Gas supply method, semiconductor device manufacturing method, substrate processing apparatus and program, and flow rate controller

Abstract

The present invention includes a first step of supplying a gas to a container while controlling a flow rate of the gas by adjusting valve opening, and a second step of adjusting the valve opening on the basis of a pressure in the container and supplying the gas to the container.

Description

Gas supply method, semiconductor device manufacturing method, substrate processing apparatus, program, and flow rate controller

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

[0002] As one step in the manufacturing process of a semiconductor device, a substrate processing process may be performed in which a processing gas (e.g., a raw material gas, a reactive gas, etc.) is supplied to a substrate to form a film on the substrate, and a large amount of processing gas accumulated in a tank (hereinafter also referred to as a container) is supplied all at once in a very short period of time (see, for example, JP 2022-085236 A).

[0003] The present disclosure provides techniques for filling a vessel with a large volume of process gas.

[0004] According to one aspect of the present disclosure, there is provided a technique comprising: a first step of supplying a gas to a container while controlling the flow rate of the gas by adjusting the aperture of a valve provided in a gas supply line; and a second step of supplying the gas to the container by adjusting the aperture of the valve based on the pressure inside the container.

[0005] According to the present disclosure, the vessel can be filled with large amounts of process gas.

[0006] FIG. 1 is a schematic configuration diagram of a substrate processing apparatus suitable for use in one embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a schematic configuration diagram of a controller 121 of a substrate processing apparatus suitable for use in one embodiment of the present disclosure, and is a block diagram illustrating a control system of the controller 121. FIG. 4 is a flow diagram illustrating a film formation sequence in one embodiment of the present disclosure. FIG. 5 is a diagram illustrating a source gas supply system in one embodiment of the present disclosure. FIG. 6 is a flow diagram illustrating switching control of a control mode for supplying a source gas into a tank in one embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example of the time progression of the pressure inside the tank and the valve opening when the flow of FIG. 6 is executed.

[0007] <One Aspect of the Present Disclosure> One aspect of the present disclosure will be described below, mainly with reference to Figures 1 to 7. Note that all drawings used in the following description are schematic, and the dimensional relationships, ratios, etc. of elements in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships, ratios, etc. of elements between multiple drawings do not necessarily match.

[0008] (1) Configuration of the Substrate Processing Apparatus As shown in Fig. 1, the processing furnace 202 has a heater 207 as a temperature regulator (heating unit). The heater 207 is cylindrical and is installed vertically by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gases by heat.

[0009] 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 ２ The reaction tube 203 is made of a heat-resistant material such as silicon carbide (SiC) or silicon carbide (SiC) and has a cylindrical shape with a closed top end and an open bottom 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 material such as stainless steel (SUS) and has a cylindrical shape with open top and bottom ends. 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 serving as a sealing member is provided 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 is formed in the cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to accommodate wafers 200 as substrates. In this processing chamber 201, processing of the wafer 200 is performed.

[0010] In the processing chamber 201, a nozzle 249a as a first supply unit and a nozzle 249b as a second supply unit are provided so as to penetrate the sidewall of the manifold 209. The nozzles 249a and 249b are also referred to as a first and a second nozzle, respectively. The nozzles 249a and 249b are made of a heat-resistant material such as quartz or SiC. Gas supply pipes 232a and 232b are connected to the nozzles 249a and 249b, respectively. The nozzles 249a and 249b are different nozzles, and the nozzles 249a and 249b are provided adjacent to each other.

[0011] The gas supply pipe 232a is provided with, in order from the upstream side of the gas flow, a vaporizer 241a that converts a raw material into a gaseous gas (raw material gas as a first process gas), a vaporizer 248 including a mass flow controller (MFC) 251 that is a flow rate controller (flow rate control section) including a valve 243a that is a first valve that is a piezoelectric valve, a storage section 240a that is an example of a container configured to temporarily store the gas vaporized by the vaporizer 248, and a valve 242a that is a second valve. Furthermore, a pressure sensor 247 is provided between the vaporizer 248 and the storage section 240a. The pressure sensor 247 can detect the pressure inside the storage section 240a. Hereinafter, in this specification, a configuration in which the MFC 251 is included in the vaporizer 248 will be described, but the above-described vaporizer 248 is merely an example, and the MFC 251 does not necessarily have to be included in the vaporizer 248.

[0012] A gas supply pipe 232c is connected to the gas supply pipe 232a downstream of the valve 242a. An MFC 241c and a valve 243c are provided in the gas supply pipe 232c, in this order from the upstream side of the gas flow. The gas supply pipes 232a and 232c and the reservoir 240a are made of a metal material such as SUS. A source gas supply system (source gas supply line) is mainly composed of the gas supply pipe 232a, the vaporizer 248 including the vaporizer 241a and the valve 243a, the reservoir 240a, and the valve 242a.

[0013] The reservoir 240a has a larger cross-sectional area than a normal pipe, and is configured as, for example, a gas tank with a larger gas capacity than a normal pipe. By opening and closing a valve 243a upstream of the reservoir 240a and a valve 242a downstream of the reservoir 240a, it is possible to fill the reservoir 240a with a gas obtained by gasifying a raw material supplied from the gas supply pipe 232a, or to supply the gas filled in the reservoir 240a to the processing chamber 201. Details of the vaporizer 248 will be described later.

[0014] By closing the valve 242a and adjusting the aperture of the valve 243a, the gas vaporized by the vaporizer 241a and having its flow rate adjusted by the MFC 251 can be filled into the storage section 240a. When the pressure in the storage section 240a reaches a first predetermined pressure (hereinafter, sometimes referred to as the first predetermined value), flow control by the MFC 251 is switched to control that determines the aperture of the valve 243a based on the pressure in the storage section 240a. When a predetermined amount of gas is filled into the storage section 240a and the pressure in the storage section 240a reaches a second predetermined pressure (hereinafter, sometimes referred to as the second predetermined value), the valve 243a is closed and the valve 242a is opened, thereby allowing the high-pressure gas filled in the storage section 240a to be supplied (flush-supplied) to the process chamber 201 all at once (in a short time) via the gas supply pipe 232a and the nozzle 249a. Details of the gas supply method in this source gas supply system (source gas supply line) will be described later. During the flush supply, the valve 243a may be open.

[0015] The gas supply pipe 232b is provided with, in order from the upstream side of the gas flow, an MFC 241b and a valve 243b which is an on-off valve. A gas supply pipe 232d is connected to the gas supply pipe 232b downstream of the valve 243b. The gas supply pipe 232d is provided with, in order from the upstream side of the gas flow, an MFC 241d and a valve 243d. The gas supply pipes 232b and 232d are made of a metal material such as SUS.

[0016] As shown in FIG. 2 , the nozzles 249 a and 249 b are respectively provided in a circular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, extending from the lower part to the upper part of the inner wall of the reaction tube 203 and rising upward in the arrangement direction of the wafers 200. That is, the nozzles 249 a and 249 b are respectively provided in regions horizontally surrounding the wafer arrangement region on the sides of the wafer arrangement region where the wafers 200 are arranged, extending along the wafer arrangement region. In a plan view, the nozzle 249 a is disposed opposite an exhaust port 231 a (described later) across the center of the wafer 200 loaded into the processing chamber 201. The nozzle 249 b is disposed adjacent to the nozzle 249 a and along the inner wall of the reaction tube 203 (the outer periphery of the wafers 200). Gas supply holes 250 a and 250 b for supplying gas are provided on the side surfaces of the nozzles 249 a and 249 b, respectively. The gas supply holes 250a and 250b are each open to face (face) the exhaust port 231a in a plan view, and are capable of supplying gas 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] 5, the vaporizer 248 constituting the raw material gas supply system includes a vaporizer 241a and an MFC 251 having a flow rate sensor 252 and a valve 243a. The vaporizer 241a is provided on the raw material supply line (here, on the gas supply pipe 232a). As described above, the vaporizer 241a has the function of vaporizing the raw material into a gaseous state. The MFC 251 is provided on the raw material supply line. Specifically, it is provided downstream of the vaporizer 241a in the gas flow.

[0018] Furthermore, the MFC 251 is configured to be able to supply gas to the storage section 240a while controlling the gas flow rate by adjusting the aperture of a valve 243a provided in the supply line. Specifically, the MFC 251 has a flow rate sensor 252 and a valve 243a. The flow rate sensor 252 is an example of a sensor, and is provided in the supply line and has the function of detecting the flow rate of the vaporized raw material (hereinafter referred to as "gas" as appropriate). In the present embodiment, as an example, the MFC 251 adjusts the aperture of the valve 243a based on the flow rate detected by the flow rate sensor 252. The valve 243a is provided in the supply line and has the function of supplying gas to the storage section 240a. Specifically, the supply and stop of gas to the storage section 240a can be switched on and off by opening and closing the valve 243a.

[0019] The MFC 251 is configured to be able to supply gas to the storage section 240a while controlling the gas flow rate by adjusting the opening of the valve 243a based on the flow rate detected by the flow sensor 252 within the range of pressure that can be controlled by the flow rate.

[0020] Furthermore, the MFC 251 is configured to be able to supply gas to the storage unit 240a by adjusting the aperture of the valve 243a based on the pressure in the storage unit 240a when the pressure is outside the range of pressure that can be controlled by the flow rate of the MFC 251. Specifically, when the pressure value of the storage unit 240a is outside the pressure range that can be controlled by the MFC 251, the flow rate control by the MFC 251 is switched to the aperture control of the valve 243a by the controller 121. In this embodiment, a system that switches between the flow rate control by the MFC 251 and the aperture control of the valve 243a by the controller 121 is referred to as a vaporization system. As shown in FIG. 5 , the vaporization system is mainly composed of the vaporizer 248 and the controller 121.

[0021] Note that a certain level of pressure differential is required for the MFC 251 to achieve flow rate control. Therefore, as gas is filled into the storage portion 240a, the pressure within the storage portion 240a increases, and the pressure differential decreases accordingly, approaching the limit of control by the MFC 251. In this embodiment, when the MFC 251 reaches its control limit, the flow rate control by the MFC 251 is switched to the controller 121 controlling the opening of the valve 243a, thereby increasing the amount of gas that can be filled into the storage portion 240a. Furthermore, when a certain level of pressure differential is required as a flow rate control condition, the reason for controlling the gas flow rate by the MFC 251 is that the vaporization rate can be stably controlled to be greater than the gas supply rate. Here, the vaporization rate refers to the amount of gas vaporized in the vaporizer 241a, and the gas supply rate refers to the amount of gas flowing through the valve 243a. If the relationship of vaporization rate > gas supply rate is not maintained, a mixture of liquid and gas is likely to flow into the storage portion 240a, potentially becoming a particle source. Therefore, the MFC 251 is configured to adjust the opening of the valve 243a so as to maintain the relationship of vaporization amount > gas supply amount. Furthermore, since the operation amount of the valve 243a is controlled based on the flow rate sensor 252 located closest to the valve 243a, it is estimated that both responsiveness and accuracy are significantly improved by controlling the operation amount of the valve 243a based on the pressure inside the storage portion 240a.

[0022] A reactive gas serving as a second process gas is supplied from the gas supply pipe 232b via an MFC 241b, a valve 243b, and a nozzle 249b to the process chamber 201. The reactive gas is a substance having a molecular structure (chemical structure) different from that of the source gas.

[0023] Inert gas is supplied from the gas supply pipes 232c and 232d to the processing chamber 201 via the MFCs 241c and 241d, the valves 243c and 243d, the gas supply pipes 232a and 232b, and the nozzles 249a and 249b, respectively. The inert gas acts as a purge gas, a carrier gas, a dilution gas, etc.

[0024] A reactive gas supply system (reactive gas supply line) is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. An inert gas supply system (inert gas supply line) is mainly composed of the gas supply pipes 232c and 232d, the MFCs 241c and 241d, and the valves 243c and 243d.

[0025] Either or both of the source gas and the reactive gas are also referred to as a film-forming gas, and either or both of the source gas supply system and the reactive gas supply system are also referred to as a film-forming gas supply system (film-forming gas supply line).

[0026] In addition, an inert gas supply system (inert gas supply line) configured by a gas supply pipe 232c, an MFC 241c, and a valve 243c may be included in the raw material gas supply system, and an inert gas supply system (inert gas supply line) configured by a gas supply pipe 232d, an MFC 241d, and a valve 243d may be included in the reaction gas supply system.

[0027] The opening and closing operations of the valves 243a, 242a, 243b, 243c, and 243d of the vaporizer 248, and the flow rate adjustment operations of the MFCs 241b, 241c, and 241d are controlled by a controller 121, which will be described later.

[0028] An exhaust port 231a for exhausting the atmosphere in the processing chamber 201 is provided at the bottom of the sidewall of the reaction tube 203. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is made of a metal material such as SUS. A vacuum pump 246 serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 can evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, 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 while the vacuum pump 246 is operating. An exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. A vacuum pump 246 may be included in the exhaust system.

[0029] A seal cap 219 is provided below the manifold 209 as a furnace port cover (hereinafter referred to as the cover) capable of airtightly closing the lower end opening of the manifold 209. The cover 219 is made of a metal material such as SUS and is disk-shaped. An O-ring 220b is provided on the upper surface of the cover 219 as a sealing member that abuts against the lower end of the manifold 209. A rotation mechanism 267 is provided below the cover 219 to rotate the boat 217 (described later). A rotation shaft 255 of the rotation mechanism 267 is made of a metal material such as SUS and is connected to the boat 217 through the cover 219. The rotation mechanism 267 is configured to rotate the boat 217, thereby rotating the wafers 200. The cover 219 is configured to be vertically raised and lowered by a boat elevator 115, which serves as an elevating mechanism, installed outside the reaction tube 203. The lifting mechanism 115 is configured as a transfer device that lifts and lowers the lid 219 to load and unload (transport) the wafer 200 into and out of the processing chamber 201 .

[0030] The boat 217 as a substrate support is configured to support a plurality of wafers 200, for example, 25 to 200 wafers 200, in a horizontal position and aligned vertically with their centers aligned, i.e., arranged at intervals, in multiple stages. A heat insulating section 218 made of a heat-resistant material such as quartz or SiC is supported in multiple stages at the bottom of the boat 217.

[0031] 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 set to a desired value 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 installed along the inner wall of the reaction tube 203.

[0032] 3, the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to 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.

[0033] The storage device 121c is composed of, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), etc. Control programs for controlling the operation of the substrate processing apparatus, process recipes describing procedures and conditions for substrate processing (described later), etc., are readably stored in the storage device 121c. The process recipe is a combination of procedures for substrate processing (described later) that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipes, control programs, etc. are collectively referred to simply as programs. The process recipes are also simply referred to as recipes. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (work area) for temporarily storing programs, data, etc. read by the CPU 121a.

[0034] The I / O port 121d is connected to the above-mentioned MFCs 251, 241b, 241c, 241d, valves 243a, 242a, 243b, 243c, 243d, vaporization section 241a, pressure sensors 245, 247, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, lifting mechanism 115, etc.

[0035] 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 an input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 251, 241b, 241c, and 241d, the opening and closing operations of the valves 243a, 242a, and 243b, 243c, and 243d, the vaporization operation (also referred to as heating operation) of the raw material by the vaporizer 241a, 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 lifting mechanism 115, and the like.

[0036] The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory or an SSD. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be 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. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0037] (2) Substrate Processing Step An example of a sequence for processing a wafer 200 as a substrate as one step in the manufacturing process of a semiconductor device using the substrate processing apparatus described above, i.e., an example of a film formation sequence for forming a film on the wafer 200, will be described mainly with reference to Fig. 4. In the following description, the operation of each part constituting the substrate processing apparatus is configured so as to be controllable by the controller 121.

[0038] In the film formation sequence in this embodiment, a film is formed on the wafer 200 by performing a cycle including step A of supplying a raw material gas from a raw material gas supply line to the processing chamber 201 containing the wafer 200 and step B of supplying a reactive gas to the processing chamber 201 containing the wafer 200 a predetermined number of times (n times, where n is an integer greater than or equal to 1).

[0039] In the film formation sequence of this embodiment, when the source gas is supplied, the source gas is filled in advance in the reservoir 240a provided in the source gas supply line and then supplied to the processing chamber 201. However, there are also cases where a supply method is appropriately selected depending on the sequence, and the source gas is supplied to the processing chamber 201 without filling the reservoir 240a in advance.

[0040] In the film formation sequence of this embodiment, when Step A and Step B are alternately performed n times (n is an integer of 1 or more), it is preferable to insert a step of purging the process chamber 201 between them. Note that, here, "purging" refers to removing source gases and intermediates present in the process chamber 201 by supplying an inert gas to the process chamber 201. "Exhaust" refers to removing source gases and intermediates present in the process chamber 201 without supplying an inert gas to the process chamber 201.

[0041] In this specification, the term "wafer" may refer to the wafer itself or a laminate of the wafer and a predetermined layer or film formed on its surface. In this specification, the term "surface of a wafer" may refer to the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. In this specification, the phrase "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. In this specification, the term "substrate" is also synonymous with the term "wafer".

[0042] (Substrate Loading S1: Wafer Charging and Boat Loading) After a plurality of wafers 200 are loaded into the boat 217 (wafer charging), the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209 (shutter open). Thereafter, as shown in FIG. 1 , the boat 217 supporting the plurality of wafers 200 is lifted by the lifting mechanism 115 and loaded into the processing chamber 201 (boat loading). In this state, the lid 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0043] (Pre-processing S2: Pressure Adjustment and Temperature Adjustment) After the boat loading is completed, the processing chamber 201, i.e., the space in which the wafers 200 are present, is evacuated (reduced pressure exhausted) by the vacuum pump 246 so as to reach a desired pressure (vacuum level). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on this measured pressure information (pressure adjustment). Furthermore, the wafers 200 in the processing chamber 201 are heated by the heater 207 so as to reach a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so as to achieve a desired temperature distribution in the processing chamber 201 (temperature adjustment). Furthermore, the rotation mechanism 267 starts to rotate the wafers 200. The evacuation of the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0044] (Substrate Processing S3: Film Formation Processing) Thereafter, the following steps A and B are performed in sequence.

[0045] [Step A] In this step, a source gas is supplied to the wafer 200 in the processing chamber 201. First, the valve 242a is closed, and the valve 243a is opened. The source gas is supplied to the reservoir 240a while controlling the flow rate of the source gas by adjusting the aperture of the valve 243a (first step). Then, the aperture of the valve 243a is adjusted based on the pressure in the reservoir 240a to supply the source gas to the reservoir 240a (second step).

[0046] First, the first process will be described. The first process includes steps S100, S102, and S104 shown in Fig. 6. In the first process, the supply of gas to the storage section 240a is controlled by the MFC 251.

[0047] In step S100, the flow rate of the source gas is set in the MFC 251. The flow rate of the source gas in the MFC 251 is adjusted by adjusting the opening of the valve 243 a. The flow rate control in the MFC 251 may be controlled so that the flow rate is constant, for example.

[0048] In step S102, it is determined whether a preset time T1 has elapsed. If the time T1 has elapsed, the process proceeds to step S104. On the other hand, if the time T1 has not elapsed, the process returns to step S100.

[0049] In step S104, the target pressure gradient R ０ Specifically, as shown in FIG. 7, the time T1 and pressure P1 within the range controlled by the MFC 251 are calculated, and the target pressure gradient R is calculated from the time T1 and pressure P1. ０ The calculated target pressure gradient R ０ is stored in the RAM 121b or the storage device 121c. ０ is R ０ = P1 / T1.

[0050] In FIG. 7, the vertical axis represents the pressure P in the reservoir 240a and the opening degree of the valve 243a, and the horizontal axis represents time T.

[0051] The first step is thus completed. When the first step is completed, the process proceeds to the second step. That is, in this embodiment, the process proceeds from the first step to the second step. Note that the present disclosure is not limited to this configuration. For example, the process may proceed from the first step to the second step when the pressure difference with the storage section 240a to which the gas is supplied decreases and the valve 243a is closed. Furthermore, for example, in the first step, the process may proceed from the first step to the second step when the pressure value in the storage section 240a, i.e., the pressure value detected by the pressure sensor 247, reaches a first predetermined value (e.g., pressure P1). Furthermore, for example, in the first step, the process may proceed to the second step when the pressure value in the storage section 240a converges at the first predetermined value.

[0052] Next, the second process will be described. The second process includes steps S106, S108, S110, and S112 shown in Fig. 6. In the second process, the supply of gas to the storage section 240a is controlled by the controller 121.

[0053] First, when the process shifts from the first step to the second step, the opening of the valve 243a is adjusted to a preset opening.

[0054] In step S106, the current pressure gradient R is calculated. Specifically, as shown in Fig. 7, the time T and pressure P within the range controlled by the controller 121 are obtained, and the pressure gradient R is calculated from the time T and pressure P. The calculated pressure gradient R is stored in the RAM 121b or the storage device 121c. The pressure gradient R can be calculated by R = P / T.

[0055] In step S108, the target value (target pressure gradient) R ０ The manipulated variable Y is calculated from the control variable (pressure gradient) R.

[0056] In step S110, the calculated manipulated variable Y is set as the aperture of the valve 243a. That is, in the second step, the aperture of the valve 243a is changed based on the pressure inside the storage section 240a. Then, by setting the aperture of the valve 243a to the manipulated variable Y, the flow rate of gas into the storage section 240a is adjusted. Note that the aperture of the valve 243a may be adjusted multiple times during the second step.

[0057] In addition, the pressure gradient R in the second step is set to the target pressure gradient R in the first step. ０ It is preferable to set the manipulated variable Y as follows:

[0058] In step S112, it is determined whether a preset time T2 has elapsed. If the time T2 has elapsed, the second step ends. Note that the present disclosure is not limited to this configuration. For example, the second step may be performed until the pressure value in the storage section 240a reaches a second predetermined value that is greater than the first predetermined value, or until the pressure value in the storage section 240a converges at the second predetermined value for a preset time. If the time T2 has not elapsed, the process returns to (transitions to) step S106.

[0059] After the second step is completed, the valve 243a is closed to maintain the state in which the source gas is filled in the reservoir 240a.

[0060] In this embodiment, the third step may be performed after the second step. The third step is a step of supplying gas from the storage part 240a to the processing chamber 201 by opening the valve 242a, which serves as a supply valve provided downstream of the storage part 240a. In this embodiment, as an example, the process transitions from the second step to the third step when the pressure value in the storage part 240a reaches a second predetermined value.

[0061] In the third step, the valve 242a is opened, and the high-pressure source gas stored in the reservoir 240a is suddenly supplied to the processing chamber 201. This results in the source gas being suddenly supplied to the wafer 200 (source gas flush supply). Here, the valves 243c and 243d may be opened to supply an inert gas to the processing chamber 201 via the nozzles 249a and 249b, respectively. This step is preferably performed with the exhaust system substantially fully closed (the APC valve 244 is substantially fully closed). Here, "substantially closed" includes a state in which the APC valve 244 is open by 0.1% to several percent, and a state in which the APC valve 244 is exhausted to the exhaust system even when controlled to be 100% closed due to its performance.

[0062] Then, the valves 243a and 242a are closed to stop the supply of the source gas to the processing chamber 201. Then, the APC valve 244 is, for example, fully opened to evacuate the processing chamber 201 and remove gases and the like remaining in the processing chamber 201 from the processing chamber 201.

[0063] In the second step described above, the opening degree of the valve 243a is set multiple times during the second step, but the present disclosure is not limited to this configuration. For example, the opening degree of the valve 243a may be set to a constant opening degree during the second step.

[0064] In addition, in the above step A, the first step is performed for time T1, and then the second step is performed for time T2. However, the present disclosure is not limited to this configuration. For example, the first step may be performed within a pressure range where the MFC 251 can control the flow rate, and the second step may be performed outside the pressure range where the MFC 251 can control the flow rate.

[0065] After the third step is completed, the valves 243a and 242a may be closed to execute the first or second step.

[0066] [Step B] After step A is completed, a reaction gas is supplied to the wafer 200 in the processing chamber 201, that is, to the first layer formed on the wafer 200, for example, the raw material element-containing layer.

[0067] Specifically, the valve 243b is opened to allow the reactive gas to flow into the gas supply pipe 232b. The reactive gas has a flow rate adjusted by the MFC 241b, is supplied to the processing chamber 201 via the nozzle 249b, and is exhausted from the exhaust port 231a. At this time, the reactive gas is supplied to the wafer 200 (reactive gas supply). At this time, the valves 243c and 243d may be opened to supply an inert gas to the processing chamber 201 via the nozzles 249a and 249b, respectively.

[0068] When a nitriding gas, for example, which will be described later, is used as the reactive gas, supplying the nitriding gas to the wafer 200 under processing conditions, which will be described later, nitrides (modifies) at least a portion of the first layer formed on the wafer 200. As a result, a nitride layer is formed as a second layer on the top surface of the wafer 200, which serves as a base.

[0069] After the second layer is formed, the valve 243b is closed to stop the supply of the nitriding gas to the processing chamber 201. Then, gases remaining in the processing chamber 201 are removed from the processing chamber 201 (purging) by a processing procedure similar to that of the purging in step A.

[0070] [Performance Predetermined Number of Times] A film can be formed on the surface of the wafer 200 by performing a cycle including the above-described steps A and B a predetermined number of times (n times, where n is an integer greater than or equal to 1). The above-described cycle is preferably repeated multiple times. That is, it is preferable to set the thickness of the layer formed per cycle thinner than the desired film thickness, and repeat the above-described cycle multiple times until the thickness of the film formed by stacking these layers reaches the desired thickness. In this case, in step A, it is preferable to pre-fill the reservoir 240a with a constant amount of source gas for each cycle. Furthermore, in the second and subsequent cycles, it is preferable to fill the reservoir 240a with source gas in step A in parallel with the supply of the reaction gas in step B of the previous cycle.

[0071] (Post-processing S4: After-purging and atmospheric pressure return) After the formation of a film of a desired thickness on the wafer 200 is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a and 249b into the processing chamber 201 and exhausted from the exhaust port 231a. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purging). Thereafter, 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 return).

[0072] (Substrate Unloading S5: Boat Unloading and Wafer Discharge) Thereafter, the lifting mechanism 115 lowers the lid 219, opening the lower end of the manifold 209. Then, the processed wafers 200, supported by the boat 217, are unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After the boat unloading, the shutter 219s is moved, and the opening at the lower end of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). After being unloaded to the outside of the reaction tube 203, the processed wafers 200 are removed from the boat 217 (wafer discharging).

[0073] (4) Effects of this Aspect According to this aspect, one or more of the following effects can be obtained.

[0074] (a) According to this aspect, a larger amount of gas can be stored in the storage unit 240a than can be charged into the storage unit 240a by flow rate control using the MFC 251, by combining flow rate control using the MFC 251 and opening degree control of the valve 243a using the controller 121. This allows a large amount of gas to be supplied to the processing chamber 201 at one time.

[0075] (b) According to this aspect, even if the gas cannot be charged into the storage unit 240 a by flow rate control using the MFC 251, or even if the pressure in the container (tank) rises (goes outside the pressure range in which the MFC 251 can control the flow rate) and the MFC 251 cannot control the flow rate, the gas can still be stored in the storage unit 240 a. This allows a large amount of gas to be supplied to the processing chamber 201 at one time.

[0076] (c) According to this aspect, the opening degree of the valve 243a is determined so that the pressure gradient is smaller than that when the gas whose flow rate is controlled by the MFC 251 is being charged into the storage section 240a, thereby making it possible to suppress liquefaction of the gas due to changes in pressure within the storage section 240a.

[0077] (d) According to this aspect, the gas whose flow rate is controlled by the MFC 251 is charged into the storage section 240a, so that the relationship of vaporization amount > gas supply amount can be maintained while the gas is stored in the storage section 240a. Particularly in the initial stage, the differential pressure between the vaporization section 241a and the storage section 240a is large, and the opening of the valve 243a fluctuates up and down, but the relationship of vaporization amount > gas supply amount can be maintained. Therefore, it is possible to prevent liquid gas from flowing into the storage section 240a, and only vaporized gas can be stored in the storage section 240a, so that the vaporized gas can be stably flush-supplied to the wafer 200.

[0078] (e) According to this aspect, by varying the valve opening, the pressure gradient can be adjusted, and liquefaction due to pressure changes can be suppressed. Therefore, the liquid gas can be prevented from flowing into the reservoir 240a, and only the vaporized gas can be stored in the reservoir 240a, so that the vaporized gas can be stably flush-supplied to the wafer 200.

[0079] (f) According to this aspect, in step A, the source gas for the wafer 200 is supplied to the processing chamber 201 after being previously filled in the reservoir 240a provided in the source gas supply line. That is, a flush supply is performed. As a result, the first intermediate (for example, SiCl when the source gas is HCDS gas) is dispersed over the entire surface of the wafer 200. ２ ) is uniformly adsorbed onto the surface of the wafer 200, and the second intermediate (for example, SiCl when the source gas is HCDS gas) is uniformly adsorbed onto the surface of the wafer 200. ４ ) can be suppressed. This makes it possible to improve the step coverage of the film formed on the wafer 200 and the uniformity of the film thickness within the substrate surface. As a result, the quality of the film formed on the wafer 200 can be improved, and the yield can be increased.

[0080] (g) According to this aspect, in step A, when the source gas is supplied, the source gas is supplied to the processing chamber 201 with the exhaust system that exhausts the atmosphere in the processing chamber 201 substantially closed, i.e., with the exhaust system substantially fully closed. This makes it possible to quickly increase the pressure in the processing chamber 201 to a predetermined pressure required to adsorb the first intermediate onto the entire surface of the wafer 200 in a short period of time. This makes it possible to shorten the cycle time and improve the productivity of the film formation process.

[0081] Other Aspects of the Present Disclosure The above describes specific aspects of the present disclosure. However, the present disclosure is not limited to the above aspects and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0082] In the above-described embodiment, the source gas may be, for example, a silane-based gas containing Si as the main element constituting the film formed on the wafer 200. The silane-based gas may be, for example, a gas containing Si and a halogen, i.e., a halosilane gas. Halogen includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), and the like. The halosilane gas may be, for example, a chlorosilane gas containing Si and Cl.

[0083] In addition to these, a gas containing Si and an amino group, i.e., an aminosilane gas, can also be used as the source gas. The amino group is a monovalent functional group obtained by removing hydrogen (H) from ammonia, a primary amine, or a secondary amine, and is represented by -NH ２ , -NHR, -NR ２ where R represents an alkyl group, and —NR ２ The two R's may be the same or different.

[0084] Furthermore, as the source gas, a source gas containing a metal element such as aluminum (Al), titanium (Ti), hafnium (Hf), zirconium (Zr), tantalum (Ta), molybdenum (Mo), or tungsten (W) is used, and by the above-mentioned film formation sequence, an aluminum nitride film (AlN film), a titanium nitride film (TiN film), a hafnium nitride film (HfN film), a zirconium nitride film (ZrN film), a tantalum nitride film (TaN film), a molybdenum nitride film (MoN), a tungsten nitride film, or the like is formed on the substrate. The present disclosure can also be applied to the formation of films containing metal elements, such as titanium oxide films (WN), aluminum oxide films (AlO films), titanium oxide films (TiO films), hafnium oxide films (HfO films), zirconium oxide films (ZrO films), tantalum oxide films (TaO films), molybdenum oxide films (MoO), tungsten oxide films (WO), titanium oxynitride films (TiON films), titanium aluminum carbonitride films (TiAlCN films), titanium aluminum carbide films (TiAlC films), and titanium carbonitride films (TiCN films). In these cases, at least some of the effects described in the above aspects can be obtained.

[0085] As the reactive gas, for example, a nitrogen (N) and hydrogen (H) containing gas, which is a nitriding gas (nitriding agent), can be used. The N and H containing gas is both an N containing gas and an H containing gas. The N and H containing gas preferably has an N-H bond.

[0086] The reactive gas may be, for example, ammonia (NH ３ ) gas, diazene (N ２ H ２ ) gas, hydrazine (N ２ H ４ ) gas, N ３ H ８ As the reactive gas, one or more of these gases can be used.

[0087] Furthermore, in the above-described aspect, the present disclosure can be applied to the case where a film containing Si is formed on wafer 200 in substrate processing, such as a silicon nitride film (SiN film), a silicon carbonitride film (SiCN film), a silicon oxynitride film (SiON film), a silicon oxycarbide film (SiOC film), a silicon oxycarbonitride film (SiOCN film), a silicon boronitride film (SiBCN film), a silicon boronitride film (SiBN film), a silicon oxide film (SiO film), etc. In these cases, at least some of the effects described in the above-described aspect can be obtained.

[0088] The above-mentioned recipes may not necessarily be newly created, but may be prepared by modifying an existing recipe already installed in the substrate processing apparatus. When modifying a recipe, the modified recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the modified recipe is recorded. Alternatively, an existing recipe already installed in the substrate processing apparatus may be directly modified by operating the input / output device 122 provided in the existing substrate processing apparatus.

[0089] In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace.

[0090] Even when using these substrate processing apparatuses, each process can be performed using the same processing procedures and conditions as those in the above-mentioned embodiments and variations, and the same effects as those in the above-mentioned embodiments and variations can be obtained.

[0091] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and processing conditions in such a case may be the same as those in the above-described embodiments and modifications, for example.

[0092] 243a Valve 240a Storage section (an example of a container)

Claims

1. A first step of supplying the gas to a container while controlling the flow rate of the gas by adjusting the opening degree of a valve provided in a gas supply line; a second step of adjusting the opening degree of the valve based on the pressure in the container and supplying the gas to the container; A gas supply method having.

2. The gas supply method according to claim 1, which proceeds in order from the first step to the second step.

3. The gas supply method according to claim 1, wherein in the first step, when the valve is in a closed state, the process proceeds to the second step.

4. The gas supply method according to claim 1, wherein in the first step, when the pressure value in the container reaches a first predetermined value, the process proceeds to the second step.

5. The gas supply method according to claim 1, wherein in the first step, when the pressure value in the container converges to a first predetermined value, the process proceeds to the second step.

6. The gas supply method according to claim 1, wherein when shifting from the first step to the second step, the opening degree of the valve is set to a preset opening degree.

7. The gas supply method according to claim 6, wherein the preset opening degree is set a plurality of times during the second step.

8. The gas supply method according to claim 6, wherein the preset opening degree is set to a constant opening degree during the second step.

9. The gas supply method according to claim 1, wherein in the second step, the opening degree of the valve is changed based on the pressure in the container.

10. The gas supply method according to claim 1, wherein the pressure gradient in the second step is made equal to or less than the pressure gradient in the first step.

11. The gas supply method according to claim 4 or claim 5, wherein the second step is performed until the pressure value in the container becomes a second predetermined value greater than the first predetermined value.

12. The gas supply method according to claim 11, wherein when the pressure value in the container converges at the second predetermined value for a preset time, the second step is terminated.

13. Further having a third step of opening a supply valve provided on the downstream side of the container and supplying the gas from the container to a processing chamber; when the pressure value in the container reaches the second predetermined value, shifting from the second step to the third step The gas supply method according to claim 12.

14. The gas supply method according to claim 13, wherein when the third step is completed, the supply valve is closed and the first step or the second step is executed.

15. The gas supply method according to claim 14, wherein the first step is performed within the range of the pressure controllable by the flow controller, and the second step is performed outside the range of the pressure controllable by the flow controller.

16. A method for manufacturing a semiconductor device, comprising a step of supplying a gas to a processing chamber using the gas supply method according to any one of claims 1 to 15.

17. A processing apparatus, comprising: a processing chamber for processing a substrate; a container provided in a supply line for supplying a gas to the processing chamber; a flow controller configured to supply the gas to the container while controlling the flow rate of the gas by adjusting the opening degree of a valve provided in the supply line; and a control unit configured to adjust the opening degree of the valve based on the pressure in the container to supply the gas to the container.

18. A program for causing the processing apparatus according to claim 17 to execute a procedure of supplying a gas to a container while controlling the flow rate of the gas by adjusting the opening degree of a valve provided in a supply line for supplying the gas to a processing chamber for processing a substrate, and a procedure of adjusting the opening degree of the valve based on the pressure in the container to supply the gas to the container.

19. A flow controller, comprising: a sensor provided in a supply line of a raw material for detecting the flow rate of the raw material; and a valve provided in the supply line for supplying the raw material to a container, configured to supply the raw material to the container while controlling the flow rate of the raw material by adjusting the opening degree of the valve based on the flow rate detected by the sensor, and configured to adjust the opening degree of the valve based on the pressure in the container to supply the raw material to the container.

20. The flow controller according to claim 19, configured to supply the raw material to the container while controlling the flow rate of the raw material by adjusting the opening degree of the valve based on the flow rate detected by the sensor within the range of the pressure controllable by the flow controller, and configured to adjust the opening degree of the valve based on the pressure in the container to supply the raw material to the container outside the range of the pressure controllable by the flow controller.

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