WO2025074668A1 - Gas supply system, processing device, gas supply method, production method for semiconductor device, and program - Google Patents

Abstract

The present invention comprises a first opening/closing unit that is provided on a flow path for a vaporized starting material gas and opens/closes the flow path, a second opening/closing unit that is provided in parallel with the first opening/closing unit and has a valve that can be opened to different degrees, a buffer container that is provided on the flow path downstream of the first opening/closing unit and the second opening/closing unit and temporarily retains the starting material gas, a flow rate control unit that is provided downstream of the buffer container, controls the flow rate of the starting material gas, and supplies the starting material gas to a processing space, and a monitoring unit that monitors the value of the pressure inside the buffer container and can control the opening/closing operation of the first opening/closing unit, the opening/closing operation of the second opening/closing unit, and the flow rate control operation of the flow rate control unit in accordance with the value of the pressure.

Description

GAS SUPPLY SYSTEM, PROCESSING APPARATUS, GAS SUPPLY METHOD, AND PROGRAM FOR MANUFACTURING SEMICONDUCTOR DEVICE

This disclosure relates to a gas supply system, a processing device, a gas supply method, a method for manufacturing a semiconductor device, and a program.

One example of a substrate processing apparatus is a semiconductor manufacturing apparatus that manufactures semiconductor devices. For example, substrate processing is performed by supplying a constant flow rate of processing gas to a substrate (hereinafter also referred to as a "wafer") for processing. Due to recent reasons such as the miniaturization of devices, various processing gases such as gas produced by vaporizing a liquid or gas produced by sublimating a solid are used as the processing gas, and a more constant flow rate of processing gas may be required. For example, in Patent Document 1, a constant flow rate of processing gas is supplied by switching between multiple containers.

International Publication No. 2019/181603

This disclosure provides a technology for supplying a constant flow rate of raw material gas to a processing space.

According to one aspect of the present disclosure,
a first opening/closing unit that is provided on a flow path of the vaporized source gas and opens and closes the flow path;
A second opening/closing unit having a valve unit whose opening degree is adjustable and provided in parallel with the first opening/closing unit;
a buffer container provided downstream of the first opening/closing unit and the second opening/closing unit of the flow path, the buffer container temporarily storing the source gas;
a flow rate control unit provided downstream of the buffer container, the flow rate control unit controlling a flow rate of the source gas to supply the source gas to a processing space;
a monitoring unit configured to monitor a pressure value in the buffer container and to be able to control an opening/closing operation of the first opening/closing unit, an opening/closing operation of the second opening/closing unit, and a flow control operation of the flow control unit in response to the pressure value;
The present invention provides a technique having the following features:

According to the present disclosure, a constant flow rate of raw material gas can be supplied to the processing space.

1 is a vertical cross-sectional view showing a schematic configuration of a processing furnace of a substrate processing apparatus according to an embodiment of the present disclosure. 2 is a schematic cross-sectional view taken along line AA in FIG. 1. FIG. 2 is a schematic configuration diagram of a controller of the substrate processing apparatus according to an embodiment of the present disclosure, showing a control system of the controller in a block diagram. 1 is a flow chart of a substrate processing process according to an embodiment of the present disclosure. 1 is a schematic diagram illustrating a configuration of a gas supply system of a substrate processing apparatus according to an embodiment of the present disclosure. 6(A) is a diagram showing the state at the start of the supply of the raw material gas, FIG. 6(B) is a diagram showing the state when the remaining amount in the raw material container 270 decreases from the state of FIG. 6(A) and the opening degree of the control valve of the MFC 241a exceeds a threshold value, and FIG. 6(C) is a diagram showing the state when a predetermined time has passed from the state of FIG. 6(B). FIG. 2 is a diagram for explaining flow rate control of a raw material monitoring system according to an embodiment of the present disclosure.

The configuration of a substrate processing apparatus 100 according to one embodiment of the present disclosure will be described below with reference to Figures 1 and 2. Note that all drawings used in the following description are schematic, and the dimensional relationships between elements, ratios between elements, etc. shown in the drawings do not necessarily match the actual relationships. Furthermore, the dimensional relationships between elements, ratios between elements, etc. do not necessarily match between multiple drawings.

(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.

A reaction tube 203 is disposed concentrically with the heater 207 inside the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO ₂ ) or silicon carbide (SiC), and is formed in a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is disposed concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is made of a metal such as stainless steel (SUS), and is formed in a cylindrical shape with an open upper end and a closed lower end. The upper end of the manifold 209 is engaged 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 manifold 209 and the reaction tube 203 as a seal member. The reaction tube 203 is installed vertically like the heater 207. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 serving as a processing space is formed in a cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to be capable of accommodating a wafer 200 as a processing target.

Nozzles 249a and 249b are provided in the processing chamber 201 so as to penetrate the side wall of the manifold 209. Gas supply pipes (piping) 232a and 232b are connected to the nozzles 249a and 249b, respectively. The nozzle 249a and the gas supply pipe 232a form a flow path through which not only gas resulting from a phase change from liquid or solid raw materials at room temperature to gaseous state, but also gas containing raw materials that are gaseous at room temperature (hereinafter referred to as raw material gas) flows.

The raw material container 270 is connected to the gas supply pipe 232a via a valve 243e. Therefore, the raw material container 270, the valve 243e, the buffer container 280, the valve 243a, and the mass flow controller (MFC) 241a, which is a flow rate controller, are provided in the gas supply pipe 232a in this order from the upstream side. Note that the raw material container 270 is not limited to a raw material gas container that is gaseous at room temperature, but may be a container that stores a liquid or solid raw material, or a container that temporarily stores a predetermined flow rate from such a container of liquid or solid raw material.

In addition, the gas supply pipe 232a is provided with a bypass pipe 233 that bypasses the valve 243e. This bypass pipe 233 is provided with a valve 243f.

In addition, the gas supply pipe 232b is provided with, in order from the upstream side, an MFC 241b and a valve 243b which is an on-off valve.

Furthermore, gas supply pipes 232c and 232d that supply inert gas are connected to the gas supply pipes 232a and 232b downstream of the valves 243a and 243b, respectively. MFCs 241c and 241d and valves 243c and 243d are provided in the gas supply pipes 232c and 232d, in that order from the upstream side, respectively.

As shown in FIG. 2, the nozzles 249a and 249b are provided in a circular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, and are arranged to rise upward in the loading direction of the wafers 200 along the inner wall of the reaction tube 203 from the lower part to the upper part. Gas supply holes 250a and 250b for supplying gas as a material are provided on the side of the nozzles 249a and 249b. The gas supply holes 250a and 250b are each open toward the center of the reaction tube 203, making it possible to supply gas toward the wafers 200. A plurality of gas supply holes 250a and 250b are provided from the lower part to the upper part of the reaction tube 203.

From the gas supply pipe 232a, the raw material gas as the material is supplied from the raw material container 270 via the valve 243e and/or the valve 243f to the processing chamber 201 via the buffer container 280, the valve 243a, the MFC 241a, and the nozzle 249a.

A reactive gas, such as a nitrogen-containing gas, that reacts with the raw material gas is supplied from the gas supply pipe 232b to the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b. A reducing gas can be used as the reactive gas. Hereinafter, the raw material gas and the reactive gas are sometimes collectively referred to as the processing gas.

Inert gas is supplied from gas supply pipes 232c and 232d to the processing chamber 201 via MFCs 241c and 241d, valves 243c and 243d, gas supply pipes 232a and 232b, and nozzles 249a and 249b. Hereinafter, the inert gas and processing gas are collectively referred to as the gas supplied to the processing chamber 201, and may be referred to as the material gas or simply as the gas.

The raw gas supply system is mainly composed of valves 243e and 243f, gas supply pipe 232a, bypass pipe 233, buffer container 280, valve 243a, and MFC 241a. The reactive gas supply system is mainly composed of gas supply pipe 232b, MFC 241b, and valve 243b. The raw gas supply system and reactive gas supply system can be collectively referred to as the gas supply system. The inert gas supply system is mainly composed of gas supply pipes 232c and 232d, MFCs 241c and 241d, and valves 243c and 243d. The inert gas supply system may be included in the gas supply system.

The opening and closing operations of the valves 243a to 243f and the flow rate adjustment operations by the MFCs 241a to 241d are configured to be controlled by a controller 121, which will be described later. Hereinafter, the MFCs 241a to 241d may be collectively referred to as MFC 241, and the valves 243a to 243f may be collectively referred to as valves 243. The same applies to the other components.

The reaction tube 203 is provided with an exhaust pipe 231 for exhausting the atmosphere of the processing chamber 201. The exhaust pipe 231 is connected to a vacuum pump 246 as a vacuum exhaust device via a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure of the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure adjustment unit). The APC valve 244 can evacuate and stop the vacuum exhaust of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is in operation, and is further configured to adjust the pressure of the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is in operation. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

Below the manifold 209, a seal cap 219 is provided as a lid that can airtightly close the lower end opening of the manifold 209. The lid 219 is made of a metal such as SUS and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the lid 219 as a seal member that abuts against the lower end of the manifold 209. Below the lid 219, a rotation mechanism 267 is installed to rotate the boat 217 described later. The rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217 through the seal cap 219. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The lid 219 is configured to be raised and lowered in the vertical direction by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203. The lifting mechanism 115 is configured to raise and lower the lid 219 so that the boat 217 can be transported in and out of the processing chamber 201. The lifting mechanism 115 is configured as a transport device (transport mechanism) that transports the boat 217, i.e., the wafers 200, into and out of the processing chamber 201.

The boat 217, which serves as a substrate support, is configured to arrange multiple wafers 200, for example 25 to 200, in a horizontal position with their centers aligned and spaced apart. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported in multiple stages. Note that in this specification, a numerical range such as "25 to 200" means that the lower and upper limits are included in the range. Thus, for example, "25 to 200" means "25 or more and 200 or less." The same applies to other numerical ranges.

A temperature sensor 263 is installed inside the reaction tube 203 as a temperature detector. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature of the processing chamber 201 is adjusted to the desired temperature distribution. The temperature sensor 263 is configured in an L-shape and is installed along the inner wall of the reaction tube 203.

(Raw material container)
Each of the source containers 270 is equipped with a heating unit such as a heater for heating the contained source materials such as liquid source materials and solid source materials. Here, the liquid source materials are those that exist as liquids at normal temperature and pressure, and the solid source materials are those that exist as solids at normal temperature and pressure. The controller 121 is configured to be able to control the temperature of the source container 270 to a temperature equal to or higher than the vaporization temperature by heating the heating unit.

(Flow Controller)
The MFC 241 is composed of a flow sensor section and a flow rate adjustment section. The flow rate sensor section converts the pressure difference caused by the flow of the fluid into a mass flow rate. The mass flow rate thus obtained is compared with the set flow rate set by the user, and the opening of the valve (control valve) is adjusted to achieve the set flow rate through feedback control such as PID control. Note that the controllable pressure conditions for the flow rate adjustment section are set according to the respective specifications.

The MFC 241 may also be provided with a function for outputting the valve opening as an electrical signal to the outside during this flow control. This valve opening signal is input to the controller 121 as an electrical signal such as a voltage signal, and a calculation is performed to convert the electrical signal into an opening (%), making it possible to grasp the opening.

Next, the controller 121, which is the control unit (control means), will be described. As shown in FIG. 3, the controller 121, which is the control unit (control means), is configured as a computer equipped with 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 be able to exchange data with the CPU 121a via an internal bus 121e. An input/output device 122, which is configured as, for example, a touch panel, is connected to the controller 121.

The storage device 121c is composed of, for example, a flash memory, a HDD (Hard Disk Drive), etc. 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 later, etc. are readably stored in the storage device 121c. The process recipe is a combination of procedures in the substrate processing described later that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe and the control program are collectively referred to simply as a program. In addition, the process recipe is also simply referred to as a recipe. When the word program is used in this specification, it may include only the recipe alone, only the control program alone, or both. The RAM 121b is configured as a memory area (work area) in which the programs and data read by the CPU 121a are temporarily stored.

The I/O port 121d is connected to the above-mentioned MFC 241, valve 243, pressure sensor 245, APC valve 244, vacuum pump 246, heater 207, temperature sensor 263, rotation mechanism 267, boat elevator 115, etc.

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

The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 (for example, a magnetic disk such as a hard disk, an optical disk such as a CD, a magneto-optical disk such as an MO, or a semiconductor memory such as a USB memory) into the 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 are collectively referred to 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. 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. Furthermore, the controller 121 is provided with a receiving unit 124 connected to the higher-level device 75 via a network. The receiving unit 124 is capable of receiving information of other devices from the higher-level device 75.

<Substrate Processing Method>
Next, a substrate processing method using the substrate processing apparatus 100 according to an embodiment of the present disclosure will be described with reference to the flowchart of Fig. 4. Here, as an example of a semiconductor device manufacturing process, a cycle process in which a source gas (raw material gas) and a reactant gas (reaction gas) are alternately supplied to a processing chamber 201 to perform processing will be described. In this embodiment, an example of forming a film on a wafer 200 will be described.

The term "wafer" used in this specification can mean the wafer itself, or a laminate of the wafer and a specified layer or film formed on its surface. The term "surface of a wafer" used in this specification can mean the surface of the wafer itself, or the surface of a specified layer, etc. formed on the wafer. When it is stated in this specification that "a specified layer is formed on a wafer," it can mean that a specified layer is formed directly on the surface of the wafer itself, or that a specified layer is formed on a layer, etc. formed on the wafer. When the term "substrate" is used in this specification, it is synonymous with the term "wafer."

In the process of this embodiment, a film is formed on the wafer 200 by performing a cycle of non-simultaneous operations a predetermined number of times (one or more) including a process of supplying a raw material gas to the wafer 200 in the process chamber 201 (film formation process 1: step S3), a purging process of removing the raw material gas (residual gas) from the process chamber 201 (film formation process 2: step S4), a process of supplying a reactive gas to the wafer 200 in the process chamber 201 (film formation process 3: step S5), and a purging process of removing the reactive gas (residual gas) from the process chamber 201 (film formation process 4: step S6).

First, as described above, the wafers 200 are loaded into the boat 217 and then loaded into the processing chamber 201 (step S1). After the boat 217 is loaded into the processing chamber 201, the pressure and temperature of the processing chamber 201 are adjusted (step S2). Next, the four steps of the film formation process 1 to 4 are carried out in sequence. Each step will be described in detail below.

(Film formation process 1)
In the film formation process 1, first, a source gas is adsorbed onto the surface of the wafer 200. Specifically, in a source gas supply system (source gas supply line), a valve 243a is opened, and a source gas whose flow rate is controlled by an MFC 241a is supplied to the processing chamber 201.

(Film formation process 2)
Next, in the film forming process 2, the valve 243a of the source gas supply system and the valve 243c of the inert gas supply system are closed to stop the supply of the source gas and the inert gas. The APC valve 244 of the exhaust pipe 231 is left open, and the process furnace 202 is evacuated by the vacuum pump 246 so that the pressure therein is equal to or lower than a predetermined value, and the remaining source gas is removed from the process chamber 201. If an inert gas such as _N2 is supplied to the process furnace 202 at this time, the effect of removing the remaining source gas is further enhanced.

(Film forming process 3)
In the film forming process 3, a reactive gas and an inert gas are flowed into the processing chamber 201. First, the valve 243b provided on the gas supply pipe 232b and the valve 243d provided on the gas supply pipe 232d are both opened, and the reactive gas whose flow rate is adjusted by the MFC 241b from the gas supply pipe 232d and the inert gas whose flow rate is adjusted by the MFC 241d from the gas supply pipe 232d are mixed, and the mixed gas is supplied to the processing chamber 201 from the gas supply hole 250b of the nozzle 249b while being exhausted from the exhaust pipe 231. By supplying the reactive gas, the film on the base film of the wafer 200 reacts with the reactive gas, and a predetermined film is formed on the wafer 200.

(Film formation process 4)
In the film forming process 4, after forming a film on the wafer 200, the valves 243b and 243d are closed, and the process chamber 201 is evacuated by the vacuum pump 246 as an exhaust device to remove the reaction gas remaining after contributing to the film formation. If an inert gas such as _N2 is supplied to the process chamber 201 at this time, the effect of removing the remaining reaction gas from the process chamber 201 is further enhanced.

The above-mentioned film formation steps 1 to 4 constitute one cycle, and in step S7, the cycle of film formation steps 1 to 4 is performed a predetermined number of times to form a film of a predetermined thickness on the wafer 200. In this embodiment, film formation steps 1 to 4 are repeated multiple times.

After the above-mentioned film formation process is completed, in step S8, the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure). Specifically, for example, an inert gas such as _N2 gas is supplied to the processing chamber 201 and exhausted. As a result, the processing chamber 201 is purged with the inert gas, and gas remaining in the processing chamber 201 is removed from the processing chamber 201 (inert gas purge). After that, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure). Then, in step S9, the wafer 200 is unloaded from the processing chamber 201, and the substrate processing according to this embodiment is completed.

Next, the configuration of the gas supply system in this embodiment will be described with reference to FIG. 5.

The gas supply system in this embodiment mainly includes a valve 243e as an example of a first opening/closing unit, a buffer container 280, a valve 243f as an example of a second opening/closing unit, an MFC 241a as an example of a flow control unit, and a controller 121 as an example of a monitoring unit. The gas supply system in this embodiment may also include a raw material container 270, a gas supply pipe 232a, a valve 243a, and a bypass pipe 233 as an example of a bypass flow path.

The valve 243e is provided upstream of the gas supply pipe 232a and downstream of the raw material container 270. As an example, the valve 243e is an on-off valve, and the opening and closing operation is controlled by the controller 121. The valve 243e is larger than the valve 243f in at least one of the flow path diameter, flow path cross-sectional area, and Cv value. Here, the Cv value is an inherent coefficient that indicates the ease of flow of a fluid, and is one of the capacity coefficients of a valve defined by the JIS standard (JIS B0100). The valves 243e and 243f are provided in parallel upstream of the buffer container 280. Specifically, the valve 243e is provided in the gas supply pipe 232a, and the valve 243f is provided in the bypass pipe 233.

The buffer container 280 is provided downstream of the valve 243e of the gas supply pipe 232a. The buffer container 280 has a function of temporarily storing the raw material gas flowing out from the raw material container 270. A valve 243a is provided downstream of the buffer container 280 of the gas supply pipe 232a. As an example, this valve 231a is an on-off valve, and its opening and closing operation is controlled by the controller 121. In addition, a pressure sensor 281 is provided between the valve 243a of the gas supply pipe 232a and the buffer container 280. The pressure sensor 281 measures the pressure inside the buffer container 280. In addition, the pressure value P inside the buffer container 280 measured by the pressure sensor 281 is transmitted to the controller 121.

Valve 243f is provided in bypass pipe 233 that bypasses valve 243e. This valve 243f is a control valve having a valve portion whose opening degree can be adjusted, and its opening and closing operation is controlled by controller 121. Specifically, the opening and closing operation of valve 243f, including its opening degree, is controlled by controller 121. Valves 243e and 243f are disposed between raw material container 270 and buffer container 280. Also, as an example of valve 243f, the same valve as the control valve of MFC 241a may be used.

The MFC 241a is provided downstream of the buffer container 280 of the gas supply pipe 232a. Specifically, the MFC 241a is provided downstream of the valve 231a of the gas supply pipe 232a. More specifically, the MFC 241a is disposed between the valve 231a and the portion where the gas supply pipe 232a joins the gas supply pipe 232c. The MFC 241a can also control the flow rate of the source gas under controllable pressure conditions. The source gas is controlled to a constant flow rate by the MFC 241a and supplied to the process chamber 201 via the gas supply pipe 232a and the nozzle 249a.

The controller 121 monitors the pressure value P. Specifically, it monitors the pressure value P received from the pressure sensor 281. The controller 121 is configured to be able to control the opening and closing operation of the valve 243e, the opening and closing operation of the valve 243f, and the flow control operation of the MFC 241a according to the pressure value P. Here, when the valve 243e is opened and the valve 243f is closed, the raw material gas can be sent to the buffer container 280 via the valve 243e. When the valve 243e is closed and the valve 243f is opened, the raw material gas can be sent to the buffer container 280 via the valve 243f. That is, the controller 121 can switch the route of the raw material gas sent from the raw material container 270 to the buffer container 280 between the route via the valve 243e and the route via the valve 243f (bypass pipe 233) by controlling the opening and closing operation of each of the valves 243e and 243f. In addition, since at least one of the flow path diameter, flow path cross-sectional area, and capacity coefficient (Cv value) of valve 243e is larger than that of valve 243f, it is possible to send the raw material gas to buffer container 280 more quickly than when using a route via valve 243f. On the other hand, since valve 243f is a control valve whose opening can be adjusted, when using a route via valve 243f, it is possible to send the raw material gas to buffer container 280 while finely adjusting the flow rate.

The controller 121 also controls the opening and closing of the valve 243a. When the controller 121 opens the valve 243a, the raw material stored in the buffer container 280 is sent to the processing chamber 201 via the MFC 241a. When either the valve 243e or the valve 243f is open, the raw material gas that flows into the buffer container 280 via the open valve is sent directly to the processing chamber 201 via the valve 243a and the MFC 241a. On the other hand, when the controller 121 closes the valve 243a, the raw material gas is stored in the buffer container 280 if either the valve 243e or the valve 243f is open.

The controller 121 also controls the control valve of the MFC 241a so that the flow rate of the raw material gas supplied to the processing chamber 201 is constant in the MFC 241a.

The controller 121 also controls the opening and closing of the valve 243f so that the pressure value P falls within the pressure management range R of the buffer vessel 280, which is a predetermined pressure range. Specifically, the controller 121 controls the opening of the valve 243f so that the pressure value P falls within the pressure management range R. Note that a 100% opening of the valve 243f is a fully open state, and a 0% opening of the valve 243f is a fully closed state. It is also preferable that the pressure management range R of the buffer vessel 280 is set to a pressure band in which the MFC 241a can control the flow rate to a constant flow rate under controllable pressure conditions.

The controller 121 also controls the valves 243e and 243f to be closed when the pressure value P reaches the upper limit value R1 of the pressure management range R. Specifically, when the pressure value P reaches the upper limit value R1 while the raw material gas is being stored in the buffer container 280 with the valve 243a in the closed state, the controller 121 closes the valves 243e and 243f to stop the raw material gas from being sent to the buffer container 280. The upper limit value R1 is preferably determined, for example, based on the saturated vapor pressure characteristics at the heat resistance temperature of the MFC 241a and the controllable pressure conditions of the MFC 241a. When the pressure value P exceeds the upper limit value R1, an alarm may be issued.

The controller 121 may also control the valve 243e to be in an open state when the pressure value P reaches the lower limit value R2 of the pressure management range R. For example, the controller 121 may control the valve 243f to be in a closed state and the valve 243e to be in an open state when the pressure value P reaches the lower limit value R2 or just before (just before) the lower limit value R2 while the valve 243f is in an open state. In particular, by the controller 121 closing the valve 243f and opening the valve 243e just before the pressure value P reaches the lower limit value R2, it becomes possible to store the raw material gas in the buffer container 280 without the pressure value P falling below the lower limit value R2. Note that an alarm may be issued when the pressure value P falls below the lower limit value R2.

The controller 121 may also control the valve 243e to be in a closed state and the valve 243f to be in an open state, based on a threshold value T that is preset within the pressure management range R. For example, the threshold value T is set within the pressure management range R and near the upper limit value R1. Here, when the threshold value T is set near the upper limit value R1, the controller 121 closes the valve 243e and opens the valve 243f when the pressure value P reaches the threshold value T, thereby making it possible to finely adjust the amount of raw material gas sent to the buffer container 280. By setting the threshold value T near the upper limit value R1 or near the lower limit value R2 within the pressure management range R, the controller 121 can control the opening and closing operations of the valves 243e and 243f just before the upper limit value R1 or the lower limit value R2 is reached. The threshold value T may also be set near the upper limit value R1 and near the lower limit value R2, respectively.

The controller 121 may also control the valve 243e or the valve 243f to be kept open while the vaporized raw material gas is being stored in the buffer container 280 until the pressure value P reaches the threshold value T. Here, when the raw material gas is being rapidly stored in the buffer container 280, it is preferable that the controller 121 opens the valve 243e and keeps it open until the pressure value P reaches the threshold value T.

The controller 121 may open the valve 243e when the difference between the pressure value P detected by the pressure sensor 281 and the set pressure value including the pressure management range R of the buffer container 280 is large, specifically, when the pressure value P is significantly lower than the set pressure value, and close the valve 243e when the pressure value P is significantly higher than the set pressure value.

Next, an example of the operation of the gas supply system in this embodiment will be described with reference to FIG. 6. Each component of the gas supply system is controlled by the controller 121.

First, in the gas supply system, before the start of the film formation process (film formation process 1 described above), valves 243a and 243f are closed and valve 243e is open to store the raw material gas in the buffer container 280. For example, the raw material gas is stored in the buffer container 280 until the pressure value P reaches the threshold value T. When the pressure value P reaches the threshold value T, valve 243e is closed and valve 243f is opened. This allows the raw material gas to be sent into the buffer container 280 while the flow rate is finely adjusted. When the pressure value P reaches the upper limit value R1, valve 243f is closed. At this time, all of valves 243a, 243f, and 243e are fully closed.

When the film formation process (film formation process 1 described above) is started, the gas supply system opens valve 243a and supplies raw material gas from buffer container 280 to processing chamber 201 via MFC 241a. At this time, valve 243f may be opened while adjusting the aperture to send raw material gas to buffer container 280. This allows the pressure value P of buffer container 280 to be adjusted to fall within pressure control range R.

When the film formation process (film formation process 1 described above) is completed, the raw material gas is filled into the buffer container 280. Valve 243f is opened and valve 243a is closed, and the raw material gas is stored in the buffer container 280. In FIG. 6, since the pressure value P is within the pressure control range R, the opening of valve 243f is adjusted to bring the pressure value P closer to the upper limit value R1.

When the film formation process (film formation process 1 described above) is completed as described above, a filling process is performed so that the filling of the raw material gas into the buffer container 280 is completed between each of the film formation processes 2 to 4 described above.

Next, another example of the operation of the gas supply system in this embodiment will be described with reference to FIG. 7. Here, the same means and configuration as in FIG. 6 may be omitted.

First, the filling process for storing the source gas in the buffer container 280 before starting the film formation process is the same as that shown in FIG. 6, so a description thereof will be omitted.

When the film formation process (film formation process 1 described above) is started, the gas supply system opens the valve 243a and supplies the raw material gas from the buffer container 280 to the processing chamber 201 via the MFC 241a. At this time, the valve 243f is opened while adjusting the opening degree, and the raw material gas is sent to the buffer container 280. Here, if the amount of raw material gas supplied to the processing chamber 201 is large, the pressure value P may reach the lower limit value R2. When the pressure value P reaches the lower limit value R2, the valve 243e opens, and the pressure value P increases rapidly. Then, with the pressure value P within the pressure control range R, the raw material gas is sent to the buffer container 280, and the raw material gas sent to the buffer container 280 is supplied directly to the processing chamber 201 via the valve 243a and the MFC 241a.

When the film formation process is completed (film formation process 1 described above), the process of filling the buffer container 280 with the raw material gas is performed. The filling process is the same as that shown in FIG. 6, so a description thereof is omitted. In this way, when the film formation process (film formation process 1 described above) is completed, the filling process is performed so that filling of the raw material gas into the buffer container 280 is completed between each of the film formation processes 2 to 4 described above.

6 and 7, the valve 243a is opened and the raw gas is supplied from the buffer container 280 to the processing chamber 201 via the MFC 241a, and the valve 243f is opened. However, this is not the only option. For example, when the pressure value P starts to drop, the valve 243f may be changed from a closed state to an open state. Also, in the example of FIG. 7, when the valve 243a is opened and the raw gas is supplied from the buffer container 280 to the processing chamber 201 via the MFC 241a, the valve 243e is opened when the pressure value P reaches or is about to reach the lower limit value R2, and the MFC 241a is kept open while the raw gas is being supplied to the processing chamber 201. However, this is not the only option. For example, the valve 243e may be opened when the pressure value P reaches or is about to reach the lower limit value R2, and the valve 243e is closed when the pressure value P reaches the threshold value T.

This embodiment provides one or more of the following advantages:

By controlling the opening and closing operation of valve 243e, the opening and closing operation of valve 243f, and the flow rate control operation of MFC 241a according to the pressure value P in the buffer container 280, it is possible to stably supply the raw material gas at a constant flow rate set by MFC 241a to the processing chamber 201.

Also, valves 243e and 243f can be opened and closed as appropriate so that pressure value P falls within pressure control range R, so that raw material gas can be stably supplied to processing chamber 201 at the flow rate set by MFC 241a. For example, when pressure value P reaches lower limit value R2, the route can be switched to via valve 243e, so that raw material gas can be stably and continuously supplied without pressure value P exceeding the lower limit value of pressure control range R.

In addition, when pressure value P reaches threshold value T, the route can be switched from via valve 243e to via valve 243f, so that the source gas can be supplied stably and continuously without pressure value P exceeding upper limit value R1 of pressure control range R. By setting threshold value T in this manner, it is possible to prevent the pressure in buffer vessel 280 from going outside the set range by switching from the route via valve 243e, which is an on/off valve, to the route via valve 243f, which is a control valve.

When the pressure value P is less than the lower limit value R2, the pressure in the buffer container 280 can be increased by opening the valve 243e, and the raw material can be quickly stored in the buffer container 280.

Since the flow rate can be controlled by the MFC 241a within the pressure control range R, the raw material gas can be stably supplied to the processing chamber 201 at a constant flow rate set by the MFC 241a.

By setting the threshold T close to the upper limit R1, the time until the pressure inside the buffer container 280 reaches the lower limit R2 while the opening of the valve 243f is being adjusted can be extended, so replacement of the raw material container 270 can be delayed.

Other Embodiments
Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

For example, in the above-described embodiment, the film formation process performed by the substrate processing apparatus is configured to use a solid raw material as a raw material source, heat the solid raw material to sublimate it, and generate a raw material gas. Although an example has been given in which a nitrogen-containing gas is used as a reactant (reaction gas), and a nitride film is formed on the wafer 200 by alternately supplying the gases, the present disclosure is not limited to such a case.

In addition, as the solid source, a solid source chemical, particularly an inorganic solid source metal, or a semiconductor precursor can be used, for example, _HfCl4 , _ZrCl4 , _AlCl3 , _MoO2Cl2 , _{MoCl5 ,} or _SiI4 can be used as the solid source.

The present invention can also be applied to a case where a raw material supplied in a liquid state is heated and vaporized to generate a raw material gas. Examples of such liquid raw material gas include chlorosilane gases such as monochlorosilane ( _SiH3Cl , abbreviated as MCS) gas, _{dichlorosilane} ( _SiH2Cl2 , abbreviated as DCS) gas, trichlorosilane ( _SiHCl3 , abbreviated as TCS) gas, tetrachlorosilane ( _SiCl4 , abbreviated as _STC ) gas, hexachlorodisilane gas ( _Si2Cl6 , abbreviated as HCDS) gas, _and octachlorotrisilane ( _Si3Cl8 , abbreviated as OCTS) gas. In addition, as the raw material gas, for example, fluorosilane-based gases such as tetrafluorosilane ( _SiF4 ) gas and difluorosilane _{( SiH2F2} ) gas, bromosilane-based gases such as tetrabromosilane ( _SiBr4 ) gas and dibromosilane ( _SiH2Br2 ) gas, and _iodosilane -based gases such as tetraiodosilane ( _SiI4 ) gas _and diiodosilane ( _SiH2I2 ) gas can be used. Also, as the source gas, for example, aminosilane-based gases such as tetrakis(dimethylamino)silane (Si[N(CH ₃ ) ₂ ] ₄ ) gas, tris(dimethylamino)silane (Si[N(CH ₃ ) ₂ ] ₃ H) gas, bis(diethylamino)silane (Si[N(C ₂ H ₅ ) ₂ ] ₂ H ₂ ) gas, and bis(tertiary butylamino)silane (SiH ₂ [NH(C ₄ H ₉ )] ₂ ) gas can be used. Also, as the source gas, for example, organic silane source gases such as tetraethoxysilane (Si(OC ₂ H ₅ ) ₄ ) gas can be used. As the source gas, one or more of these can be used. In other words, the source gas may include a source stored in liquid form by pressurization or cooling.

As the nitrogen-containing gas, one or more of nitrous oxide (N ₂ O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO ₂ ) gas, ammonia (NH 3 ) gas, and the like can be used.

In addition, the reactant is not limited to a nitrogen-containing gas, and other types of thin films may be formed using gases that react with the source to perform film processing. Furthermore, film formation may be performed using three or more types of processing gases.

In addition, in the above embodiment, an example has been described in which _N2 gas is used as the inert gas, but the inert gas is not limited thereto, and a rare gas such as Ar gas, He gas, Ne gas, or Xe gas may also be used.

In addition, for example, in each of the above-mentioned embodiments, a film formation process in a semiconductor device is given as an example of a process performed by a substrate processing apparatus, but the present disclosure is not limited to this. The technology of the present disclosure can be applied to all processes performed by exposing a workpiece on which a pattern with a high aspect ratio (i.e., a depth greater than a width) is formed to a vaporized gas. That is, in addition to film formation processes, the technology may also be processes for forming oxide films or nitride films, and processes for forming films containing metals. In addition, in the present embodiment, a semiconductor manufacturing process is described, but the present disclosure is not limited to this. For example, the present disclosure can be applied to substrate processes such as a liquid crystal device manufacturing process, a solar cell manufacturing process, a light-emitting device manufacturing process, a glass substrate processing process, a ceramic substrate processing process, and a conductive substrate processing process.

It is also possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

This application claims the benefit of priority from Japanese Patent Application No. 2023-174746, filed on October 6, 2023, the entire disclosure of which is incorporated herein by reference.

This technology can be applied to the manufacture of semiconductor devices by supplying raw materials with low vapor pressure characteristics and forming a film on the workpiece, including semiconductors.

121 Controller (an example of a monitoring unit)
280 Buffer container 241a Mass flow controller (an example of a flow rate control unit)
243e Valve (an example of a first opening/closing unit)
243f Valve (an example of a second opening/closing unit)

Claims (19)

a first opening/closing unit that is provided on a flow path of the vaporized source gas and opens and closes the flow path;
A second opening/closing unit having a valve unit whose opening degree is adjustable and provided in parallel with the first opening/closing unit;
a buffer container provided downstream of the first opening/closing unit and the second opening/closing unit of the flow path, for temporarily storing the source gas; and a flow rate control unit provided downstream of the buffer container, for controlling a flow rate of the source gas to supply the source gas to a processing space.
a monitoring unit configured to monitor a pressure value in the buffer container and to be able to control an opening/closing operation of the first opening/closing unit, an opening/closing operation of the second opening/closing unit, and a flow control operation of the flow control unit in response to the pressure value;
A gas supply system comprising: The gas supply system according to claim 1 , wherein the monitoring unit controls the opening and closing operation of the second opening and closing unit so that the pressure value falls within a predetermined pressure range. The gas supply system according to claim 1 , wherein the monitoring unit controls the first opening/closing unit and the second opening/closing unit to be in a closed state when the pressure value reaches an upper limit value of a predetermined pressure range. The gas supply system according to claim 1 , wherein the monitoring unit controls the first opening/closing unit to be in an open state when the pressure value reaches a lower limit value of a predetermined pressure range. The gas supply system according to claim 4 , wherein the monitoring unit controls the second opening/closing unit to be in a closed state when the pressure value reaches a lower limit value of a predetermined pressure range or is about to reach the lower limit value when the second opening/closing unit is in an open state. The gas supply system according to claim 1 , wherein the monitoring unit controls the second opening/closing unit to be in an open state based on a threshold value that is preset within a predetermined pressure range of the buffer container. The gas supply system according to claim 6 , wherein the monitoring unit controls the first opening/closing unit to a closed state when the pressure value reaches a threshold value that is preset within a predetermined pressure range while the first opening/closing unit is in an open state. 7. The gas supply system according to claim 6, wherein the monitoring unit controls the first opening/closing unit to be kept open until the pressure value reaches the threshold value while the vaporized source gas is being stored in the buffer container. A pressure sensor for detecting a pressure in the buffer container is further provided.
2. The gas supply system according to claim 1, wherein the monitoring unit controls the first opening/closing unit to open or close when a difference between a pressure value detected by the pressure sensor and a pressure value in the buffer container is equal to or greater than the predetermined pressure range. a source container for accommodating a source of the source gas is provided on the upstream side of the first opening/closing part of the flow path,
The gas supply system according to claim 1 , wherein the first opening/closing unit and the second opening/closing unit are disposed between the source container and the buffer container. The gas supply system according to claim 10 , wherein the second opening/closing unit is provided in a bypass flow path that constitutes a part of the flow path and bypasses the first opening/closing unit. The gas supply system according to claim 1 , wherein the predetermined pressure range of the buffer container is a pressure zone in which the flow rate control unit can control the flow rate to a constant flow rate. The gas supply system according to claim 1 , wherein an upper limit of the predetermined pressure range of the buffer container is determined by a saturated vapor pressure characteristic at a heat resistant temperature of the flow rate control section and a controllable pressure condition of the flow rate control section. The gas supply system according to claim 1 , wherein the monitoring unit is configured to be able to set a preset threshold value within a predetermined pressure range of the buffer container and in the vicinity of an upper limit value of the predetermined pressure range. The gas supply system according to claim 1 , wherein the first opening/closing section is larger than the second opening/closing section in at least one of a flow passage diameter, a flow passage cross-sectional area, and a flow passage capacity coefficient. a first opening/closing unit that is provided on a flow path of the vaporized source gas and opens and closes the flow path;
A second opening/closing unit having a valve unit whose opening degree is adjustable and provided in parallel with the first opening/closing unit;
a buffer container provided downstream of the first opening/closing unit and the second opening/closing unit of the flow path, the buffer container temporarily storing the source gas;
a flow rate control unit provided downstream of the buffer container and configured to control a flow rate of the source gas to supply the source gas to a processing space;
a monitoring unit configured to monitor a pressure value in the buffer container and to be able to control an opening/closing operation of the first opening/closing unit, an opening/closing operation of the second opening/closing unit, and a flow control operation of the flow control unit in response to the pressure value;
A processing device comprising: A first step of storing a source gas in the buffer container by the gas supply system according to any one of claims 1 to 15;
a second step of supplying the source gas in the buffer container to a processing space. A method for manufacturing a semiconductor device in which the source gas is supplied to a surface of a processing object placed in the processing space by the gas supply method according to claim 17, and the processing object is processed. a first opening/closing unit that is provided on a flow path of the vaporized source gas and opens and closes the flow path;
A second opening/closing unit having a valve unit whose opening degree is adjustable and provided in parallel with the first opening/closing unit;
a buffer container provided downstream of the first opening/closing unit and the second opening/closing unit of the flow path, the buffer container temporarily storing the source gas;
a flow rate control unit provided downstream of the buffer container in the flow path and configured to control a flow rate of the source gas to supply the source gas to a processing space;
A program executed by a processing device comprising:
A program that causes the processing device to execute a procedure of monitoring a pressure value in the buffer container and controlling the opening and closing operation of the first opening and closing unit, the opening and closing operation of the second opening and closing unit, and the flow control operation of the flow control unit in accordance with the pressure value.

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