Gas supply system, processing device, gas supply method, production method for semiconductor device, and program

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 device, gas supply method, semiconductor device manufacturing method, and program

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

[0002] A known example of a substrate processing apparatus is a semiconductor manufacturing apparatus for manufacturing semiconductor devices. For example, substrate processing is performed by supplying a constant flow rate of a process gas to a substrate (hereinafter also referred to as a "wafer") for processing. Due to recent trends toward miniaturization of devices, various process gases, such as gas obtained by vaporizing a liquid or gas obtained by sublimating a solid, are used as the process gas, and a more constant flow rate of the process gas is sometimes required. For example, in Patent Document 1, a process gas is supplied at a constant flow rate by switching between multiple containers.

[0003] International Publication No. 2019 / 181603

[0004] The present disclosure provides a technique for supplying a source gas at a constant flow rate to a processing space.

[0005] According to one aspect of the present disclosure, there is provided a technology including: a first opening / closing unit that is provided on a flow path of vaporized raw material gas and that opens and closes the flow path; a second opening / closing unit that has a valve unit whose opening degree is adjustable and is provided in parallel to the first opening / closing unit; a buffer container that is provided on the flow path downstream of the first opening / closing unit and the second opening / closing unit and that temporarily stores the raw material gas; a flow rate control unit that is provided downstream of the buffer container and that controls the flow rate of the raw material gas to supply the raw material gas to a processing space; and a monitoring unit that is configured to monitor a pressure value in the buffer container and to be able to 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 according to the pressure value.

[0006] According to the present disclosure, a source gas can be supplied to a processing space at a constant flow rate.

[0007] 6A is a longitudinal cross-sectional view showing a schematic configuration of a processing furnace of a substrate processing apparatus according to an embodiment of the present disclosure; FIG. 6B is a schematic cross-sectional view taken along line A-A in FIG. 1; FIG. 6C is a schematic cross-sectional view showing a schematic configuration of a controller of a substrate processing apparatus according to an embodiment of the present disclosure, and a block diagram of a control system of the controller; FIG. 6D is a schematic diagram showing a substrate processing process according to an embodiment of the present disclosure; FIG. 6E is a schematic diagram showing a gas supply system configuration of a substrate processing apparatus according to an embodiment of the present disclosure; FIG. 6F is a schematic diagram showing a state at the start of supply of a source gas; FIG. 6G is a schematic diagram showing a state in which the remaining amount of a source gas in a source container 270 has decreased from the state of FIG. 6A and the aperture of the control valve of the MFC 241a has exceeded a threshold; and FIG. 6H is a schematic diagram showing a state in which a predetermined time has elapsed since the state of FIG. 6B. A diagram for explaining flow rate control of a source material monitoring system according to an embodiment of the present disclosure.

[0008] 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 the drawings used in the following description are all schematic, and the dimensional relationships, ratios, etc. of elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships, ratios, etc. of elements between multiple drawings do not necessarily correspond to the actual ones.

[0009] (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.

[0010] A reaction tube 203 is disposed inside the heater 207 concentrically with the heater 207. The reaction tube 203 is made of, for example, quartz (SiO ２The reaction tube 203 is made of a heat-resistant material such as silicon carbide (SiC) or silicon carbide (SiC), and is cylindrically shaped with a closed top and an open bottom. A manifold 209 is disposed concentrically below the reaction tube 203. The manifold 209 is made of a metal such as stainless steel (SUS), and is cylindrically shaped with both an open top and a closed bottom. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 to support the reaction tube 203. An O-ring 220a is provided as a sealing member between the manifold 209 and the reaction tube 203. The reaction tube 203 is installed vertically, similar to 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 the cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to accommodate wafers 200 to be processed.

[0011] Nozzles 249a and 249b are provided in the processing chamber 201 so as to penetrate the sidewall 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 a gas obtained by phase-changing a liquid or solid source material at room temperature into a gaseous state, but also a gas containing a gaseous source material at room temperature (hereinafter referred to as source gas) flows.

[0012] A source container 270 is connected to the gas supply pipe 232a via a valve 243e. Therefore, the gas supply pipe 232a is provided with, in this order from the upstream side, the source container 270, a valve 243e, a buffer container 280, a valve 243a, and a mass flow controller (MFC) 241a, which is a flow rate controller. The source container 270 does not simply have to be a source gas container that is gaseous at room temperature, but may also be a container that stores a liquid or solid source, or a container that temporarily stores a predetermined flow rate from such a container of a liquid or solid source.

[0013] The gas supply pipe 232a is provided with a bypass pipe 233 that bypasses the valve 243e. The bypass pipe 233 is provided with a valve 243f.

[0014] Further, the gas supply pipe 232b is provided with an MFC 241b and a valve 243b, which is an on-off valve, in this order from the upstream side.

[0015] Furthermore, gas supply pipes 232c and 232d for supplying 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 respectively provided in the gas supply pipes 232c and 232d in this order from the upstream side.

[0016] 2, the nozzles 249a and 249b are respectively provided in an annular space in a plan view between the inner wall of the reaction tube 203 and the wafers 200, along the inner wall of the reaction tube 203 from the bottom to the top, rising upward in the stacking direction of the wafers 200. Gas supply holes 250a and 250b for supplying gas as a material are respectively provided on the side surfaces of the nozzles 249a and 249b. The gas supply holes 250a and 250b are each open toward the center of the reaction tube 203, allowing gas to be supplied toward the wafers 200. A plurality of gas supply holes 250a and 250b are provided from the bottom to the top of the reaction tube 203.

[0017] From the gas supply pipe 232a, a source gas as a material is supplied from the source 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.

[0018] A reactive gas, such as a nitrogen-containing gas, which reacts with the source 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 source gas and the reactive gas may be collectively referred to as processing gas.

[0019] Inert gas is supplied from the 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, respectively. Hereinafter, the inert gas and processing gas will be collectively referred to as a material gas or simply as a gas, and the gas supplied to the processing chamber 201 may be referred to as a material gas or simply as a gas.

[0020] A source gas supply system is mainly composed of the valves 243e and 243f, the gas supply pipe 232a, the bypass pipe 233, the buffer container 280, the valve 243a, and the MFC 241a. A reactive gas supply system is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. The source gas supply system and the reactive gas supply system can be collectively referred to as the gas supply system. An inert gas supply system is mainly composed of the gas supply pipes 232c and 232d, the MFCs 241c and 241d, and the valves 243c and 243d. The inert gas supply system may be included in the gas supply system.

[0021] The opening and closing operations of the valves 243a to 243f and the flow rate adjustment operations of the MFCs 241a to 241d are 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.

[0022] The reaction tube 203 is provided with an exhaust pipe 231 for exhausting the atmosphere in 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 in 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 evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, while the vacuum pump 246 is operating, the pressure in the processing chamber 201 can be adjusted by adjusting the valve opening based on pressure information detected by the pressure sensor 245. The exhaust pipe 231, the APC valve 244, and the pressure sensor 245 mainly constitute an exhaust system. The vacuum pump 246 may be considered to be included in the exhaust system.

[0023] A seal cap 219 serving as a lid capable of airtightly closing the lower end opening of the manifold 209 is provided below 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 serving as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the lid 219. A rotation mechanism 267 for rotating the boat 217 (described later) is provided below the lid 219. A rotation shaft 255 of the rotation mechanism 267 passes through the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The lid 219 is configured to be raised and lowered vertically by a boat elevator 115 serving as a lifting mechanism installed outside the reaction tube 203. The lifting mechanism 115 is configured to raise and lower the lid 219 so as to load and unload the boat 217 into and out of the processing chamber 201. The lifting mechanism 115 is configured as a transfer device (transfer mechanism) that transfers the boat 217 , that is, the wafers 200 , into and out of the processing chamber 201 .

[0024] The boat 217, which serves as a substrate support, is configured to hold a plurality of wafers 200, for example, 25 to 200, arranged horizontally and with their centers aligned at intervals. The boat 217 is made of a heat-resistant material such as quartz or SiC. A thermal insulating plate 218, also made of a heat-resistant material such as quartz or SiC, is supported in multiple stages below the boat 217. Note that in this specification, a numerical range such as "25 to 200" means that the lower and upper limits are included in the range. Thus, for example, "25 to 200" means "25 to 200." The same applies to other numerical ranges.

[0025] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. The temperature distribution in the processing chamber 201 is achieved as desired by adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263. The temperature sensor 263 is configured in an L-shape and is installed along the inner wall of the reaction tube 203.

[0026] (Raw Material Container) Each raw material container 270 is equipped with a heating unit such as a heater that heats the contained raw material, such as a liquid raw material or a solid raw material. Here, a liquid raw material is a raw material that exists as a liquid at room temperature and normal pressure, and a solid raw material is a raw material that exists as a solid at room temperature and normal pressure. The controller 121 is configured to heat this heating unit so as to be able to control the temperature of the raw material container 270 to a temperature equal to or higher than the vaporization temperature.

[0027] (Flow Rate Controller) The MFC 241 is composed of a flow rate sensor and a flow rate adjustment unit. The flow rate sensor converts the pressure difference caused by the flow of fluid into a mass flow rate. The mass flow rate thus determined is compared with the set flow rate set by the user, and the opening of the valve (control valve) is adjusted by feedback control such as PID control so that the set flow rate is achieved. The flow rate adjustment unit has controllable pressure conditions set according to its specifications.

[0028] The MFC 241 may also have a function to output the valve opening as an electrical signal to the outside during this flow rate 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 (%), thereby making it possible to grasp the opening.

[0029] 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 including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to 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.

[0030] The storage device 121c includes, for example, a flash memory, an HDD (Hard Disk Drive), etc. The storage device 121c readably stores a control program for controlling the operation of the substrate processing apparatus 100, a process recipe describing the procedures and conditions of the substrate processing described below, and the like. The process recipe is a combination of procedures for the substrate processing described below that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. The process recipe is also simply referred to as a recipe. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (work area) in which programs, data, etc. read by the CPU 121a are temporarily stored.

[0031] 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, and the like.

[0032] 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. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFC 241, the opening and closing operation of the valve 243, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the boat elevator 115, and the like.

[0033] The controller 121 can be configured by installing the above-described program stored in an external storage device 123 (e.g., 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 a computer. The storage device 121c and the external storage device 123 are configured as computer-readable recording media on which the program is recorded. Hereinafter, these will be collectively referred to as recording media. When the term recording media is used in this specification, it may refer to only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer via 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 host device 75 via a network. The receiving unit 124 is capable of receiving information about other devices from the host device 75.

[0034] <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 in Fig. 4. Here, as an example of a semiconductor device manufacturing process, a cycle process will be described in which a process is performed by alternately supplying a source gas (raw material gas) and a reactant gas (reaction gas) to the process chamber 201. In this embodiment, an example of forming a film on a wafer 200 will be described.

[0035] The term "wafer" used in this specification may refer to the wafer itself or to a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may refer to the surface of the wafer itself or to the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0036] In the process of this embodiment, a film is formed on the wafer 200 by performing a cycle of non-simultaneously a predetermined number of times (one or more times) of the following steps: a step of supplying a raw material gas to the wafer 200 in the processing chamber 201 (film formation process 1: step S3); a purge step of removing the raw material gas (residual gas) from the processing chamber 201 (film formation process 2: step S4); a step of supplying a reactive gas to the wafer 200 in the processing chamber 201 (film formation process 3: step S5); and a purge step of removing the reactive gas (residual gas) from the processing chamber 201 (film formation process 4: step S6).

[0037] 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, four steps of film formation processes 1 to 4 are performed in sequence. Each step will be described in detail below.

[0038] (Film Forming Process 1) In the film forming process 1, first, a source gas is adsorbed onto the surface of the wafer 200. Specifically, in the source gas supply system (source gas supply line), the valve 243 a is opened, and the source gas, the flow rate of which is controlled by the MFC 241 a, is supplied to the processing chamber 201.

[0039] (Film Forming 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 processing furnace 202 is evacuated by the vacuum pump 246 to a pressure below a predetermined value, thereby removing the remaining source gas from the processing chamber 201. At this time, N ２ Supplying an inert gas such as HCl or HCl to the processing furnace 202 further enhances the effect of removing the remaining source gas.

[0040] (Film Forming Process 3) In 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 is mixed with the inert gas whose flow rate is adjusted by the MFC 241d from the gas supply pipe 232d. 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. The supply of the reactive gas causes the film on the base film of the wafer 200 to react with the reactive gas, and a predetermined film is formed on the wafer 200.

[0041] (Film Formation Process 4) In film formation process 4, after a film is formed on the wafer 200, the valves 243b and 243d are closed, and the processing 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. ２ Supplying an inert gas such as HCl or HClO into the processing chamber 201 further enhances the effect of removing the remaining reaction gas from the processing chamber 201 .

[0042] The above-described 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 with a predetermined thickness on wafer 200. In this embodiment, film formation steps 1 to 4 are repeated multiple times.

[0043] After the above-described film formation process is completed, in step S8, the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure). ２ An inert gas such as a gas is supplied to the processing chamber 201 and then exhausted. As a result, the processing chamber 201 is purged with the inert gas, and any gas remaining in the processing chamber 201 is removed from the processing chamber 201 (inert gas purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the 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, completing the substrate processing according to this embodiment.

[0044] Next, the configuration of the gas supply system according to this embodiment will be described with reference to FIG.

[0045] 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 rate control unit, and a controller 121 as an example of a monitoring unit. The gas supply system in this embodiment may also include a source container 270, a gas supply pipe 232a, a valve 243a, and a bypass pipe 233 as an example of a bypass flow path.

[0046] The valve 243e is provided upstream of the gas supply pipe 232a and downstream of the source material container 270. The valve 243e is, for example, an on-off valve, and its 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. The Cv value is an inherent coefficient indicating 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.

[0047] 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 source gas flowing out from the source container 270. A valve 243a is provided downstream of the buffer container 280 of the gas supply pipe 232a. This valve 243a is, for example, an on-off valve, and its opening and closing operation is controlled by the controller 121. 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. A pressure value P inside the buffer container 280 measured by the pressure sensor 281 is transmitted to the controller 121.

[0048] The valve 243f is provided in the bypass pipe 233 that bypasses the valve 243e. The valve 243f is a control valve having a valve portion whose opening degree can be adjusted, and the opening and closing operation of the valve 243f is controlled by the controller 121. Specifically, the opening and closing operation of the valve 243f, including the opening degree, is controlled by the controller 121. The valves 243e and 243f are disposed between the source material container 270 and the buffer container 280. As an example of the valve 243f, the same valve as the control valve of the MFC 241a may be used.

[0049] The MFC 241a is provided downstream of the buffer container 280 on the gas supply pipe 232a. Specifically, the MFC 241a is provided downstream of the valve 231a on the gas supply pipe 232a. More specifically, the MFC 241a is disposed between the valve 231a and a portion where the gas supply pipe 232a and the gas supply pipe 232c join. The MFC 241a can 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 processing chamber 201 via the gas supply pipe 232a and the nozzle 249a.

[0050] The controller 121 monitors the pressure value P. Specifically, the controller 121 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 operations of the valve 243e, the opening and closing operations of the valve 243f, and the flow rate control operation of the MFC 241a according to the pressure value P. Here, when the valve 243e is in an open state and the valve 243f is in a closed state, the source gas can be sent to the buffer container 280 via the valve 243e. When the valve 243e is in a closed state and the valve 243f is in an open state, the source gas can be sent to the buffer container 280 via the valve 243f. That is, by controlling the opening and closing operations of the valves 243e and 243f, the controller 121 can switch the route of the source gas sent from the source container 270 to the buffer container 280 between the route via the valve 243e and the route via the valve 243f (the bypass pipe 233). Since the valve 243e has at least one of a flow path diameter, a flow path cross-sectional area, and a capacity coefficient (Cv value) larger than those of the valve 243f, it is possible to send the source gas to the buffer container 280 more quickly than when using a route via the valve 243f. On the other hand, since the valve 243f is a control valve whose opening degree can be adjusted, when using a route via the valve 243f, it is possible to send the source gas to the buffer container 280 while finely adjusting the flow rate of the source gas.

[0051] The controller 121 also controls the opening and closing operation of the valve 243a. Here, when the controller 121 opens the valve 243a, the source material stored in the buffer container 280 is sent to the processing chamber 201 via the MFC 241a. Note that when either the valve 243e or the valve 243f is open, the source gas that has flowed 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 source gas is stored in the buffer container 280 when either the valve 243e or the valve 243f is open.

[0052] The controller 121 also controls the control valve of the MFC 241a so that the flow rate of the source gas supplied to the processing chamber 201 is kept constant in the MFC 241a.

[0053] Furthermore, the controller 121 controls the opening and closing operation of the valve 243f so that the pressure value P falls within a pressure control range R of the buffer container 280, which is a predetermined pressure range. Specifically, the controller 121 controls the opening degree of the valve 243f so that the pressure value P falls within the pressure control range R. Note that a 100% opening degree of the valve 243f corresponds to a fully open state, and a 0% opening degree of the valve 243f corresponds to a fully closed state. Furthermore, it is preferable that the pressure control range R of the buffer container 280 be set to a pressure band in which the MFC 241a can control the flow rate to a constant flow rate under controllable pressure conditions.

[0054] Furthermore, the controller 121 controls the valves 243e and 243f to close when the pressure value P reaches the upper limit R1 of the pressure control range R. Specifically, if the pressure value P reaches the upper limit R1 while the source gas is being stored in the buffer container 280 with the valve 243a in a closed state, the controller 121 closes the valves 243e and 243f to stop the source gas from being sent to the buffer container 280. Note that the upper limit R1 is preferably determined based on, for example, the saturated vapor pressure characteristics at the heat resistance temperature of the MFC 241a and the controllable pressure conditions of the MFC 241a. Furthermore, if the pressure value P exceeds the upper limit R1, an alarm may be issued.

[0055] Furthermore, the controller 121 may control the valve 243e to be in an open state when the pressure value P reaches the lower limit value R2 of the pressure control range R. For example, when the valve 243f is in an open state, 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 (immediately before) reaching the lower limit value R2. In particular, by having the controller 121 close the valve 243f and open the valve 243e just before the pressure value P reaches the lower limit value R2, it becomes possible to store the source 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.

[0056] The controller 121 may also control the valve 243e to be closed and the valve 243f to be open based on a threshold T that is preset within the pressure control range R. This threshold T may be set, for example, within the pressure control range R and near an upper limit R1. If the threshold T is set near the upper limit R1, the controller 121 closes the valve 243e and opens the valve 243f when the pressure value P reaches the threshold T, thereby enabling fine adjustment of the amount of source gas sent to the buffer container 280. Note that by setting the threshold T near the upper limit R1 or near the lower limit R2 within the pressure control range R, the controller 121 can control the opening and closing operations of the valves 243e and 243f just before the pressure reaches the upper limit R1 or the lower limit R2. The threshold T may also be set near the upper limit R1 and the lower limit R2, respectively.

[0057] Furthermore, the controller 121 may perform control so as to maintain the valve 243e or the valve 243f in an open state while the vaporized source gas is being stored in the buffer container 280 until the pressure value P reaches the threshold value T. Here, when the source gas is being rapidly stored in the buffer container 280, it is preferable that the controller 121 open the valve 243e and maintain the open state until the pressure value P reaches the threshold value T.

[0058] The controller 121 may open the valve 243e when there is a large difference between the pressure value P detected by the pressure sensor 281 and the set pressure value including the pressure control range R of the buffer container 280, specifically when the pressure value P is significantly lower than the set pressure value, and may close the valve 243e when the pressure value P is significantly higher than the set pressure value.

[0059] Next, an example of 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 a controller 121.

[0060] First, in the gas supply system, before the start of the film formation process (the above-described film formation process 1), the valves 243a and 243f are closed and the valve 243e is opened to store the source gas in the buffer container 280. For example, the source 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, the valve 243e is closed and the valve 243f is opened. As a result, the source gas is sent into the buffer container 280 while the flow rate is finely adjusted. When the pressure value P reaches the upper limit value R1, the valve 243f is closed. At this time, all of the valves 243a, 243f, and 243e are fully closed.

[0061] Then, when the film formation process (the above-described film formation process 1) is started, the gas supply system opens the valve 243a and supplies the source gas from the buffer container 280 to the processing chamber 201 via the MFC 241a. At this time, the valve 243f may be opened while adjusting its opening to send the source gas to the buffer container 280. This allows the pressure value P of the buffer container 280 to be adjusted to fall within the pressure control range R.

[0062] When the film formation process (the above-described film formation process 1) is completed, a process of filling the buffer container 280 with the source gas is performed. With the valve 243f open and the valve 243a closed, the source 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 the valve 243f is adjusted to bring the pressure value P closer to the upper limit value R1.

[0063] When the film forming process (the above-mentioned film forming process 1) is completed as described above, a filling process is carried out so that filling of the source gas into the buffer container 280 is completed between the above-mentioned film forming processes 2 to 4.

[0064] Next, another example of the operation of the gas supply system according to this embodiment will be described with reference to Fig. 7. Here, the same means and configuration as those in Fig. 6 may be omitted.

[0065] First, the filling process for storing the source gas in the buffer container 280 before the start of the film forming process is the same as that shown in FIG. 6, and therefore the description thereof will be omitted.

[0066] Then, when the film formation process (the above-described film formation process 1) is started, the gas supply system opens the valve 243a and supplies the source 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 its aperture to send the source gas to the buffer container 280. Here, if the amount of source 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 remaining within the pressure control range R, the source gas is sent to the buffer container 280, and the source gas sent to the buffer container 280 is directly supplied to the processing chamber 201 via the valve 243a and the MFC 241a.

[0067] When the film formation process is completed (the above-described film formation process 1), a process of filling the buffer container 280 with the source gas is performed. The filling process is the same as that shown in FIG. 6, so a description thereof will be omitted. In this way, when the film formation process (the above-described film formation process 1) is completed, a filling process is performed so that filling of the buffer container 280 with the source gas is completed between the above-described film formation processes 2 to 4.

[0068] 6 and 7 , the valve 243 a is opened and the valve 243 f is opened when the source gas is supplied from the buffer container 280 to the processing chamber 201 via the MFC 241 a. However, this is not limited to this. For example, the valve 243 f may be changed from a closed state to an open state when the pressure value P starts to drop. In the example of FIG. 7 , the valve 243 a is opened and the source gas is supplied from the buffer container 280 to the processing chamber 201 via the MFC 241 a. When the valve 243 a is opened and the source gas is supplied from the buffer container 280 to the processing chamber 201 via the MFC 241 a, the valve 243 e is opened when the pressure value P reaches or is about to reach the lower limit value R2, and the MFC 241 a is kept open while the source gas is being supplied to the processing chamber 201. However, this is not limited to this. For example, the valve 243 e may be opened when the pressure value P reaches or is about to reach the lower limit value R2, and closed when the pressure value P reaches the threshold value T.

[0069] According to this embodiment, one or more of the following effects are achieved.

[0070] 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.

[0071] Furthermore, the valves 243e and 243f can be opened and closed as appropriate so that the pressure value P falls within the pressure control range R, thereby enabling a stable supply of the source gas at a flow rate set by the MFC 241a to the processing chamber 201. For example, when the pressure value P reaches the lower limit value R2, the route can be switched to one via the valve 243e, preventing the pressure value P from exceeding the lower limit value of the pressure control range R, thereby enabling a stable and continuous supply of the source gas.

[0072] Furthermore, when the pressure value P reaches the threshold value T, the route can be switched from via the valve 243e to via the valve 243f, so that the source gas can be supplied stably and continuously without the pressure value P exceeding the upper limit value R1 of the pressure control range R. By setting the threshold value T in this manner, the pressure in the buffer container 280 can be prevented from deviating from the set range by switching from the route via the valve 243e, which is an on / off valve, to the route via the valve 243f, which is a control valve.

[0073] When the pressure value P is less than the lower limit value R2, the valve 243e is opened to increase the pressure in the buffer container 280, and the raw material can be stored in the buffer container 280 quickly.

[0074] Since the flow rate can be controlled by the MFC 241a within the pressure control range R, the source gas can be stably supplied to the processing chamber 201 at a constant flow rate set by the MFC 241a.

[0075] By setting the threshold value T to a value close to the upper limit value R1, the time until the pressure in the buffer container 280 reaches the lower limit value R2 while the opening degree is being adjusted by the valve 243f can be extended, thereby postponing the replacement of the raw material container 270.

[0076] (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 of the present disclosure.

[0077] For example, in the above-described embodiment, the substrate processing apparatus is configured to perform a film formation process using a solid source material as a source material, heating the solid source material to sublimate it, and generating a source gas. While the present disclosure is not limited to this example, a case has been given in which a nitrogen-containing gas is used as a reactant (reaction gas) and the reactant gases are alternately supplied to form a nitride film on the wafer 200.

[0078] Also, as the solid source, a solid source chemical, particularly an inorganic solid source metal, or a semiconductor precursor can be used, for example, HfCl ４ , ZrCl４ , AlCl ３ , MoO ２ Cl ２ , MoCl ５ or SiI ４ etc. can be used as the solid raw material.

[0079] The present invention is also applicable to a case where a raw material supplied in a liquid state is heated and vaporized to generate a raw material gas. Such a liquid raw material gas may be, for example, monochlorosilane (SiH ３ Cl, abbreviated as MCS) gas, dichlorosilane (SiH ２ Cl ２ , abbreviated as DCS) gas, trichlorosilane (SiHCl ３ , abbreviated as TCS) gas, tetrachlorosilane (SiCl ４ , abbreviation: STC) gas, hexachlorodisilane gas (Si ２ Cl ６ , abbreviation: HCDS) gas, octachlorotrisilane (Si ３ Cl ８ , abbreviated as OCTS) gas can be used. Also, as the source gas, for example, tetrafluorosilane (SiF ４ ) gas, difluorosilane (SiH ２ F ２ fluorosilane-based gases such as tetrabromosilane (SiBr ４ ) gas, dibromosilane (SiH ２ Br ２ ) gas, bromosilane-based gases such as tetraiodosilane (SiI ４ ) gas, diiodosilane (SiH ２ I ２ An iodosilane-based gas 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 ] ２H ２ ) gas, bis(tert-butylamino)silane (SiH ２ [NH(C ４ H ９ )] ２ An aminosilane-based gas such as tetraethoxysilane (Si(OC)) can also be used as the source gas. ２ H ５ ) ４ Alternatively, organic silane source gases such as silane nitrate, ...

[0080] Nitrogen-containing gases include nitrous oxide (N ２ O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO ２ ) gas, ammonia (NH 3 ) gas, or the like can be used.

[0081] 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 processing may be performed using three or more types of processing gases.

[0082] In the above embodiment, N is used as the inert gas. ２ Although an example using gas has been described, the present invention is not limited to this, and rare gases such as Ar gas, He gas, Ne gas, and Xe gas may also be used.

[0083] Furthermore, for example, in the above-described embodiments, a film formation process for a semiconductor device has been described as an example of a process performed by a substrate processing apparatus, but the present disclosure is not limited thereto. 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 pattern with a depth greater than its width) is formed to a vaporized gas. That is, in addition to film formation processes, processes for forming oxide films, nitride films, and metal-containing films may also be used. Furthermore, although the present embodiments describe a semiconductor manufacturing process, the present disclosure is not limited thereto. For example, the present disclosure can also 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.

[0084] It is also possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment, or to add, delete, or replace part of the configuration of each embodiment with another configuration.

[0085] This application claims the benefit of priority based on Japanese Patent Application No. 2023-174746, filed October 6, 2023, the entire disclosure of which is incorporated herein by reference.

[0086] The present invention can be applied to a technology for manufacturing semiconductor devices by supplying a raw material with low vapor pressure characteristics and forming a film on a workpiece including a semiconductor.

[0087] 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

1. A gas supply system comprising: a first opening / closing unit provided on a flow path of vaporized raw material gas for opening and closing the flow path; a second opening / closing unit having a valve unit whose opening degree can be adjusted and provided in parallel to the first opening / closing unit; a buffer container provided downstream of the first opening / closing unit and the second opening / closing unit on the flow path for temporarily storing the raw material gas; a flow rate control unit provided downstream of the buffer container for controlling a flow rate of the raw material gas to supply the raw material gas to a processing space; and a monitoring unit configured to monitor a pressure value within the buffer container, and to be able to 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 pressure value.

2. 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.

3. 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.

4. The gas supply system according to claim 1, wherein the monitoring unit controls the first opening / closing unit to be opened when the pressure value reaches a lower limit value of a predetermined pressure range.

5. A gas supply system as described in claim 4, wherein the monitoring unit controls the second opening / closing unit to be closed when the pressure value reaches a lower limit value of a predetermined pressure range or is about to reach the lower limit value while the second opening / closing unit is in an open state.

6. 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.

7. A gas supply system as described in claim 6, wherein the monitoring unit controls the first opening / closing unit to a closed state when the pressure value reaches a preset threshold value within a predetermined pressure range while the first opening / closing unit is in an open state.

8. 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.

9. The gas supply system according to claim 1, further comprising a pressure sensor for detecting the pressure inside the buffer vessel, wherein the monitoring unit controls the first opening / closing unit to open / close when a difference between a pressure value detected by the pressure sensor and a pressure value inside the buffer vessel is equal to or greater than the predetermined pressure range.

10. The gas supply system according to claim 1, wherein a source container containing a source of the source gas is provided upstream of the first opening / closing unit of the flow path, and the first opening / closing unit and the second opening / closing unit are disposed between the source container and the buffer container.

11. The gas supply system according to claim 10, wherein the second opening / closing unit constitutes a part of the flow path and is provided in a bypass flow path that bypasses the first opening / closing unit.

12. The gas supply system according to claim 1, wherein the predetermined pressure range of the buffer container is a pressure zone within which the flow rate control section can control the flow rate to a constant flow rate.

13. The gas supply system according to claim 1, wherein an upper limit of the predetermined pressure range of the buffer vessel is determined by the saturated vapor pressure characteristics at the heat resistance temperature of the flow control section and the controllable pressure conditions of the flow control section.

14. 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 near an upper limit value of the predetermined pressure range.

15. 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 path diameter, a flow path cross-sectional area, and a flow path capacity coefficient.

16. A processing apparatus comprising: a first opening / closing unit provided on a flow path of vaporized raw material gas for opening and closing the flow path; a second opening / closing unit having a valve unit whose opening degree can be adjusted and provided in parallel to the first opening / closing unit; a buffer container provided on the flow path downstream of the first opening / closing unit and the second opening / closing unit for temporarily storing the raw material gas; a flow rate control unit provided downstream of the buffer container for controlling the flow rate of the raw material gas to supply the raw material gas to a processing space; and a monitoring unit configured to monitor a pressure value within the buffer container and to be able to 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 pressure value.

17. A gas supply method comprising: a first step of storing a source gas in the buffer vessel by using the gas supply system according to any one of claims 1 to 15; and a second step of supplying the source gas in the buffer vessel to a processing space.

18. A method of manufacturing a semiconductor device, comprising the steps of: supplying the source gas to a surface of an object to be processed that is placed in the processing space, by the gas supply method according to claim 17; and processing the object.

19. A program executed by a processing device including: a first opening / closing unit provided on a flow path of vaporized raw material gas for opening and closing the flow path; a second opening / closing unit having a valve unit whose opening degree can be adjusted and provided in parallel to the first opening / closing unit; a buffer container provided on the flow path downstream of the first opening / closing unit and the second opening / closing unit for temporarily storing the raw material gas; and a flow rate control unit provided on the flow path downstream of the buffer container for controlling the flow rate of the raw material gas to supply the raw material gas to a processing space, the program monitoring a pressure value within the buffer container and causing a computer to execute a procedure for controlling 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 pressure value.

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