Processing method and processing apparatus

Abstract

To provide a processing method and a processing device, capable of removing a metal oxide film in a processing container with a dry process.SOLUTION: A method having a step of supplying a halogen containing gas into a processing container, and removing a metal oxide film in the processing container, contains: a precoat process step S10; a deposition step S20; a determination step S30; and a film removing step S40. The precoat process step S10, the deposition step S20, and the film removing step S40 are performed in the same processing container.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a processing method and a processing apparatus. [Background Art]

[0002] A technique is known that removes a metal oxide film adhering to a surface of an object to be cleaned by cleaning using a cleaning solution (see, for example, Patent Document 1). [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Laid-Open No. 2005-167087 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] The present disclosure provides a technique capable of removing a metal oxide film by a dry process. [Means for Solving the Problem]

[0005] A processing method according to one aspect of the present disclosure includes the step of supplying a halogen-containing gas into a processing container to remove a metal oxide film in the processing container The process includes supplying oxygen radicals into the processing container and removing metal halides generated in the process of removing the metal oxide film, and alternatingly repeating the process of removing the metal oxide film and the process of removing the metal halide. . [Effect of the Invention]

[0006] According to the present disclosure, a metal oxide film can be removed by a dry process. [Brief Description of the Drawings]

[0007] [Figure 1] It is a flowchart showing the processing method according to an embodiment. [Figure 2] It is a flowchart showing an example of a film removal step. [Figure 3] It is a longitudinal sectional view showing the processing apparatus according to an embodiment. [Figure 4] This is a cross-sectional view showing the processing apparatus according to the embodiment. [Figure 5] This figure shows the relationship between etching pressure and the amount of etching of the AlO film. [Modes for carrying out the invention]

[0008] Hereinafter, exemplary embodiments of the present disclosure, not limited to those described herein, will be described with reference to the attached drawings. In all attached drawings, identical or corresponding members or components are denoted by the same or corresponding reference numerals, and redundant descriptions are omitted.

[0009] [Processing method] The processing method according to the embodiment will be described with reference to Figures 1 and 2. Figure 1 is a flowchart of the processing method according to the embodiment. Figure 2 is a flowchart of an example of the film removal step S40.

[0010] As shown in Figure 1, the processing method according to the embodiment includes a pre-coating step S10, a film formation step S20, a determination step S30, and a film removal step S40. The pre-coating step S10, the film formation step S20, and the film removal step S40 are performed in the same processing container.

[0011] The pre-coating step S10 includes coating the inside of the processing container with a pre-coating film. The pre-coating step S10 is performed, for example, before a metal oxide film is formed inside the processing container. The pre-coating film is a film that has higher etching resistance to halogen-containing gases than the material constituting the processing container. Suitable materials for the pre-coating film include amorphous silicon (a-Si), silicon nitride (SiN), silicon carbonitride (SiCN), titanium nitride (TiN), and tungsten. The object to be coated with the pre-coating film (hereinafter also referred to as the "coated object") includes at least a component that will be etched by the halogen-containing gas supplied into the processing container in the film removal step S40, such as a component made of quartz. For example, if a processing container made of quartz is used, the coated object includes the inner wall of the processing container. For example, if a component made of quartz is used inside the processing container, the coated object includes the component made of quartz.

[0012] The pre-coating process S10 coats the surface of the quartz component with a pre-coating film. This prevents etching of the quartz component in the film removal process S40. As a result, the lifespan of the quartz component can be extended. The pre-coating process S10 may be omitted if the processing container does not contain any components to be etched by a halogen-containing gas, or if the inside of the processing container is already coated with a pre-coating film.

[0013] The film deposition process S20 is performed after the pre-coating process S10. The film deposition process S20 includes placing the substrate inside a processing container and depositing a metal oxide film on the substrate. In the film deposition process S20, a metal oxide film is deposited on the surface of the substrate, and a metal oxide film is also deposited inside the processing container. The metal oxide film may be a high-k film such as an aluminum oxide (AlO) film, a titanium oxide (TiO) film, or a hafnium oxide (HfO) film.

[0014] The determination step S30 is performed after the film deposition step S20. In the determination step S30, it is determined whether the film deposition step S20 has been performed the set number of times. If the number of times has not reached the set number (NO in the determination step S30), the film deposition step S20 is performed again. If the number of times has reached the set number (YES in the determination step S30), the film removal step S40 is performed. In this way, the film deposition step S20 is repeated until the number of times has reached the set number. The set number of times may be one or two or more. The set number of times is determined, for example, according to the thickness of the metal oxide film deposited inside the processing container in the film deposition step S20.

[0015] The film removal step S40 is performed after the determination step S30. As shown in Figure 2, the film removal step S40 includes a halogen-containing gas supply step S41, an oxygen radical supply step S42, and a determination step S43.

[0016] The halogen-containing gas supply step S41 comprises supplying a halogen-containing gas into a processing vessel to remove a metal oxide film inside the processing vessel. The metal oxide film includes a metal oxide film deposited inside the processing vessel in the film formation step S20. The halogen-containing gas may be hydrogen halide gas. Examples of the hydrogen halide gas include hydrogen fluoride (HF) gas, hydrogen chloride (HCl) gas, hydrogen bromide (HBr) gas, and hydrogen iodide (HI) gas. The halogen-containing gas may be halogen gas. Examples of the halogen gas include fluorine (F2) gas, chlorine (Cl2) gas, bromine (Br2) gas, and iodine (I2) gas. The halogen-containing gas may be a mixed gas of hydrogen halide gas and halogen gas.

[0017] Metal oxide films are easily etched by wet etching using dilute hydrofluoric acid (DHF). In contrast, in dry etching using a halogen-containing gas, particularly a highly reactive fluorine-containing gas, the halogen-containing gas reacts with the metal oxide film to produce metal fluoride. Since metal fluoride has a very high melting point, it is difficult to etch and remove it.

[0018] Therefore, in the halogen-containing gas supply step S41, the metal oxide film inside the processing vessel is removed by forming an environment in which a wet (liquid phase)-like reaction using the halogen-containing gas occurs inside the processing vessel. Specifically, an environment where a wet-like reaction occurs can be formed by maintaining the inside of the processing vessel at a temperature of not lower than room temperature and not higher than 40°C, and maintaining the inside of the processing vessel at a high pressure. Room temperature may be a temperature of not lower than 10°C and not higher than 30°C, for example 23°C. For example, when the metal oxide film is an AlO film and the halogen-containing gas is hydrogen fluoride gas, an environment where a wet-like reaction occurs can be formed by maintaining the inside of the processing vessel at a temperature of not lower than room temperature and not higher than 40°C, and maintaining the pressure inside the processing vessel at a high pressure of 100 Torr (13.3 kPa) or higher.

[0019] In the halogen-containing gas supply step S41, since the metal oxide film is not removed by a complete wet etching reaction, metal halides can be generated. In particular, if the halogen-containing gas supply step S41 is performed continuously, halogenation of the metal oxide film progresses from the surface to a deep position, which may cause stagnation of the etching of the metal oxide film. Therefore, it is preferable to perform the oxygen radical supply step S42 described below to remove the metal halides every time the halogen-containing gas supply step S41 is continuously performed for a predetermined period of time.

[0020] The oxygen radical supply step S42 includes supplying oxygen radicals into the processing container. The metal halides (for example, AlF) generated in the halogen-containing gas supply step S41 are converted into gases such as metal oxides (for example, AlO) and halogens (for example, F) by the oxygen radicals and discharged from the inside of the processing container. Thereby, the metal halides generated in the halogen-containing gas supply step S41 are removed. Oxygen radicals can be obtained, for example, by supplying an oxygen-containing gas into the processing container and generating plasma from the oxygen-containing gas. The oxygen-containing gas may be oxygen (O2) gas, ozone (O3) gas, water vapor (H2O), or a combination thereof. Hydrogen (H2) gas may be added to the oxygen-containing gas. Note that the oxygen radical supply step S42 may be omitted, for example, in cases where the etching rate of the metal oxide film does not decrease.

[0021] The determination step S43 is performed after the oxygen radical supply step S42. In the determination step S43, it is determined whether the halogen-containing gas supply step S41 and the oxygen radical supply step S42 have been performed the set number of times. If the number of times has not reached the set number (NO in the determination step S43), the halogen-containing gas supply step S41 and the oxygen radical supply step S42 are performed again. If the number of times has reached the set number (YES in the determination step S43), the film removal step S40 is terminated. In this way, the halogen-containing gas supply step S41 and the oxygen radical supply step S42 are repeated alternately until the number of times has reached the set number. In this case, the metal oxide film can be continuously etched without significantly reducing the etching rate. The set number of times may be one or two or more. The set number of times is determined, for example, according to the thickness of the metal oxide film deposited inside the processing container immediately before starting the film removal step S40.

[0022] As described above, according to the processing method of the embodiment, a halogen-containing gas is supplied into the processing container to remove the metal oxide film inside the processing container. In this case, the metal oxide film can be removed by a dry process. This reduces the downtime of the processing device that occurs in order to remove the metal oxide film inside the processing container. As a result, the operating rate of the processing device is improved.

[0023] In contrast, when removing the metal oxide film inside the processing container by wet etching using a cleaning solution, for example, the processing container is opened to the atmosphere, and the parts to be cleaned are removed from the processing device and washed. As a result, the downtime of the device caused by removing the metal oxide film inside the processing container becomes longer. Consequently, the operating rate of the processing device decreases.

[0024] [Processing device] Referring to Figures 3 and 4, the apparatus 100 according to the embodiment will be described. As shown in Figures 3 and 4, the apparatus 100 mainly comprises a processing container 1, a gas supply unit 20, a plasma generation unit 30, an exhaust unit 40, a heating unit 50, and a control unit 60.

[0025] The processing container 1 has a vertical, cylindrical shape with a top that is open at the bottom. The entire processing container 1 is made of, for example, quartz. A top plate 2 is provided near the top of the processing container 1, and the area below the top plate 2 is sealed. The top plate 2 is made of, for example, quartz. A cylindrical metal manifold 3 is connected to the opening at the bottom of the processing container 1 via a sealing member 4. The sealing member 4 may be, for example, an O-ring.

[0026] The manifold 3 supports the lower end of the processing container 1. The boat 5 is inserted into the processing container 1 from below the manifold 3. The boat 5 holds multiple substrates W (e.g., 25 to 150) in a substantially horizontal position with spacing along the vertical direction. The substrates W may be, for example, semiconductor wafers. The boat 5 is made of, for example, quartz. The boat 5 has, for example, three support columns 6, and the multiple substrates W are supported by grooves formed in the support columns 6.

[0027] Boat 5 is placed on a turntable 8 via an insulating tube 7. The insulating tube 7 is made of, for example, quartz. The insulating tube 7 suppresses heat dissipation from the opening at the lower end of the manifold 3. The turntable 8 is supported on a rotating shaft 10. The opening at the lower end of the manifold 3 is opened and closed by a cover 9. The cover 9 is made of, for example, a metal material such as stainless steel. The rotating shaft 10 passes through the cover 9.

[0028] A magnetic fluid seal 11 is provided at the penetration portion of the rotating shaft 10. The magnetic fluid seal 11 hermetically seals the rotating shaft 10 and supports it so that it can rotate. A sealing member 12 is provided between the periphery of the lid 9 and the lower end of the manifold 3 to maintain airtightness inside the processing container 1. The sealing member 12 may be, for example, an O-ring.

[0029] The rotating shaft 10 is attached to the tip of an arm 13 supported by a lifting mechanism such as a boat elevator. As the arm 13 moves up and down, the boat 5, the insulation cylinder 7, the turntable 8, and the lid 9 move up and down together with the rotating shaft 10, and are inserted into and removed from the processing container 1.

[0030] The gas supply unit 20 supplies various gases into the processing container 1. The gas supply unit 20 has, for example, four gas nozzles 21 to 24. The gas supply unit 20 may also have, for example, another gas nozzle in addition to the four gas nozzles 21 to 24.

[0031] The gas nozzle 21 is made of, for example, quartz and has an L-shape that penetrates the side wall of the manifold 3 inward, is bent upward, and extends vertically. The vertical portion of the gas nozzle 21 is located outside the plasma generation space P, for example, on the side of the plasma generation space P that is closer to the center C of the processing vessel 1 within the processing vessel 1. The vertical portion of the gas nozzle 21 may also be located on the side of the exhaust port 41 that is closer to the center C of the processing vessel 1 within the processing vessel 1. The gas nozzle 21 is connected to one or more processing gas sources. The processing gas may include various gases used in the pre-coat process S10, the film deposition process S20, and the film removal process S40. For example, the processing gas may include a silicon-containing gas and a metal-containing gas. Multiple gas holes 21a are formed at intervals in the vertical portion of the gas nozzle 21 over a length in the vertical direction corresponding to the substrate support range of the boat 5. The gas vent 21a is oriented, for example, towards the center C of the processing container 1, and discharges the processing gas horizontally toward the center C of the processing container 1. The gas vent 21a may be oriented, for example, toward the plasma generation space P, or toward the inner wall near the processing container 1.

[0032] The gas nozzle 22 is made of, for example, quartz and has an L-shape that penetrates the side wall of the manifold 3 inward, is bent upward, and extends vertically. The vertical portion of the gas nozzle 22 is located outside the plasma generation space P, for example, on the side of the plasma generation space P that is closer to the center C of the processing container 1 within the processing container 1. The vertical portion of the gas nozzle 22 may also be located on the side of the exhaust port 41 that is closer to the center C of the processing container 1 within the processing container 1. The gas nozzle 22 is connected to one or more processing gas sources. The processing gas may include various gases used in the pre-coat process S10, the film formation process S20, and the film removal process S40. For example, the processing gas may include a halogen-containing gas. Multiple gas holes 22a are formed at intervals in the vertical portion of the gas nozzle 22 along the vertical length corresponding to the substrate support range of the boat 5. The gas holes 22a are oriented, for example, toward the center C of the processing container 1 and discharge the processing gas horizontally toward the center C of the processing container 1. The gas pore 22a may be oriented, for example, toward the plasma generation space P, or toward the inner wall near the processing vessel 1.

[0033] The gas nozzle 23 is made of, for example, quartz and has an L-shape that penetrates the side wall of the manifold 3 inward, is bent upward, and extends vertically. The vertical portion of the gas nozzle 23 is provided in the plasma generation space P. The gas nozzle 23 is connected to one or more processing gas supply sources. The processing gas may include various gases used in the pre-coat process S10, the film deposition process S20, and the film removal process S40. For example, the processing gas may include an oxygen-containing gas. Multiple gas holes 23a are formed at intervals in the vertical portion of the gas nozzle 23 along the vertical length corresponding to the substrate support range of the boat 5. The gas holes 23a are oriented, for example, toward the center C of the processing container 1 and discharge the processing gas horizontally toward the center C of the processing container 1.

[0034] The gas nozzle 24 is made of, for example, quartz and has a straight pipe shape that extends horizontally through the side wall of the manifold 3. The tip of the gas nozzle 24 is located outside the plasma generation space P, for example, inside the processing container 1. The gas nozzle 24 is connected to a purge gas supply source. The tip of the gas nozzle 24 is open, and the purge gas is supplied into the processing container 1 from the opening. Examples of purge gases include inert gases such as argon (Ar) gas and nitrogen (N2) gas.

[0035] The plasma generation unit 30 is provided in a part of the side wall of the processing vessel 1. The plasma generation unit 30 generates plasma from the processing gas supplied from the gas nozzle 23. The plasma generation unit 30 includes a plasma compartment wall 32, a pair of plasma electrodes 33, a power supply line 34, an RF power supply 35, and an insulating protective cover 36.

[0036] The plasma compartment wall 32 is airtightly welded to the outer wall of the processing vessel 1. The plasma compartment wall 32 is made of, for example, quartz. The plasma compartment wall 32 has a concave cross-section and covers the opening 31 formed in the side wall of the processing vessel 1. The opening 31 is formed to be elongated in the vertical direction so as to cover all the substrates W supported by the boat 5 in the vertical direction. Gas nozzles 23 are arranged in the plasma generation space P, which is an inner space defined by the plasma compartment wall 32 and in communication with the inside of the processing vessel 1. Gas nozzles 21 and 22 are provided at positions close to the substrates W along the inner wall of the processing vessel 1 outside the plasma generation space P.

[0037] A pair of plasma electrodes 33 each have an elongated shape and are arranged facing each other vertically on the outer surfaces of the walls on both sides of the plasma compartment wall 32. A power supply line 34 is connected to the lower end of each plasma electrode 33.

[0038] The power supply line 34 electrically connects each plasma electrode 33 to the RF power supply 35. For example, one end of the power supply line 34 is connected to the lower end, which is the side of the short edge of each plasma electrode 33, and the other end is connected to the RF power supply 35.

[0039] The RF power supply 35 is electrically connected to the lower end of each plasma electrode 33 via a power supply line 34. The RF power supply 35 supplies RF power of, for example, 13.56 MHz to a pair of plasma electrodes 33. This applies RF power to the plasma generation space P defined by the plasma partition wall 32.

[0040] The insulating protective cover 36 is attached to the outside of the plasma compartment wall 32 so as to cover the plasma compartment wall 32. A refrigerant passage (not shown) is provided in the inner portion of the insulating protective cover 36. The plasma electrode 33 is cooled by flowing a refrigerant such as cooled nitrogen gas through the refrigerant passage. A shield (not shown) may be provided between the plasma electrode 33 and the insulating protective cover 36 so as to cover the plasma electrode 33. The shield is made of a good conductor such as metal and is electrically grounded.

[0041] The exhaust unit 40 is provided in an exhaust port 41 formed in the side wall portion of the processing container 1 facing the opening 31. The exhaust port 41 is formed to be long and narrow vertically, corresponding to the boat 5. A cover member 42, formed in a U-shape in cross-section, is attached to the portion of the processing container 1 corresponding to the exhaust port 41 so as to cover the exhaust port 41. The cover member 42 extends upward along the side wall of the processing container 1. An exhaust pipe 43 is connected to the lower part of the cover member 42. A pressure regulating valve 44 and a vacuum pump 45 are provided in the exhaust pipe 43 in order from the upstream side to the downstream side in the direction of gas flow. Based on the control of the control unit 60, the exhaust unit 40 operates the pressure regulating valve 44 and the vacuum pump 45, adjusting the pressure inside the processing container 1 by the pressure regulating valve 44 while drawing gas from inside the processing container 1 into the vacuum pump 45.

[0042] The heating section 50 includes a heater 51. The heater 51 has a cylindrical shape that surrounds the processing container 1 on its radially outer side. The heater 51 heats each substrate W housed inside the processing container 1 by heating the entire side circumference of the processing container 1.

[0043] The control unit 60 controls the operation of each part of the processing unit 100, for example. The control unit 60 may be, for example, a computer. The computer program that controls the operation of each part of the processing unit 100 is stored in a storage medium. The storage medium may be, for example, a flexible disk, a compact disk, a hard disk, a flash memory, a DVD, etc.

[0044] [Processing device operation] The operation when the processing method according to the embodiment is carried out in the processing apparatus 100 will be described below. In the following description, the case in which the precoat film is an a-Si film and the metal oxide film is an AlO film will be used as an example. The same may apply when the precoat film is a film other than an a-Si film and the metal oxide film is a film other than an AlO film.

[0045] First, the control unit 60 controls the operation of each part of the processing apparatus 100 to execute the pre-coating process S10. Specifically, the control unit 60 controls the lifting mechanism to load the empty boat 5, which does not hold the substrate W, into the processing container 1, and then seals the opening at the lower end of the processing container 1 airtight with the lid 9. Next, the control unit 60 controls the exhaust unit 40 to reduce the pressure inside the processing container 1 to a predetermined level, and controls the heating unit 50 to adjust and stabilize the temperature inside the processing container 1 to a predetermined level. Subsequently, the control unit 60 controls the gas supply unit 20 to supply silicon-containing gas into the processing container 1. As a result, the inside of the processing container is coated with an a-Si film. Next, the control unit 60 increases the pressure inside the processing container 1 to atmospheric pressure, cools the inside of the processing container 1 to the discharge temperature, and then controls the lifting mechanism to discharge the boat 5 from inside the processing container 1.

[0046] Next, the control unit 60 controls the operation of each part of the processing apparatus 100 to execute the film deposition process S20. Specifically, the control unit 60 controls the lifting mechanism to load the boat 5 holding the multiple substrates W into the processing container 1, and seals the opening at the lower end of the processing container 1 airtight with the lid 9. Subsequently, the control unit 60 controls the exhaust unit 40 to reduce the pressure inside the processing container 1 to a predetermined level, and controls the heating unit 50 to adjust and stabilize the temperature inside the processing container 1 to a predetermined level. Subsequently, the control unit 60 controls the gas supply unit 20 to supply Al-containing gas and oxygen-containing gas into the processing container 1. As a result, an AlO film is deposited on each substrate W. At this time, the control unit 60 may also control the plasma generation unit 30 to supply RF power from the RF power supply 35 to a pair of plasma electrodes 33 and generate plasma from the oxygen-containing gas supplied into the processing container 1. Next, the control unit 60 increases the pressure inside the processing container 1 to atmospheric pressure, then lowers the temperature inside the processing container 1 to the discharge temperature, and then controls the lifting mechanism to discharge the boat 5 from inside the processing container 1.

[0047] Next, the control unit 60 controls the operation of each part of the processing apparatus 100 so that the film deposition process S20 is repeated until the number of times the film deposition process S20 is performed reaches a set number (determination process S30).

[0048] After the number of times the film deposition process S20 has been performed reaches a set number, the control unit 60 controls the operation of each part of the processing apparatus 100 to execute the film removal process S40. Specifically, the control unit 60 controls the lifting mechanism to load an empty boat 5 that does not hold the substrate W into the processing container 1, and seals the opening at the lower end of the processing container 1 airtight with the lid 9. Next, the control unit 60 controls the exhaust unit 40 to reduce the pressure inside the processing container 1 to a predetermined level, and controls the heating unit 50 to adjust and stabilize the temperature inside the processing container 1 to a predetermined level. Subsequently, the control unit 60 controls the gas supply unit 20 to supply halogen-containing gas into the processing container 1. At this time, the control unit 60 controls the exhaust unit 40 to adjust the pressure inside the processing container 1, thereby creating an environment inside the processing container where a wet (liquid phase)-like reaction using halogen-containing gas occurs. As a result, the AlO film deposited on the inner wall of the processing container 1, the boat 5, etc. can be removed by repeatedly performing the film deposition process S20. Furthermore, since the AlO film is not removed by a complete wet etching reaction, AlF may be generated. In particular, if the halogen-containing gas is continuously supplied for a long time, halogenation of the AlO film progresses to a depth from the surface, and etching of the AlO film may stagnate. Therefore, the control unit 60 stops the supply of halogen-containing gas to the processing container 1 each time halogen-containing gas is supplied to the processing container 1 for a predetermined time. Subsequently, the control unit 60 controls the gas supply unit 20 to supply oxygen-containing gas to the processing container 1 and controls the plasma generation unit 30 to supply RF electrodes from the RF power supply 35 to the pair of plasma electrodes 33, thereby generating plasma from the oxygen-containing gas supplied to the processing container 1. As a result, AlF is converted into gases such as AlO and halogens (e.g., F) by oxygen radicals and discharged from inside the processing container. In this way, the control unit 60 controls the gas supply unit 20 to stop the supply of halogen gas to the processing container 1 and supply oxygen radicals to the processing container 1 each time halogen-containing gas is supplied to the processing container 1 for a predetermined time. In this case, the metal oxide film can be continuously etched without significantly reducing the etching rate. Subsequently, the control unit 60 increases the pressure inside the processing container 1 to atmospheric pressure, cools the inside of the processing container 1 to the discharge temperature, and then controls the lifting mechanism to discharge the boat 5 from inside the processing container 1.

[0049] [Examples] An example confirming that the AlO film, which is a metal oxide film, can be removed by the processing method according to the embodiment will be described.

[0050] In the embodiment, a silicon wafer having an AlO film on its surface was prepared, the prepared silicon wafer was placed in the processing apparatus 100 described above, and the film removal step S40 according to the embodiment was performed. In the embodiment, the film removal step S40 was performed under multiple conditions with different pressures inside the processing container 1, and the amount of etching of the AlO film formed on the surface of the silicon wafer was measured. The conditions for the film removal step S40 are as follows.

[0051] (Halogen-containing gas supply process S41) Temperature: room temperature Pressure: 40 Torr, 50 Torr, 60 Torr, 70 Torr, 100 Torr Halogen-containing gases: Hydrogen fluoride gas + Nitrogen gas Time: 10 minutes (Oxygen radical supply process S42) Temperature: room temperature Pressure: 0.3 Torr Oxygen-containing gas: Oxygen gas RF power: 100W Time: 10 minutes (Judgment step S43) Number of settings: 10

[0052] Figure 5 shows the relationship between etching pressure and the amount of etching of the AlO film. In Figure 5, the horizontal axis represents the etching pressure [Torr], which is the pressure inside the processing vessel 1 during the halogen-containing gas supply process S41, and the vertical axis represents the amount of etching of the AlO film [nm].

[0053] As shown in Figure 5, the AlO film is not etched when the etching pressure is between 40 Torr and 70 Torr, but it is etched when the etching pressure is 100 Torr. From this result, it is shown that the AlO film can be etched by increasing the pressure inside the processing container 1 to 100 Torr or higher in the halogen-containing gas supply step S41.

[0054] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0055] In the embodiments described above, the processing apparatus is a batch-type apparatus that processes multiple substrates at once, but the disclosure is not limited thereto. For example, the processing apparatus may be a single-wafer apparatus that processes substrates one at a time. For example, the processing apparatus may be a semi-batch-type apparatus that processes multiple substrates placed on a rotary table in a processing container by rotating the rotary table and passing them sequentially through a region supplied with a first gas and a region supplied with a second gas.

[0056] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of Symbols]

[0057] 1. Processing container 20 Gas Supply Department 60 Control Unit 100 Processing Units

Claims

1. A process of supplying a halogen-containing gas into a processing container to remove the metal oxide film inside the processing container, A step of supplying oxygen radicals into the processing container and removing metal halides generated in the step of removing the metal oxide film, A step of alternately repeating the step of removing the metal oxide film and the step of removing the metal halide, Having, Processing method.

2. The step of removing the metal oxide film includes maintaining the temperature inside the processing container at room temperature or above 40°C. The processing method according to claim 1.

3. The halogen-containing gas is hydrogen fluoride gas. The aforementioned metal oxide film is an aluminum oxide film. The step of removing the metal oxide film includes maintaining the temperature inside the processing container at 13.3 kPa or higher. The processing method according to claim 2.

4. A step of coating the inside of the processing container with a film that has higher etching resistance to the halogen-containing gas than the material constituting the processing container, A step of placing the substrate in the processing container and forming the metal oxide film on the substrate, performed once or twice or more times, It has, The steps of coating, forming the metal oxide film once or twice or more, and repeating the process are performed in this order. The processing method according to any one of claims 1 to 3.

5. Processing container and A gas supply unit that supplies halogen-containing gas into the processing container, Control unit and Equipped with, The control unit, A step of supplying the halogen-containing gas into the processing container and removing the metal oxide film inside the processing container, A step of supplying oxygen radicals into the processing container and removing metal halides generated in the step of removing the metal oxide film, A step of alternately repeating the step of removing the metal oxide film and the step of removing the metal halide, Control the gas supply unit to perform the following actions: Processing device.

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