includes the following steps: (e) prior to (a), the atmosphere in the first gas tube is discharged from the third gas tube.

10. The substrate processing method according to claim 8, characterized in that, The substrate processing method includes the following steps: (f) prior to (d), the atmosphere in the first gas tube is discharged from the third gas tube.

11. The substrate processing method according to claim 1, characterized in that, It includes: a second valve, which is located upstream of the first valve in the first gas pipe. In (a), the second valve is closed, and the raw material gas is stored downstream of the second valve.

12. The substrate processing method according to claim 11, characterized in that, It includes: a third valve, which is located upstream of the second valve in the first gas pipe. In (a), one of the second valve and the third valve is closed according to specified data, and the raw material gas is stored downstream of the closed valve.

13. The substrate processing method according to claim 1, characterized in that, It includes: a fourth valve, which is located upstream of the first valve in the first gas pipe. 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 container housing the substrate.

14. The substrate processing method according to claim 1, characterized in that, The vapor pressure of the raw material gas is lower than the vapor pressure of other gases supplied to the substrate.

15. The substrate processing method according to claim 1, characterized in that, The raw material gas is a gas containing at least one element selected from Mo, Zr, Hf, Al, In, and Ga, and a halogen element.

16. A method for manufacturing a semiconductor device, characterized in that, It has the following processes: (a) Closing the first valve of the first gas pipe, supplying 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) Open the first valve of the first gas pipe, supply the first inert gas from the upstream side of the first gas pipe, and supply the raw material gas and the first inert gas from the first gas pipe to the substrate.

17. A program, characterized in that, The following process is executed by the substrate processing device using a computer: (a) Close the first valve of the first gas pipe, supply raw material gas from the upstream side of the first gas pipe, and store the raw material gas in the first gas pipe; as well as (b) Open the first valve of the first gas pipe, supply the first inert gas from the upstream side of the first gas pipe, and supply the raw material gas and the first inert gas from the first gas pipe to the substrate.

18. A substrate processing apparatus, characterized in that, have: The first gas pipe supplies raw material gas to the substrate; A first valve is disposed in the first gas pipe; A first inert gas supply unit supplies a first inert gas from the upstream side of the first gas pipe; and The control unit is configured to control the first valve and the first inert gas supply unit to perform the following processes: (a) Close the first valve of the first gas pipe, supply the raw material gas from the upstream side of the first gas pipe, and store the raw material gas in the first gas pipe; as well as (b) Open the first valve of the first gas pipe, supply the first inert gas from the upstream side of the first gas pipe, and supply the raw material gas and the first inert gas from the first gas pipe to the substrate.

19. A gas supply system, characterized in that, have: The first gas pipe supplies raw material gas to the substrate; A first valve, which is disposed in the first gas pipe; and A first inert gas supply unit supplies a first inert gas from the upstream side of the first gas pipe. The gas supply system is configured to control the first valve and the first inert gas supply unit to perform the following processes: (a) Close the first valve of the first gas pipe, supply the raw material gas from the upstream side of the first gas pipe, and store the raw material gas in the first gas pipe; as well as (b) Open the first valve of the first gas pipe, supply the first inert gas from the upstream side of the first gas pipe, and supply the raw material gas and the first inert gas from the first gas pipe to the substrate.

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