Cleaning method, method for manufacturing semiconductor device, recording medium, and substrate processing apparatus

Abstract

The present invention relates to a cleaning method, a manufacturing method of a semiconductor device, a recording medium, and a substrate processing apparatus. Removal of a deposition film formed on an inner surface of a reaction vessel is facilitated by plasma processing of a substrate. A deposition film is modified to a film containing an oxidized layer and a nitrided layer by performing a cycle including the following steps a predetermined number of times: (a) a step of supplying an oxygen-containing gas into the reaction vessel having the deposition film formed on the inner surface and plasma-exciting the oxygen-containing gas to oxidize the deposition film; and (b) a step of supplying a nitrogen-containing gas into the reaction vessel and plasma-exciting the nitrogen-containing gas to nitride the deposition film.

Description

Technical Field

[0001] This invention relates to cleaning methods, methods for manufacturing semiconductor devices, recording media, and substrate processing apparatus. Background Technology

[0002] Patent document 1 describes a substrate processing apparatus that performs substrate processing by plasma excitation of a processing gas by supplying high-frequency power to a coil.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-75579 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in the substrate processing apparatus described above, there is a situation where a deposited film is formed on the inner surface of the reaction vessel due to plasma treatment of the substrate, and this deposited film becomes a major cause of particles when it peels off.

[0008] The object of the present invention is to provide a technique for facilitating the removal of deposited films formed on the inner surface of a reaction vessel by plasma treatment of the substrate.

[0009] Methods for solving problems

[0010] According to one aspect of the present invention, a technique is provided that modifies the aforementioned deposited film into a film comprising an oxide layer and a nitride layer by performing a predetermined number of cycles comprising the following steps:

[0011] (a) A step of supplying oxygen-containing gas into a reaction vessel on which a deposited film has been formed on its inner surface, and subjecting the oxygen-containing gas to plasma excitation, thereby oxidizing the deposited film; and

[0012] (b) The process of supplying nitrogen-containing gas into the aforementioned reaction vessel and subjecting the aforementioned nitrogen-containing gas to plasma excitation, thereby nitriding the aforementioned deposited film.

[0013] The effects of the invention

[0014] According to the present invention, the removal of the deposited film formed on the inner surface of the reaction vessel can be facilitated by plasma treatment of the substrate. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a substrate processing apparatus preferably used in one embodiment of the present invention.

[0016] Figure 2 This is a diagram illustrating the configuration of the control unit (control unit) of a substrate processing apparatus preferably used in one embodiment of the present invention.

[0017] Figure 3 This is a flowchart illustrating a preferred substrate processing step used in one embodiment of the present invention.

[0018] Figure 4 This is an explanatory diagram showing the resonant coil, electric field strength, and current-voltage relationship, etc., preferably used in one aspect of the present invention.

[0019] Figure 5 This is a diagram illustrating the state of the inner wall surface of the substrate processing apparatus after a substrate processing step, which is preferably used in one embodiment of the present invention.

[0020] Figure 6 This is a flowchart illustrating a preferred cleaning procedure used in one aspect of the present invention.

[0021] Figure 7 middle, Figure 7 (A) is a diagram showing the state of the inner wall surface of the substrate processing apparatus after the substrate processing process. Figure 7 (B) is a diagram showing the state of the inner wall surface of the substrate processing apparatus after the cleaning process. Figure 7 (C) is a diagram showing the appearance of the inner wall surface of the substrate processing device during wiping.

[0022] Explanation of reference numerals in the attached figures

[0023] 200 wafers (substrates)

[0024] 201 Processing Room

[0025] 203 Processing Container

[0026] 210 Upper container

[0027] 211 Lower container

[0028] 212 resonant coil

[0029] 217 Substrate Stage

[0030] 273 High Frequency Power Supply Detailed Implementation

[0031] <One aspect of the invention>

[0032] The following is for reference Figures 1 to 7One aspect of the present invention will be described below. It should be noted that the accompanying drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings may not necessarily match reality. Furthermore, the dimensional relationships and ratios of the elements may not be consistent across multiple drawings.

[0033] (1) Composition of substrate processing device

[0034] The following uses Figure 1 A substrate processing apparatus 100 according to one aspect of the present invention will be described. This substrate processing apparatus according to one aspect of the present invention is configured to primarily perform oxidation treatment on a film or substrate formed on a substrate surface.

[0035] (Processing Room)

[0036] The substrate processing apparatus 100 includes a processing furnace 202, which serves as a reaction vessel for plasma processing of a wafer 200 serving as a substrate. A processing container 203 constituting a processing chamber 201 is disposed within the processing furnace 202. The processing container 203 includes a dome-shaped upper container 210 serving as a first container, and a bowl-shaped lower container 211 serving as a second container. The processing chamber 201 is formed by covering the lower container 211 with the upper container 210. The upper container 210 is formed of quartz. Furthermore, the upper container 210 constitutes a plasma container, which forms a plasma generation space where processing gases are excited by plasma.

[0037] In addition, a gate valve 244 is provided on the lower side wall of the lower container 211.

[0038] The processing chamber 201 includes: a plasma generation space in which coils, i.e., resonant coils 212 serving as electrodes, are arranged around the plasma generation space; and a substrate processing space communicating with the plasma generation space and serving as a substrate processing chamber for processing the wafer 200. The plasma generation space is the space where plasma is generated, specifically the space within the processing chamber 201 that is above and below the lower end of the resonant coil 212. Conversely, the substrate processing space is the space where plasma is used to process the substrate, specifically the space below the lower end of the resonant coil 212. In one embodiment of the invention, the horizontal diameters of the plasma generation space and the substrate processing space are configured to be approximately the same.

[0039] (Support)

[0040] A substrate support 217 is disposed at the center of the bottom side of the processing chamber 201 as a substrate stage for mounting the wafer 200. The substrate support 217 is located below the resonant coil 212 inside the processing chamber 201.

[0041] A heater 217b, which serves as a heating mechanism, is integrally embedded inside the support 217.

[0042] The support 217 is electrically insulated from the lower container 211. In order to further improve the uniformity of the plasma density generated on the wafer 200 placed on the support 217, an impedance adjustment electrode 217c is provided inside the support 217 and grounded via an impedance variable mechanism 275, which serves as an impedance adjustment unit.

[0043] The support 217 is provided with a support lifting mechanism 268, which includes a drive mechanism for raising and lowering the support 217. Additionally, the support 217 has a through hole 217a, and a wafer mounting pin 266 is provided on the bottom surface of the lower container 211. The support 217 is configured such that when the support 217 is lowered by the support lifting mechanism 268, the wafer mounting pin 266 passes through the through hole 217a without contacting the support 217.

[0044] (Gas Supply Department)

[0045] A gas supply head 236 is provided above the processing chamber 201, that is, above the upper container 210. The gas supply head 236 is configured to supply reactive gas into the processing chamber 201 by means of a cover-shaped cover 233, a gas inlet 234, a buffer chamber 237, an opening 238, a shielding plate 240, and a gas outlet 239.

[0046] The oxygen-containing gas supply pipe 232a (for oxygen-containing gas), the downstream end of the hydrogen-containing gas supply pipe 232b (for hydrogen-containing gas), and the nitrogen-containing gas supply pipe 232c (for nitrogen-containing gas) are connected to the gas inlet 234 in a confluence manner. On the oxygen-containing gas supply pipe 232a, from the upstream side, an oxygen-containing gas supply source 250a, a mass flow controller (MFC) 252a (for flow control), and a valve 253a (for on / off control) are sequentially arranged. On the hydrogen-containing gas supply pipe 232b, from the upstream side, a hydrogen-containing gas supply source 250b, an MFC 252b, and a valve 253b are sequentially arranged. On the nitrogen-containing gas supply pipe 232c, from the upstream side, a nitrogen-containing gas supply source 250c, an MFC 252c, and a valve 253c are sequentially arranged. A valve 243a is provided on the downstream side where the oxygen-containing gas supply pipe 232a, the hydrogen-containing gas supply pipe 232b, and the nitrogen-containing gas supply pipe 232c merge, and is connected to the upstream end of the gas inlet 234.

[0047] The gas supply unit (gas supply system) according to one aspect of the present invention mainly consists of a gas supply head 236, an oxygen-containing gas supply pipe 232a, a hydrogen-containing gas supply pipe 232b, a nitrogen-containing gas supply pipe 232c, MFCs 252a, 252b, and 252c, and valves 253a, 253b, 253c, and 243a. The gas supply unit (gas supply system) is configured to supply processing gas into the processing container 203.

[0048] Additionally, the gas supply head 236, oxygen-containing gas supply pipe 232a, MFC 252a, and valves 253a and 243a constitute one aspect of the oxygen-containing gas supply system according to the present invention. Furthermore, the gas supply head 236, hydrogen-containing gas supply pipe 232b, MFC 252b, and valves 253b and 243a constitute one aspect of the hydrogen-containing gas supply system according to the present invention. Furthermore, the gas supply head 236, nitrogen-containing gas supply pipe 232c, MFC 252c, and valves 253c and 243a constitute one aspect of the nitrogen-containing gas supply system according to the present invention.

[0049] (Exhaust section)

[0050] A gas exhaust port 235 is provided on the side wall of the lower container 211 to discharge the reaction gas from the processing chamber 201. The upstream end of the gas exhaust pipe 231 is connected to the gas exhaust port 235. On the gas exhaust pipe 231, starting from the upstream, an APC (Automatic Pressure Controller) valve 242 serving as a pressure regulator (pressure regulating unit), a valve 243b serving as an on / off valve, and a vacuum pump 246 serving as a vacuum exhaust device are sequentially arranged. The gas exhaust port 235, the gas exhaust pipe 231, the APC valve 242, and the valve 243b mainly constitute the exhaust unit according to one aspect of the present invention.

[0051] (Plasma Generation Unit)

[0052] A resonant coil 212 is provided on the outer periphery of the processing chamber 201, that is, on the outer side of the side wall of the upper container 210, in a spiral manner wound multiple times along the outer periphery of the upper container 210. An RF sensor 272, a high-frequency power supply 273, and a matching circuit 274 that integrates the impedance and output frequency of the high-frequency power supply 273 are connected to the resonant coil 212.

[0053] A high-frequency power supply 273 supplies high-frequency power (RF power) to the resonant coil 212. An RF sensor 272 is located on the output side of the high-frequency power supply 273 to monitor the traveling wave and reflected wave information of the supplied high-frequency power. The reflected wave power detected by the RF sensor 272 is input to a matching converter 274. The matching converter 274 controls the impedance of the high-frequency power supply 273 and the frequency of the output high-frequency power in a manner that minimizes the reflected wave information based on the reflected wave information input from the RF sensor 272.

[0054] The high-frequency power supply 273 includes: a power control unit (control circuit) comprising a high-frequency oscillation circuit and a preamplifier for specifying the oscillation frequency and output; and an amplifier (output circuit) for amplifying to the specified output. The power control unit controls the amplifier based on frequency and power-related output conditions preset via an operation panel. The amplifier supplies a certain high-frequency power to the resonant coil 212 via a transmission line.

[0055] Regarding the resonant coil 212, in order to form a standing wave of a specified wavelength, the winding diameter, winding pitch, and number of windings are set to achieve resonance at a certain wavelength. That is, the electrical length of the resonant coil 212 is set to be an integer multiple (1, 2, ...) of the wavelength of the specified frequency of the high-frequency power supplied from the high-frequency power source 273.

[0056] In order to shield the electric field outside the resonant coil 212 and to form the capacitance component (C component) required to constitute the resonant circuit between the shielding plate 223 and the resonant coil 212.

[0057] The plasma generation unit according to one embodiment of the present invention mainly consists of a resonant coil 212, an RF sensor 272, and a matching unit 274. It should be noted that a high-frequency power supply 273 may also be included as the plasma generation unit.

[0058] (Control Department)

[0059] The controller 221, as the control unit, is configured to control APC valves 242 and 243b and vacuum pump 246 via signal line A, the liner lifting mechanism 268 via signal line B, the heater power regulating mechanism 276 and impedance variable mechanism 275 via signal line C, the gate valve 244 via signal line D, the RF sensor 272, high-frequency power supply 273 and matching device 274 via signal line E, and the MFCs 252a to 252c and valves 253a to 253c and 243a via signal line F.

[0060] like Figure 2 As shown, the controller 221, which serves as the control unit (control unit), is configured as a computer equipped with a CPU (Central Processing Unit) 221a, RAM (Random Access Memory) 221b, storage device 221c, and I / O port 221d. The RAM 221b, storage device 221c, and I / O port 221d are configured to exchange data with the CPU 221a via an internal bus 221e. An input / output device 225, such as a touch panel or display, is connected to the controller 221.

[0061] The storage device 221c is composed of, for example, flash memory or an HDD (Hard Disk Drive). Within the storage device 221c, control programs that control the operation of the substrate processing apparatus and program processes that describe the substrate processing steps and conditions (described later) are stored in a readable manner. The process processes are combined in a way that enables the controller 221 to execute each step of the substrate processing steps described later and obtain a predetermined result, thus functioning as a program. Hereinafter, the program processes, control programs, etc., will be collectively referred to as a program. It should be noted that when the term "program" is used in this specification, there may be cases where only the program processes are included, cases where only the control programs are included, or cases where both are included. Furthermore, RAM 221b is configured as a storage area (working area) for temporarily holding programs, data, etc., read by the CPU 221a.

[0062] I / O port 221d is connected to the aforementioned MFCs 252a-252c, valves 253a-253c, 243a, 243b, gate valve 244, APC valve 242, vacuum pump 246, RF sensor 272, high-frequency power supply 273, matching unit 274, support lifting mechanism 268, impedance variable mechanism 275, heater power regulating mechanism 276, etc.

[0063] CPU 221a is configured to read and execute a control program from storage device 221c, and to read the process technology from storage device 221c based on input of operation instructions from input / output device 225. Furthermore, the CPU221a is configured to control the opening adjustment of the APC valve 242, the opening and closing of the valve 243b, and the start and stop of the vacuum pump 246 via the I / O port 221d and signal line A, according to the read process information; control the lifting action of the liner lifting mechanism 268 via signal line B; control the power supply adjustment (temperature adjustment) of the heater 217b using the heater power adjustment mechanism 276 and the impedance adjustment using the impedance variable mechanism 275 via signal line C; control the opening and closing of the gate valve 244 via signal line D; control the operation of the RF sensor 272, the matching device 274, and the high-frequency power supply 273 via signal line E; and control the flow rate adjustment of various processing gases using MFCs 252a to 252c, as well as the opening and closing of valves 253a to 253c and 243a via signal line F, etc.

[0064] The controller 221 is configured to install the aforementioned program stored in an external storage device (e.g., magnetic disks such as magnetic tape, floppy disks, and hard disks; optical discs such as CDs and DVDs; optical disks such as MO; semiconductor memories such as USB storage devices and memory cards) 226 onto a computer. The storage device 221c and the external storage device 226 are configured in the form of a computer-readable recording medium. Hereinafter, they will be collectively referred to simply as recording media. In this specification, the term "recording medium" may refer to a case containing only the storage device 221c, a case containing only the external storage device 226, or a case containing both. It should be noted that providing the program to the computer may also be done without using the external storage device 226, but rather using communication means such as the Internet or dedicated lines.

[0065] (2) Substrate processing process

[0066] Next, we will mainly use Figure 3 The substrate processing step in one embodiment of the present invention will be described. Figure 3 This is a flowchart illustrating a substrate processing step according to one aspect of the present invention. As a step in the manufacturing process of semiconductor devices such as flash memory, the substrate processing step according to one aspect of the present invention is performed by the aforementioned substrate processing apparatus 100. In the following description, the operation of each component constituting the substrate processing apparatus 100 is controlled by a controller 221. Hereinafter, the case of using plasma processing, specifically the oxidation treatment of the silicon (Si) layer on the surface of the wafer 200, will be described as an example.

[0067] (Substrate transfer process S110)

[0068] First, the wafer 200 is moved into the processing chamber 201. Specifically, the support lifting mechanism 268 lowers the support 217 to the wafer 200 transport position, so that the through hole 217a of the support 217 is pushed through the wafer 266.

[0069] Then, gate valve 244 is opened, and wafer 200 is moved from a vacuum transfer chamber adjacent to processing chamber 201 into processing chamber 201 using a wafer transfer mechanism (not shown). The moved-in wafer 200 is supported horizontally on wafer pushers 266 protruding from the surface of substrate 217. Then, the wafer transfer mechanism retracts out of processing chamber 201, and gate valve 244 is closed to seal processing chamber 201. Then, substrate lifting mechanism 268 raises substrate 217, thereby supporting wafer 200 on the upper surface of substrate 217.

[0070] (Heating and vacuum degassing process S120)

[0071] Then, the wafer 200, which is brought into the processing chamber 201, is heated using heater 217b. In addition, during the heating of the wafer 200, vacuum pump 246 is used to vent the processing chamber 201 through gas exhaust pipe 231 to bring the pressure inside the processing chamber 201 to a specified value.

[0072] (Reaction gas supply process S130)

[0073] Next, oxygen-containing gas and hydrogen-containing gas are supplied as reaction gases. Specifically, valves 253a and 253b are opened, and oxygen-containing gas and hydrogen-containing gas are supplied into the processing chamber 201 while the flow is controlled by MFCs 252a and 252b.

[0074] Furthermore, the opening of APC valve 242 is adjusted to control the venting within processing chamber 201 by adjusting the pressure within the processing chamber 201 to a predetermined pressure within, for example, the range of 1 to 250 Pa. Thus, while appropriately venting the processing chamber 201, oxygen-containing gas and hydrogen-containing gas are continuously supplied until the plasma processing step S140 described later is completed. It should be noted that the numerical range "1 to 250 Pa" in this specification refers to the inclusion of both the lower and upper limits within that range. Therefore, for example, "1 to 250 Pa" means "more than 1 Pa and less than 250 Pa". Other numerical ranges are similar.

[0075] As an oxygen-containing gas, it is possible to use, for example, oxygen (O2), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), ozone (O3), water vapor (H2O), carbon monoxide (CO), carbon dioxide (CO2), etc. It is also possible to use one or more of these as an oxygen-containing gas.

[0076] In addition, hydrogen (H2), deuterium (D2), H2O, and ammonia (NH3) can be used as hydrogen-containing gases. One or more of these can be used. It should be noted that when using H2O as the oxygen-containing gas, it is preferable to use a gas other than H2O as the hydrogen-containing gas; conversely, when using H2O as the hydrogen-containing gas, it is preferable to use a gas other than H2O as the oxygen-containing gas.

[0077] As a nitrogen-containing gas, nitrogen (N2) gas, a mixture of N2 and H2 gas, ammonia (NH3) gas, NH2 gas, etc. can be used. One or more of these can be used as a nitrogen-containing gas.

[0078] (Plasma treatment process S140)

[0079] After the pressure inside the processing chamber 201 stabilizes, high-frequency power is applied to the resonant coil 212 from the high-frequency power supply 273 via the RF sensor 272.

[0080] Thus, a high-frequency electromagnetic field is formed within the plasma generation space supplying oxygen-containing and hydrogen-containing gases. Through this electromagnetic field, a ring-shaped ICP with the highest plasma density is excited at height positions corresponding to the electrical midpoint of resonant coil 212 and near the upper and lower ends of resonant coil 212. The plasma-like oxygen-containing and hydrogen-containing gases dissociate, generating reactive species such as oxygen-containing reactive species (oxidized species) and hydrogen-containing reactive species (hydrogen species).

[0081] The reactive species such as oxides and hydrogens generated by plasma excitation are uniformly supplied to the wafer 200. The reactive species supplied to the wafer 200 react within the processing container 203, modifying the surface layer (e.g., Si layer) into an oxide layer (e.g., Si oxide layer).

[0082] Then, after the prescribed processing time, the power output from the high-frequency power supply 273 is stopped, thereby stopping the plasma discharge in the processing chamber 201. Additionally, valves 253a and 253b are closed, thereby stopping the supply of oxygen-containing gas and hydrogen-containing gas to the processing chamber 201. At this point, the plasma processing step S140 is complete.

[0083] (Vacuum exhaust process S150)

[0084] After the supply of oxygen-containing gas and hydrogen-containing gas is stopped, vacuum exhaust is performed on the processing chamber 201 through the gas exhaust pipe 231.

[0085] (Substrate removal process S160)

[0086] Once the pressure inside the processing chamber 201 reaches the specified level, the support 217 is lowered to the wafer 200 transport position, supporting the wafer 200 on the wafer pusher 266. Then, the gate valve 244 is opened, and the wafer transport mechanism is used to move the wafer 200 out of the processing chamber 201.

[0087] This concludes one aspect of the substrate processing steps involved in the present invention.

[0088] Here, in the aforementioned plasma processing step (S140), when the electrical length of the resonant coil 212 is equivalent to one wavelength of the high-frequency power supplied from the high-frequency power source 273, a standing wave of current and voltage with a length equal to one wavelength of the supplied high-frequency power is formed on the circuit of the resonant coil 212. Figure 4 In the waveform on the right, the dashed line represents current and the solid line represents voltage. For example... Figure 4As shown in the waveform on the right, the amplitude of the current standing wave is maximum at the two ends (lower and upper ends) and the midpoint of the resonant coil 212, and minimum in between. The amplitude of the voltage standing wave is minimum at the two ends (lower and upper ends) and the midpoint of the resonant coil 212, and maximum in between.

[0089] A high-frequency magnetic field is formed near the location where the current amplitude is at its maximum. The high-frequency electric field induced by this magnetic field causes a discharge in the processing gas supplied to the processing chamber 201. Accompanying this discharge, the processing gas is excited, thereby generating a plasma of the processing gas. Hereinafter, the plasma of the processing gas generated by such a high-frequency magnetic field near a location (region) with a large current amplitude will be referred to as ICP (Inductively Coupled Plasma) plasma. Figure 4 As shown in the left figure, ICP plasma is generated in a concentrated, ring-shaped region (referred to as the ICP region) near the two ends and midpoint of the resonant coil 212 in the space along the inner wall surface 203b of the processing container 203. Then, through multiple substrate processing steps, a film 300 is formed on the inner wall surface of the processing container 203 as a deposited film, i.e., as shown in the figure on the left. Figure 5 As shown, in the region near the two ends and center of the resonant coil 212, and in the region of plasma that forms the ICP component, sublimation of the wafer 200 is deposited in a convex shape to form a film 300 as a deposition film. Here, film 300 is the main component of wafer 200. For example, for a Si (silicon) film, if the substrate processing in the substrate processing step is an oxidation process, film 300 is a Si oxide film; if the substrate processing in the substrate processing step is a nitriding process, film 300 is a Si nitriding film.

[0090] In contrast, such as Figure 4 As shown in the waveform on the right, the amplitude of the voltage standing wave is smallest at both ends (lower and upper ends) and the midpoint of the resonant coil 212, and largest in the area between them.

[0091] It should be noted that, Figure 4 The waveform on the left represents the intensity of the high-frequency electric field formed according to the voltage amplitude of the resonant coil 212. A high-frequency electric field with exceptionally high intensity is formed near the location where the voltage amplitude is maximum, causing the processing gas supplied to the processing chamber 201 to discharge. Accompanying this discharge, the processing gas is excited, thereby generating a plasma of the processing gas.

[0092] Hereinafter, the plasma of the processing gas generated by such a high-frequency electric field near a location (region) with a large voltage amplitude will be referred to as CCP (Capacitively Coupled Plasma) plasma. For example... Figure 4 As shown in the figure on the left, the plasma of CCP composition is generated in a ring-shaped and concentrated manner in the region between the upper end and the midpoint of the resonant coil 212 and the region between the lower end and the midpoint (together referred to as the CCP region) in the space along the inner wall surface 203b of the processing container 203.

[0093] Here, reactive species such as oxides and nitrides, as well as electrons (charges), are generated by plasma containing CCP components. These generated electrons are attracted to the inner wall surface 203b of the processing container 203 by the electric field of the plasma containing CCP components, thereby filling the inner wall surface 203b of the processing container 203 with electrons (charges). As a result, the reactive species generated by exciting the plasma containing CCP components are accelerated and impacted towards the inner wall surface 203b filled with electrons (charges). Consequently, the film 300 formed on the inner wall surface 203b of the processing container 203 and / or the surface of the inner wall surface 203b are sputtered and etched, releasing and diffusing the components of the material constituting the processing container 203 into the processing chamber 201. In this embodiment, by sputtering and etching the film 300 formed on the inner wall surface 203b, components such as silicon (Si) and oxygen (O) constituting quartz are released and diffused into the processing chamber 201. Therefore, the film 300 not only contains the sublimation of the wafer 200, but also contains silicon (Si) and oxygen (O) constituting quartz that are released and diffused into the processing chamber 201 by etching of the inner wall surface 203b of the processing container 203 through sputtering or the like. That is, the convex film 300 formed in the ICP region is a nitride film or an oxide film formed by nitriding or oxidation treatment, but the film contains components released by sputtering and etching in the CCP region.

[0094] There is a possibility that released or diffused components such as Si and O may enter the oxide film or other films formed by plasma processing on the wafer 200 as impurities, thereby degrading the film properties. Furthermore, since the inner wall surface 203b of the processing container 203 is sputtered and etched, particles may be generated in the processing chamber 201. These particles may adhere to the film surface on the wafer 200, causing effects such as reduced equipment performance and yield.

[0095] In this invention, the cleaning process described later is performed after the substrate processing process described above, so that the deposited film deposited in the processing container 203 can be easily removed.

[0096] (3) Cleaning process

[0097] use Figure 6 , Figure 7(A) Figure 7 Section (C) describes a process (cleaning process) that modifies the film 300 formed and deposited within the processing container 203 during the substrate processing process. In one aspect of the invention, the cleaning process is performed as a step in the manufacturing process of a semiconductor device (equipment), and is carried out by the substrate processing apparatus 100 in the same manner as the substrate processing process described above.

[0098] This process is performed when the wafer 200 is not housed within the processing chamber 201. This prevents substances from the wafer 200 from re-adhering to the inner wall surface 203b of the processing container 203 during this process. Figure 7 As shown in (A), a film 300, which serves as a deposition film, is formed on the inner wall surface 203b of the processing container 203. Here, the film 300 is a Si (silicon) film, which is a sublimation of the wafer 200, or a SiO (silicon oxide) film, which serves as an oxide film.

[0099] (Heating and vacuum degassing process S210)

[0100] First, with the wafer 200 not housed in the processing chamber 201, the gate valve 244 is closed and the processing chamber 201 is sealed, and the temperature inside the processing chamber 201 is increased. For example, the temperature of the inner wall surface 203b of the processing container 203 is increased to approximately 200°C. Furthermore, during the temperature increase in the processing chamber 201, a vacuum pump 246 is used to evacuate the processing chamber 201 via a gas exhaust pipe 231, bringing the pressure inside the processing chamber 201 to a predetermined value. The vacuum pump 246 operates until the cleaning process is completed. It should be noted that, at this time, it is preferable to maintain a temperature higher than the temperature of the inner wall surface 203b of the processing container 203 in the plasma processing step (S140) of the substrate processing step described above. By increasing the temperature in this process, the temperature difference with the temperature in the subsequent cooling process increases, resulting in greater stress generated by cooling, thereby promoting the peeling of the film 300.

[0101] (Plasma oxidation treatment process S220)

[0102] [Oxygen-containing gas supply]

[0103] Next, the supply of oxygen-containing gas is initiated. Specifically, valve 253a is opened, and oxygen-containing gas is supplied to the processing chamber 201 while the flow rate is controlled by MFC 252a. At this time, the flow rate of the oxygen-containing gas is set to a predetermined value within, for example, the range of 200 to 2000 sccm.

[0104] In addition, the pressure inside the processing chamber 201 is a specified pressure in the range of, for example, 50 to 200 Pa, and preferably the opening of the APC valve 242 is adjusted to be 50 to 100 Pa to control the exhaust in the processing chamber 201.

[0105] As an oxygen-containing gas, it is possible to use, for example, O2 gas, N2O gas, NO gas, NO2 gas, O3 gas, H2O gas, CO gas, CO2 gas, hydrogen peroxide (H2O2) gas, and a mixture of O2 gas and H2 gas. As an oxygen-containing gas, it is possible to use one or more of them.

[0106] When using a mixture of O2 and H2 gases as the oxygen-containing gas, the oxidation rate in each cycle can be controlled by adjusting the hydrogen ratio in the mixture. For example, the oxidation rate can be reduced by increasing the hydrogen ratio in the mixture to be more than 5% outside the range where the oxidation rate increases.

[0107] [Plasma Processing]

[0108] After the pressure inside the processing chamber 201 stabilizes, a predetermined power, such as high-frequency power, within the range of 500 to 3500 W is applied to the resonant coil 212 from the high-frequency power supply 273 via the RF sensor 272. The oxygen-containing gas supplied to the processing chamber 201 is excited by plasma, causing the film 300 to oxidize. Preferably, the power of the electromagnetic field applied for plasma excitation of the oxygen-containing gas is lower than the power of the electromagnetic field applied for plasma excitation of the oxygen-containing gas in the plasma processing step (S140) of the substrate processing step described above. That is, the plasma oxidation power during the substrate processing step is greater than the plasma oxidation power during the cleaning step. As a result, the oxidation force on the film 300 is suppressed, and in subsequent cycles, the nitride layer formed on the surface of the film 300 is not completely oxidized, making it easier to form a film containing both a nitride layer and an oxide layer.

[0109] It should be noted that the pressure inside the processing chamber 201 in this process can also be greater than the pressure inside the processing chamber 201 during the plasma processing process (S140). That is, the plasma oxidation processing pressure during the substrate processing process is less than the plasma oxidation processing pressure during the cleaning process. Under this condition, the oxidation force on the film 300 is also suppressed, and in subsequent cycles, the nitride layer formed on the surface of the film 300 will not be completely oxidized, thereby facilitating the formation of the oxide layer and the nitride layer. It should be noted that the processing pressure refers to the pressure inside the processing chamber 201. The same applies in the following description.

[0110] Alternatively, the execution time in this step can be shorter than that in the plasma treatment step (S140). That is, the plasma oxidation treatment time in the substrate treatment step can be greater than the plasma oxidation treatment time in the cleaning step. Using this condition, the oxidation force on the film 300 is also suppressed, and in subsequent cycles, the nitride layer formed on the surface of the film 300 will not be completely oxidized, thereby facilitating the formation of the oxide and nitride layers. The execution time in this step is preferably set to, for example, 2 minutes or less.

[0111] Thus, a high-frequency electromagnetic field is formed within the plasma generation space supplying oxygen-containing gas. Through this electromagnetic field, a ring-shaped ICP with the highest plasma density is excited at heights corresponding to the electrical midpoint of the resonant coil 212 within the plasma generation space, and at heights near the upper and lower ends of the resonant coil 212. The plasma-like oxygen-containing gas dissociates, generating reactive species such as oxygen-containing oxides. In other words, a ring-shaped ICP is formed at heights corresponding to the electrical midpoint of the resonant coil 212 and at heights near the upper and lower ends of the resonant coil 212, and at positions substantially equal to those within the processing chamber 201 where the oxygen-containing plasma is excited in the aforementioned plasma processing step (S140). Therefore, in the cleaning process, by generating plasma at the same positions as the ICP regions locally formed on the inner wall surface 203b within the processing container 203 during the substrate processing step, concentrated oxidation treatment can be performed on the convex portions of the locally convex film 300, and film stress is generated on the convex portions, making peeling from the inner wall surface 203b and the like easier.

[0112] The oxide seed supplied to the processing chamber 201 reacts with the membrane 300, modifying the surface layer of the membrane 300 into an oxide layer. For example, the surface of a Si-containing membrane formed on the inner wall 203b is oxidized and modified into a Si-containing oxide layer.

[0113] (Plasma nitriding treatment process S230)

[0114] [Nitrogen gas supply]

[0115] Next, the supply of nitrogen-containing gas is initiated. Specifically, valve 253c is opened, and nitrogen-containing gas is supplied to the processing chamber 201 while the flow rate is controlled by MFC 252c. At this time, the flow rate of the nitrogen-containing gas is set to a specified value within, for example, the range of 100 to 1000 sccm.

[0116] Furthermore, the pressure inside the processing chamber 201 is lower than the pressure in the plasma oxidation treatment step (S220) described above, for example, a specified pressure within the range of 5 to 20 Pa. Preferably, the opening of the APC valve 242 is adjusted to achieve 5 Pa, and the exhaust gas inside the processing chamber 201 is controlled. That is, the pressure inside the processing chamber 201 in this step is lower than the pressure inside the processing chamber 201 in the plasma oxidation treatment step (S220) described above. In other words, in the cleaning step, the plasma oxidation treatment pressure is greater than the plasma nitriding treatment pressure. This pressure difference weakens the oxidation conditions of the plasma oxidation treatment and strengthens the plasma nitriding treatment conditions. As a result, it is possible to prevent the nitrided layer formed by the plasma nitriding treatment from being completely oxidized by the plasma oxidation treatment. Therefore, it is easier to form the stacking of the oxide layer and the nitrided layer.

[0117] As a nitrogen-containing gas, nitrogen (N2) gas, a mixture of N2 and H2 gas, ammonia (NH3) gas, NH2 gas, etc. can be used. One or more of these can be used as a nitrogen-containing gas.

[0118] As a nitrogen-containing gas, when using a mixture of N2 and H2 gases, the oxidation rate in each cycle can be controlled by adjusting the ratio of hydrogen in the mixture.

[0119] [Plasma Processing]

[0120] After the pressure inside the processing chamber 201 stabilizes, a predetermined power, for example, within the range of 500 to 2000 W, is applied to the resonant coil 212 from the high-frequency power supply 273 via the RF sensor 272. The nitrogen-containing gas supplied to the processing chamber 201 is excited by plasma, causing the membrane 300 to nitride. The power of the electromagnetic field applied to excite the nitrogen-containing gas in this process is equal to or greater than the power of the electromagnetic field applied to excite the oxygen-containing gas in the plasma oxidation process (S220). That is, in the cleaning process, the plasma oxidation power is less than or equal to the plasma nitride power. This power condition weakens the oxidation conditions of the plasma oxidation process and strengthens the plasma nitride conditions. This method also prevents the nitride layer formed by the plasma nitride process from being completely oxidized by the plasma oxidation process. Therefore, it facilitates the formation of the oxide layer and the nitride layer.

[0121] The execution time in this step is, for example, about 2 minutes, which is preferably longer than the execution time in the plasma oxidation treatment step (S220) described above. That is, in the cleaning step, the plasma oxidation treatment time is less than or equal to the plasma nitriding treatment time. This time condition allows the oxidation conditions of the plasma oxidation treatment to be weakened and the plasma nitriding treatment conditions to be strengthened. This method also prevents the nitriding layer formed by the plasma nitriding treatment from being completely oxidized by the plasma oxidation treatment. Therefore, it makes it easier to form the stacking of the oxide layer and the nitriding layer.

[0122] At this time, similar to the plasma oxidation process S220 using oxygen-containing gas in the cleaning process, in the cleaning process, plasma containing nitrogen-containing reactive species is generated at the same position as the ICP region locally formed in the inner wall surface 203b of the processing container 203 by the substrate processing process. As a result, the convex portion of the locally formed convex film 300 can be nitrided in a concentrated manner.

[0123] The nitriding seed supplied to the processing chamber 201 reacts with the membrane 300 to modify the surface layer of the membrane 300 (e.g., a Si oxide layer) into a nitriding layer (e.g., a Si nitriding layer). For example, the surface of a Si oxide layer formed on the inner wall surface 203b, etc., is nitrided to modify it into a Si nitriding layer.

[0124] (S240 is implemented a specified number of times)

[0125] The plasma oxidation treatment step S220 and the plasma nitriding treatment step S230 are performed a predetermined number of times (multiple times). Thus, as... Figure 7 As shown in (B), the film 300 formed on the inner wall surface 203b of the processing container 203 during the substrate processing process is modified into a film 400 containing an oxide layer and a nitride layer.

[0126] (Cooling process S250)

[0127] Next, the temperature inside the processing chamber 201, i.e. the temperature of the inner wall surface 203b of the processing container 203, is reduced from the temperature of the inner wall surface 203b of the processing container 203 in the plasma oxidation treatment process (S220) and the plasma nitriding treatment process (S230) to, for example, room temperature, i.e., about 25°C.

[0128] Here, the oxide layer and the nitride layer have different coefficients of thermal expansion as the volume increases with temperature. The oxide layer has a larger coefficient of thermal expansion than the nitride layer, and when cooled from a high-temperature environment to, for example, room temperature, the oxide layer shrinks more than the nitride layer. Therefore, by modifying the film 300 into a film 400 containing a Si-containing oxide layer and a Si-containing nitride layer with different coefficients of thermal expansion, interlayer (interface) stress due to the difference in thermal expansion coefficients can be generated inside the film 400 during the cooling process (S250). As a result, the film 400 deposited in the processing container 203 can be made into an unstable state with high internal stress, and can be made into a state that is easy to peel off. Therefore, the deposited film can be removed efficiently. It should be noted that the greater the temperature difference with the plasma oxidation treatment process and the plasma nitride treatment process, the greater the stress applied to the film 400, and the more it can promote the peeling of the film 400.

[0129] Next, as Figure 7 As shown in (C), the film 400, which includes the oxide layer and the nitride layer, is peeled off from the inner wall of the processing container 203. Specifically, the inner wall surface 203b of the processing container 203 is wiped, that is, the film 400 is removed from the inner wall surface 203b by wiping. Thus, it becomes easy to remove the film 400, which includes the oxide layer and the nitride layer, formed on the inner wall surface 203b of the processing container 203 (e.g., by wiping). Wiping can be performed periodically, such as once every few weeks or after a predetermined number of substrate treatments, or at the time when foreign matter such as particles appears.

[0130] That is, through the cooling process S250, stress is generated at the interlayer (interface) within the membrane 400, making it easy to peel off. Therefore, the membrane 400 can be easily removed (peeled off). In this way, by improving removal efficiency, the risk of metal contamination accompanying the removal can be reduced, and the utilization rate of the equipment can be increased.

[0131] It should be noted that, not limited to wiping the inner wall surface 203b to remove the membrane 400, methods other than wiping with etching gases, cleaning gases, or similar gases can be used to modify the membrane 400 into an easily peelable membrane 400, thus making it easier to remove (peel off) the membrane 400 from the inner wall surface 203b. Therefore, by improving removal efficiency, the risk of metal contamination accompanying the removal can be reduced, and the utilization rate of the equipment can be increased.

[0132] (4) Variations

[0133] The cleaning process in the above embodiments can be modified in the manner shown in the following variations. Unless otherwise specified, the configuration in each variation is the same as that in the above embodiments, and the description is omitted.

[0134] (Variation Example 1)

[0135] In Modification 1, during the cleaning process described above, when performing the predetermined number of times (S240), the power of the electromagnetic field applied for plasma excitation of oxygen-containing gas in the first cycle, i.e., the nth plasma oxidation treatment process (S220), is greater than the power of the electromagnetic field applied for plasma excitation of oxygen-containing gas in the second cycle, i.e., the (n+1)th cycle, which is performed after the first cycle. That is, the plasma oxidation power of the nth layer > the plasma oxidation power of the (n+1)th layer. At this time, the processing conditions in the plasma nitriding treatment process (S230) of the nth cycle are made the same as the processing conditions in the plasma nitriding treatment process (S230) of the (n+1)th cycle.

[0136] In this case, the pressure in the treatment chamber 201 of the plasma oxidation treatment process (S220) in the nth cycle can also be made smaller than the pressure in the treatment chamber 201 of the plasma oxidation treatment process (S220) in the (n+1)th cycle. That is, the oxidation treatment pressure of the nth layer can also be set to be less than the oxidation treatment pressure of the (n+1)th layer.

[0137] Alternatively, the execution time of the plasma oxidation process (S220) in the nth cycle can be made longer than the execution time of the plasma oxidation process (S220) in the (n+1)th cycle. That is, the oxidation time of the nth layer can be set to be greater than the oxidation time of the (n+1)th layer.

[0138] Therefore, compared with the oxidizing force when forming the nth oxide layer, the oxidizing force when forming the (n+1)th oxide layer can be suppressed (weakened). As a result, the nitride layer formed in the plasma nitriding process (S230) will not be completely oxidized, making it easier to form a film 400 containing both an oxide layer and a nitride layer, and enabling the film 400 to be easily removed (peeled) from the inner wall surface 203b.

[0139] Furthermore, when using a mixture of O2 and H2 gases as the oxygen-containing gas, the ratio of hydrogen in the oxygen-containing gas supplied to the processing chamber 201 in the plasma oxidation treatment step (S220) of the nth cycle can be different from the ratio of hydrogen in the oxygen-containing gas supplied to the processing chamber 201 in the plasma oxidation treatment step (S220) of the n+1th cycle. This allows for adjustment of the oxidizing power.

[0140] <Other methods>

[0141] Various typical embodiments and modifications of the present invention have been described above, but the present invention is not limited to these embodiments and modifications, and can also be used in appropriate combinations.

[0142] For example, in the above embodiments, it was described that after plasma oxidation treatment in the substrate processing step, the oxide film formed on the inner wall surface 203b is modified and removed from the inner wall surface 203b, etc. However, the present invention is not limited to this. In the substrate processing step, after plasma nitriding treatment, the nitride film formed on the inner wall surface 203b is modified and removed from the inner wall surface 203b, etc. The technology of the present invention can also be applied.

[0143] In this case, during the cleaning process, the power of the electromagnetic field applied for plasma excitation of nitrogen-containing gas in the plasma nitriding process (S230) is greater than the power of the electromagnetic field applied for plasma excitation of nitrogen-containing gas in the substrate treatment process, thereby strengthening the nitriding force on the deposited film. That is, the plasma nitriding power during the substrate treatment process is less than the plasma nitriding power during the cleaning process. As a result, it becomes easier to form the stack of oxide and nitrided layers.

[0144] It should be noted that the pressure in the treatment chamber 201 during the plasma nitriding process (S230) can also be lower than the pressure in the treatment chamber 201 during the plasma nitriding process in the substrate treatment process, thereby increasing the nitriding force on the deposited film. That is, the plasma nitriding pressure during the substrate treatment process can also be greater than the plasma nitriding pressure during the cleaning process.

[0145] Alternatively, the execution time of the plasma nitriding process (S230) can be longer than the execution time of the plasma nitriding process in the substrate processing process, thereby increasing the nitriding force on the deposited film. That is, the plasma nitriding time in the substrate processing process can also be less than the plasma nitriding time in the cleaning process.

[0146] Furthermore, the above embodiment describes a case where the deposited film formed in the processing container 203 before the cleaning process is a Si-containing film. However, the present invention is not limited to this. The technology of the present invention can be applied to any film composed of elements sublimated from the surface of the wafer 200 by substrate processing (plasma processing) of the wafer 200, and to any film with different thermal expansion rates between these oxide layers and nitride layers. Specifically, the deposited film may also be a film containing the following elements: metallic elements such as aluminum (Al), titanium (Ti), hafnium (Hf), tungsten (W), molybdenum (Mo), copper (Cu), sodium (Na), and potassium (K) sublimated from the surface of the wafer 200, and elements such as carbon (C), boron (B), phosphorus (P), and arsenic (As).

[0147] Furthermore, the above embodiment describes the cleaning process when the wafer 200 is not housed in the processing container 203, but the present invention is not limited thereto, and the cleaning process can also be performed when the wafer 200 is housed in the processing container 203.

[0148] It should be noted that the present invention has been described in detail with reference to specific embodiments and modifications, but the present invention is not limited to these embodiments and modifications. Those skilled in the art can adopt various other embodiments within the scope of the present invention.

Claims

1. A cleaning method comprising a step of modifying a deposited film into a film containing an oxide layer and a nitride layer by performing a predetermined number of cycles including the following steps: (a) The step of supplying oxygen-containing gas into a reaction vessel on which a deposited film has been formed on its inner surface, and plasma-exciting the oxygen-containing gas to oxidize the deposited film; and (b) The process of supplying nitrogen-containing gas into the reaction vessel and subjecting the nitrogen-containing gas to plasma excitation, thereby nitriding the deposited film. The cleaning method further comprises: (c) cooling the temperature inside the reaction vessel from the temperature of the reaction vessel in (a) and (b) to modify it into a film containing the oxide layer and the nitride layer with different thermal expansion coefficients, and making the film in a peelable state.

2. The cleaning method as described in claim 1, further comprising the following steps: (d) The step of removing the film containing the oxide layer and the nitride layer from the inner wall of the reaction vessel after (c).

3. The cleaning method as described in claim 2, wherein, In (d), the cleaning method is performed by peeling a membrane containing the oxide layer and the nitride layer from the inner wall of the reaction vessel.

4. The cleaning method as described in claim 1, wherein, The deposited film is a Si-containing film, the oxide layer is a Si-containing oxide layer, and the nitride layer is a Si-containing nitride layer.

5. The cleaning method as described in claim 1, wherein, The deposited film is an oxide film.

6. The cleaning method as described in claim 1, wherein, The power of the electromagnetic field applied in (a) for plasma excitation of the oxygen-containing gas is smaller than the power of the electromagnetic field applied in (b) for plasma excitation of the nitrogen-containing gas.

7. The cleaning method as described in claim 1, wherein, The pressure inside the reaction vessel in (a) is greater than the pressure inside the reaction vessel in (b).

8. The cleaning method as described in claim 1, wherein, The execution time of (a) in each loop is shorter than the execution time of (b).

9. The cleaning method as described in claim 1, wherein, The cycle is executed multiple times, and the power of the electromagnetic field applied in (a) of the first cycle for plasma excitation of the oxygen-containing gas is greater than the power of the electromagnetic field applied in (a) of the second cycle executed after the first cycle for plasma excitation of the oxygen-containing gas.

10. The cleaning method as described in claim 1, wherein, The cycle is executed multiple times, and the pressure inside the reaction vessel in (a) of the first cycle is lower than the pressure inside the reaction vessel in (a) of the second cycle executed after the first cycle.

11. The cleaning method as described in claim 1, wherein, The loop is executed multiple times, and the execution time of (a) in the first loop is longer than the execution time of (a) in the second loop, which is executed after the first loop.

12. The cleaning method as described in claim 1, wherein, (a) and (b) are performed with the substrate not contained within the reaction vessel.

13. The cleaning method of claim 1, further comprising the step of performing the following steps prior to performing the cycle comprising (a) and (b): (e) The process of supplying the oxygen-containing gas into the reaction vessel into which the substrate has been placed, and plasma-exciting the oxygen-containing gas to oxidize the surface of the substrate; and (f) The process of removing the substrate from the reaction vessel after (e).

14. The cleaning method as described in claim 13, wherein, The power of the electromagnetic field applied in (a) for plasma excitation of the oxygen-containing gas is smaller than the power of the electromagnetic field applied in (e) for plasma excitation of the oxygen-containing gas.

15. The cleaning method as described in claim 13, wherein, The pressure inside the reaction vessel in (a) is greater than the pressure inside the reaction vessel in (e).

16. The cleaning method as described in claim 13, wherein, The execution time of (a) is shorter than that of (e).

17. A cleaning method, which has the following characteristics: The process of modifying a deposited film into a film containing an oxide layer and a nitride layer by performing the following steps a specified number of cycles: (a) The step of supplying plasma-excited oxygen-containing gas into a reaction vessel on which a deposited film has been formed on its inner surface, thereby oxidizing the deposited film; and (b) The process of supplying plasma-excited nitrogen-containing gas into the reaction vessel to nitrid the deposited film, and (c) A process of cooling the temperature inside the reaction vessel from the temperature of the reaction vessel in (a) and (b) to modify it into a film containing the oxide layer and the nitride layer with different thermal expansion coefficients and making the film peelable.

18. A method for manufacturing a semiconductor device, comprising a step of modifying a deposited film into a film containing an oxide layer and a nitride layer by performing a predetermined number of cycles including the following steps: (a) The step of supplying oxygen-containing gas into a reaction vessel on which a deposited film has been formed on its inner surface, and plasma-exciting the oxygen-containing gas to oxidize the deposited film; and (b) The process of supplying nitrogen-containing gas into the reaction vessel and subjecting the nitrogen-containing gas to plasma excitation, thereby nitriding the deposited film. The manufacturing method further comprises: (c) a step of cooling the temperature inside the reaction vessel from the temperature of the reaction vessel in (a) and (b) to modify it into a film containing the oxide layer and the nitride layer with different thermal expansion coefficients, and making the film in a peelable state. in, Before (a) and (b), the following steps are performed: (e) A process of supplying a processing gas into a reaction vessel containing a substrate and subjecting the processing gas to plasma excitation, thereby modifying the surface of the substrate; (d) The process of removing the substrate from the reaction vessel after (e).

19. A recording medium having a program that enables a substrate processing apparatus to perform the following steps using a computer: The steps of modifying a deposited film into a film comprising an oxide layer and a nitrided layer by performing cycles including (a) and (b) a predetermined number of times are as follows: (a) supplying an oxygen-containing gas into a reaction vessel on which the deposited film is formed on its inner surface and subjecting the oxygen-containing gas to plasma excitation, thereby oxidizing the deposited film; (b) supplying a nitrogen-containing gas into the reaction vessel and subjecting the nitrogen-containing gas to plasma excitation, thereby nitriding the deposited film; and, (c) The step of cooling the temperature inside the reaction vessel from the temperature of the reaction vessel in (a) and (b) to modify it into a film containing the oxide layer and the nitride layer with different thermal expansion coefficients and making the film in a peelable state.

20. A substrate processing apparatus, comprising: The reaction vessel from which the substrate is processed; An oxygen-containing gas supply system that supplies oxygen-containing gas into the reaction vessel; A nitrogen-containing gas supply system that supplies nitrogen-containing gas into the reaction vessel; The plasma generation unit is configured to separately excite the oxygen-containing gas and the nitrogen-containing gas with plasma; and The control unit is configured to control the oxygen-containing gas supply system, the nitrogen-containing gas supply system, and the plasma generation unit to perform the following: A process that modifies a deposited film into a film containing an oxide layer and a nitride layer by performing cycles including the following treatments a specified number of times: (a) A process of supplying oxygen-containing gas into the reaction vessel on which a deposited film has been formed on its inner surface, and subjecting the oxygen-containing gas to plasma excitation, thereby oxidizing the deposited film; and (b) Supplying the nitrogen-containing gas into the reaction vessel and subjecting the nitrogen-containing gas to plasma excitation, thereby nitriding the deposited film, and (c) A process of cooling the temperature inside the reaction vessel from the temperature of the reaction vessel in (a) and (b) to modify it into a film containing the oxide layer and the nitride layer with different thermal expansion coefficients and making the film peelable.

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