Substrate processing method, method for manufacturing semiconductor device, program, and substrate processing apparatus

Abstract

The present invention etches a surface of a substrate by performing: (a) a step for filling a storage tank that is provided in a supply pipe of an etching gas or a storage section of the supply pipe with the etching gas and boosting the pressure of the etching gas; and (b) a step for supplying the etching gas boosted in the storage tank or the storage section to the substrate along the surface of the substrate from the outer edge of the substrate toward the inside of the surface.

Description

Substrate processing method, semiconductor device manufacturing method, program, and substrate processing apparatus.

[0001] This disclosure relates to a substrate processing method, a semiconductor device manufacturing method, a program, and a substrate processing apparatus.

[0002] As part of the manufacturing process for semiconductor devices, an etching gas is sometimes supplied to the substrate (see, for example, Patent Document 1).

[0003] WO2017 / 022086 publication

[0004] This disclosure provides a technology that can improve the controllability of the in-plane distribution of etching amount on the surface of a substrate.

[0005] According to one aspect of the present disclosure, a technique is provided for etching the surface of a substrate by: (a) filling a storage tank provided in an etching gas supply pipe, or a storage section of the supply pipe, with the etching gas and pressurizing it; and (b) supplying the etching gas, which has been pressurized in the storage tank or the storage section, to the substrate, from the outer edge of the substrate toward the in-plane direction, along the surface of the substrate.

[0006] According to this disclosure, it is possible to improve the controllability of the in-plane distribution of etching amount on the surface of the substrate.

[0007] Figure 1 is a schematic diagram of a vertical processing furnace of a processing apparatus preferably used in one embodiment of the present disclosure, showing the processing furnace 202 portion in a vertical cross-sectional view. Figure 2 is a schematic diagram of a vertical processing furnace of a processing apparatus preferably used in one embodiment of the present disclosure, showing the processing furnace 202 portion in a cross-sectional view along line A-A in Figure 1. Figure 3 is a schematic diagram of a controller 121 of a processing apparatus preferably used in one embodiment of the present disclosure, showing the control system of the controller 121 in a block diagram. This figure shows an example of a gas supply sequence in one embodiment of the present disclosure. This figure shows a modification 1 of the gas supply sequence in one embodiment of the present disclosure. This figure shows a modification 2 of the gas supply sequence in one embodiment of the present disclosure. This figure shows a modification 3 of the gas supply sequence in one embodiment of the present disclosure. This figure shows a modification 4 of the gas supply sequence in one embodiment of the present disclosure.

[0008] <An Embodiment of the Disclosure> An embodiment of the disclosure will be described below, mainly with reference to Figures 1 to 4. Note that the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings do not necessarily correspond to reality. Furthermore, the dimensional relationships and ratios of the elements do not necessarily correspond between multiple drawings.

[0009] (1) As shown in the configuration diagram 1 of the processing apparatus, the processing furnace 202 of the processing apparatus has a heater 207 as a temperature regulator (heating unit). The heater 207 is cylindrical and is mounted vertically by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) the gas with heat.

[0010] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of, for example, quartz (SiO₂ ２The reaction tube is made of a heat-resistant material such as silicon carbide (SiC) and is formed in a cylindrical shape with a closed upper end and an open lower end. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The upper end of the manifold 209 is engaged with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing member. The processing vessel (reaction vessel) is mainly composed of the reaction tube 203 and the manifold 209. In the hollow cylindrical part of the processing vessel, a region where wafers 200 as substrates are placed, i.e., a processing chamber 201, is formed. The processing chamber 201 is configured to accommodate wafers 200 as substrates, arranged so that multiple wafers 200 are stacked in a direction perpendicular to the surface of the wafers 200. Processing of the wafers 200 is performed in this processing chamber 201.

[0011] Within the processing chamber 201, nozzles 249a and 249b, serving as first and second supply units, are provided so as to penetrate the side walls of the manifold 209. Nozzles 249a and 249b are also referred to as the first and second nozzles, respectively. Nozzles 249a and 249b are made of a heat-resistant material such as quartz or SiC. Nozzles 249a and 249b are each configured as common nozzles used for supplying multiple types of gases.

[0012] Nozzles 249a and 249b are connected to gas supply pipes 232a and 232b, respectively, which serve as gas supply piping. Gas supply pipes 232a and 232b are configured as shared piping used for supplying multiple types of gas. From the upstream side of the gas flow, gas supply pipes 232a and 232b are equipped with, in order, mass flow controllers (MFCs) 241a and 241b, which are flow control devices (flow control units), valves 243a and 243b, storage tanks 260a and 260b configured to temporarily store gas, and valves 247a and 247b, respectively. Downstream of valve 247a on gas supply pipe 232a, gas supply pipe 232c is connected. Downstream of valve 247b on gas supply pipe 232b, gas supply pipe 232d is connected. The gas supply pipes 232c and 232d are provided with MFCs 241c and 241d and valves 243c and 243d, respectively, from the upstream side of the gas flow.

[0013] The conductance between the storage tank 260a and the processing chamber 201 is, for example, 1.5 × 10⁻⁶. －３ I understand ３ It is preferable to configure it so that the ratio is 1 / s or more. Also, considering the ratio of the volume of the processing chamber 201 to the volume of the storage tank 260a, when the volume of the processing chamber 201 is 100 L (liters), it is preferable that the volume of the storage tank 260a be, for example, 100 to 300 cc, which is, for example, 1 / 1000 to 3 / 1000 times the volume of the processing chamber 201. The same applies to the storage tank 260b.

[0014] As shown in Figure 2, nozzles 249a and 249b are provided in the space between the inner wall of the reaction tube 203 and the wafer 200, extending upward in the direction of wafer arrangement of the wafer 200, along the upper part of the inner wall of the reaction tube 203 from the lower part. That is, nozzles 249a and 249b are provided in the region horizontally surrounding the wafer arrangement region, on the side of the wafer arrangement region where the wafers 200 are arranged, and along the wafer arrangement region. On the sides of nozzles 249a and 249b, there are gas supply holes 250a as a first supply port and gas supply holes 250b as a second supply port, which are different from the first supply port, for supplying (discharging) gas. In a plan view, gas supply holes 250a and 250b each open so as to face (oppose) the exhaust port 231a, which will be described later, and gas can be supplied. Multiple gas supply holes 250a and 250b are provided extending from the lower to the upper part of the reaction tube 203.

[0015] Both gas supply holes 250a and 250b are configured to supply gas along the surface of the wafer 200, specifically from the outer edge of the wafer 200 toward the center of the wafer 200. The gas supply holes 250a and 250b are configured so that the gas discharged from these gas supply holes is supplied in substantially parallel directions.

[0016] Etching gas is supplied from the gas supply pipe 232a into the processing chamber 201 via the MFC 241a, valve 243a, storage tank 260a, valve 247a, and nozzle 249a.

[0017] From the gas supply pipe 232b, hydrogen (H)-containing gas is supplied into the processing chamber 201 via the MFC 241b, valve 243b, storage tank 260b, valve 247b, and nozzle 249b.

[0018] Inert gas is supplied from gas supply pipes 232c and 232d into the processing chamber 201 via MFCs 241c and 241d, valves 243c and 243d, gas supply pipes 232a and 232b, and nozzles 249a and 249b, respectively. The inert gas acts as a purge gas, carrier gas, diluent gas, etc.

[0019] The etching gas supply system mainly consists of gas supply pipes 232a, MFC 241a, valves 243a and 247a, and storage tank 260a. The H-containing gas supply system mainly consists of gas supply pipes 232b, MFC 241b, valves 243b and 247b, and storage tank 260b. The inert gas supply system mainly consists of gas supply pipes 232c and 232d, MFCs 241c and 241d, and valves 243c and 243d.

[0020] Of the various supply systems described above, any or all of them may be configured as an integrated supply system 248, which includes valves 243a to 243d, 247a, 247b, MFCs 241a to 241d, storage tanks 260a, 260b, etc. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232d, and the supply operation of various substances (various gases) into the gas supply pipes 232a to 232d and storage tanks 260a, 260b, that is, the opening and closing operation of valves 243a to 243d, 247a, 247b and the flow rate adjustment operation by MFCs 241a to 241d, etc., is controlled by a controller 121, which will be described later.

[0021] An exhaust port 231a for exhausting the atmosphere inside the processing chamber 201 is provided at the lower part of the side wall of the reaction tube 203. As shown in Figure 2, in a plan view, the exhaust port 231a is located opposite the nozzles 249a and 249b (gas supply holes 250a and 250b) with the wafer 200 in between. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246, which is a vacuum evacuation device, is connected to the exhaust pipe 231 via a pressure sensor 245, which is a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201, and an APC (Auto Pressure Controller) valve 244, which is a pressure regulator (pressure adjustment unit). The APC valve 244 can be opened and closed while the vacuum pump 246 is operating to evacuate and stop the vacuum evacuation from the processing chamber 201. Furthermore, while the vacuum pump 246 is operating, the valve opening (degree of opening) can be adjusted based on the pressure information detected by the pressure sensor 245 to adjust the pressure inside the processing chamber 201. The exhaust system mainly consists of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may also be included in the exhaust system.

[0022] Below the manifold 209, a seal cap 219 is provided as a furnace opening cover capable of airtightly closing the lower end opening of the manifold 209. An O-ring 220b is provided on the upper surface of the seal cap 219 as a sealing member that contacts the lower end of the manifold 209. Below the seal cap 219, a rotating mechanism 267 for rotating the boat 217, which will be described later, is installed. The rotation shaft 255 of the rotating mechanism 267 passes through the seal cap 219 and is connected to the boat 217. The rotating mechanism 267 is configured to rotate the wafer 200 around the center of the surface of the wafer 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered vertically by a boat elevator 115, which is a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transport device (transport mechanism) that moves the seal cap 219 in and out (transports) the wafer 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219.

[0023] Below the manifold 209, a shutter 219s is provided as a furnace opening cover that can airtightly close the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is removed from the processing chamber 201. An O-ring 220c is provided on the upper surface of the shutter 219s as a sealing member that contacts the lower end of the manifold 209. The opening and closing operation of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0024] The boat 217, which serves as a substrate support, is configured to support multiple wafers 200, for example 25 to 200 wafers 200, in a horizontal position and aligned vertically with their centers aligned, in a multi-stage arrangement, that is, arranged with spacing between them. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, a multi-stage insulation plate 218, also made of a heat-resistant material such as quartz or SiC, is supported.

[0025] A temperature sensor 263 is installed inside the reaction tube 203 as a temperature detector. By adjusting the amount of power supplied to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 is adjusted to the desired temperature distribution. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0026] As shown in FIG. 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 configured as, for example, a touch panel or the like is connected to the controller 121. Further, an external storage device 123 can be connected to the controller 121. Note that the processing device may be configured to include one control unit or may be configured to include a plurality of control units. That is, control for performing a processing sequence described later may be performed using one control unit or may be performed using a plurality of control units. Further, the plurality of control units may be configured as a control system connected to each other by a wired or wireless communication network, and control for performing a processing sequence described later may be performed by the entire control system. When the term "control unit" is used in this specification, it may include one control unit, a plurality of control units, or a control system constituted by a plurality of control units in addition to the case including one control unit.

[0027] The storage device 121c is composed of, for example, flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. The storage device 121c contains, in a readable format, control programs that control the operation of the processing device, and process recipes that describe the procedures and conditions for substrate processing, etc. The process recipe is a combination of steps in the substrate processing (film deposition, etc.), described later, which the controller 121 uses to cause the processing device to execute and obtain predetermined results; it functions as a program. Hereinafter, process recipes and control programs will be collectively referred to simply as "programs" (program products). Similarly, process recipes will be simply referred to as "recipes." In this specification, the term "program" may include only recipes, only control programs, or both. The RAM 121b is configured as a memory area (work area) where programs and data read by the CPU 121a are temporarily held.

[0028] The I / O port 121d is connected to the MFCs 241a to 241d, valves 243a to 243d, 247a, 247b, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotating mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, etc.

[0029] The CPU 121a is configured to read out a control program from the storage device 121c and execute it, and to be able to read out a recipe from the storage device 121c in response to the input of an operation command from the input / output device 122 or the like. The CPU 121a is configured to control the flow rate adjustment operations of various substances (various gases) by the MFCs 241a to 241d, the opening and closing operations of the valves 243a to 243d, 247a, 247b, the opening and closing operation of the APC valve 244, 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 operations of the boat 217 by the rotation mechanism 267, the lifting and lowering operations of the boat 217 by the boat elevator 115, the opening and closing operations of the shutter 219s by the shutter opening and closing mechanism 115s, etc., in accordance with the content of the read-out recipe.

[0030] The controller 121 can be configured by installing the above-described program recorded and 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 semiconductor memory such as a USB memory or an SSD, and the like. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as recording media. When the term "recording medium" is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both of them. Note that the program may be provided to the computer without using the external storage device 123 and by using communication means such as the Internet or a dedicated line.

[0031] (2) Processing Process Using the processing apparatus described above, an example of a processing sequence for processing a substrate as one step in the manufacturing process (manufacturing method) of a semiconductor device, that is, for etching the surface of a wafer 200 as a substrate, will be explained mainly with reference to Figure 4. In this embodiment, as an example of the target of the etching process, the case in which a silicon film (Si film) is formed on the surface of the wafer 200, or the case in which the surface of a Si wafer is exposed will be explained. In the following explanation, the operation of each part constituting the processing apparatus is controlled by the controller 121. The processing apparatus will also be referred to as a substrate processing apparatus, etching processing apparatus, or etching apparatus. The processing method will also be referred to as a substrate processing method, etching processing method, or etching method.

[0032] In the processing sequence of this embodiment, the surface of the wafer 200 is etched by performing the following steps: (a) step A, which is to fill and pressurize the storage tank 260a provided in the gas supply pipe 232a, which is to serve as a supply pipe for etching gas; and (b) step B, which is to supply the etching gas pressurized in the storage tank 260a to the wafer 200, from the outer edge of the wafer 200 toward the in-plane direction, along the surface of the wafer 200.

[0033] In the following example, we will explain the case where step D is performed, which involves executing a cycle including steps A and B multiple times (n times, where n is an integer of 2 or more).

[0034] Furthermore, in the following example, we will explain the case in which, in step B, the pressurized etching gas is supplied to the wafer 200 by opening the valve 247a located downstream of the storage tank 260a, and the supply of etching gas to the storage tank 260a is continued while the valve 247a remains open, that is, the supply of etching gas to the wafer 200 is continued.

[0035] Furthermore, the following example describes a case in which the above-described cycle includes step C of supplying a hydrogen (H)-containing gas to the wafer 200, and during the execution of the above-described cycle, step C involves continuously supplying the H-containing gas to the wafer 200. That is, in this embodiment, the case in which the etching gas is flash-supplied intermittently and the H-containing gas is supplied continuously during the execution of the above-described cycle is described.

[0036] In Figure 4, the implementation periods for steps A, B, C, and D are represented as A, B, C, and D, respectively. The state with the valve closed is represented as "S," and the state with the valve open is represented as "O." Furthermore, the graphs in Figure 4, labeled "etching gas" and "hydrogen-containing gas," schematically represent the changes in the magnitude of the partial pressure of each gas during the processing period. The same applies to Figures 5 to 8.

[0037] In this specification, the term "wafer" may refer to the wafer itself or to a laminate of a wafer and a predetermined layer or film formed on its surface. In this specification, the term "surface of the wafer" may refer to the surface of the wafer itself or to the surface of a predetermined layer formed on the wafer. In this specification, when it is stated that "a predetermined layer is formed on the surface of the wafer," it may mean that the predetermined layer is formed directly on the surface of the wafer itself or that the predetermined layer is formed on a layer or other layer already formed on the wafer. In this specification, the term "substrate" has the same meaning as when it is used with the term "wafer."

[0038] As used herein, the term "substance" includes at least one of gaseous substances and liquid substances. Liquid substances include mist substances.

[0039] In this specification, intermittent gas supply is also referred to as pulse supply, and continuous gas supply is also referred to as continuous supply.

[0040] (Wafer Charging and Boat Loading) Once multiple wafers 200 are loaded into the boat 217, the lower end opening of the manifold 209 is opened. Then, as shown in Figure 1, the boat 217 supporting the multiple wafers 200 is lifted by the boat elevator 115 and transported into the processing chamber 201. In this way, the wafers 200 are prepared in the processing chamber 201.

[0041] (Pressure and Temperature Adjustment) After the boat loading is complete, the processing chamber 201 is evacuated (reduced pressure exhaust) by the vacuum pump 246 so that the pressure (vacuum level) inside the processing chamber 201 reaches the desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback controlled based on this measured pressure information. The wafer 200 inside the processing chamber 201 is also heated by the heater 207 so that it reaches the desired processing temperature. At this time, the amount of power supplied to the heater 207 is feedback controlled based on the temperature information detected by the temperature sensor 263 so that the processing chamber 201 has the desired temperature distribution. The rotation of the wafer 200 by the rotation mechanism 267 is also started. The exhaust of the processing chamber 201, the heating of the wafer 200, and the rotation are all continued at least until the processing of the wafer 200 is completed.

[0042] (Etching process) Then, steps A, B, and C are performed. Specifically, steps A and B are performed sequentially while step C is performed in parallel. In other words, steps A and C are performed in parallel (step A + step C), and then steps B and C are performed in parallel (step B + step C).

[0043] (Step A + Step C) In this step, etching gas is filled into the storage tank 260a (Step A), while H-containing gas is supplied to the wafer 200 in the processing chamber 201 (Step C).

[0044] In step A, with valve 247a closed, valve 243a is opened to allow etching gas to flow into the gas supply pipe 232a. The etching gas flow rate is adjusted by MFC 241a and supplied to the storage tank 260a.

[0045] By supplying etching gas into the storage tank 260a under the processing conditions described later, a predetermined amount of etching gas can be filled into the storage tank 260a at a pressurized level up to the filling pressure (completion of etching gas filling).

[0046] In step C, valves 243b and 247b are opened, and hydrogen-containing gas is allowed to flow into the gas supply pipe 232b. The hydrogen-containing gas is flow-controlled by the MFC 241b and supplied into the processing chamber 201 via the storage tank 260b and nozzle 249b, and exhausted from the exhaust port 231a. At this time, hydrogen-containing gas is supplied to the wafer 200 (hydrogen-containing gas supply). At this time, valves 243c and 243d may also be opened to supply inert gas into the processing chamber 201 via nozzles 249a and 249b, respectively.

[0047] By supplying an H-containing gas to the wafer 200 under the processing conditions described later, at least a portion of the molecular structure of the molecules constituting the H-containing gas can be adsorbed onto the surface of the wafer 200. Specifically, the OH terminations formed on the surface of the wafer 200 react with the H-containing gas to adsorb at least a portion of the molecular structure of the molecules constituting the H-containing gas onto the surface of the wafer 200. This allows, for example, H terminations to be formed on at least a portion of the surface of the wafer 200. In this way, the H terminations formed on the surface of the wafer 200 can suppress the adhesion of impurities to the surface of the wafer 200. In other words, in this embodiment, the H-containing gas acts as a modifying gas that modifies the surface of the wafer 200.

[0048] (Step B + Step C) In this step, after the etching gas has been filled into the storage tank 260a, etching gas is supplied to the wafer 200 in the processing chamber 201 (Step B), while H-containing gas is supplied to the wafer 200 in the processing chamber 201 (Step C).

[0049] In step B, valve 247a is opened, and etching gas from storage tank 260a is supplied into processing chamber 201. The etching gas, which has been filled into storage tank 260a and pressurized, is supplied all at once to the depressurized processing chamber 201 via nozzle 249a and exhausted from exhaust port 231a. In this disclosure, this method of supplying gas to the wafer 200 using a pressure difference is also called flash supply. At this time, valve 243a is left open.

[0050] In step C, H-containing gas is continuously supplied to the wafer 200 in the processing chamber 201.

[0051] By performing steps B and C in parallel, etching gas and H-containing gas are supplied to the wafer 200 (flash supply of etching gas + supply of H-containing gas). At this time, the etching gas is supplied along the surface of the wafer 200, from the outer edge toward the plane of the wafer 200, more specifically toward the center of the wafer 200. The H-containing gas is supplied in a direction substantially parallel to the supply direction of the etching gas.

[0052] Under the processing conditions described later, by flash-supplying the pressurized etching gas in the storage tank 260a to the wafer 200 under reduced pressure, the etching gas can be supplied at a sufficient partial pressure from the outer edge to the center of the wafer 200. This improves the controllability of the in-plane distribution of etching on the surface of the wafer 200. As a result, for example, the in-plane uniformity of etching on the surface of the wafer 200 can be improved.

[0053] In this embodiment, even after the flash supply of etching gas is performed and the pressure in the storage tank 260a and the flow velocity of the etching gas flowing over the wafer 200 have decreased to predetermined values, the valves 243a and 247a are kept open for a predetermined time (for example, 1 to 60 seconds). During this time, the supply of etching gas to the storage tank 260a is continued. As a result, etching gas is continuously supplied to the wafer 200 even after the flash supply of etching gas has been performed.

[0054] By continuing to supply etching gas to the wafer 200 even after performing a flash supply of etching gas, the amount of etching gas supplied per cycle can be ensured. This prevents a decrease in the etching rate on the surface of the wafer 200 and avoids a decrease in the productivity of the etching process.

[0055] Furthermore, by continuously supplying the etching gas in this manner, the amount of etching at the outer edge of the wafer 200 can be selectively (i.e., preferentially) increased compared to the amount of etching in the central part of the wafer 200. This is because continuously supplying the etching gas without flash supply promotes the diffusion of the etching gas to the outer periphery of the wafer 200, making etching more likely to occur in the outer periphery compared to the central part of the wafer 200. As a result, even if the etching gas is supplied under conditions where the amount of etching in the central part of the wafer 200 is greater than the amount of etching at the outer edge during flash supply, the controllability of the etching distribution within the wafer 200 surface can be further improved by adjusting the duration of continuous supply of the etching gas.

[0056] Under the processing conditions described later, by supplying an etching gas and an H-containing gas to the wafer 200, reaction products can be generated by the reaction between the etching gas and the H-containing gas. In this way, by supplying the reaction products to the wafer 200 in addition to the etching gas, the etching gas reacts with the Si film formed on the surface of the wafer 200, and further, the reaction products react with the Si film formed on the surface of the wafer 200, thereby removing the Si film from the wafer 200. In other words, the Si film on the wafer 200 is removed not only by the reaction between the Si film and the etching gas, but also by the reaction between the Si film and the reaction products. That is, in this embodiment, the H-containing gas also acts as a reaction gas that reacts with the etching gas to generate reaction products that promote etching.

[0057] Also, in this embodiment, the H-containing gas also acts as an adjustment gas (which can also be described as a carrier gas, dilution gas, etc. for the etching gas) for adjusting the flow and partial pressure distribution of the etching gas in the processing chamber 201, particularly in the space on the surface of the wafer 200.

[0058] After a predetermined time has elapsed since the start of the supply of the etching gas, the valve 247a is closed to stop the supply of the etching gas into the processing chamber 201. At this time, the valve 243a is left open, and the supply of the etching gas to the storage tank 260a is continued. Therefore, at the timing when the valve 247a is closed, step A of the next cycle is started. At this time, the H-containing gas is continuously supplied to the wafer 200.

[0059] As the etching gas, a halogen element-containing gas can be used. Examples of the halogen element-containing gas include gases composed only of a single halogen element such as chlorine gas (Cl ２ gas), fluorine gas (F ２ gas), bromine gas (Br ２ gas), iodine gas (I ２ gas), etc., compound gases composed only of halogen elements such as chlorine monofluoride (ClF) gas, chlorine trifluoride (ClF ３ ) gas, iodine heptafluoride (IF ７ ) gas, etc., and compound gases composed of a halogen element and other elements other than the halogen element such as boron trichloride (BCl ３ ) gas, nitrosyl fluoride (FNO) gas, etc. As the etching gas, one or more of these can be used.

[0060] As the inert gas, nitrogen (N ２ ) gas, noble gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, etc. can be used. As the inert gas, one or more of these can be used. This also applies to each step described later.

[0061] Examples of the H-containing gas include H ２Gases composed solely of elemental hydrogen, such as gases, can be used. Examples of hydrogen-containing gases include ammonia (NH₄). ３ ) gas, phosphine (PH ３ ) Gas, Monoborane (BH ３ ) Gas, water vapor (H ２ O) Gas, hydrogen peroxide (H ２ O ２ Compound gases composed of H element and other elements other than H element, such as hydrogen (H) gas, can be used. Furthermore, as H-containing gases, compound gases composed of H element and halogen elements, such as hydrogen chloride (HCl) gas and hydrogen fluoride (HF) gas, can be used. Furthermore, as H-containing gases, for example, hydrogen (H) ２ ) gas + oxygen (O ２ ) Gas, H ２ Gas + Ozone (O ３ A mixed gas composed of H element and other elements other than H element, such as a gas, can be used. One or more of these can be used as the H-containing gas.

[0062] Furthermore, in this specification, "H ２ Gas + O ２ The joint listing of two gases, such as "gas," is H ２ Gas and O ２ This refers to a mixed gas. When supplying a mixed gas, the two gases may be mixed (premixed) in the supply pipe before being supplied into the processing chamber 201, or the two gases may be supplied separately to the processing chamber 201 from different supply pipes and then mixed (postmixed) within the processing chamber 201.

[0063] [Performed a predetermined number of times] (Step D) By performing the above steps A and B non-simultaneously, that is, in this order without synchronization, a predetermined number of cycles (m times, where m is an integer of 1 or more) can be performed, for example, to etch a predetermined amount of the Si film formed on the surface of the wafer 200. Furthermore, in this embodiment, it is desirable to perform the above steps A and B non-simultaneously multiple times (n times, where n is an integer of 2 or more) in this order. In step D, the amount of etching on the surface of the wafer 200 per cycle is made less than a predetermined etching amount (a predetermined amount), and the above cycle is repeated until the predetermined etching amount is reached.

[0064] The following are examples of the processing conditions in steps A, B, and C described above.

[0065] Examples of processing conditions when filling with etching gas in step A include: Etching gas filling pressure: 60 to 1500 Torr, preferably 200 to 1200 Torr Etching gas filling amount: 50 to 3000 cc, preferably 100 to 2000 cc

[0066] Examples of processing conditions when supplying H-containing gas in step A + step C include: Processing temperature: 250 to 800°C, preferably 450 to 550°C; Processing pressure: 1 to 2666 Pa, preferably 20 to 1333 Pa; H-containing gas supply flow rate: 0 to 20 slm, preferably 0.1 to 10 slm; Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm.

[0067] In step B + step C, the processing conditions when supplying the etching gas and H-containing gas are exemplified as follows: Processing time: 1 to 180 seconds, preferably 5 to 60 seconds; Etching gas partial pressure: 5 to 2666 Pa, preferably 10 to 1333 Pa. Other conditions can be the same as the processing conditions in step A + step C.

[0068] In this specification, numerical ranges such as "250 to 800°C" mean that the lower and upper limits are included within that range. For example, "250 to 800°C" means "250°C or more and 800°C or less." The same applies to other numerical ranges. In this specification, processing temperature means the temperature of the wafer 200 or the temperature inside the processing chamber 201, and processing pressure means the pressure inside the processing chamber 201. Processing time means the time during which the processing is continued. Supply flow rate means the flow rate of the gas supplied into the processing chamber 201. If the supply flow rate includes 0 slm, 0 slm means the case in which the substance (gas) is not supplied. These also apply in the following explanations.

[0069] In step D, it is desirable to adjust at least one of the following conditions so that the distribution of etching amount within the plane of the wafer 200 becomes a predetermined distribution: (i) the number of cycles described above performed during one rotation of the wafer 200, (ii) the pressure at which etching gas is filled into the storage tank 260a in step A, (iii) the amount of etching gas (i.e., amount of substance (number of moles)) filled into the storage tank 260a in step A, and (iv) the pressure in the space in which the wafer 200 is located at the time when etching gas is supplied in step B.

[0070] Specifically, it is desirable to adjust at least one of the above conditions (i) to (iv) so that the amount of etching of the central part of the wafer 200 by the execution of step D is equal to or greater than the amount of etching of the outer edge of the wafer 200 by the execution of step D. Alternatively, at least one of the above conditions (i) to (iv) may be adjusted so that the amount of etching of the central part of the wafer 200 by the execution of step D is the same as or approximately the same as the amount of etching of the outer edge of the wafer 200 by the execution of step D (for example, the ratio of the difference between the etching amounts of the outer edge and the central part (Ee-Ec) to the etching amount of the outer edge (Ee) (Ee-Ec / Ee) is within ±5%).

[0071] Furthermore, by increasing the pressure at which etching gas is filled into the storage tank 260a in step A, the flow velocity of the etching gas in step B can be increased. Also, by decreasing the pressure in the space where the wafer 200 is located at the time the etching gas is supplied in step B, the flow velocity of the etching gas in step B can be increased.

[0072] Here, for example, if the etching gas flow rate in step B is too low, the partial pressure of the etching gas in the central part of the wafer 200 may not be large enough. In this case, the distribution of etching amount in the plane of the wafer 200 may become concave, making it impossible to achieve a uniform or convex shape. On the other hand, for example, if the etching gas flow rate in step B is too high, the partial pressure of the etching gas at the outer edge of the wafer 200 located on the opposite side of the gas supply hole 250a may become too large. In this case, as a result of the above cycle being repeated multiple times in step D, the distribution of etching amount in the plane of the wafer 200 may become concave, making it impossible to achieve a uniform or convex shape, as a superposition of the etching amount distributions in each cycle. Therefore, in order to ensure that the amount etched in the central part of the wafer 200 by the execution of step D is greater than or equal to the amount etched in the outer edge of the wafer 200 by the execution of step D, it is desirable to set the etching gas flow rate in step B to a value within a predetermined range.

[0073] Furthermore, while step D is being executed, it is desirable that at least one of the time required per rotation of the wafer 200 (hereinafter sometimes referred to as Tr) and the time required per cycle of the above-mentioned cycle (hereinafter sometimes referred to as Tc) be set (adjusted) so that the same location on the outer edge of the wafer 200 does not repeatedly position itself opposite the gas supply hole 250a (i.e., the closest position) at the start of the etching gas supply for each cycle. In other words, it is desirable that at least one of Tr and Tc be set so that the rotation period of the wafer 200 and the period of the above-mentioned cycle are not synchronized (i.e., asynchronous) while step D is being executed. For example, at least one of Tr and Tc can be set so that Tr is not an integer multiple or a fraction of Tc. In this way, it is desirable to adjust the relationship between the cycle period and the rotation period of the wafer 200 so that etching gas is not repeatedly supplied periodically to the same position on the wafer 200.

[0074] (After-purging and return to atmospheric pressure) After the etching process is complete, inert gas is supplied as a purge gas into the processing chamber 201 from nozzles 249a and 249b, respectively, and exhausted from exhaust port 231a. This purges the processing chamber 201, removing any remaining gases and reaction products. Subsequently, the atmosphere inside the processing chamber 201 is replaced with inert gas, and the pressure inside the processing chamber 201 is returned to atmospheric pressure.

[0075] (Boat unloading and wafer discharge) The seal cap 219 is then lowered by the boat elevator 115, opening the lower end of the manifold 209. The processed wafers 200 are then discharged from the lower end of the manifold 209 to the outside of the reaction tube 203, supported by the boat 217. After being discharged from the outside of the reaction tube 203, the processed wafers 200 are removed from the boat 217.

[0076] (3) Effects of this embodiment According to this embodiment, one or more of the following effects can be obtained.

[0077] (a) By performing steps A and B, it becomes possible to supply etching gas over a wide area from the outer edge of the wafer 200 toward the in-plane surface, and as a result, it becomes possible to improve the controllability of the in-plane distribution of etching amount on the surface of the wafer 200. This will be explained below.

[0078] Generally, the etching gas supplied into the processing chamber 201 flows from the outer edge of the wafer 200 towards the center of the wafer 200. That is, the etching gas supplied into the processing chamber 201 contacts the outer edge of the wafer 200 before contacting the center of the wafer 200. A portion of the etching gas that contacts the outer edge of the wafer 200 is consumed by the etching reaction. In addition, the etching gas flowing from the outer edge of the wafer 200 diffuses towards the outer periphery of the wafer 200 before reaching the center of the wafer 200. Therefore, the amount of etching gas supplied to the center of the wafer 200 is less than the amount supplied to the outer edge of the wafer 200. As a result, the etching rate of the etchable film (Si film) in the center of the wafer 200 tends to be lower than the etching rate of the etchable film at the outer edge of the wafer 200. In other words, when etching gas is supplied to these wafers 200 from the outer edge towards the center, as in this embodiment, the in-plane uniformity of the etching process tends to decrease between the outer edge and the center.

[0079] In this disclosure, by performing steps A and B, when supplying etching gas from the outer edge (periphery) of the wafer 200, a sufficient partial pressure can be maintained all the way to the center of the wafer 200. In other words, by supplying the pressurized etching gas into the processing chamber 201 at a high flow rate, the flow of the etching gas can be made directional, allowing it to reach the center of the wafer 200 while suppressing diffusion of the etching gas. This makes it possible to improve the controllability of the in-plane distribution of etching on the surface of the wafer 200. Furthermore, this makes it possible to suppress the occurrence of localized etching on the outer periphery of the wafer 200 and improve the in-plane uniformity of etching on the surface of the wafer 200.

[0080] (b) In step B, by supplying the etching gas from the outer edge of the wafer 200 toward the center of the wafer 200, it becomes possible to further improve the controllability of the in-plane distribution of the etching amount on the surface of the wafer 200.

[0081] (c) In step B, by rotating the wafer 200 around the center of the wafer 200's surface as an axis, it becomes possible to improve the in-plane uniformity of the etching amount on the surface of the wafer 200.

[0082] (d) When the cycle including steps A and B is performed only once, it may be difficult to control the distribution of etching amount within the plane of the wafer 200. By performing the cycle including steps A and B multiple times, it becomes possible to precisely control the distribution of etching amount within the plane of the wafer 200.

[0083] (e) Step D is performed while rotating the wafer 200 around the center of the wafer 200's surface. Furthermore, when performing step D, at least one of the following conditions is adjusted so that the distribution of etching amount on the surface of the wafer 200 becomes a predetermined distribution: (i) the number of cycles described above performed during one rotation of the wafer 200, (ii) the pressure at which etching gas is filled into the storage tank 260a in step A, (iii) the amount of etching gas filled into the storage tank 260a in step A, and (iv) the pressure in the processing chamber 201 at the time etching gas is supplied in step B. By doing so, it is possible to further improve the controllability of the in-plane distribution of etching amount on the surface of the wafer 200.

[0084] (f) When performing step D, adjust at least one of the above conditions (i) to (iv) so that the amount etched in the central part of the wafer 200 is greater than or equal to the amount etched in the outer edge of the wafer 200. This makes it possible to improve the in-plane uniformity of the etching amount on the surface of the wafer 200.

[0085] (g) In step D, the wafer 200 is rotated around the center of the wafer 200's surface as an axis. Furthermore, in step D, at least one of the above-mentioned time Tr and time Tc is set so that the rotation period of the wafer 200 and the period of the above-mentioned cycle are not synchronized. This makes it possible to improve the in-plane uniformity of the etching amount on the surface of the wafer 200.

[0086] (h) The wafers 200 are arranged so that multiple wafers 200 are stacked perpendicular to the surface of each wafer 200, which allows etching gas to be supplied to multiple wafers in step B, thereby improving productivity. Although arranging the wafers 200 in this manner may cause the aforementioned problems, these problems can be resolved by performing steps A and B.

[0087] (i) In step B, pressurized etching gas is supplied to the wafer 200 by opening valve 247a located downstream of storage tank 260a. Furthermore, while valve 247a remains open, the supply of etching gas to storage tank 260a is continued. This ensures that the amount of etching gas supplied per cycle is maintained, thereby preventing a decrease in the etching rate on the surface of the wafer 200 and avoiding a decrease in the productivity of the etching process. Additionally, by adjusting the duration of continuous etching gas supply after flash supply (i.e., the duration for which valve 247a remains open), the amount of etching at the outer edge of the wafer 200 can be adjusted. As a result, a decrease in the etching rate on the surface of the wafer 200 is prevented, and a decrease in the productivity of the etching process can be avoided.

[0088] (j) By including step C of supplying H-containing gas in the above cycle, H-terminants are formed on the surface of the wafer 200 to be etched, suppressing the adhesion of impurities to this surface and keeping the surface clean. Furthermore, by mixing the etching gas and the H-containing gas and reacting them to generate active reaction products, it is possible to utilize the action of these reaction products to advance the etching of the surface of the wafer 200. As a result, the etching rate on the surface of the wafer 200 can be improved, and the productivity of the etching process can be increased.

[0089] (k) The H-containing gas and the etching gas are supplied from different gas supply holes. This allows the etching gas and the H-containing gas to be mixed in the plane of the wafer 200, making it possible to generate active reaction products in the plane of the wafer 200. As a result, the etching rate on the surface of the wafer 200 can be improved, and the productivity of the etching process can be increased.

[0090] (l) By continuously supplying the H-containing gas to the wafer 200 while the above cycle is being performed, the above-mentioned effects obtained by supplying the H-containing gas together with the etching gas can be obtained more effectively.

[0091] (m) While the above cycle is being executed, the valve of the APC valve 244 is kept in a predetermined open state and the processing chamber 201 is continuously exhausted, thereby increasing the directivity of the etching gas and H-containing gas supplied to the wafer 200, and the above effects can be effectively obtained.

[0092] (4) Modifications The substrate processing sequence in this embodiment can be modified as shown below. These modifications can be combined in any way. Unless otherwise specified, the processing procedures and processing conditions in each step of each modification can be the same as those in each step of the substrate processing sequence described above.

[0093] (Modification 1) In step B, valve 247a may be closed when the pressure in the storage tank 260a drops to a predetermined pressure value from the start of etching gas supply, or when the flow velocity of the etching gas flowing over the wafer 200 drops to a predetermined flow velocity (end of step B). Alternatively, in step A, valve 243a may be closed after filling the storage tank 260a with etching gas at a predetermined pressure and in a predetermined amount. This stops the supply of etching gas to the storage tank 260a after the filling of the etching gas is complete, and stops the supply of etching gas to the processing chamber 201 when the flow velocity of the etching gas drops to a predetermined value after the start of flash supply of etching gas. Note that step C may be executed continuously even after step B is completed (see Figure 5).

[0094] In this modified example, the same effects as in the above-described embodiment can be obtained. In this modified example, by supplying the etching gas only for a period during which a high flow velocity can be maintained, the diffusion of the etching gas is suppressed, its directionality is maintained, and the etching gas can be supplied to the center of the wafer 200 at a sufficient partial pressure. As a result, it becomes possible to improve the controllability of the in-plane distribution of the etching amount on the surface of the wafer 200. Furthermore, in this modified example, by continuing to execute step C after the completion of step B, a period during which H-containing gas is supplied without supplying etching gas can be secured, making it possible to sufficiently form H-terminants and the like on the surface of the wafer 200.

[0095] (Modification 2) During the execution of the cycle described above, the H-containing gas may be supplied to the wafer 200 intermittently. Specifically, for example, in step C, the H-containing gas may be flash-supplied to the wafer 200, and the flash-supply of the H-containing gas may be performed multiple times during the execution of the cycle described above (see Figure 6). Note that the H-containing gas is not limited to flash-supplying in step C as long as it is supplied intermittently during the execution of the cycle described above, but in this modification, the case in which the H-containing gas is flash-supplied will be described as an example.

[0096] Specifically, before starting step C, with valve 247b closed, valve 243b is opened and H-containing gas is allowed to flow into the gas supply pipe 232b. The H-containing gas is flow-controlled by MFC 241b and supplied to the storage tank 260b. By supplying H-containing gas to the storage tank 260b under predetermined processing conditions, a predetermined amount of H-containing gas can be filled into the storage tank 260b at the filling pressure (completion of H-containing gas filling).

[0097] Subsequently, in step C, valve 247b is opened to supply the H-containing gas from storage tank 260b into the processing chamber 201. The H-containing gas, which has been filled into storage tank 260c and pressurized, is supplied all at once to the depressurized processing chamber 201 via nozzle 249b and exhausted from exhaust port 231a (flash supply of H-containing gas). At this time, valves 243c and 243d may be opened to supply inert gas into the processing chamber 201 via nozzles 249a and 249b, respectively.

[0098] After a predetermined time has elapsed since the start of supplying the H-containing gas, valve 247b is closed to stop the supply of H-containing gas into the processing chamber 201.

[0099] During the execution of the cycle described above, the supply period of the etching gas and the supply period of the H-containing gas may overlap (conform) (see Figure 6).

[0100] Furthermore, the cycle described above may include a step of evacuating the processing chamber 201 with the supply of etching gas and H-containing gas stopped after each cycle.

[0101] In this modified example, the same effects as those in the above-described embodiment can be obtained. Furthermore, in this modified example, when the H-containing gas is supplied in a flash, it becomes possible to supply the H-containing gas over a wide area from the outer edge of the wafer 200 toward the in-plane surface. Therefore, the above-mentioned effects obtained by supplying the H-containing gas together with the etching gas can be obtained over a wide area within the plane of the wafer 200. In addition, in this modified example, by overlapping the supply period of the etching gas and the supply period of the H-containing gas, it becomes possible to obtain the above-mentioned effects obtained by supplying the H-containing gas together with the etching gas more effectively. Furthermore, in this modified example, the surface of the wafer 200 can be cleaned (reset) with each cycle, making it possible to control the etching process effectively.

[0102] (Modification 3) The etching gas and H-containing gas may be supplied to the wafer 200 such that the supply period of the etching gas and a portion of the supply period of the H-containing gas overlap while the above-described cycle is being executed (see Figure 7). As in this modification, the supply period of the etching gas and a portion of the supply period of the H-containing gas may be made to overlap while the above-described cycle is being executed, or as in Modification 2, the supply period of the etching gas and the supply period of the H-containing gas may be made to overlap (match). In other words, the etching gas and H-containing gas may be supplied to the wafer 200 such that at least a portion of the supply period of the etching gas and the supply period of the H-containing gas overlap while the above-described cycle is being executed.

[0103] In this modified example, the same effects as in the above-described embodiment can be obtained. Furthermore, in this modified example, by overlapping the supply period of the etching gas with (at least) a portion of the supply period of the H-containing gas, it becomes possible to more effectively obtain the above-described effects obtained by supplying the H-containing gas together with the etching gas. In addition, in this modified example, by continuing step C after the completion of step B, a period can be secured during which the H-containing gas is supplied without supplying the etching gas, making it possible to sufficiently form H-terminants and the like on the surface of the wafer 200.

[0104] Furthermore, although Figure 7 illustrates a case where the start times of step B and step C are substantially simultaneous, in this modified example, for example, step C may be started before step B. This allows for the efficient acquisition of both the effects obtained by supplying the H-containing gas together with the etching gas and the effects obtained by supplying the H-containing gas alone.

[0105] (Modification 4) The valve may be opened and closed as shown in Figure 8, and the etching gas and H-containing gas may be supplied alternately to the wafer 200 so that the supply period of the etching gas and the supply period of the H-containing gas do not overlap while the above-described cycle is being executed.

[0106] In this modified example, the same effects as in the above-described embodiment can be obtained. Furthermore, in this modified example, since the supply period of the etching gas and the supply period of the H-containing gas do not overlap, it becomes possible to sufficiently form H-terminants on the surface of the wafer 200 in step C. In addition, in this modified example, since the step of purging the inside of the processing chamber 201 is not performed between step B and step C, a predetermined amount of etching gas supplied in step B remains in the processing chamber 201 during the execution of step C. As a result, in this modified example, the above-described effects obtained by supplying H-containing gas while supplying etching gas can be obtained in step C.

[0107] <Other Aspects of the Disclosure> The aspects of the Disclosure have been described in detail above. However, the Disclosure is not limited to the aspects described above and can be modified in various ways without departing from its essence.

[0108] In the above-described embodiment, an example was given in which etching gas is filled into storage tank 260a in step A and H-containing gas is filled into storage tank 260b in step C. However, the disclosure is not limited thereto. For example, etching gas may be filled into the storage section of gas supply pipe 232a (the storage section between valve 243a and valve 247a) in step A, and H-containing gas may be filled into the storage section of gas supply pipe 232b (the storage section between valve 243a and valve 247a) in step C. In this embodiment as well, the above-described pressure adjustment can be performed in steps B and C, and the same effects as in the above-described embodiment can be obtained.

[0109] In the above-described embodiment, an example was given in which the storage tank 260a and the valves 243a and 247a provided on its upstream and downstream sides, respectively, are located upstream of the confluence of the gas supply pipes 232a and 232c. However, this disclosure is not limited to this. For example, the storage tank 260a and the valves 243a and 247a can also be located downstream of the confluence of the gas supply pipes 232a and 232c. The same applies to the storage tank 260b and the valves 243b and 247b provided on its upstream and downstream sides, respectively.

[0110] In the above-described embodiment, an example of supplying H-containing gas into the processing chamber 201 via nozzle 249b was explained, but the disclosure is not limited thereto. For example, instead of H-containing gas, an inert gas may be supplied into the processing chamber 201 via nozzle 249b. The same effects as in the above-described embodiment can be obtained in this embodiment as well. Furthermore, in this embodiment, by supplying an inert gas from nozzle 249b, the flow and partial pressure distribution of etching gas in the processing chamber 201, particularly in the space on the surface of the wafer 200, can be adjusted.

[0111] In the above-described embodiment, an example of supplying H-containing gas into the processing chamber 201 via nozzle 249b was explained, but the disclosure is not limited thereto. For example, instead of H-containing gas, or in addition to H-containing gas, deuterium (D)-containing gas may be supplied into the processing chamber 201 via nozzle 249b. That is, in the above-described embodiment, instead of H-containing gas, a gas containing at least one of H-containing gas and D-containing gas can be used. The D-containing gas may be supplied from gas supply pipe 232b, from another gas supply pipe that merges with gas supply pipe 232b, or from a gas supply pipe different from gas supply pipe 232b, and into the processing chamber 201 via a nozzle different from nozzle 249b. In this embodiment as well, the same effects as in the above-described embodiment can be obtained.

[0112] Examples of D-containing gases include D ２ A gas composed solely of element D can be used. Examples of D-containing gases include ND ３ Gas, PD ３ Gas, BD ３ Gas, D ２ O gas, D ２ O ２ Compound gases composed of element D and other elements other than element D can be used. Examples of D-containing gases include D ２ Gas + O ２ Gas, D ２ Gas + O ３ A mixed gas composed of element D and other elements other than element D can be used. One or more of these can be used as the D-containing gas.

[0113] The embodiments described above illustrate an example in which the cycle including steps A and B is performed multiple times. However, the disclosure is not limited thereto. The cycle may be performed only once. In this embodiment, at least some of the effects described in the embodiments above can be obtained.

[0114] Although not specifically described in the above embodiments, the exhaust port 231a is positioned in a plan view opposite (facing) the nozzle 249a (gas supply hole 250a) across the wafer 200. This allows the etching gas to be supplied in a straight line from the outer edge to the center of the wafer 200 in step B, thereby effectively obtaining the above-mentioned effects.

[0115] It is preferable that the recipes used for each process be prepared individually according to the processing content, recorded and stored in the storage device 121c via a telecommunications line or external storage device 123. When starting each process, it is preferable that the CPU 121a appropriately selects the appropriate recipe from among the multiple recipes recorded and stored in the storage device 121c according to the processing content. This allows the processing device to perform various processes with good reproducibility on films of various film types, composition ratios, film quality, and film thickness. Furthermore, it reduces the burden on the operator and allows each process to be started quickly while avoiding operational errors.

[0116] The above-mentioned recipes are not limited to newly created ones; they may also be prepared, for example, by modifying existing recipes already installed on the processing unit. When modifying a recipe, the modified recipe may be installed on the processing unit via a telecommunications line or a recording medium on which the recipe is stored. Alternatively, existing recipes already installed on the processing unit may be directly modified by operating the input / output device 122 provided on the existing processing unit.

[0117] The above-described embodiments describe an example of performing a film deposition process using a processing apparatus having a hot-wall type furnace. This disclosure is not limited to the above-described embodiments and can also be applied to cases where a film deposition process is performed using a processing apparatus having a cold-wall type furnace.

[0118] Even when using these processing devices, each process can be carried out using the same processing procedures and conditions as described above for the embodiments and modifications, and the same effects as described above for the embodiments and modifications can be obtained.

[0119] The above-described embodiments and modifications can be used in combination as appropriate. The processing procedure and processing conditions in this case can be the same as, for example, the processing procedure and processing conditions of the above-described embodiments and modifications.

[0120] 200 Wafers (substrates) 232a, 232b Gas supply pipes (supply piping) 260a, 260b Storage tanks

Claims

1. A substrate processing method comprising: (a) filling a storage tank provided in the supply piping for etching gas with etching gas and pressurizing it in the storage section of the supply piping; and (b) supplying the etching gas, which has been pressurized in the storage tank or the storage section, to the substrate in a manner that follows the surface of the substrate, from the outer edge of the substrate toward the in-plane surface.

2. (b) The substrate processing method according to claim 1, wherein the etching gas is supplied from the outer edge of the substrate toward the central part of the substrate.

3. (b) The substrate processing method according to claim 1, wherein the substrate is rotated about the center of the surface of the substrate as an axis.

4. A substrate processing method according to any one of claims 1 to 3, comprising the step of performing a cycle including (d), (a), and (b) multiple times.

5. A substrate processing method according to claim 1, comprising the step of performing a cycle including (a) and (b) multiple times while rotating the substrate about the center of the surface of the substrate as an axis, wherein in (d), at least one of the following conditions is adjusted so that the distribution of etching amount on the surface of the substrate within the surface of the substrate becomes a predetermined distribution: (i) the number of times the cycle is performed while the substrate is rotated once; (ii) the pressure at which the etching gas is filled into the storage tank or the storage section in (a); (iii) the amount of etching gas filled into the storage tank or the storage section in (a); and (iv) the pressure in the space in which the substrate exists at the time the etching gas is supplied in (b).

6. The substrate processing method according to claim 5, wherein at least one of the conditions (i) to (iv) is adjusted so that the amount of etching of the central part of the substrate by performing (d) is equal to or greater than the amount of etching of the outer edge of the substrate by performing (d).

7. The substrate processing method according to claim 4, wherein in (d), the substrate is rotated about the center of the surface of the substrate as an axis, and at least one of the time required per cycle of the cycle and the time required per rotation of the substrate is set such that the rotation period of the substrate and the cycle are asynchronous while (d) is being performed.

8. The substrate processing method according to claim 1, wherein the substrates are arranged such that a plurality of the substrates are stacked in a direction perpendicular to the surface of the substrate.

9. (b) The substrate processing method according to claim 1, wherein the supply of the etching gas is stopped when the pressure in the storage tank or the storage section drops to a predetermined pressure value from the start of supplying the etching gas.

10. (b) The substrate processing method according to claim 1, wherein the supply of the etching gas is stopped at the timing when the flow velocity of the etching gas flowing over the substrate decreases to a predetermined flow velocity from the start of supplying the etching gas.

11. The substrate processing method according to claim 1, wherein (b) a valve provided downstream of the storage tank or the storage section is opened to supply the pressurized etching gas to the substrate, and the supply of the etching gas to the storage tank or the storage section is continued while the valve remains open.

12. The cycle includes (c) supplying the substrate with a gas containing at least one of a hydrogen-containing gas and a deuterium-containing gas. The substrate processing method according to claim 4.

13. The substrate processing method according to claim 12, wherein the gas containing at least one of the hydrogen-containing gas and the deuterium-containing gas is supplied to the substrate from a second supply port different from the first supply port from which the etching gas is discharged.

14. The substrate processing method according to claim 12, wherein a gas containing at least one of the hydrogen-containing gas and the deuterium-containing gas is continuously supplied to the substrate while the cycle is being performed.

15. The substrate processing method according to claim 12, wherein a gas containing at least one of the hydrogen-containing gas and the deuterium-containing gas is intermittently supplied to the substrate while the cycle is being performed.

16. The substrate processing method according to claim 15, wherein, during the execution of the cycle, the etching gas and the gas containing at least one of the hydrogen-containing gas and the deuterium-containing gas are supplied to the substrate such that the supply period of the etching gas and at least a portion of the supply period of the gas containing at least one of the hydrogen-containing gas and the deuterium-containing gas overlap.

17. The substrate processing method according to claim 12, wherein the etching gas is a halogen element-containing gas.

18. A method for manufacturing a semiconductor device, comprising: (a) filling a storage tank provided in an etching gas supply pipe, or a storage section of the supply pipe, with etching gas and pressurizing it; and (b) supplying the etching gas, which has been pressurized in the storage tank or the storage section, to a substrate, from the outer edge of the substrate toward the in-plane direction, along the surface of the substrate.

19. A program that causes a substrate processing apparatus to perform, by computer, a procedure of etching the surface of a substrate by: (a) filling a storage tank provided in the etching gas supply pipe, or a storage section of the supply pipe, with the etching gas and pressurizing it; and (b) supplying the etching gas, which has been pressurized in the storage tank or the storage section, to the substrate, from the outer edge of the substrate toward the in-plane direction, along the surface of the substrate.

20. A substrate processing apparatus comprising: an etching gas supply system having a storage tank or storage section of the supply piping provided in the supply piping, and a valve provided downstream of the storage tank or the storage section; and a control unit configured to control the etching gas supply system to perform an etching process on the surface of the substrate by performing (a) a process of filling the storage tank or the storage section with etching gas and pressurizing it, and (b) a process of supplying the etching gas pressurized in the storage tank or the storage section to the substrate, from the outer edge of the substrate toward the in-plane direction, along the surface of the substrate.

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