Substrate processing method, method of manufacturing semiconductor device, substrate processing apparatus, and recording medium

Abstract

The invention relates to a substrate processing method, a method of manufacturing a semiconductor device, a substrate processing apparatus, and a recording medium. Provided is a technique capable of reducing the amount of impurities contained in a film after etching. The substrate processing method includes: (a) a step of removing at least a portion of a film on a substrate by performing a cycle twice or more, the cycle including (a1) a step of supplying a first fluorine-containing gas to the substrate and (a2) a step of supplying a reaction gas including a predetermined element to the substrate; and (b) a step in which a second fluorine-containing gas is supplied to the substrate after (a), in which a substance X containing the prescribed element is generated in (a), and in which the second fluorine-containing gas is supplied under conditions in which the substance X is further converted into a substance having a vapor pressure.

Description

Technical Field

[0001] The present invention relates to a substrate processing method, a method for manufacturing a semiconductor device, a substrate processing apparatus and a recording medium. Background Art

[0002] As one of the steps of a substrate processing step (a manufacturing step of a semiconductor device), a step of etching a film may be performed by performing a cycle of supplying different types of gases a predetermined number of times (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-158142 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The present invention provides a technology capable of reducing the amount of impurities contained in a film after etching.

[0008] Means for solving problems

[0009] According to one embodiment of the present invention, there is provided a technique comprising the following steps:

[0010] (a): a step of removing at least a portion of a film on the substrate by performing a cycle comprising (a1) supplying a first fluorine-containing gas to a substrate and (a2) supplying a reaction gas containing a predetermined element to the substrate two or more times; and

[0011] (b): After (a), a step of supplying a second fluorine-containing gas to the substrate,

[0012] wherein, in (a), a substance X containing the predetermined element is generated,

[0013] In (b), the second fluorine-containing gas is supplied under the condition that the substance X is further converted into a substance having a low vapor pressure.

[0014] Effects of the Invention

[0015] According to the present invention, the amount of impurities contained in the film after etching can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of a vertical processing furnace of a substrate processing apparatus preferably used in one embodiment of the present invention, and shows a processing furnace portion in a longitudinal sectional view.

[0017] Figure 2This is a schematic diagram of a vertical processing furnace of a substrate processing device preferably used in one embodiment of the present invention. Figure 1 The AA line cross-sectional view shows a portion of the processing furnace.

[0018] Figure 3 This is a schematic configuration diagram of a controller of a substrate processing apparatus preferably used in one embodiment of the present invention, and is a diagram showing a control system of the controller in the form of a block diagram.

[0019] Figure 4 This is a flowchart showing a substrate processing step according to one embodiment of the present invention.

[0020] Figure 5 (A) is a schematic diagram of the membrane in the experimental example; Figure 5 (B) in FIG. 1 is a diagram showing the results of SIMS analysis in the experimental example.

[0021] Description of Reference Numerals

[0022] 200 wafers (substrate) DETAILED DESCRIPTION

[0023] <One embodiment of the present invention>

[0024] The following mainly refers to Figure 1 to Figure 4 One embodiment of the present invention is described. It should be noted that the drawings used in the following description are schematic, and the relationship between the dimensions of the elements shown in the drawings, the ratio of the elements, etc. may not be consistent with reality. In addition, the relationship between the dimensions of the elements, the ratio of the elements, etc. may not be consistent between multiple drawings.

[0025] (1) Configuration of substrate processing apparatus

[0026] like Figure 1 As shown, a processing furnace 202 as a substrate processing device has a heater 207 as a heating mechanism (temperature adjustment unit). The heater 207 is also used as an activation mechanism (excitation unit) for activating (exciting) the gas by heat. A reaction tube 203 is arranged inside the heater 207. A processing chamber 201 capable of accommodating a wafer 200 as a substrate is formed in the hollow portion of the reaction tube 203. The wafer 200 is processed in the processing chamber 201. In the processing chamber 201, nozzles 249a to 249c are arranged in a manner that penetrates the lower side wall of the reaction tube 203. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively.

[0027] On the gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c as flow controllers (flow control units) and valves 243a to 243c as on-off valves are respectively provided in order from the upstream side of the gas flow. A gas supply pipe 232d is connected to the gas supply pipe 232a on the downstream side of the valve 243a. A gas supply pipe 232e is connected to the gas supply pipe 232b on the downstream side of the valve 243b. A gas supply pipe 232f is connected to the gas supply pipe 232c on the downstream side of the valve 243c. On the gas supply pipes 232d to 232f, MFCs 241d to 241f and valves 243d to 243f are provided in order from the upstream side of the gas flow.

[0028] The nozzles 249a to 249b are respectively provided in a circular ring-shaped space between the inner wall of the reaction tube 203 and the wafer 200 in a plan view, so as to stand up from the lower part of the inner wall of the reaction tube 203 along the upper part toward the upper side of the arrangement direction of the wafer 200. Gas supply holes 250a and 250b for supplying gas are respectively provided on the side surfaces of the nozzles 249a to 249b. The gas supply holes 250a and 250b are respectively opened toward the center of the reaction tube 203, and can supply gas toward the wafer 200. A plurality of gas supply holes 250a and 250b are provided from the lower part to the upper part of the reaction tube 203.

[0029] The nozzle 249c is disposed in the buffer chamber 237. The buffer chamber 237 is disposed in the space between the inner wall of the reaction tube 203 and the wafer 200 along the arrangement direction of the wafers 200. A gas supply hole 250d is provided on a portion of the wall constituting the buffer chamber 237 and is opened toward the center of the reaction tube 203. The gas supplied from the nozzle 249c into the buffer chamber 237 is supplied to the wafer 200 via the gas supply hole 250d. A plurality of gas supply holes 250d are provided from the lower portion to the upper portion of the wall constituting the buffer chamber 237.

[0030] The nozzle 249c is provided at the end of the buffer chamber 237 on the opposite side to the end where the gas supply hole 250d is provided, so as to stand from the lower part of the inner wall of the reaction tube 203 along the upper part toward the upper side of the arrangement direction of the wafers 200. A gas supply hole 250c for supplying gas is provided on the side of the nozzle 249c. The gas supply hole 250c opens toward the center of the buffer chamber 237. A plurality of gas supply holes 250c are provided from the lower part to the upper part of the reaction tube 203, similarly to the gas supply hole 250d.

[0031] As described above, in this embodiment, gas is transported (supplied) into a space defined by the inner wall of the side wall of the reaction tube 203 and the ends (peripheral portions) of the plurality of wafers 200 arranged in the reaction tube 203 via the nozzles 249a to 249c and the buffer chamber 237. Gas is supplied to the wafers 200 in the reaction tube 203 from the gas supply holes 250a to 250d opened in the nozzles 249a to 249c and the buffer chamber 237, respectively.

[0032] The first fluorine-containing gas or the second fluorine-containing gas containing fluorine (F) is supplied into the processing chamber 201 from the gas supply pipe 232 a via the MFC 241 a , the valve 243 a , and the nozzle 249 a .

[0033] A reaction gas containing a predetermined element is supplied into the processing chamber 201 from the gas supply pipe 232 b via the MFC 241 b , the valve 243 b , and the nozzle 249 b .

[0034] The modifying agent is supplied into the processing chamber 201 from the gas supply pipe 232 c via the MFC 241 c , the valve 243 c , the nozzle 249 c , and the buffer chamber 237 .

[0035] The term "agent" used in this specification includes at least one of a gaseous substance and a liquid substance. It should be noted that a liquid substance includes a mist substance. That is, a modifier may include a gaseous substance, a liquid substance such as a mist substance, or both.

[0036] Inert gas is supplied from gas supply pipes 232d to 232f into the processing chamber 201 via MFCs 241d to 241f, valves 243d to 243f, gas supply pipes 232a to 232c, nozzles 249a to 249c, and a buffer chamber 237. The inert gas functions as a purge gas, a carrier gas, a dilution gas, and the like.

[0037] The first fluorine-containing gas supply system for supplying the first fluorine-containing gas or the second fluorine-containing gas supply system for supplying the second fluorine-containing gas is mainly composed of the gas supply pipe 232a, MFC241a, and valve 243a. The reaction gas supply system for supplying the reaction gas is mainly composed of the gas supply pipe 232b, MFC241b, and valve 243b. The modifier supply system for supplying the modifier is mainly composed of the gas supply pipe 232c, MFC241c, and valve 243c. The inert gas supply system for supplying the inert gas is mainly composed of the gas supply pipes 232d to 232f, MFC241d to 241f, and valves 243d to 243f.

[0038] like Figure 2As shown, in the buffer chamber 237, two rod-shaped electrodes 269 and 270 made of a conductor are arranged from the bottom to the top of the reaction tube 203 along the stacking direction of the wafer 200. Each of the rod-shaped electrodes 269 and 270 is arranged in parallel with the nozzle 249c. Each of the rod-shaped electrodes 269 and 270 is covered by an electrode protection tube 275 from the top to the bottom. One of the rod-shaped electrodes 269 and 270 is connected to a high-frequency power supply 273 via a matching device 272, and the other is connected to a ground as a reference potential. By applying high-frequency (RF) power from the high-frequency power supply 273 to between the rod-shaped electrodes 269 and 270 via the matching device 272, plasma is generated in a plasma generation region 224 between the rod-shaped electrodes 269 and 270. The rod-shaped electrodes 269 and 270 and the electrode protection tube 275 constitute a plasma source as a plasma generator (plasma generation unit). It is also possible to include the matching device 272 and the high frequency power supply 273 in the plasma source. As described later, the plasma source functions as an excitation unit (activation mechanism) that excites gas plasma, that is, excites (activates) the gas plasma into a plasma state.

[0039] An exhaust pipe 231 for exhausting the gas in the processing chamber 201 is connected to the lower side wall of the reaction tube 203. A vacuum pump 246 as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure regulation unit). The APC valve 244 is configured to open and close the valve while the vacuum pump 246 is in operation, thereby enabling vacuum exhaust and vacuum exhaust stop in the processing chamber 201. Furthermore, while the vacuum pump 246 is in operation, the valve opening is adjusted based on the pressure information detected by the pressure sensor 245, thereby enabling the pressure in the processing chamber 201 to be adjusted. The exhaust system is mainly composed of the exhaust pipe 231, the pressure sensor 245, and the APC valve 244. The vacuum pump 246 may also be included in the exhaust system.

[0040] A sealing cover 219 capable of hermetically sealing the lower end opening of the reaction tube 203 is provided below the reaction tube 203. A rotating mechanism 267 for rotating a wafer boat 217 described later is provided below the sealing cover 219. A rotating shaft 255 of the rotating mechanism 267 passes through the sealing cover 219 and is connected to the wafer boat 217. The rotating mechanism 267 is configured to rotate the wafer 200 by rotating the wafer boat 217. The sealing cover 219 is configured to be lifted and lowered in a vertical direction by a wafer boat elevator 115 as a lifting mechanism provided outside the reaction tube 203. The wafer boat elevator 115 is configured as a conveying device (conveying mechanism) for carrying in and out (conveying) the wafer 200 into and out of the processing chamber 201 by lifting and lowering the sealing cover 219.

[0041] The wafer boat 217 as a substrate support is configured to support a plurality of wafers 200, for example 25 to 200 wafers, in a horizontal posture in multiple layers. At the lower part of the wafer boat 217, a heat insulation plate 218 is supported in a horizontal posture in multiple layers. It should be noted that the expression of a numerical range such as "25 to 200 sheets" in the present invention means that the lower limit and the upper limit are included in the range. Therefore, "25 to 200 sheets" means "more than 25 sheets and less than 200 sheets". The same applies to other numerical ranges.

[0042] A temperature sensor 263 as a temperature detector is provided in the reaction tube 203. The temperature in the processing chamber 201 is set to a desired temperature distribution by adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263.

[0043] like Figure 3 As shown, the controller 121 as a control unit (control unit) is configured as a computer having a CPU (Central Processing Unit; Central Processing Unit) 121a, a RAM (Random Access Memory; Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. RAM121b, a storage device 121c, and an I / O port 121d are configured to be able to exchange data with the CPU121a via an internal bus 121e. An input and output device 122 such as a touch panel is connected to the controller 121. In addition, an external storage device 123 can be connected to the controller 121. It should be noted that the substrate processing device can have one control unit or multiple control units. That is, the control for performing the substrate processing process described later can be performed using one control unit or multiple control units. When the term control unit is used in this specification, in addition to the case where one control unit is included, multiple control units are sometimes included.

[0044] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), etc. A control program for controlling the operation of the substrate processing device, a process recipe recording the steps and conditions of the etching process described later, etc., are stored in a readable manner in the storage device 121c. The process recipe is a combination of processes that enable the controller 121 to execute the steps in the etching process described later and obtain a specified result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to as a program. In addition, the process recipe is also referred to as a recipe. When the term "program" is used in this specification, sometimes only the recipe is included alone, sometimes only the control program is included alone, or sometimes both are included. RAM121b is configured as a memory area (work area) for temporarily holding programs, data, etc. read by CPU121a.

[0045] The I / O port 121d is connected to MFC241a~241f, valves 243a~243f, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, matcher 272, high frequency power supply 273, rotation mechanism 267, wafer boat elevator 115 and the like.

[0046] The CPU 121a is configured to read and execute the control program from the storage device 121c, and read the recipe from the storage device 121c according to the input of the operation command from the input / output device 122. The CPU 121a is configured to be able to perform flow rate adjustment operations of various gases based on the MFCs 241a to 241f, opening and closing operations of the valves 243a to 243f, opening and closing operations of the APC valve 244 and pressure adjustment operations using the APC valve 244 based on the pressure sensor 245, start and stop of the vacuum pump 246, temperature adjustment operations of the heater 207 based on the temperature sensor 263, power supply based on the high frequency power supply 273, impedance adjustment operations based on the matching device 272, rotation of the wafer boat 217 and rotation speed adjustment operations based on the rotation mechanism 267, and lifting and lowering operations of the wafer boat 217 based on the wafer boat elevator 115, etc. according to the contents of the read recipe.

[0047] The controller 121 can be constructed by installing the above-mentioned program stored in the external storage device 123 into the computer. The external storage device 123 includes, for example, a disk such as an HDD, an optical disk such as a CD, an optical disk such as an MO, a semiconductor memory such as a USB memory, etc. The storage device 121c and the external storage device 123 are configured as a computer-readable recording medium on which a program is recorded. Hereinafter, they are collectively referred to as recording media. When the term recording medium is used in this specification, sometimes only the storage device 121c is included alone, sometimes only the external storage device 123 is included alone, or sometimes both are included. It should be noted that it is also possible to provide the program to the computer using a communication unit such as the Internet or a dedicated line instead of using the external storage device 123.

[0048] (2) Substrate processing step

[0049] use Figure 4 An example of etching at least a portion of a film formed on the surface of the wafer 200 using the above-described processing furnace 202 as one step of a semiconductor device manufacturing process will be described. In the following description, the operations of the various components constituting the processing furnace 202 can be controlled by the controller 121 .

[0050] In this manual, for convenience, Figure 4 The order of substrate processing shown is expressed as follows. The same expression is used in the following description.

[0051] (first fluorine-containing gas→reactive gas)×n→second fluorine-containing gas×m→modifier

[0052] The term "wafer" used in this specification may refer to the wafer itself or a laminate of a wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may refer to the surface of the wafer itself or the surface of a predetermined layer, etc. formed on the wafer. When the term "a predetermined layer is formed on the wafer" is used in this specification, it may refer to directly forming a predetermined layer on the surface of the wafer itself or forming a predetermined layer on a layer, etc. formed on the wafer. The term "substrate" used in this specification is also synonymous with the term "wafer".

[0053] (Wafer filling and wafer boat loading)

[0054] A plurality of wafers 200 on which films to be etched are formed are loaded (wafer filling) into the wafer boat 217. Then, the wafer boat 217 supporting the plurality of wafers 200 is lifted by the wafer boat elevator 115 and carried into the processing chamber 201 (wafer loading).

[0055] (Pressure regulation and temperature regulation)

[0056] The vacuum pump 246 is used to perform vacuum exhaust (decompression exhaust) so that the space in the processing chamber 201, that is, the space where the wafer 200 is located, becomes the desired processing pressure (vacuum degree). In addition, the heater 207 is used to heat the wafer 200 in the processing chamber 201 so that the wafer 200 becomes the desired processing temperature. In addition, the rotation of the wafer 200 by the rotation mechanism 267 is started. The operation of the vacuum pump 246 and the heating and rotation of the wafer 200 are all continued until at least the processing of the wafer 200 is completed.

[0057] In this specification, the processing temperature refers to the temperature of the wafer 200 or the temperature in the processing chamber 201, and the processing pressure refers to the pressure in the processing chamber 201. In addition, the processing time refers to the time during which the processing is continued. This also applies to the following description.

[0058] Thereafter, the following steps S11 to S20 are performed on the wafer 200 on which the film to be etched is formed.

[0059] Here, as the film to be etched, for example, a metal oxide film and a metal nitride film can be cited. As the metal elements contained in the metal oxide film and the metal nitride film, for example, aluminum (Al), zirconium (Zr), hafnium (Hf), titanium (Ti), yttrium (Y), lanthanum (La), tantalum (Ta), niobium (Nb), ruthenium (Ru), vanadium (V), zinc (Zn), manganese (Mn), cobalt (Co), indium (In), gallium (Ga), etc. The metal oxide film and the metal nitride film can also be a film containing two or more of the above-mentioned metal elements. In particular, when etching a high dielectric constant film (High-k film) such as an aluminum oxide (Al2O3) film, a zirconium oxide (ZrO2) film, a hafnium oxide (HfO2) film, a titanium oxide (TiO2) film, a lanthanum oxide (La2O3) film, and a tantalum oxide (Ta2O5) film, the technology of the present invention can be appropriately applied.

[0060] (Supply of First Fluorine-Containing Gas, Step S11)

[0061] In this step, the first fluorine-containing gas is supplied to the wafer 200 in the processing chamber 201. Specifically, the valve 243a is opened to allow the first fluorine-containing gas to flow into the gas supply pipe 232a. The first fluorine-containing gas is flow-regulated by the MFC 241a, supplied to the processing chamber 201 through the nozzle 249a, and exhausted from the exhaust pipe 231. At this time, the valves 243d to 243f are opened, and the inert gas flows into the gas supply pipes 232d to 232f.

[0062] In this step, the first fluorine-containing gas is supplied to the wafer 200 on which the film to be etched is formed. As a result, at least a portion of the outermost atomic layer of the wafer 200 is converted into a substance containing F. That is, the outermost atomic layer of the film on the wafer 200 is modified into a layer containing F or the like.

[0063] As the processing conditions when the first fluorine-containing gas is supplied in this step, the following can be exemplified:

[0064] Processing temperature: 200~900℃

[0065] Processing pressure: 10~7000Pa

[0066] Each gas supply time: 20 to 1000 seconds

[0067] The first fluorine-containing gas treatment partial pressure: 10 ~ 4000Pa.

[0068] In addition, the processing temperature is set to substantially the same temperature in any steps described below.

[0069] In the present invention, the supply time of a certain gas refers to the time during which the gas is supplied to the wafer 200 or the processing chamber 201. In addition, the processing partial pressure of a certain gas refers to the partial pressure of the gas in the processing chamber 201. This also applies to the following description.

[0070] As the first fluorine-containing gas, for example, at least one of fluorine (F2), nitrogen trifluoride (NF3), hydrogen fluoride (HF), carbon tetrafluoride (CF4), tungsten hexafluoride (WF6), chlorine trifluoride (ClF3), sulfur tetrafluoride (SF4), xenon difluoride (XeF2), etc. can be used. As the first fluorine-containing gas, one or more of them can be used. In addition, as the first fluorine-containing gas, it is preferred to use a gas that does not contain a metal element. As a result, it becomes difficult to include impurities from the first fluorine-containing gas in the film, which can improve the electrical properties of the film. In addition, as the first fluorine-containing gas, for example, it is preferred to use a gas having an element that does not constitute a film alone, and F, such as F2, NF3, HF, and XeF2. As a result, the amount of impurity elements contained in the film can be further reduced, so that the reduction in the electrical properties of the film can be suppressed.

[0071] As the inert gas, in addition to nitrogen (N 2 ) gas, rare gases such as argon (Ar), helium (He), neon (Ne), and xenon (Xe) can be used. As the inert gas, one or more of these can be used.

[0072] (Exhaust, step S12)

[0073] The valve 243a is closed to stop the supply of the first fluorine-containing gas. At this time, the APC valve 244 of the exhaust pipe 231 remains open, and the processing chamber 201 is evacuated by the vacuum pump 246. In this way, residual gas, such as the unreacted first fluorine-containing gas remaining on the wafer 200 and / or in the processing chamber 201, and reaction byproducts are removed from the processing chamber 201. At this time, the supply of inert gas to the processing chamber 201 may be maintained while the valves 243d to 243f are opened, thereby purging the processing chamber 201. The inert gas acts as a purge gas, which can improve the effect of removing the residual gas from the wafer 200.

[0074] In this step, it is preferred to perform vacuum exhaust and purge in the processing chamber 201, which is the space where the wafer 200 exists. This can reduce the amount of impurities contained in the film after the etching process. That is, it is possible to suppress the reduction of the electrical characteristics of the film caused by the impurities in the film.

[0075] The vacuum exhaust conditions in this step may be:

[0076] Processing pressure: 10~200Pa

[0077] Processing time: 10 to 180 seconds.

[0078] The purge conditions in this step may include:

[0079] Processing pressure: 10~7000Pa

[0080] Processing time: 30 to 180 seconds.

[0081] (Reaction Gas Supply, Step S13)

[0082] Next, the reaction gas is supplied to the wafer 200 in the processing chamber 201. Specifically, the valve 243b is opened to allow the reaction gas to flow into the gas supply pipe 232b. The reaction gas is flow-regulated by the MFC 241b, supplied into the processing chamber 201 through the nozzle 249b, and exhausted from the exhaust pipe 231. At this time, the valves 243d to 243f are opened to allow the inert gas to flow into the gas supply pipes 232d to 232f.

[0083] In this step, a reaction gas is supplied to the wafer 200 having a layer of a substance containing F formed on the surface. As a result, at least a portion of the substance containing F on the wafer 200 can be converted into a volatile product containing an element derived from the film to be etched. That is, at least a portion of the film on the wafer 200 can be removed.

[0084] As the processing conditions when supplying the reaction gas in this step, the following can be exemplified:

[0085] Processing pressure: 10~7000Pa

[0086] Each gas supply time: 60 to 600 seconds

[0087] Processing partial pressure of reaction gas: 10~4000Pa.

[0088] As a reaction gas, for example, a gas containing a prescribed element and chlorine (Cl) can be used. As the prescribed element, for example, one or more of boron (B), carbon (C), sulfur (S), phosphorus (P), titanium (Ti), silicon (Si), aluminum (Al), tin (Sn), etc. can be used. As a gas containing these prescribed elements and Cl, for example, boron trichloride (BCl3), carbon tetrachloride (CCl4), thionyl chloride (SOCl2), sulfuryl chloride (SO2Cl2), phosgene (COCl2), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), titanium tetrachloride (TiCl4), silicon tetrachloride (SiCl4), chlorodimethylaluminum (C2H6AlCl), etc. can be used.

[0089] In addition, as a reaction gas, a gas containing a prescribed element and an organic ligand can be used. In this case, it can also be regarded as that C contained in the organic ligand is also one of the prescribed elements. As a gas containing the above prescribed element and an organic ligand, for example, trimethylaluminum ((CH3)3Al), C2H6AlCl, tin (II) acetylacetonate (Sn(acac)2) and the like can be used. As a reaction gas, one or more of these gases can be used.

[0090] When a reaction gas containing a semi-metallic element or a metal element (e.g., B, Ti, Si, Al, Sn) as a prescribed element is used, the prescribed element is likely to remain in the film. According to the technology of the present invention, since the amount of the prescribed element contained in the film can be reduced, the technology of the present invention can be appropriately applied. In addition, as the prescribed element, among the semi-metallic elements or metal elements, elements belonging to the second period or the third period (e.g., B, C, P, Si, Al) are easily removed by a fluorine-containing gas, so the technology of the present invention can be appropriately applied.

[0091] At this time, a substance containing a predetermined element contained in the reaction gas (hereinafter also referred to as substance X) is sometimes generated on the surface of the film. Examples of substance X include a simple substance of the predetermined element, a compound of oxygen and fluorine, an oxide, a compound of nitrogen and fluorine, and a nitride. Depending on the selection of the type of the predetermined element and the type of the reaction gas, a volatile substance X can sometimes be generated. However, even in such a case, there is a case where a portion of substance X is not removed from the wafer 200 and the predetermined element remains in the film. By selecting the type of the predetermined element and the type of the reaction gas, substance X can be removed from the wafer 200 as a volatile substance. However, even in such a case, there is a case where a portion of substance X is not removed from the wafer 200 and the predetermined element remains in the film.

[0092] (Exhaust, step S14)

[0093] The valve 243b is closed to stop the supply of the reaction gas. At this time, the APC valve 244 of the exhaust pipe 231 is kept open, and the processing chamber 201 is evacuated by the vacuum pump 246. In this way, residual gas, such as unreacted reaction gas and reaction byproducts remaining on the wafer 200 and / or in the processing chamber 201, is removed from the processing chamber 201. At this time, the supply of inert gas to the processing chamber 201 can be maintained while the valves 243d to 243f are kept open, thereby purging the processing chamber 201.

[0094] In this step, it is preferable to perform vacuum exhaust and purge in the processing chamber 201, which is the space where the wafer 200 exists. This can reduce the amount of substance X contained in the film of the wafer 200 after the etching process. That is, it is possible to prevent the electrical characteristics of the film from being deteriorated due to the inclusion of a predetermined element in the film.

[0095] As the conditions for vacuum exhaust and purging in this step, the conditions exemplified as the conditions for vacuum exhaust and purging in step S12 can be used.

[0096] (Perform a specified number of times, step S15)

[0097] By performing the cycle of steps S11 to S14 in sequence a predetermined number of times (n times, where n is an integer greater than or equal to 2) (hereinafter also referred to as etching cycle), at least a portion of the film on the wafer 200 can be removed (hereinafter also referred to as etching). For example, n is 2 to 100.

[0098] In step S11 of the second and subsequent etching cycles, the first fluorine-containing gas is preferably supplied under the condition that the substance X is further converted into a substance with a lower vapor pressure. This can reduce the amount of the predetermined element remaining in the film to be etched.

[0099] Here, in the second and subsequent etching cycles, it is preferable to perform step S11 under the condition that a part of the substance X containing the predetermined element as an impurity is not removed from the wafer 200. Thus, the time in the etching process can be shortened. In addition, the substance X that is not removed from the wafer 200 in this step and remains can be removed from the film in step S16 described later. Therefore, the productivity can be improved and the amount of the predetermined element remaining in the film to be etched can be reduced.

[0100] For example, in step S11 of the second and subsequent etching cycles, the exposure amount of the first fluorine-containing gas may be smaller than the exposure amount of the first fluorine-containing gas in the case where all of the substance X on the wafer 200 is removed. In this case, step S11 can be performed without removing part of the substance X from the wafer 200.

[0101] Here, the "exposure amount of the first fluorine-containing gas in step S11" is calculated, for example, as "a value obtained by integrating the processing partial pressure of the first fluorine-containing gas in the space where the chip 200 exists in step S11 (inside the processing chamber 201) with the time from the start to the end of step S11." In addition, the "processing partial pressure of the first fluorine-containing gas" is calculated, for example, as "the product of the molar fraction of the first fluorine-containing gas at a certain moment and the pressure (total pressure) in the space where the chip 200 exists." In addition, when the processing partial pressure of the first fluorine-containing gas in the space where the chip 200 exists in step S11 is considered to be constant, it is calculated as "the product of the processing partial pressure of the first fluorine-containing gas and the time from the start to the end of step S11."

[0102] That is, in step S11 of the etching cycle after the second time, the supply time of the first fluorine-containing gas may be made shorter than the supply time of the first fluorine-containing gas in the case where all the substance X on the wafer 200 is removed. In addition, the process partial pressure of the first fluorine-containing gas may be made lower than the process partial pressure of the first fluorine-containing gas in the case where all the substance X on the wafer 200 is removed. By one or both of these, in step S11 of the etching cycle after the second time, the exposure amount of the first fluorine-containing gas can be made smaller than the exposure amount of the first fluorine-containing gas in the case where all the substance X on the wafer 200 is removed.

[0103] Furthermore, in step S11 of the etching cycle after the second time, the processing pressure may be made larger than the processing pressure of the first fluorine-containing gas when all the substance X on the wafer 200 is removed. Alternatively, the molar fraction of the first fluorine-containing gas in the processing chamber 201 may be made higher than the molar fraction of the first fluorine-containing gas in the processing chamber 201 when all the substance X on the wafer 200 is removed. By one or both of these, in step S11 of the etching cycle after the second time, the processing partial pressure of the first fluorine-containing gas can be made larger than the processing partial pressure of the first fluorine-containing gas when all the substance X on the wafer 200 is removed.

[0104] Furthermore, in step S11 of the etching cycle after the second time, the supply flow rate of the first fluorine-containing gas may be made larger than the supply flow rate of the first fluorine-containing gas when all the substance X on the wafer 200 is removed. Alternatively, the supply flow rate of the inert gas in this step may be made smaller than the supply flow rate of the inert gas when all the substance X on the wafer 200 is removed. By one or both of these, in step S11 of the etching cycle after the second time, the molar fraction of the first fluorine-containing gas in the processing chamber 201 can be made higher than the molar fraction of the first fluorine-containing gas in the processing chamber 201 when all the substance X on the wafer 200 is removed.

[0105] In the present invention, the supply flow rate of a certain gas refers to the flow rate of the gas supplied to the wafer 200 or the processing chamber 201. This also applies to the following description.

[0106] In this embodiment, after the etching cycle is performed a predetermined number of times, the second fluorine-containing gas is supplied ( S16 ).

[0107] (Supply of the second fluorine-containing gas, step S16)

[0108] In this step, the second fluorine-containing gas is supplied to the wafer 200 in the processing chamber 201. Specifically, the valve 243a is opened to allow the second fluorine-containing gas to flow into the gas supply pipe 232a. The second fluorine-containing gas is flow-regulated by the MFC 241a, supplied to the processing chamber 201 through the nozzle 249a, and exhausted from the exhaust pipe 231. At this time, the valves 243d to 243f are opened to allow the inert gas to flow into the gas supply pipes 232d to 232f.

[0109] In this step, under the condition that the substance X is further converted into a substance with a low vapor pressure, the second fluorine-containing gas is supplied to the wafer 200. That is, in this step, the substance X containing the predetermined element is converted into a volatile substance and is exhausted from the processing chamber 201. Thus, the amount of the predetermined element contained in the film of the wafer 200 can be further reduced, so that the electrical characteristics of the film can be improved.

[0110] Here, it is preferred that the exposure amount of the second fluorine-containing gas in this step is greater than the exposure amount of the first fluorine-containing gas in the above-mentioned step S11. Thus, the amount of the predetermined element contained in the film as an impurity can be reduced, and the electrical characteristics of the film can be improved. For example, when the first fluorine-containing gas is used as the second fluorine-containing gas, the exposure amount of the second fluorine-containing gas in this step is greater than the exposure amount of the first fluorine-containing gas in the above-mentioned step S11. Thus, the amount of the predetermined element contained in the film can be reduced.

[0111] Here, the supply time of the second fluorine-containing gas in this step may be longer than the supply time of the first fluorine-containing gas in step S11. Alternatively, the treatment partial pressure of the second fluorine-containing gas in this step may be higher than the treatment partial pressure of the first fluorine-containing gas in step S11. By one or both of these, the exposure amount of the second fluorine-containing gas in this step can be greater than the exposure amount of the first fluorine-containing gas in step S11.

[0112] Here, the processing pressure in this step may be made greater than the processing pressure in step S11. Alternatively, the molar fraction of the second fluorine-containing gas in the processing chamber 201 in this step may be made greater than the molar fraction of the first fluorine-containing gas in the processing chamber 201 in step S11. By one or both of these, the processing partial pressure of the second fluorine-containing gas in this step can be made greater than the processing partial pressure of the first fluorine-containing gas in step S11.

[0113] Here, the supply flow rate of the second fluorine-containing gas in this step may be made greater than the supply flow rate of the first fluorine-containing gas in step S11. Alternatively, the supply flow rate of the inert gas in this step may be made smaller than the supply flow rate of the inert gas in step S11. By one or both of these, the molar fraction of the second fluorine-containing gas in the processing chamber 201 in this step can be made higher than the molar fraction of the first fluorine-containing gas in the processing chamber 201 in step S11.

[0114] As the processing conditions when the second fluorine-containing gas is supplied in this step, the following can be exemplified:

[0115] Processing temperature: 200~900℃

[0116] Processing pressure: 10~10000Pa

[0117] Each gas supply time: 20 to 1200 seconds

[0118] The treatment partial pressure of the second fluorine-containing gas is 10 to 5000 Pa.

[0119] As the second fluorine-containing gas, for example, one or more of the gases exemplified as the first fluorine-containing gas can be used. In addition, as the second fluorine-containing gas, a gas of the same type as the first fluorine-containing gas (a gas having the same molecular structure as the first fluorine-containing gas) can be used. Thus, the gas supply system and the processing sequence can be simplified. In addition, as the second fluorine-containing gas, it is preferred to use a gas that does not contain metal elements. Thus, impurities from the second fluorine-containing gas are not easily contained in the film, which can improve the electrical properties of the film. In addition, as the second fluorine-containing gas, it is preferred to use a gas having F and an element that does not constitute the film alone. Thus, the amount of impurity elements contained in the film can be further reduced, thereby suppressing the reduction in the electrical properties of the film.

[0120] (Exhaust, step S17)

[0121] The valve 243a is closed to stop the supply of the second fluorine-containing gas. At this time, the APC valve 244 of the exhaust pipe 231 is kept open, and the processing chamber 201 is evacuated by the vacuum pump 246. In this way, residual gas, such as the unreacted second fluorine-containing gas remaining on the wafer 200 and / or in the processing chamber 201, and reaction byproducts are removed from the processing chamber 201. At this time, the processing chamber 201 can also be purged by maintaining the supply of inert gas to the processing chamber 201 while the valves 243d to 243f are opened.

[0122] In this step, it is preferable to perform vacuum exhaust and purge in the processing chamber 201, which is the space where the wafer 200 exists. This can reduce the amount of substance X contained in the film of the wafer 200 after the etching process. That is, it is possible to prevent the electrical characteristics of the film from being deteriorated due to the inclusion of a predetermined element in the film.

[0123] As the conditions for vacuum exhaust and purging in this step, the conditions exemplified as the conditions for vacuum exhaust and purging in step S12 can be used.

[0124] (Perform a specified number of times, step S18)

[0125] The loop of sequentially performing the above-mentioned steps S16 and S17 is performed a predetermined number of times (m times, where m is an integer greater than or equal to 1 or 2). For example, m is 1 to 20.

[0126] In this embodiment, after steps S11 to S18 , a modifying agent supplying step ( S19 ) may be performed to remove a substance (hereinafter referred to as substance Y) containing a predetermined element such as F contained in a film of the next wafer 200 .

[0127] (Modifying agent supply, step S19)

[0128] Next, a modifier for removing the substance Y contained in the film of the wafer 200 is supplied to the wafer 200 in the processing chamber 201. Specifically, the valve 243c is opened, and the modifier flows into the gas supply pipe 232c. The modifier is flow-regulated by the MFC 241c, supplied into the processing chamber 201 through the nozzle 249c and the buffer chamber 237, and discharged from the exhaust pipe 231. At this time, the valves 243d to 243f are opened, and an inert gas flows into the gas supply pipes 232d to 232f.

[0129] By supplying the modifier, the substance Y contained in the film of the wafer 200 is removed. Thus, the substance Y contained in the film of the wafer 200 can be removed after the above-mentioned steps S11 to S18. Therefore, the amount of impurities such as F contained in the film on the wafer 200 can be reduced, and the electrical characteristics of the film can be improved.

[0130] Here, the modifier may be in a liquid phase or a gas phase. As the modifier, for example, an oxidizing gas or the like may be used. In this embodiment, the case where an oxidizing gas is used as the modifier is described as an example.

[0131] In this step, the processing conditions when the oxidizing gas is supplied to the wafer 200 may be as follows:

[0132] Processing temperature: 300~1000℃

[0133] Processing pressure: 10~1000Pa

[0134] Supply time of each gas: 0.5~10h.

[0135] As an oxidizing gas, for example, a gas containing oxygen (O) and hydrogen (H) can be used. As a gas containing O and H, for example, water vapor (H2O), hydrogen peroxide (H2O2), formic acid (HCOOH), hydrogen (H2) + oxygen (O2), H2 + ozone (O3), etc. can be used. In addition, as an oxidizing gas, in addition to a gas containing O and H, for example, a gas containing oxygen (O) can also be used. As an O-containing gas, for example, O2, O3, nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), etc. can be used. It should be noted that a gas containing O and H is also a type of O-containing gas. As an oxidizing gas, one or more of them can be used. When a gas containing O and H is used as an oxidizing gas, it is possible to suppress excessive oxidation of the film on the wafer 200, its base film, etc.

[0136] It should be noted that the description of two gases such as "H2+O2" in this specification refers to a mixed gas of H2 and O2. When supplying a mixed gas, the two gases can be mixed (pre-mixed) in a supply pipe and then supplied to the processing chamber 201, or the two gases can be supplied to the processing chamber 201 from different supply pipes and mixed (post-mixed) in the processing chamber 201.

[0137] (Exhaust, step S20)

[0138] The valve 243c is closed to stop the supply of the modifier. At this time, the APC valve 244 of the exhaust pipe 231 is kept open, and the processing chamber 201 is evacuated by the vacuum pump 246. In this way, residual gas, such as unreacted modifier and reaction byproducts remaining on the wafer 200 and / or in the processing chamber 201, is removed from the processing chamber 201. At this time, the supply of inert gas to the processing chamber 201 can also be maintained while the valves 243d to 243f are kept open, thereby purging the processing chamber 201.

[0139] As the conditions for vacuum exhaust and purging in this step, the conditions exemplified as the conditions for vacuum exhaust and purging in step S12 can be used.

[0140] (Post-purge and atmospheric pressure recovery)

[0141] Inert gas is supplied from each of the gas supply pipes 232d to 232f to the processing chamber 201, and the gas is exhausted from the exhaust pipe 231. Thus, the processing chamber 201 is purged, and the gas, reaction by-products, etc. remaining in the processing chamber 201 are removed from the processing chamber 201 (post-purging). Then, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to normal pressure (atmospheric pressure restoration).

[0142] (Wafer boat unloading and wafer removal)

[0143] Then, the sealing cover 219 is lowered by the wafer boat elevator 115, and the lower end of the reaction tube 203 is opened. Then, the processed wafer 200 is carried out from the lower end of the reaction tube 203 to the outside of the reaction tube 203 while being supported on the wafer boat 217 (wafer boat unloading). The processed wafer 200 is taken out of the wafer boat 217 (wafer taking out).

[0144] <Other aspects of the present invention>

[0145] The embodiments of the present invention have been specifically described above. However, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the gist of the present invention.

[0146] (Variation Example)

[0147] This modification example is different from the modifying agent supplying step (S19) in the above-mentioned substrate processing step. In this modification example, the same effects as those of the above-mentioned embodiment can be obtained.

[0148] In this modification, in the above-mentioned modifying agent supplying step ( S19 ), a modifying agent activated by plasma is used instead of a modifying agent activated by heat. That is, plasma treatment is performed.

[0149] Specifically, the valve 243c is opened to flow the modifier into the gas supply pipe 232c. The modifier is adjusted in flow rate by the MFC 241c, excited by plasma in the nozzle 249c and the buffer chamber 237, supplied to the processing chamber 201, and exhausted through the exhaust pipe 231. At this time, the modifier activated by plasma excitation is supplied to the wafer 200. At this time, the valves 243d to 243f are opened at the same time to allow the inactive gas to flow into the gas supply pipes 232d to 232f.

[0150] In this step, the treatment conditions when supplying the plasma-activated modifier include:

[0151] Processing pressure: 1~100Pa

[0152] Each gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds

[0153] Modifier treatment partial pressure: 0.01~100Pa

[0154] High frequency power: 50~1000W.

[0155] The order of substrate processing in this modification example can be as follows: For convenience, the modifier activated by plasma is represented as modifier*.

[0156] (1st fluorine-containing gas→reactive gas)×n→2nd fluorine-containing gas×m→modifier*

[0157] As the modifier, for example, a reactive species generated by activating a gas containing at least one of a rare gas, an O-containing gas, and a H-containing gas by plasma can be used. Thus, the substance Y contained in the film can be separated and removed. Therefore, since the amount of impurities contained in the film can be reduced, the electrical characteristics of the film can be improved.

[0158] As the rare gas, for example, one or more of Ar, He, Ne, Xe, etc. can be used. As the O-containing gas, for example, one or more of O2, O3, N2O, NO, NO2, CO, CO2, H2O, H2O2, H2+O2, H2+O3, etc. can be used. In addition, as the H-containing gas, for example, one or more of H2, H2O, H2O2, H2+O2, H2+O3, etc. can be used.

[0159] (Other methods)

[0160] In the above method, the case where the first fluorine-containing gas supply process (S11) to the exhaust process (S20) are continuously (in-situ) performed in the same processing chamber 201 is used for explanation, but it is not limited to this. The first fluorine-containing gas supply process (S11) to the predetermined number of implementation process (S18), and the modifier supply process (S19) to the exhaust process (S20) can also be performed in different processing chambers (ex-situ). In this method, the same effect as the above method can be obtained. In addition, when the first fluorine-containing gas supply process (S11) to the exhaust process (S20) are performed in the same processing chamber 201, the time spent on the transportation of the chip 200 between the processing chambers can be further shortened, thereby improving productivity.

[0161] In addition, in the above description, the process of etching the film formed on the wafer 200 is described as an example. However, the present invention is not limited to this. For example, in the process of etching the film formed on the inner wall of the processing chamber 201, the surface of the wafer boat 217, etc. (cleaning process in the processing chamber 201), the technology of the present invention can also be appropriately applied. In addition, for example, in the case of forming a film on the wafer 200 in the processing chamber 201, or etching the film in the processing chamber 201, the technology of the present invention can also be appropriately applied. In these methods, the same effect as the above method can be obtained.

[0162] In addition, in the above description, as an etching cycle, the case where the first fluorine-containing gas supply process (S11), the exhaust process (S12), the reaction gas supply process (S13), and the exhaust process (S14) are sequentially performed is described as an example. However, the present invention is not limited to this. For example, as an etching cycle, the reaction gas supply process (S13), the exhaust process (S14), the first fluorine-containing gas supply process (S11), and the exhaust process (S12) may also be performed sequentially. In this method, the same effect as the above method can also be obtained.

[0163] It should be noted that the process for substrate processing is preferably prepared separately according to the processing content, and is pre-stored in the storage device 121c via the electrical communication line and the external storage device 123. In addition, when starting the substrate processing, it is preferred that the CPU 121a appropriately selects an appropriate process from the multiple processes stored in the storage device 121c according to the processing content. Thus, the substrate processing device can be used to process films of various film types, composition ratios, film qualities, and film thicknesses with good reproducibility. In addition, the burden on the operator can be reduced, and the substrate processing can be started quickly while avoiding operational errors.

[0164] The above process is not limited to the case of new preparation, and can also be prepared by, for example, changing an existing process already installed in a substrate processing device. When changing a process, the changed process can also be installed in the substrate processing device via an electrical communication line or a recording medium recording the process. In addition, the input / output device 122 of the existing substrate processing device can be operated to directly change the existing process already installed in the substrate processing device.

[0165] In the above-mentioned manner, an example of a substrate processing apparatus using a batch type that processes a plurality of substrates at a time is described. The present invention is not limited to the above-mentioned manner. For example, in the case of a substrate processing apparatus using a single-wafer type that processes one or more substrates at a time, the present invention can also be appropriately applied. In addition, in the above-mentioned manner, an example of a substrate processing apparatus using a hot-wall type processing furnace is described. The present invention is not limited to the above-mentioned aspect. For example, in the case of a substrate processing apparatus using a cold-wall type processing furnace, the present invention can also be appropriately applied.

[0166] When these substrate processing apparatuses are used, film formation processing can be performed by the same processing steps and processing conditions as those of the above-mentioned embodiment and modified examples, and the same effects as those of the above-mentioned embodiment and modified examples can be obtained.

[0167] In addition, the above-mentioned aspects and modifications can be used in combination as appropriate. The processing steps and processing conditions in this case can be, for example, the same as those of the above-mentioned aspects and modifications.

[0168] Hereinafter, examples will be described.

[0169] Example

[0170] like Figure 5As shown in (A) in FIG. 1 , samples 1 to 3 are prepared in which a metal oxide film 300 is formed on the surface of a wafer 200. Sample 1 is a sample in which a metal oxide film 300 is formed on the surface of a wafer 200. Sample 2 is a sample in which a reaction gas is supplied to a wafer 200 having a metal oxide film 300 formed on the surface under the same conditions as those of sample 1, and then a fluorine-containing gas is supplied, thereby obtaining sample 2. Sample 3 is a sample in which a reaction gas is supplied to a wafer 200 having a metal oxide film 300 formed on the surface under the same conditions as those of sample 1, and then a fluorine-containing gas is supplied, thereby obtaining sample 3.

[0171] Figure 5 (B) is a graph showing the results of secondary ion mass spectrometry (SIMS) analysis of the concentration of a predetermined element in the metal oxide film 300 of each of Samples 1 to 3. The processing conditions in each step when preparing Samples 2 and 3 are the predetermined processing conditions within the range of the processing conditions in each step of the above-mentioned method. Figure 5 In (B), the horizontal axis represents the depth from the surface of the metal oxide film 300, and the vertical axis represents the concentration of a predetermined element.

[0172] Comparison between Sample 1 and Sample 3 shows that the concentration of the predetermined element near the surface of the metal oxide film 300 is high in Sample 3. This indicates that the predetermined element is captured in the metal oxide film 300 by the supply of the reaction gas.

[0173] In addition, by comparing Sample 2 and Sample 3, it was confirmed that the concentration of the predetermined element near the surface of the metal oxide film 300 was low in Sample 2. This shows that the material including the predetermined element captured in the metal oxide film 300 was partially removed by supplying the fluorine-containing gas.

[0174] Therefore, as described in the substrate processing step of the above embodiment, it is found that the amount of the predetermined element contained in the film can be reduced by supplying the fluorine-containing gas after supplying the fluorine-containing gas and the reaction gas twice or more.

Claims

1. A substrate processing method, comprising the following steps: (a): a step of removing at least a portion of a film on the substrate by performing a cycle comprising (a1) supplying a first fluorine-containing gas to a substrate and (a2) supplying a reaction gas containing a predetermined element to the substrate two or more times; and (b): After (a), a step of supplying a second fluorine-containing gas to the substrate, in, In (a), a substance X containing the predetermined element is generated, In (b), the second fluorine-containing gas is supplied under the condition that the substance X is further converted into a substance having a low vapor pressure.

2. The substrate processing method according to claim 1, wherein: In (a1), the first fluorine-containing gas is supplied under the condition that the substance X is further converted into a substance having a low vapor pressure.

3. The substrate processing method according to claim 2, wherein: (a1) is performed under the condition that a part of the substance X is not removed from the substrate.

4. The substrate processing method according to claim 3, wherein: In (a1), the exposure dose of the first fluorine-containing gas is made smaller than the exposure dose of the first fluorine-containing gas in the case where all of the substance X on the substrate is removed.

5. The substrate processing method according to claim 4, wherein: In (a1), the supply time of the first fluorine-containing gas is made shorter than the supply time of the first fluorine-containing gas in the case where all of the substance X on the substrate is removed.

6. The substrate processing method according to claim 4, wherein: In (a1), the process partial pressure of the first fluorine-containing gas is made lower than the process partial pressure of the first fluorine-containing gas when all of the substance X on the substrate is removed.

7. The substrate processing method according to claim 1, wherein: The exposure amount of the second fluorine-containing gas in (b) is made larger than the exposure amount of the first fluorine-containing gas in (a1).

8. The substrate processing method according to claim 7, wherein: The supply time of the second fluorine-containing gas in (b) is made longer than the supply time of the first fluorine-containing gas in (a1).

9. The substrate processing method according to claim 7, wherein: The treatment partial pressure of the second fluorine-containing gas in (b) is made higher than the treatment partial pressure of the first fluorine-containing gas in (a1).

10. The substrate processing method according to claim 1, wherein: The second fluorine-containing gas is the first fluorine-containing gas.

11. The substrate processing method according to claim 1, wherein: The second fluorine-containing gas is a gas that does not contain a metal element.

12. The substrate processing method according to claim 1, wherein: The predetermined element is a metal element or a semi-metal element.

13. The substrate processing method according to any one of claims 1 to 12, wherein: The method further includes (c): after step (b), supplying a modifying agent to the substrate for removing fluorine-containing substances on the substrate.

14. The substrate processing method according to claim 13, wherein: (a), (b) and (c) are performed in the same processing chamber.

15. The substrate processing method according to claim 13, wherein: The modifier is an oxidizing gas.

16. The substrate processing method according to claim 13, wherein: The modifier is a reactive species generated by activating a gas including at least one of a rare gas, an oxygen-containing gas, and a hydrogen-containing gas using plasma.

17. A method for manufacturing a semiconductor device, comprising the following steps: (a): a step of removing at least a portion of a film on the substrate by performing a cycle comprising (a1) supplying a first fluorine-containing gas to a substrate and (a2) supplying a reaction gas containing a predetermined element to the substrate two or more times; and (b): After (a), a step of supplying a second fluorine-containing gas to the substrate, in, In (a), a substance X containing the predetermined element is generated, In (b), the second fluorine-containing gas is supplied under the condition that the substance X is further converted into a substance having a low vapor pressure.

18. A substrate processing apparatus comprising: a first fluorine-containing gas supply system for supplying a first fluorine-containing gas; a reaction gas supply system for supplying a reaction gas containing a predetermined element; a second fluorine-containing gas supply system for supplying a second fluorine-containing gas; and A control unit configured to control the first fluorine-containing gas supply system, the reaction gas supply system, and the second fluorine-containing gas supply system to perform the following process, wherein: (a): a process comprising: performing a cycle of (a1) supplying the first fluorine-containing gas to a substrate and (a2) supplying the reaction gas to the substrate two or more times, thereby removing at least a portion of a film on the substrate; and (b): After (a), supplying the second fluorine-containing gas to the substrate, in, In (a), a substance X containing the predetermined element is generated, In (b), the second fluorine-containing gas is supplied under the condition that the substance X is further converted into a substance having a low vapor pressure.

19. A computer-readable recording medium having a program recorded thereon for causing a substrate processing apparatus to execute the following steps through a computer, the steps comprising: (a) a step of removing at least a portion of a film on the substrate by performing a cycle comprising (a1) supplying a first fluorine-containing gas to a substrate and (a2) supplying a reaction gas containing a predetermined element to the substrate two or more times; and (b): After (a), a step of supplying a second fluorine-containing gas to the substrate, in, In (a), a substance X containing the predetermined element is generated, In (b), the second fluorine-containing gas is supplied under the condition that the substance X is further converted into a substance having a low vapor pressure.

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