Substrate processing method and substrate processing device

Abstract

This substrate processing method includes step (a), step (b), and step (c). In step (a), a processing gas is supplied to a processing container in which a substrate is accommodated, and the processing gas in the processing container is exhausted. In step (b), the inside of the processing container is sealed by stopping the supplying and exhausting of the processing gas. In step (c), the processing gas in the processing container is exhausted.

Description

Substrate processing method and substrate processing apparatus

[0001] Various aspects and embodiments of the present disclosure relate to substrate processing methods and substrate processing apparatus.

[0002] The following Patent Document 1 states that "This substrate processing apparatus 1 has a processing chamber 11 in which a vacuum atmosphere is formed, and a SiO ２ The wafer W on which the film is formed is stored, and the SiO ２ More specifically, the substrate processing apparatus 1 supplies HF gas and NH3 gas as processing gases to the wafer W, and etches a SiO ２ A process for modifying the film to generate reaction products and a process for sublimating the reaction products by stopping the supply of the process gas are performed, and SiO ２ The film is removed. The reaction product is ammonia fluorosilicate (AFS).

[0003] Patent No. 7415594

[0004] The present disclosure provides a substrate processing method and a substrate processing apparatus that can improve the in-plane processing uniformity of a substrate.

[0005] A substrate processing method according to one aspect of the present disclosure includes steps (a), (b), and (c). In step (a), a processing gas is supplied into a processing vessel containing a substrate, and the processing gas is exhausted from the processing vessel. In step (b), the supply and exhaust of the processing gas are stopped, thereby sealing the processing vessel. In step (c), the processing gas is exhausted from the processing vessel.

[0006] According to various aspects and embodiments of the present disclosure, it is possible to improve the in-plane processing uniformity on a substrate.

[0007] FIG. 1 is a schematic cross-sectional view showing an example of a substrate processing apparatus according to this embodiment. FIG. 2 is a diagram showing an example of changes in pressure and supply amounts of each gas during etching in a reference example. FIG. 3 is a diagram showing an example of distribution of etching amount in a reference example. FIG. 4A is a diagram showing an example of an etching process in a reference example. FIG. 4B is a diagram showing an example of an etching process in a reference example. FIG. 4C is a diagram showing an example of an etching process in a reference example. FIG. 4D is a diagram showing an example of an etching process in a reference example. FIG. 5 is a diagram showing an example of changes in pressure and supply amounts of each gas during etching in this embodiment. FIG. 6 is a diagram showing an example of in-plane uniformity of etching amount in the reference example and this embodiment. FIG. 7A is a diagram showing an example of an etching process in this embodiment. FIG. 7B is a diagram showing an example of an etching process in this embodiment. FIG. 7C is a diagram showing an example of an etching process in this embodiment. FIG. 7D is a diagram showing an example of an etching process in this embodiment. FIG. 8 is a flowchart showing an example of a substrate processing method according to this embodiment.

[0008] Hereinafter, embodiments of a substrate processing method and a substrate processing apparatus will be described in detail with reference to the drawings. However, the substrate processing method and the substrate processing apparatus disclosed below are not limited to the following embodiments.

[0009] In processing a substrate using gas, the gas distribution may become uneven depending on the gas flow, depending on the structure of the processing vessel, such as the arrangement of the gas supply port, the arrangement of the exhaust port, and the arrangement of the gate valve for loading and unloading the substrate into the processing vessel. When the gas distribution becomes uneven in an area of ​​the substrate, a difference in the progress of processing occurs between an area with a high gas concentration and an area with a low gas concentration. This causes uneven processing of the substrate, reducing the in-plane uniformity of the processing of the substrate.

[0010] Therefore, the present disclosure provides a technique that can improve the in-plane uniformity of processing on a substrate.

[0011] 1 is a schematic cross-sectional view showing an example of a substrate processing apparatus 1 according to the present embodiment. The substrate processing apparatus 1 according to the present embodiment is an etching apparatus that performs isotropic etching using a processing gas. The substrate processing apparatus 1 includes a processing vessel 11. An opening 12 is formed in a sidewall of the processing vessel 11 for loading and unloading a substrate W. The opening 12 is opened and closed by a gate valve 13.

[0012] A stage 21 for supporting a substrate W is provided within the processing vessel 11. In this embodiment, a silicon oxide film is formed on the surface of the substrate W. A heating unit 22 for heating the substrate W placed on the stage 21 is embedded within the stage 21. The heating unit 22 is configured as a flow path that forms part of a circulation path through which a temperature-regulating fluid, such as water, flows, and the substrate W is heated by heat exchange with the fluid. As another example, the heating unit 22 may be configured as a heater such as a resistance heater. Also, elevating pins (not shown) are provided within the stage 21 for transferring the substrate W to and from a transfer device (not shown).

[0013] An exhaust unit 25 such as a vacuum pump is connected to the bottom of the processing vessel 11 via an exhaust pipe 23 and a pressure control valve 24. The pressure control valve 24 is an example of a pressure adjustment unit. The exhaust unit 25 exhausts gas from the processing vessel 11, and the pressure control valve 24 adjusts the pressure inside the processing vessel 11.

[0014] A shower head 26 is provided at the top of the processing chamber 11 so as to face the stage 21. A gas supply unit 30 is connected to the shower head 26 via pipes 31 to 34. The gas supply unit 30 has gas supply sources 36 to 39 and flow rate controllers 35a to 35d. The pipe 31 is connected to the gas supply source 36 via the flow rate controller 35a. The pipe 32 is connected to the gas supply source 37 via the flow rate controller 35b. The pipe 33 is connected to the gas supply source 38 via the flow rate controller 35c. The pipe 34 is connected to the gas supply source 39 via the flow rate controller 35d.

[0015] The gas supply source 36 is a supply source of HF (hydrogen fluoride) gas, and the HF gas supplied from the gas supply source 36 has its flow rate adjusted by a flow rate controller 35 a and is supplied to the shower head 26 via the pipe 31 .

[0016] The gas supply source 37 is a supply source of NH 3 (ammonia) gas, and the flow rate of the NH 3 gas supplied from the gas supply source 37 is adjusted by the flow rate controller 35 b, and the NH 3 gas is supplied to the shower head 26 via the pipe 32 .

[0017] The gas supply source 38 is a supply source of Ar (argon) gas, and the flow rate of Ar supplied from the gas supply source 38 is adjusted by a flow rate controller 35c, and the Ar gas is supplied to the shower head 26 via the pipe 33. Ar gas is an example of a rare gas.

[0018] The gas supply source 39 is a supply source of N (nitrogen) gas, and the flow rate of the N gas supplied from the gas supply source 39 is adjusted by the flow rate controller 35d, and the N gas is supplied to the shower head 26 via the pipe 34. A gas containing at least one of Ar gas and N gas is an example of an inert gas. Each gas supplied to the shower head 26 is supplied into the processing vessel 11 in a shower-like manner from a plurality of outlets formed on the lower surface of the shower head 26. Note that the inert gas does not necessarily have to be added to the processing gas.

[0019] The substrate processing apparatus 1 has a control unit 10. The control unit 10 has a memory, a processor, and an input / output interface. The memory stores programs executed by the processor, recipes including conditions for each process, and the like. The processor reads the programs from the memory, executes them, and controls each unit of the substrate processing apparatus 1 via the input / output interface based on the recipes stored in the memory. For example, the processor of the control unit 10 controls the pressure control valve 24 and the flow rate controllers 35a to 35d via the input / output interface.

[0020] 2 is a diagram showing an example of changes in pressure and supply amounts of each gas during etching in a reference example, in which a substrate W is etched using the substrate processing apparatus 1 illustrated in FIG.

[0021] 2, in the etching process of the reference example, a process gas containing HF gas and NH gas and an inert gas containing N gas and Ar gas are supplied into the process vessel 11 in the etching step. Then, in the purging step, the supply of the process gas is stopped, the substrate W is heated to a predetermined temperature, and the surface of the substrate W is purged with the inert gas. Then, in the exhausting step, the supply of the inert gas is stopped, and the gas in the process vessel 11 is exhausted.

[0022] Here, in the etching process of the reference example, the supply of the process gas and the inert gas and the exhaust of the process vessel 11 are continuously performed, and a flow of the process gas and the inert gas occurs within the process vessel 11. Therefore, within the process vessel 11, a bias in the gas distribution occurs according to the gas flow, depending on the structure of the process vessel 11, such as the arrangement of the outlet of the shower head 26, the arrangement of the exhaust pipe 23, and the arrangement of the openings 12 formed in the sidewall of the process vessel 11. When the bias in the process gas distribution occurs, a difference in the degree of etching progress occurs between a region of the substrate W where the process gas concentration is high and a region of the substrate W where the process gas concentration is low.

[0023] This causes a bias in the amount of etching on the substrate W, reducing the in-plane uniformity of the amount of etching on the substrate W, as shown in Fig. 3, for example. In the example of Fig. 3, the exhaust pipe 23 is disposed at the upper right of the substrate W, and the flow of the processing gas is concentrated at the upper right of the substrate W. As a result, the amount of etching on the upper right of the substrate W is large and the amount of etching on the lower left is small.

[0024] Furthermore, etching of the substrate W in the reference example progresses, for example, as shown in Figures 4A to 4D. Figures 4A to 4D are diagrams showing an example of the etching process in the reference example.

[0025] 4A, a substrate W having a pattern 40 formed on a silicon oxide film on its surface is prepared in a processing vessel 11. Then, a processing gas containing HF gas and NH gas and an inert gas containing N gas and Ar gas are supplied into the processing vessel 11, and ammonium fluoride (AF) 41 is deposited on the surface of the substrate W by a gas-phase reaction between NH and N, as shown in FIG.

[0026] 4C , the AF 41 deposited on the surface of the substrate W reacts with the silicon oxide film on the surface of the substrate W to form ammonium fluorosilicate (AFS) 42 on the surface of the substrate W. Then, the supply of the processing gas is stopped, the substrate W is heated to a predetermined temperature, and the surface of the substrate W is purged with an inert gas. As a result, the AF 41 and AFS 42 are sublimated and removed from the surface of the substrate W.

[0027] However, when AF41 and AFS42 are sublimated, the compressive stress of AF41 and AFS42 may attract adjacent patterns, causing pattern collapse, as shown in Fig. 4D, for example. As the aspect ratio of pattern 40 increases, the probability of pattern collapse increases.

[0028] 5 is a diagram showing an example of changes in pressure and supply amounts of each gas during etching in this embodiment. In this embodiment, the substrate W is also etched using the substrate processing apparatus 1 shown in FIG.

[0029] 5, in the etching process of this embodiment, a process gas containing HF gas and NH gas and an inert gas containing N gas and Ar gas are supplied into the process vessel 11. The amount of gas exhausted from the process vessel 11 is then adjusted so that the inside of the process vessel 11 is at a first pressure, and the temperature of the substrate W is adjusted to a first temperature. The supply of the process gas and inert gas and the exhaust of gas from the process vessel 11 are then stopped, and the process vessel 11 is sealed at the first pressure. In this embodiment, etching of the substrate W progresses while the inside of the process vessel 11 is sealed.

[0030] Thereafter, the supply of the inert gas into the processing vessel 11 is resumed, and evacuation of the processing vessel 11 is resumed, thereby purging the surface of the substrate W with the inert gas. By evacuation of the processing vessel 11, the pressure inside the processing vessel 11 is controlled to a pressure equal to or lower than a second pressure that is lower than the first pressure.

[0031] In this embodiment, the processing vessel 11 is sealed during etching of the substrate W. This blocks the flow of processing gas within the processing vessel 11, and suppresses uneven distribution of the processing gas within the processing vessel 11 due to the flow of processing gas. This improves the in-plane uniformity of the etching amount of the substrate W.

[0032] 6 is a diagram showing an example of the in-plane uniformity of the etching amount in the reference example and this embodiment. The smaller the in-plane uniformity (%) shown in FIG. 6, the better the in-plane uniformity. In this embodiment, as shown in FIG. 6, the in-plane uniformity of the etching amount is improved compared to the reference example. In particular, when the etching amount is small, the improvement in in-plane uniformity is greater than in the reference example.

[0033] Furthermore, etching of the substrate W in this embodiment progresses, for example, as shown in Figures 7A to 7E, which are diagrams showing an example of the etching process in this embodiment.

[0034] First, as shown in Fig. 7A, for example, a substrate W having a pattern 40 formed on a silicon oxide film on its surface is prepared in a processing chamber 11. Then, the temperature of the substrate W is controlled to a first temperature, and a processing gas containing HF gas and NH gas and an inert gas containing N gas and Ar gas are supplied into the processing chamber 11, and the pressure inside the processing chamber 11 is adjusted to a first pressure. Then, AF41 is deposited on the surface of the substrate W by a gas-phase reaction between NH and N, as shown in Fig. 7B, for example.

[0035] In this embodiment, the flow rate, first temperature, and first pressure of each gas are, for example, as follows: In the following values, 1 sccm corresponds to approximately 1.69×10 -3 pa・m 3 / s, and 1 mT is approximately 0.133 Pa. HF gas: 20 sccm or more and 1000 sccm or less NH gas: 20 sccm or more and 1000 sccm or less Flow rate ratio of HF gas to NH gas: 0.1 or more and 10 or less N gas: 100 sccm or more and 2000 sccm or less Ar gas: 20 sccm or more and 1000 sccm or less Flow rate ratio of inert gas to process gas: 0 or more and 20 or less Temperature of substrate W: 10° C. or more and 135° C. or less First pressure: 20 mT or more and 50,000 mT or less

[0036] Next, the supply of the process gas and the inert gas and the exhaust of the gas in the process vessel 11 are stopped, and the process vessel 11 is sealed at a first pressure. While the process vessel 11 is sealed, the AF41 deposited on the surface of the substrate W reacts with the silicon oxide film on the surface of the substrate W to form AFS42 on the surface of the substrate W, as shown in Fig. 7C, for example. Because the process vessel 11 is sealed, the AF41 in the process vessel 11 is consumed by the formation of AFS42, as shown in Fig. 7D, for example.

[0037] 7D , there is no AF 41 between the patterns 40 having AFS 42 formed on the surface, or even if there is, there is much less of it than in the reference example. When there is no AF 41 between adjacent patterns 40, no compressive stress of the AF 41 occurs when the AF 41 sublimes. Therefore, the occurrence of pattern collapse between adjacent patterns 40 is suppressed.

[0038] Furthermore, even if AF 41 remains between adjacent patterns 40, the amount of AF 41 remaining between the adjacent patterns 40 is small, and therefore the compressive stress of AF 41 when the AF 41 between the adjacent patterns 40 sublimes is smaller than in the reference example. Therefore, pattern collapse between the adjacent patterns 40 is unlikely to occur.

[0039] 7D , because the inside of the processing chamber 11 is maintained at a high pressure (first pressure), the AFS 42 does not sublimate and remains on the sidewall of the pattern 40. The presence of the AFS 42 on the sidewall of the pattern 40 increases the mechanical strength of the pattern 40 compared to when the AFS 42 is not present on the sidewall. Therefore, even if compressive stress occurs when a small amount of AF 41 remaining between adjacent patterns 40 sublimes, pattern collapse between the adjacent patterns 40 is less likely to occur than in the reference example.

[0040] Next, the supply of the inert gas into the processing vessel 11 is resumed, and evacuation of the processing vessel 11 is resumed, thereby purging the surface of the substrate W. Furthermore, by evacuation of the processing vessel 11, the pressure inside the processing vessel 11 becomes equal to or lower than a second pressure that is lower than the first pressure.

[0041] In this embodiment, the second pressure and the flow rates of the gases during purging are, for example, as follows: N2 gas: 100 sccm or more and 2000 sccm or less Ar gas: 20 sccm or more and 1000 sccm or less Temperature of the substrate W: 10° C. or more and 135° C. Second pressure: 0.1 mT or more and 1000 mT or less

[0042] When the pressure in the processing chamber 11 becomes equal to or lower than the second pressure, the AFS 42 on the substrate W sublimes. For example, as shown in Fig. 7D, the AFS 42 is hardly present between adjacent patterns 40. Therefore, the adjacent patterns 40 are not attracted to each other by the compressive stress generated when the AFS 42 sublimes. Therefore, when the AFS 42 sublimes, the surface of the pattern 40 can be etched without causing pattern collapse, as shown in Fig. 7E, for example.

[0043] 8 is a flowchart showing an example of a substrate processing method according to the present embodiment. The processes illustrated in FIG. 8 are realized by the control unit 10 controlling each part of the substrate processing apparatus 1.

[0044] First, the substrate W is loaded into the processing vessel 11 (step S10). In step S10, the gate valve 13 is opened, and the substrate W is loaded into the processing vessel 11 through the opening 12 and placed on the stage 21. Then, the gate valve 13 is closed.

[0045] Next, the temperature of the substrate W is adjusted (step S11). In step S11, the temperature of the substrate W is adjusted to a first temperature by the heater 22 embedded in the stage 21.

[0046] Next, a processing gas is supplied into the processing vessel 11 (step S12). Step S12 is an example of process (a). In step S12, a processing gas containing HF gas and NH gas, and an inert gas containing N gas and Ar gas are supplied into the processing vessel 11 at predetermined flow rates.

[0047] Next, the pressure inside the processing vessel 11 is adjusted (step S13). In step S13, the gas inside the processing vessel 11 is exhausted by the exhaust unit 25, and the pressure inside the processing vessel 11 is controlled to a first pressure by the pressure control valve 24.

[0048] Next, the processing vessel 11 is sealed (step S14). Step S14 is an example of process (b). In step S14, the supply of the processing gas and the inert gas and the exhaust of the gas in the processing vessel 11 are stopped, and the processing vessel 11 is sealed in a state of a first pressure.

[0049] Next, it is determined whether a predetermined time has elapsed since the processing vessel 11 was sealed (step S15). The predetermined time is the time required to obtain a predetermined etching amount, and is, for example, a time in the range of 10 seconds to 600 seconds. If the predetermined time has not elapsed since the processing vessel 11 was sealed (step S15: No), the process shown in step S15 is executed again.

[0050] On the other hand, if a predetermined time has elapsed since the gas in the processing vessel 11 was sealed (step S15: Yes), exhaust of the gas in the processing vessel 11 is resumed (step S16). Step S16 is an example of process (c). Then, an inert gas is supplied into the processing vessel 11 to purge the surface of the substrate W (step S17). In steps S16 and S17, the pressure in the processing vessel 11 is adjusted to be equal to or lower than the second pressure.

[0051] Next, the supply of the inert gas is stopped, and the substrate W is unloaded from the processing vessel 11 (step S18). In step S18, the gate valve 13 is opened, and the substrate W is unloaded from the processing vessel 11 through the opening 12. Then, the substrate processing method shown in this flowchart is completed.

[0052] The embodiment has been described above. As described above, the substrate processing method in this embodiment includes steps (a), (b), and (c). In step (a), a processing gas is supplied into a processing vessel (processing vessel 11) that accommodates a substrate (substrate W), and the processing gas is exhausted from the processing vessel. In step (b), the supply and exhaust of the processing gas are stopped, thereby sealing the processing vessel. In step (c), the processing gas is exhausted from the processing vessel. This can improve the in-plane processing uniformity of the substrate.

[0053] In the above-described embodiment, in step (b), the substrate is etched by the process gas in a sealed process chamber. The etching of the substrate is isotropic etching. This can improve the in-plane uniformity of the amount of etching on the substrate.

[0054] In the above-described embodiment, the processing gas contains a halogen-containing gas and a basic gas, and the substrate contains a silicon-containing film such as a silicon oxide film, thereby enabling etching of the substrate.

[0055] In the above-described embodiment, the pressure in the processing vessel is adjusted to a first pressure in the step (a), the processing vessel is sealed at the first pressure in the step (b), and the pressure in the processing vessel is controlled to a second pressure or less that is lower than the first pressure in the step (c). This allows ammonium fluorosilicate produced by the reaction between ammonium fluoride produced by the gas-phase reaction of hydrogen fluoride gas and ammonia gas and the silicon-containing film to be removed.

[0056] In the above-described embodiment, the first pressure is within a range of 20 mT or more and 50,000 mT or less, and the second pressure is within a range of 0.1 mT or more and 1,000 mT or less, thereby suppressing sublimation of ammonium fluorosilicate in the step (b) and promoting sublimation of ammonium fluorosilicate in the step (c).

[0057] In the above-described embodiment, the temperature of the substrate is controlled to a first temperature in step (b) and is also controlled to the same temperature in step (c). In another embodiment, the temperature of the substrate may be controlled to a second temperature higher than the first temperature.

[0058] In the above-described embodiment, step (b) is continued for a time period ranging from 10 seconds to 600 seconds, thereby allowing ammonium fluoride produced by the gas-phase reaction of hydrogen fluoride gas and ammonia gas in step (b) to be consumed in the production of ammonium fluorosilicate.

[0059] The substrate processing apparatus (substrate processing apparatus 1) in the above-described embodiment includes a processing vessel (processing vessel 11), a gas supply unit (gas supply unit 30), an exhaust unit (exhaust unit 25), a pressure adjustment unit (pressure control valve 24), and a controller (control unit 10). The processing vessel accommodates a substrate (substrate W). The gas supply unit supplies a processing gas into the processing vessel. The exhaust unit exhausts the processing gas from the processing vessel. The pressure adjustment unit adjusts the pressure inside the processing vessel. The controller is configured to perform steps (a), (b), and (c). In step (a), the controller controls the gas supply unit, the exhaust unit, and the pressure adjustment unit to supply the processing gas into the processing vessel and exhaust the processing gas from the processing vessel, thereby adjusting the pressure inside the processing vessel to a first pressure. In step (b), the controller controls the gas supply unit and the exhaust unit to stop the supply and exhaust of the processing gas and seal the processing vessel at the first pressure. In the step (c), the processing gas inside the processing chamber is exhausted by controlling the exhaust unit, thereby improving the in-plane processing uniformity of the substrate.

[0060] [Others] The technology disclosed in the present application is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof.

[0061] For example, in the above-described embodiment, steps (a), (b), and (c) are each performed once, but the disclosed technology is not limited to this. Alternatively, steps (a), (b), and (c) may be repeatedly performed multiple times in this order. This allows ammonium fluoride generated by the gas-phase reaction of hydrogen fluoride gas and ammonia gas to be sufficiently supplied to the surface of the substrate, even when the volume of the processing chamber 11 is small, thereby achieving the desired etching amount.

[0062] As the number of repetitions of steps (a), (b), and (c) increases, the mixing ratio of the process gas and the inert gas in steps (a) and (b) may be changed. Furthermore, as the number of repetitions of steps (a), (b), and (c) increases, the pressure, duration, etc. of step (b) may be changed.

[0063] In the above embodiment, the substrate processing apparatus 1 is an apparatus that performs etching on the substrate W, but the disclosed technology is not limited to this. In other embodiments, the disclosed technology can be applied to other apparatuses, such as a film forming apparatus or a modifying apparatus, as long as the apparatus processes the substrate W using a gas.

[0064] In the above-described embodiment, the substrate processing apparatus 1 performs isotropic etching on the substrate W, but the disclosed technology is not limited to this. As another embodiment, the disclosed technology can also be applied to a substrate processing apparatus that performs anisotropic etching on the substrate W.

[0065] In the above embodiment, the substrate processing apparatus 1 performs etching on the substrate W including a silicon oxide film, but the disclosed technology is not limited to this. In another embodiment, the substrate processing apparatus 1 may perform etching on the substrate W including other silicon-containing films such as a silicon nitride film, a silicon carbide film, a silicon oxynitride film, a carbon-containing silicon oxide film, or a carbon-containing silicon nitride film.

[0066] It should be noted that the disclosed embodiments are illustrative in all respects and should not be considered limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0067] Furthermore, the following supplementary notes are disclosed regarding the above-described embodiment.

[0068] (Supplementary Note 1) A substrate processing method comprising: (a) supplying a processing gas into a processing vessel containing a substrate and exhausting the processing gas from the processing vessel; (b) sealing the processing vessel by stopping the supply and exhaust of the processing gas; and (c) exhausting the processing gas from the processing vessel. (Supplementary Note 2) The substrate processing method of Supplementary Note 1, wherein in step (b), the substrate is etched with the processing gas in the sealed processing vessel. (Supplementary Note 3) The substrate processing method of Supplementary Note 2, wherein the etching is isotropic etching. (Supplementary Note 4) The substrate processing method of Supplementary Note 2 or 3, wherein the processing gas includes hydrogen fluoride gas and ammonia gas, and the substrate includes a silicon-containing film. (Supplementary Note 5) The substrate processing method of Supplementary Note 4, wherein the silicon-containing film is a silicon oxide film, a silicon nitride film, a silicon carbide film, a silicon oxynitride film, a carbon-containing silicon oxide film, or a carbon-containing silicon nitride film. (Supplementary Note 6) The substrate processing method according to Supplementary Note 4 or 5, wherein in the step (a), the pressure inside the processing vessel is adjusted to a first pressure; in the step (b), the processing vessel is sealed at the first pressure; and in the step (c), the pressure inside the processing vessel is controlled to a second pressure lower than the first pressure. (Supplementary Note 7) The substrate processing method according to Supplementary Note 6, wherein the first pressure is a pressure in the range of 20 mT to 50,000 mT; and the second pressure is a pressure in the range of 0.1 mT to 1,000 mT. (Supplementary Note 8) The substrate processing method according to any one of Supplements 4 to 7, wherein in the step (b), the temperature of the substrate is controlled to a first temperature; and in the step (c), the temperature of the substrate is controlled to a second temperature higher than the first temperature. (Supplementary Note 9) The substrate processing method according to Supplementary Note 8, wherein the first temperature is a temperature in the range of 10°C to 135°C. (Supplementary Note 10) The substrate processing method according to any one of Supplementary Notes 4 to 9, wherein step (b) continues for a time period ranging from 10 seconds to 600 seconds. (Supplementary Note 11) The substrate processing method according to any one of Supplementary Notes 1 to 10, wherein steps (a), (b), and (c) are repeatedly performed in this order a plurality of times.(Supplementary Note 12) A substrate processing apparatus comprising: a processing vessel for accommodating a substrate; a gas supply unit for supplying a processing gas into the processing vessel; an exhaust unit for exhausting the processing gas from the processing vessel; a pressure adjustment unit for adjusting the pressure in the processing vessel; and a control unit, wherein the control unit is configured to perform the following steps: (a) controlling the gas supply unit, the exhaust unit, and the pressure adjustment unit to supply the processing gas into the processing vessel, exhaust the processing gas from the processing vessel, and adjust the pressure in the processing vessel to a first pressure; (b) controlling the gas supply unit and the exhaust unit to stop the supply and exhaust of the processing gas and seal the processing vessel at the first pressure; and (c) controlling the exhaust unit to exhaust the processing gas from the processing vessel.

[0069] W substrate 1 substrate processing apparatus 10 control unit 11 processing vessel 12 opening 13 gate valve 21 stage 22 heating unit 23 exhaust pipe 24 pressure control valve 25 exhaust unit 26 shower head 30 gas supply unit 31 piping 32 piping 33 piping 34 piping 35 flow rate controller 36 gas supply source 37 gas supply source 38 gas supply source 39 gas supply source 40 pattern 41 AF 42 AFS

Claims

1. A substrate processing method comprising: (a) supplying a processing gas into a processing vessel containing a substrate and exhausting the processing gas from the processing vessel; (b) sealing the processing vessel by stopping the supply and exhaust of the processing gas; and (c) exhausting the processing gas from the processing vessel.

2. The substrate processing method according to claim 1, wherein in the step (b), the substrate is etched with the processing gas in the sealed processing vessel.

3. The substrate processing method according to claim 2, wherein the etching is isotropic etching.

4. The substrate processing method according to claim 2 or 3, wherein the processing gas contains hydrogen fluoride gas and ammonia gas, and the substrate contains a silicon-containing film.

5. The substrate processing method according to claim 4, wherein the silicon-containing film is a silicon oxide film, a silicon nitride film, a silicon carbide film, a silicon oxynitride film, a carbon-containing silicon oxide film, or a carbon-containing silicon nitride film.

6. A substrate processing method according to claim 4, wherein in step (a), the pressure inside the processing vessel is adjusted to a first pressure; in step (b), the processing vessel is sealed at the first pressure; and in step (c), the pressure inside the processing vessel is controlled to a pressure equal to or lower than a second pressure lower than the first pressure.

7. The substrate processing method according to claim 6, wherein the first pressure is within a range of 20 mT to 50,000 mT, and the second pressure is within a range of 0.1 mT to 1,000 mT.

8. The substrate processing method according to claim 4, wherein in step (b), the temperature of the substrate is controlled to a first temperature, and in step (c), the temperature of the substrate is controlled to a second temperature higher than the first temperature.

9. The substrate processing method according to claim 8, wherein the first temperature is within a range of 10°C to 135°C.

10. The substrate processing method according to claim 4, wherein step (b) continues for a period of time within the range of 10 seconds to 600 seconds.

11. The substrate processing method according to claim 1, wherein the steps (a), (b), and (c) are repeatedly performed in this order a plurality of times.

12. A substrate processing apparatus comprising: a processing vessel for accommodating a substrate; a gas supply unit for supplying a processing gas into the processing vessel; an exhaust unit for exhausting the processing gas from the processing vessel; a pressure adjustment unit for adjusting the pressure inside the processing vessel; and a control unit, wherein the control unit is configured to perform the following steps: (a) supplying the processing gas into the processing vessel and exhausting the processing gas from the processing vessel by controlling the gas supply unit and the exhaust unit; (b) stopping the supply and exhaust of the processing gas and sealing the processing vessel by controlling the gas supply unit and the exhaust unit; and (c) exhausting the processing gas from the processing vessel by controlling the exhaust unit.

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