Substrate processing method, semiconductor device manufacturing method, substrate processing apparatus and process

Abstract

[Problem] To provide a technique that improves the controllability of etching amount. [Solution] Includes: removing at least a portion of substance Y from a substrate by performing a predetermined number of cycles in the order of (a1) and (b1); (a1) a step of supplying a first gas containing a first halogen element to a substrate having a surface of substance Y containing element X, and forming a first product containing the first halogen element and the first element X on the substrate; (b1) a step of supplying a second gas containing a second halogen element to the substrate, and converting at least a portion of the first product into a second product containing the first element X and having a vapor pressure higher than that of the first product; wherein (b1) is performed under the condition that at least a portion of substance Y can be removed from the substrate when the second gas is supplied to substance Y on which the first halogen element is not present on the surface.

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 program. Prior Art

[0002] As one of the processes in the manufacturing process of a semiconductor device, there is sometimes a process of etching a film by repeating a cycle of supplying different types of gases a specified number of times (see, for example, Patent Document 1). [Prior Art Documents] [Patent Documents]

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-158142 Summary of the Invention

[0004] [Problems to be Solved by the Invention] The present invention provides a technique capable of improving the controllability of the etching amount. [Means for Solving the Problems]

[0005] According to one aspect of the present invention, there is provided a technique including: repeating a cycle in the order of (a1) and (b1) a specified number of times to remove at least a part of a substance Y from a substrate; (a1) is a step of supplying a first gas containing a first halogen element to a substrate having a surface of a substance Y containing an element X, and forming a first product containing the first halogen element and the element X on the substrate; (b1) is a step of supplying a second gas containing a second halogen element to the substrate and converting at least a part of the first product into a second product containing the element X and having a vapor pressure higher than that of the first product; wherein, when the second gas is supplied to the substance Y having no first halogen element on its surface, (b1) is performed under conditions capable of removing at least a part of the substance Y from the substrate. [Advantages of the Invention]

[0006] According to the present invention, the controllability of the etching amount can be improved. Brief Description of the Drawings

[0007] [Figure 1] Figure 1 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus preferably used in one embodiment of the present invention, and is a longitudinal sectional view showing the processing furnace portion. [Figure 2] Figure 2 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 block diagram showing the control system of the controller. [Figure 3] Figure 3 is a flowchart showing a substrate processing step of one embodiment of the present invention. [Figure 4] Fig. 4(A) is a schematic view when supplying a first gas to a concave portion on a substrate; Fig. 4(B) is a schematic view when the surface of a substance on the substrate is converted into a first product through the first gas; Fig. 4(C) is a schematic view when supplying a second gas to the substrate in the state of Fig. 4(B); Fig. 4(D) is a schematic view when a part of the first product is converted into a second product having a higher vapor pressure than the first product. Embodiment

[0008] <One aspect of the present invention> Hereinafter, one embodiment of the present invention will be described mainly with reference to FIGS. 1 to 4. It should be noted that the drawings used in the following description are all schematic, and the dimensional relationships of the respective elements shown in the drawings, the ratios of the respective elements, etc. are not necessarily the same as in reality. In addition, the dimensional relationships of the respective elements and the ratios of the respective elements are not necessarily the same among the multiple drawings.

[0009] (1) Configuration of Substrate Processing Apparatus As shown in FIG. 1, a processing furnace 202 of a substrate processing apparatus includes a heater 207 as a heating mechanism (temperature adjustment unit). The heater 207 also functions as an activation mechanism (excitation unit) for activating (exciting) a gas through heat. A reaction tube 203 is disposed inside the heater 207. A processing chamber 201 capable of accommodating a wafer 200 as a substrate is formed in the cylindrical hollow portion of the reaction tube 203. Processing of the wafer 200 is performed in the processing chamber 201. In the processing chamber 201, nozzles 249a and 249b are provided so as to penetrate the lower side wall of the reaction tube 203. Gas supply pipes 232a and 232b are respectively connected to the nozzles 249a and 249b.

[0010] On the gas supply pipes 232a and 232b, mass flow controllers (MFCs) 241a and 241b serving as flow controllers (flow control units) and valves 243a and 243b serving as on-off valves are provided in order from the upstream side of the gas flow. Gas supply pipes 232c and 232e are respectively connected to the downstream side of valve 243a in gas supply pipe 232a. Gas supply pipe 232d is connected to the downstream side of valve 243b in gas supply pipe 232b. On gas supply pipes 232c, 232d, and 232e, MFCs 241c, 241d, and 241e and valves 243c, 243d, and 243e are provided in order from the upstream side of the gas flow.

[0011] Nozzles 249a and 249b are respectively provided in an annular space between the inner wall of reaction tube 203 and wafer 200 in a plan view in a manner that stands upright in the arrangement direction from the lower part to the upper part of the inner wall of reaction tube 203 toward wafer 200. Gas supply holes 250a and 250b for supplying gas are respectively provided on the side surfaces of nozzles 249a and 249b. Gas supply holes 250a and 250b are respectively opened in a manner facing the center of reaction tube 203 and can supply gas toward wafer 200. A plurality of gas supply holes 250a and 250b are provided from the lower part to the upper part of reaction tube 203.

[0012] A first gas containing a first halogen element is supplied into processing chamber 201 from gas supply pipe 232a via MFC 241a, valve 243a, and nozzle 249a.

[0013] A second gas containing a second halogen element is supplied into processing chamber 201 from gas supply pipe 232b via MFC 241b, valve 243b, and nozzle 249b.

[0014] An inert gas is supplied into processing chamber 201 from gas supply pipes 232c and 232d via MFCs 241c and 241d, valves 243c and 243d, gas supply pipes 232a and 232b, and nozzles 249a and 249b. The inert gas functions as a purge gas, a carrier gas, a dilution gas, etc.

[0015] A modifier is supplied into the processing chamber 201 from the gas supply pipe 232e via the MFC241e, the valve 243e, the gas supply pipe 232a, and the nozzle 249a. The term "agent" used in this specification includes at least one of gaseous substances and liquid substances. It should be noted that liquid substances include atomized substances. That is, the modifier may include a gaseous substance, may include a liquid substance such as an atomized substance, or may include both.

[0016] The first gas supply system for supplying the first gas is mainly composed of the gas supply pipe 232a, the MFC241a, and the valve 243a. The second gas supply system for supplying the second gas is mainly composed of the gas supply pipe 232b, the MFC241b, and the valve 243b. The inert gas supply system for supplying the inert gas is mainly composed of the gas supply pipes 232c, 232d, the MFC241c, 241d, and the valves 243c, 243d. The modifier supply system for supplying the modifier is mainly composed of the gas supply pipe 232e, the MFC241e, and the valve 243e.

[0017] Any one or all of the above various supply systems may be configured as an integrated supply system 248 integrating the valves 243a to 243e, the MFCs 241a to 241e, etc. The integrated supply system 248 is respectively connected to each of the gas supply pipes 232a to 232e, and is configured to control the supply operations of various gases into the gas supply pipes 232a to 232e through the controller 121 described later, that is, the opening and closing operations of the valves 243a to 243e, the flow rate adjustment operations based on the MFCs 241a to 241e, etc.

[0018] Below the side wall of the reaction tube 203, an exhaust pipe 231 for exhausting the atmosphere in the processing chamber 201 is connected. On the exhaust pipe 231, a vacuum pump 246 as a vacuum exhaust device is connected 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 be able to perform vacuum exhaust and stop of vacuum exhaust in the processing chamber 201 by opening and closing the valve in a state where the vacuum pump 246 is operating. Further, in a state where the vacuum pump 246 is operating, the pressure in the processing chamber 201 can be adjusted by adjusting the valve opening based on the pressure information detected by the pressure sensor 245. 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.

[0019] A sealing lid 219 is provided below the reaction tube 203, which can hermetically seal the lower opening of the reaction tube 203. An O-ring 220, which serves as a sealing member and abuts against the lower end of the reaction tube 203, is provided on the upper surface of the sealing lid 219. A rotation mechanism 267 for rotating a susceptor 217 described later is provided below the sealing lid 219. The rotation shaft 255 of the rotation mechanism 267 penetrates through the sealing lid 219 and is connected to the susceptor 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the susceptor 217. The sealing lid 219 is configured to move up and down in the vertical direction by a susceptor elevator 115, which serves as a lifting mechanism and is provided outside the reaction tube 203. The susceptor elevator 115 is a transfer device (transfer mechanism) configured to transfer (carry in and out) the wafer 200 into and out of the processing chamber 201 by moving the sealing lid 219 up and down.

[0020] The susceptor 217, which serves as a substrate support, is configured to support a plurality of wafers 200, for example, 25 to 200 wafers, in a horizontal posture and arranged in a multi-layered manner in a state where their centers are aligned with each other in the vertical direction, that is, arranged at intervals. Heat insulating plates 218 are supported in a multi-layered manner in a horizontal posture at the lower part of the susceptor 217. It should be noted that the expression of the numerical range of "25 to 200 pieces" in the present invention means that the lower limit value and the upper limit value are included in this range. Therefore, "25 to 200 pieces" means "25 pieces or more and 200 pieces or less". The same applies to other numerical ranges.

[0021] A temperature sensor 263, which serves as a temperature detector, is provided inside the reaction tube 203. It is configured to adjust the energization condition of the heater 207 based on the temperature information detected by the temperature sensor 263, thereby making the temperature inside the processing chamber 201 a desired temperature distribution.

[0022] As shown in FIG. 2, the controller 121, which is a control unit (control mechanism), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a memory device 121c, and an I / O port 121d. The RAM 121b, the memory device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, which is configured as a touch panel or the like, is connected to the controller 121. In addition, an external memory device 123 can be connected to the controller 121. It should be noted that the substrate processing apparatus may have one control unit or may have a plurality of control units. That is, the control for performing the substrate processing steps described later can be performed using one control unit or can be performed using a plurality of control units. When the term "control unit" is used in this specification, it sometimes includes a plurality of control units in addition to the case of including one control unit.

[0023] The memory device 121c is constituted by, for example, a flash memory, an HDD (Hard Disk Drive), or the like. A control program for controlling the operation of the substrate processing apparatus, a process recipe such as the steps and conditions of the etching process described later, etc. are stored in the memory device 121c in a readable manner. The process recipe is combined in such a way that the controller 121 can execute each step in the etching process described later and obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. will also be collectively abbreviated as a program. In addition, the process recipe will also be abbreviated as a recipe. When the term "program" is used in this specification, it sometimes includes only the recipe alone, sometimes includes only the control program alone, or sometimes includes both of them. The RAM 121b is configured as a memory area (working area) that temporarily holds programs, data, etc. read by the CPU 121a.

[0024] The I / O port 121d is connected to the above-described MFCs 241a to 241e, valves 243a to 243e, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, susceptor elevator 115, etc.

[0025] The CPU 121a is configured to read and execute a control program from the memory device 121c, and read a recipe from the memory device 121c according to the input of an operation command from the input / output device 122 or the like. The CPU 121a is configured to be able to control, according to the content of the read recipe, the flow rate adjustment operation of various gases based on the MFCs 241a to 241e, the opening and closing operations of the valves 243a to 243e, the opening and closing operation of the APC valve 244, the pressure adjustment operation using the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the susceptor 217 based on the rotation mechanism 267, the lifting operation of the susceptor 217 based on the susceptor elevator 115, etc.

[0026] The controller 121 can be configured by installing the above program stored in the external memory device 123 into the computer. The external memory device 123 includes, for example, magnetic disks such as HDDs, optical disks such as CDs, magneto-optical disks such as MOs, semiconductor memories such as USB memories, etc. The memory device 121c and the external memory device 123 are configured as computer-readable recording media on which programs are recorded. Hereinafter, they are also collectively referred to simply as recording media. When using the term "recording medium" in this specification, it may sometimes include only the memory device 121c alone, sometimes only the external memory device 123 alone, or sometimes both. In addition, the program provided to the computer may be performed using a communication unit such as the Internet or a dedicated line instead of using the external memory device 123.

[0027] (2) Substrate processing step Using FIGS. 3 and 4, an example of etching the substance Y containing the element X formed on the surface in the concave portion of the wafer 200 as one step of the manufacturing process of the semiconductor device using the processing furnace 202 of the above substrate processing apparatus will be described. In the following description, the operations of each part constituting the substrate processing apparatus are configured to be controllable by the controller 121.

[0028] The term "wafer" used in this specification may refer to the wafer itself or a laminate of the wafer and a specified layer or film formed on its surface. The term "surface of the wafer" used in this specification may refer to the surface of the wafer itself or the surface of a specified layer or the like formed on the wafer. When it is described in this specification that "a specified layer is formed on the wafer", it may refer to the case where a specified layer is directly formed on the surface of the wafer itself or the case where a specified layer is formed on a layer or the like formed on the wafer. The case of using the term "substrate" in this specification is synonymous with the case of using the term "wafer".

[0029] (Wafer filling and susceptor loading) Multiple wafers 200 formed with a substance Y to be etched are loaded into a susceptor 217 (wafer filling). Thereafter, the susceptor 217 supporting the multiple wafers 200 is lifted by a susceptor elevator 115 and carried into the processing chamber 201 (susceptor loading). In this state, the seal cover 219 seals the lower end of the reaction tube 203 via an O-ring 220.

[0030] (Pressure adjustment and temperature adjustment) Vacuum exhaust (pressure reduction exhaust) is performed by a vacuum pump 246 so that the space inside the processing chamber 201, that is, the space where the wafers 200 are present, becomes a desired processing pressure (vacuum degree). In addition, heating is performed by a heater 207 so that the wafers 200 inside the processing chamber 201 become a desired processing temperature. In addition, rotation of the wafers 200 by a rotation mechanism 267 is started. The operation of the vacuum pump 246, the heating of the wafers 200, and the rotation are all continuously performed at least during the period until the processing of the wafers 200 is completed.

[0031] In this specification, the processing temperature refers to the temperature of the wafers 200 or the temperature inside the processing chamber 201, and the processing pressure refers to the pressure inside the processing chamber 201. In addition, the processing time refers to the time during which this processing continues. The same applies in the following description.

[0032] Thereafter, the following steps S11 to S19 are performed on the substance Y formed on the wafers 200.

[0033] Here, as the substance Y to be etched, for example, an oxide film, a nitride film, a carbide film, etc. can be cited. As the oxide film, for example, at least one metal oxide film (oxide film containing a metal element) such as an aluminum oxide (Al2O3) film, a zirconium oxide (ZrO2) film, a hafnium oxide (HfO2) film, a silicon oxide (SiO2) film, a titanium oxide (TiO2) film, a yttrium oxide (Y2O3) film, a lanthanum oxide (La2O3) film, a tantalum oxide (Ta2O5) film, a niobium oxide (Nb2O5, Nb2O3, NbO) film, a ruthenium oxide (RuO2, RuO) film, a vanadium oxide (V2O5) film, a zinc oxide (ZnO) film, a manganese oxide (MnO, Mn2O3) film, a cobalt oxide (CoO) film, etc. can be cited.

[0034] (First gas supply, step S11) In this step, a first gas is supplied to the wafer 200 in the processing chamber 201. Specifically, the valve 243a is opened, and the first gas flows into the gas supply pipe 232a. The first gas is flow - regulated by the MFC241a, supplied into the processing chamber 201 via the nozzle 249a, and exhausted from the exhaust pipe 231. At this time, the valves 243c and 243d are opened, and an inert gas flows into the gas supply pipes 232c and 232d.

[0035] In this step, as shown in (A) of FIG. 4, a first gas containing a first halogen element is supplied to the wafer 200 having a surface of a substance Y containing an element X. Thus, as shown in (B) of FIG. 4, for example, the amount of one atomic layer of the substance Y on the wafer 200 is modified to a first product Z1 containing the first halogen element and the element X, and the first product Z1 is formed on the wafer 200.

[0036] This step is preferably carried out under the condition that the amount of the formed first product Z1 is saturated. In other words, in this step, the formation of the first product Z1 is preferably self - controlled. In such a case, the difference in the amount of the formed first product Z1 between the opening side and the deep side of the concave portion of the wafer 200 can be reduced. Thereby, the uniformity of the etching amount in the concave portion of the wafer 200 can be improved.

[0037] As the processing conditions when supplying the first gas in this step, the following can be exemplified: Processing temperature: 200 - 900 °C Processing pressure: 10 - 7000 Pa Each gas supply time: 20 - 600 seconds Partial pressure of the first gas: 10 - 4000 Pa. It should be noted that the processing temperature is set to be substantially the same temperature in any of the subsequent steps.

[0038] In addition, when the supply flow rate includes 0 slm, 0 slm means that the substance (gas) is not supplied. This is the same in other descriptions of the present invention.

[0039] As the first gas, a fluorine-containing gas containing, for example, fluorine (F) as the first halogen element can be used. As the fluorine-containing gas, for example, at least one of fluorine (F₂) gas, nitrogen trifluoride (NF₃) gas, hydrogen fluoride (HF) gas, carbon tetrafluoride (CF₄) gas, tungsten hexafluoride (WF₆) gas, etc. can be used. In addition, as the first gas, for example, a hydrogen compound can be used. As the hydrogen compound, for example, HF gas can be used. As the first gas, one or more of them can be used.

[0040] As the inert gas, in addition to nitrogen (N₂) gas, rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, etc. can be used. As the inert gas, one or more of them can be used.

[0041] Specifically, for example, when the substance Y to be etched is an Al₂O₃ film and HF gas is used as the first gas, through the supply of HF gas, the Al₂O₃ on the surface of the wafer 200 reacts with HF, and a part of Al and a part of O are detached from Al₂O₃ and replaced by F, converting to AlOF and AlF₃. In addition, the O detached from Al₂O₃ combines with H to generate water vapor (H₂O gas). Then, H₂O detaches from the surface of the wafer 200 and is discharged from the inside of the processing chamber 201, thereby etching the surface of Al₂O₃. That is, through the supply of HF gas, the following reaction occurs between the Al₂O₃ on the surface of the wafer 200, and Al-F compounds such as AlF₃ and AlOF are formed on the wafer 200 as the first product Z1.

[0042]

[0043] (Exhaust, step S12) Close the valve 243a to stop the supply of the first gas. At this time, with the APC valve 244 in the exhaust pipe 231 kept open, the inside of the processing chamber 201 is evacuated by the vacuum pump 246. Thereby, residual gases, such as unreacted first gas remaining on the wafer 200 and / or inside the processing chamber 201, and reaction by-products are removed from the inside of the processing chamber 201. At this time, the supply of the inert gas to the inside of the processing chamber 201 can also be maintained while keeping the valves 243c and 243d open, thereby purging the inside of the processing chamber 201. The inert gas acts as a purge gas and can improve the effect of removing residual gases from the wafer 200. In this step, for example, unreacted HF gas remaining in the processing chamber 201, H₂O as a reaction by-product, etc. are removed from the inside of the processing chamber 201.

[0044] After step S11, it is preferable to perform vacuum exhaust and purging in the processing chamber 201 which is the space where the wafer 200 exists. Thereby, the amount of the first halogen element remaining on the wafer 200 after the etching process can be reduced. That is, it is possible to prevent the electrical characteristics of the wafer 200 from deteriorating due to the residue of the first halogen element. The vacuum exhaust and purging are performed, for example, 1 to 10 times.

[0045] At this time, it is preferable to set the processing time in this step to be equal to or longer than the processing time of the above step S11. Thereby, for example, unreacted first gas, reaction by-products containing the first halogen element, the second product Z2 generated in step S13 described later, substances containing the first halogen element, etc. can be removed from the wafer 200. Therefore, the amount of the first halogen element remaining on the wafer 200 can be reduced. That is, it is possible to prevent the electrical characteristics of the wafer 200 from deteriorating due to the residue of the first halogen element.

[0046] Also at this time, it is preferable to make the processing pressure in this step be more than half of the processing pressure in the above step S11. Thereby, the amount of the first halogen element remaining on the wafer 200 can be reduced. That is, it is possible to prevent the electrical characteristics of the wafer 200 from deteriorating due to the residue of the first halogen element.

[0047] As the conditions for the vacuum exhaust in this step, examples are: Processing pressure: 10 to 200 Pa Processing time: 10 to 180 seconds.

[0048] As the conditions for the purging in this step, examples are: Processing pressure: 10 to 7000 Pa Processing time: 30 to 180 seconds.

[0049] (Second gas supply, step S13) Next, the second gas is supplied to the wafer 200 in the processing chamber 201. Specifically, the valve 243b is opened, and the second gas flows into the gas supply pipe 232b. The second gas is flow-regulated by the MFC241b, supplied into the processing chamber 201 via the nozzle 249b, and exhausted from the exhaust pipe 231. At this time, the valves 243c and 243d are opened, and the inert gas flows into the gas supply pipes 232c and 232d.

[0050] In this step, as shown in (C) of FIG. 4, a second gas containing a second halogen element is supplied to the wafer 200 having the first product Z1 formed on its surface. As a result, as shown in (D) of FIG. 4, at least a part of the first product Z1 is converted into a second product Z2 containing element X and having a higher vapor pressure than the first product Z1. That is, in this step, at least a part of the first product Z1 on the wafer 200 is removed.

[0051] This step is preferably carried out under the condition that when the second gas is supplied to the substance Y having no first halogen element on its surface, at least a part of the substance Y can be removed from the wafer 200. In other words, this step is preferably carried out under the condition that the substance Y can be etched by the second gas alone.

[0052] Generally, for the deep part of the concave portion on the wafer 200, the second gas is less likely to reach compared to the opening side. Therefore, conversion from the first product Z1 to the second product Z2 is difficult to proceed in the deep part of the concave portion of the wafer 200. In this step, since it is carried out under the condition that the substance Y can be etched by the second gas alone, when all of the first product Z1 in the deep part is to be converted into the second product Z2, it is expected that the substance Y is etched by the second gas alone at the opening side. Therefore, the etching amount of the substance Y at the opening side becomes larger than that at the deep part, and there is a case where the uniformity of the etching amount in the concave portion of the wafer 200 is reduced. In this method, a part of the first product Z1 may not be converted into the second product Z2 in this step. Thereby, the etching of the substance Y by the second gas alone at the opening side can be suppressed, and thus the uniformity of the etching amount in the concave portion on the wafer 200 can be improved.

[0053] In this step, it is preferable that the exposure amount of the second gas to the wafer 200 is less than the exposure amount at which all of the first product Z1 on the wafer 200 is converted into the second product Z2. Thereby, this step can be carried out under the condition that at least a part of the first product Z1 on the wafer 200 is not converted into the second product Z2. Here, the "exposure amount of the second gas to the wafer 200" is calculated, for example, as "a value obtained by integrating the partial pressure of the second gas in the space where the wafer 200 exists at a certain time through the time from the start to the end of this step". In addition, the "partial pressure of the second gas" is calculated, for example, as "the product of the mole fraction of the second gas at a certain time and the pressure (total pressure) in the space where the wafer 200 exists".

[0054] Therefore, for example, at least one of the time for supplying the second gas to the wafer 200 (hereinafter also referred to as the supply time), the molar fraction of the second gas in the gas supplied to the wafer 200, and the pressure in the processing chamber 201 when supplying the second gas to the wafer 200 is made smaller than the case where all of the first product Z1 on the wafer 200 is converted to the second product Z2. Thereby, the exposure amount of the second gas to the wafer 200 can be made smaller than the exposure amount when all of the first product Z1 on the wafer 200 is converted to the second product Z2.

[0055] Regarding the molar fraction of the second gas in the gas supplied to the wafer 200, for example, in this step, it can also be controlled by the ratio of the flow rate of the second gas (also referred to as the supply flow rate of the second gas) and the flow rate of the inert gas (also referred to as the supply flow rate of the inert gas) supplied into the processing chamber 201. For example, it is also possible to make the supply flow rate of the second gas in this step smaller than the case where all of the first product Z1 on the wafer 200 is converted to the second product Z2, and / or make the supply flow rate of the inert gas in this step larger than the case where all of the first product Z1 on the wafer 200 is converted to the second product Z2. Thereby, the molar fraction of the second gas can be made smaller than the molar fraction of the second gas when all of the first product Z1 on the wafer 200 is converted to the second product Z2.

[0056] In addition, in this step, it is preferable to give priority to the conversion from the first product Z1 to the second product Z2 with respect to the removal of the substance Y. Thereby, the progress of the etching of the substance Y alone on the opening side through the second gas can be suppressed, and thus the uniformity of the etching amount in the concave portion on the wafer 200 can be improved.

[0057] Examples of the processing conditions when supplying the second gas in this step include: Processing pressure: 10 - 7000 Pa Each gas supply time: 60 - 600 seconds Partial pressure of the second gas: 10 - 4000 Pa.

[0058] As the second gas, for example, a gas containing a second halogen element can be used. As the second halogen element, for example, a gas containing a second halogen element different from the first halogen element can be used. Here, it is preferable that the atomic number of the second halogen element contained in the second gas is greater than the atomic number of the first halogen element contained in the first gas. Specifically, for example, when the first halogen element is F, the second halogen element contained in the second gas is Cl. Thereby, it becomes easy to perform this step under the condition that the substance Y is etched through the second gas alone.

[0059] As the second gas, a Cl-containing gas containing chlorine (Cl) as the second halogen element, for example, can be used. As the Cl-containing gas, for example, chlorine (Cl₂) gas, boron trichloride (BCl₃) gas, carbon tetrachloride (CCl₄) gas, thionyl chloride (SOCl₂) gas, sulfuryl chloride (SO₂Cl₂) gas, phosgene (COCl₂) gas, phosphorus trichloride (PCl₃) gas, phosphorus pentachloride (PCl₅) gas, etc. can be cited. Preferably, as the Cl-containing gas, SOCl₂ gas, COCl₂ gas, etc., which are oxygen (O)-containing gases, are used. By using an O-containing gas, O can be substituted for F, and F can be detached from the wafer 200. In addition, as the second gas, for example, a compound of a Group 13 element or a Group 15 element can be used. As the compound of the Group 13 element, compounds of boron (B), aluminum (Al), gallium (Ga), indium (In), etc. can be used. As the compound of the Group 15 element, compounds of N, phosphorus (P), arsenic (As), etc. can be used. As the second gas, one or more of them can be used.

[0060] For example, when BCl₃ gas is used as the second gas, by supplying BCl₃ gas to the wafer 200 under the above conditions, AlF₃ on the surface of the wafer 200 reacts with BCl₃, and a part of F detaches from AlF₃ and is substituted by Cl. Thereby, the molecular layer of AlF₃ formed on the surface of the wafer 200 is converted into volatile AlClₓFᵧ and detaches from the surface of the wafer 200. In addition, F detached from AlF₃ combines with B detached from BCl₃ to generate BF₂. Then, AlClₓFᵧ and BF₃ detach from the surface of the wafer 200 and are discharged from the inside of the processing chamber 201, whereby the surface of Al₂O₃ is etched. That is, by supplying BCl₃ gas, the following reaction occurs on the surface of the wafer 200, and at least a part of the first product Z1 is converted into, for example, AlCl₃F, which contains element X and has a higher vapor pressure than the Al-F compounds such as AlF₃ and AlOF as the first product Z1, as the second product Z2, and detaches from the surface of the wafer 200.

[0061]

[0062] (Exhaust, step S14) Close valve 243b to stop the supply of the second gas. At this time, with the APC valve 244 in the exhaust pipe 231 kept open, the inside of the processing chamber 201 is evacuated by the vacuum pump 246. Thereby, residual gases, such as unreacted second gas remaining on the wafer 200 and / or inside the processing chamber 201, and reaction by-products are removed from the inside of the processing chamber 201. At this time, the supply of the inert gas into the processing chamber 201 may also be maintained with valves 243c and 243d kept open, thereby purging the inside of the processing chamber 201. In this step, for example, unreacted BCl3 gas remaining in the processing chamber 201, AlCl3F, BF2, etc. as reaction by-products are removed from the inside of the processing chamber 201.

[0063] After step S13, it is preferable to perform evacuation and purging of the inside of the processing chamber 201. Thereby, at least a part of the first product Z1 containing the first halogen element and the second product Z2 can be removed from the wafer 200. Therefore, the amount of the first halogen element remaining on the wafer 200 can be reduced. That is, it is possible to prevent the electrical characteristics of the wafer 200 from deteriorating due to the residual first halogen element. The evacuation and purging are performed, for example, 1 to 10 times.

[0064] At this time, regarding the processing time in this step, it is preferable to perform the processing for a time longer than the processing time of the above step S13. Thereby, at least a part of the first product Z1 containing the first halogen element and the second product Z2 can be removed from the wafer 200. Therefore, the amount of the first halogen element remaining on the wafer 200 after the etching process can be reduced. That is, it is possible to prevent the electrical characteristics of the wafer 200 from deteriorating due to the residual first halogen element.

[0065] Also at this time, it is preferable that the processing pressure in this step is more than half of the processing pressure in the above step S13. Thereby, substances containing the first halogen element and the like can be removed from the wafer 200. Therefore, the amount of the first halogen element remaining on the wafer 200 after the etching process can be reduced. That is, it is possible to prevent the electrical characteristics of the wafer 200 from deteriorating due to the residual first halogen element.

[0066] As the conditions for the evacuation and purging in this step, the conditions exemplified as the conditions for the evacuation and purging in step S12 can be used.

[0067] (Number of implementation regulations, step S15) By performing the loop of sequentially performing the above steps S11 to S14 a specified number of times (n times, n is an integer of 1 or more), at least a part of the substance Y on the wafer 200 (hereinafter, also referred to as etching) can be achieved.

[0068] As described above, in this method, step S13 is performed under the condition that at least a part of the substance Y can be removed from the wafer 200 when supplying the second gas to the substance Y that does not have the first halogen element on its surface. In other words, step S13 is performed under the condition that the substance Y is etched by the second gas alone.

[0069] In such a case, the amount of the substance Y etched per one loop (hereinafter, referred to as the etching rate) easily changes in a linear function manner with respect to the number of etching loops. Thus, the amount of the substance Y etched can be accurately predicted based on the number of loops. For example, when the substance Y is a film, with the increase in the number of loops, the thickness of the etched film easily increases linearly (or in a linear function manner). That is, the controllability of the etching amount can be improved. In addition, in such a case, the conversion from the first product Z1 to the second product Z2 is easily performed in step S13. Therefore, the number of wafers 200 that can be processed per unit time (productivity) can be increased.

[0070] As described above, if the first gas supply step (S11) to the implementation specified number of times step (S15) are performed, sometimes the first product Z1 remains on the wafer 200, and the first halogen element remains in the film. That is, sometimes the first halogen element remains on the wafer 200. Therefore, after the above implementation specified number of times step (S15), a modification step S16 for removing the remaining first halogen element can also be performed.

[0071] (Modifier supply, step S16) Next, a modifier is supplied to the wafer 200 in the processing chamber 201. Specifically, the valve 243e is opened, and the modifier flows into the gas supply pipe 232a. The flow rate of the modifier is adjusted by the MFC241e, and it is supplied into the processing chamber 201 via the nozzle 249a, and exhausted by the exhaust pipe 231. At this time, the valves 243c and 243d are opened, and an inert gas flows into the gas supply pipes 232c and 232d.

[0072] Through the supply of the modifier, the bond between the substance Y on the surface of the wafer 200 and the first halogen element is broken, and the first halogen element is converted into a volatile and easily detachable gas, which is discharged from the processing chamber 201. That is, a modifier is supplied to the wafer 200 to convert at least a part of the first product Z1 into a third product containing element X and having a vapor pressure higher than that of the first product Z1. Thereby, the amount of the first halogen element remaining on the wafer 200 can be further reduced.

[0073] When supplying the modifier to the substance Y that does not have the first halogen element on its surface, it is preferable to perform this step under the condition that at least a part of the substance Y can be removed from the wafer 200. Thereby, the conversion of the first product Z1 in this step becomes easy to perform, and thus the number of wafers 200 that can be processed per unit time (productivity) is increased.

[0074] The reactivity of the modifier with respect to the substance Y and the first product Z1 is preferably higher than the reactivity of the second gas with respect to the substance Y and the first product Z1. In such a case, in the loop of performing steps S11 to S14, it is easy to improve the uniformity of the etching amount in the concave portion of the wafer 200. On the other hand, the conversion of the first product Z1 becomes difficult to perform. In contrast, in this step, after the loop of performing steps S11 to S14, the conversion of the first product Z1 remaining on the wafer 200 becomes easy to perform. Therefore, it is possible to simultaneously achieve an improvement in the uniformity of the etching amount and a reduction in the amount of the first halogen element remaining on the wafer 200 after the etching process.

[0075] In this step, it is preferable to give priority to the conversion from the first product Z1 to the third product rather than the removal of the substance Y. Thereby, the etching of the substance Y on the opening side alone by the second gas can be suppressed, and thus the uniformity of the etching amount in the concave portion of the wafer 200 can be improved.

[0076] The modifier can be in a liquid phase or a gas phase. As the modifier, for example, a gas containing a third halogen element (also referred to as a gas containing a third halogen element), the above-mentioned second gas, an oxidizing agent (also referred to as an oxidizing gas), a nitriding agent (also referred to as a nitriding gas), etc. can be used.

[0077] When using a gas containing a third halogen element as a modifier, it is preferable that the atomic numbers of the second halogen element and the third halogen element are greater than the atomic number of the first halogen element. Specifically, for example, the halogen element contained in the first gas is set as F, and the second halogen element and the third halogen element are set as Cl. In this case, the gas exemplified as the second gas can be used as a modifier, or the gas used as the second gas in step S13 can be used as a modifier.

[0078] In this step, as the processing conditions when supplying a gas containing a third halogen element as a modifier, examples include: Processing temperature: 200~900°C Processing pressure: 10~7000 Pa Supply time of each gas: 60~600 seconds Partial pressure of the modifier: 10~4000 Pa.

[0079] When using a gas containing a third halogen element as a modifier in this step, it is preferable that the exposure amount of the gas containing the third halogen element to the wafer 200 in this step is greater than the exposure amount of the second gas to the wafer 200 in step S13. In such a case, in the cycle of performing steps S11~S14, it is easy to improve the uniformity of the etching amount in the concave portion of the wafer 200. On the other hand, the conversion of the first product Z1 becomes difficult to proceed. In contrast, in this step, after the cycle of performing steps S11~S14, the conversion of the first product Z1 remaining on the wafer 200 becomes easy to proceed. Therefore, it is possible to simultaneously achieve the improvement of the uniformity of the etching amount and the reduction of the amount of the first halogen element remaining on the wafer 200 after the etching process.

[0080] When the substance Y is an oxide, it is preferable to use an oxidizing agent as a modifier. When the substance Y is a nitride, it is preferable to use a nitriding agent as a modifier.

[0081] As an oxidizing agent (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 gas), hydrogen peroxide (H₂O₂) gas, hydrogen (H₂) gas + oxygen (O₂) gas, H₂ gas + ozone (O₃) gas, etc. can be used. In addition, as an oxidizing agent, in addition to the gas containing O and H, for example, an oxygen (O)-containing gas can also be used. As an O-containing gas, for example, O₂ gas, O₃ gas, nitrous oxide (N₂O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO₂) gas, carbon monoxide (CO) gas, carbon dioxide (CO₂) gas, etc. can be cited. It should be noted that the gas containing O and H is also a kind of O-containing gas. As an oxidizing agent, one or more of them can be used. In addition, as a nitriding agent, for example, a hydrogen nitride-based gas can be used. As a hydrogen nitride-based gas, for example, ammonia (NH₃) gas, diazene (N₂H₂) gas, hydrazine (N₂H₄) gas, N₃H₈ gas, etc. can be cited. As a nitriding agent, one or more of them can be used. As an oxidizing agent and a nitriding agent, a substance obtained by activating one or more of these gases through plasma can be used.

[0082] In addition, when using, for example, O₃ gas as an oxidizing agent (oxidizing gas) as a modifier, by supplying O₃ gas to the wafer 200, the AlOF on the surface of the wafer 200 reacts with O₃, and the F bond of AlOF is cut off. Then, F detaches from AlOF and is replaced by O. That is, the AlOF formed on the wafer 200 is modified to Al₂O₃, causing Fₓ. That is, Fₓ detaches from the surface of the wafer 200 and is discharged from the inside of the processing chamber 201, thereby removing the residual F. Thus, by etching corresponding to each layer containing F, F can be removed. Through the supply of O₃ gas, the following reaction occurs between the O₃ gas and the AlOF on the surface of the wafer 200.

[0083]

[0084] In this step, as the processing conditions when supplying an oxidizing gas as a modifier, the following can be exemplified: Processing temperature: 200~900°C Processing pressure: 10~200 Pa Supply time of each gas: 0.1~300 seconds.

[0085] (Exhaust, step S17) Close the valve 243e to stop the supply of the modifier. At this time, with the APC valve 244 in the exhaust pipe 231 kept open, evacuate the processing chamber 201 through the vacuum pump 246. Thus, residual gases, such as unreacted modifiers and reaction by-products remaining on the wafer 200 and / or in the processing chamber 201, are removed from the processing chamber 201. At this time, the supply of the inert gas to the processing chamber 201 may also be maintained with the valves 243c and 243d kept open, thereby purging the processing chamber 201.

[0086] As the conditions for evacuation and purging in this step, the conditions exemplified as the conditions for evacuation and purging in step S12 can be used.

[0087] (Number of implementation times, step S18) Repeat the loop of the above steps S16 to S17 a specified number of times (m times, where m is an integer of 1 or more). For example, when a gas containing a halogen element is used as the modifier, m is 1 to 50. For example, when an oxidation gas or a nitriding gas is used as the modifier, m is 60 to 300.

[0088] (Number of implementation times, step S19) Repeat the loop of the above steps S11 to S18 a specified number of times (N times, where N is an integer of 1 or more). For example, N is 1 to 100.

[0089] (Post-purging and atmospheric pressure recovery) Supply an inert gas into the processing chamber 201 from each of the gas supply pipes 232c and 232d, and exhaust from the exhaust pipe 231. Thus, the processing chamber 201 is purged, and gases, 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 an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to normal pressure (atmospheric pressure recovery).

[0090] (Cassette unloading and wafer removal) Then, lower the sealing cover 219 through the cassette elevator 115 to open the lower end opening of the reaction tube 203. 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 cassette 217 (cassette unloading). The processed wafer 200 is removed from the cassette 217 (wafer removal).

[0091] <Other aspects of the present invention> The above has specifically described the aspects of the present invention. However, the present invention is not limited to the above aspects, and various changes can be made without departing from its gist.

[0092] (Modification example) This modification example is different from the second gas supply step (S13) in the above substrate processing step. In this modification example, in addition to the same effects as the above aspect, the effects described below can also be obtained.

[0093] In this modification example, in the above second gas supply step (S13), the supply of the second gas to the wafer 200 is performed multiple times, and the exhaust in the processing chamber 201 is performed during the multiple times of supplying the second gas. That is, the cycle of performing the second gas supply and removing the second product Z2 and the like based on the exhaust is performed multiple times. That is, the second gas is supplied in pulses. In other words, the second gas is intermittently supplied. Thereby, the second product Z2 generated by the second gas supply is less likely to be re-adsorbed on the wafer 200, and thus the amount of the first halogen element remaining on the wafer 200 can be reduced. Therefore, the characteristics of the substance Y such as the electrical characteristics can be further improved.

[0094] As the exhaust in this step, purging and vacuum exhaust in the processing chamber 201 can be performed, or only one of them can be performed. As the exhaust in this step, it is preferable to perform only the vacuum exhaust in the processing chamber 201. Thereby, the amount of the first halogen element remaining on the wafer 200 can be reduced while improving the productivity.

[0095] As the processing conditions in step S13 of this modification example, the following can be exemplified: Processing pressure: 10~7000 Pa Each gas supply time: 20~600 seconds Partial pressure of the second gas: 10~4000 Pa Supply times of the second gas: 2~10 times Exhaust time: 10~180 seconds Processing pressure during exhaust: 10~200 Pa.

[0096] (Other aspects) In the above description, the case where at least a part of the substance Y on the wafer 200 is etched by performing the first gas supply step (S11) to the step of performing a specified number of times (S19) has been described. The present invention is not limited to this, and even when the first gas supply step (S11) to the step of performing a specified number of times (S15) are performed, the controllability of the etching of the substance Y on the wafer 200 can be improved. That is, in this embodiment, the same effect as the above-described embodiment can also be obtained.

[0097] In addition, in the above-described embodiment, the case where the first gas supply step (S11) is performed under the condition that the amount of the first product Z1 formed in step S11 is saturated has been described. The present invention is not limited to this, and step S11 may be performed under the condition that the amount of the first product Z1 formed does not saturate. In other words, in step S11, the formation of the first product Z1 may not be self-controlled. In this embodiment, the same effect as the above-described embodiment can also be obtained. In addition, in this embodiment, the time required for step S11 can be further shortened.

[0098] In addition, in the above-described embodiment, the case where the first gas supply step (S11) to the step of performing a specified number of times (S19) are continuously performed (in-situ) in the same processing furnace 202 has been described, but it is not limited thereto, and the first gas supply step (S11) to the step of performing a specified number of times (S15) and the modification step (S16) to the step of performing a specified number of times (S18) may be performed in different processing furnaces (ex-situ). In this embodiment, the same effect as the above-described embodiment can also be obtained.

[0099] In addition, in the above description, the process of etching the substance Y formed on the wafer 200 has been described as an example. However, the present invention is not limited to this. For example, it can also be suitably applied to the process of etching the substance Y formed on the inner wall of the processing chamber 201, the surface of the susceptor 217, etc. (cleaning process in the processing chamber 201). In this embodiment, the same effect as the above-described embodiment can also be obtained.

[0100] It should be noted that the recipes for substrate processing are preferably prepared individually according to the processing content and pre-stored in the memory device 121c via a telecommunication line and an external memory device 123. Further, at the start of substrate processing, the CPU 121a preferably appropriately selects an appropriate recipe from among a plurality of recipes stored in the memory device 121c according to the processing content. Thereby, it is possible to reproduce well the processing of films of various film types, composition ratios, film qualities, and film thicknesses using the substrate processing apparatus. In addition, the burden on the operator can be reduced, and substrate processing can be started quickly while avoiding operation errors.

[0101] The above-described recipes are not limited to newly prepared ones. For example, they can also be prepared by changing existing recipes already installed in the substrate processing apparatus. In the case of changing a recipe, the changed recipe can also be installed in the substrate processing apparatus via a telecommunication line and a recording medium on which the recipe is recorded. Further, the input / output device 122 provided in the existing substrate processing apparatus can also be operated to directly change the existing recipe already installed in the substrate processing apparatus.

[0102] In the above-described manner, an example of a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present invention is not limited to the above aspect. For example, it can also be suitably applied in the case of a single-substrate type substrate processing apparatus that processes one or more substrates at a time. Further, in the above-described manner, an example of a substrate processing apparatus having a hot-wall type processing furnace has been described. The present invention is not limited to the above aspect. For example, it can also be suitably applied in the case of a substrate processing apparatus having a cold-wall type processing furnace.

[0103] When using these substrate processing apparatuses, film formation processing can also be performed in the same processing steps and processing conditions as in the above-described manner, and the same effects as in the above-described manner can be obtained.

[0104] Further, the above-described manner and modifications can be appropriately combined and used. The processing steps and processing conditions at this time can be set to be the same as those of the above-described manner and modifications, for example.

[0105] 200: Wafer (substrate)

Claims

1. A substrate processing method, comprising: The loops performed in the order of (a1) and (b1) are performed a predetermined number of times to remove at least a portion of the substance Y from the substrate; (a1) is a process of supplying a first gas containing a first halogen element to a substrate having a recess on its surface that exposes the substance Y containing element X, and forming a first product containing the first halogen element and the element X on the substrate; (b1) is a process of supplying a second gas containing a second halogen element to the substrate and converting a portion of the first product into a second product containing the element X and having a vapor pressure higher than that of the first product; wherein (b1) is performed under the condition that the second gas removes a portion of the substance Y when the substance Y does not have the first halogen element on its surface, and does not convert at least a portion of the first product formed on the deep side of the recess into the second product.

2. The substrate processing method as described in claim 1, wherein, In (b1), the exposure amount of the aforementioned second gas to the aforementioned substrate is less than the exposure amount in which all of the aforementioned first product in the aforementioned recess is converted into the aforementioned second product.

3. The substrate processing method as described in claim 1, wherein, In (b1), the conversion from the first product to the second product is preferentially carried out relative to the removal of the aforementioned substance Y.

4. The substrate processing method as described in claim 1, wherein, The process is carried out under conditions where the amount of the first product formed is saturated (a1).

5. The substrate processing method as described in claim 1, wherein, The aforementioned loop also includes: (a2) performing a vacuum degassing and cleaning process in the space where the aforementioned substrate exists after (a1).

6. The substrate processing method as described in claim 1, wherein, The aforementioned loop also includes: (a2) a process of venting the space in which the aforementioned substrate exists for a time of (a1) or more after (a1).

7. The substrate processing method as described in claim 1, wherein, The aforementioned loop also includes: (b2) performing a vacuum degassing and cleaning process in the space where the aforementioned substrate exists after (b1).

8. The substrate processing method as described in claim 1, wherein, The aforementioned loop also includes: (b2) a process of venting the space in which the aforementioned substrate exists for a time of (b1) or more after (b1).

9. The substrate processing method as described in claim 1, wherein, In (b1), the aforementioned second gas is supplied to the aforementioned substrate multiple times, and during the multiple supplying processes, exhaust is performed from the space where the aforementioned substrate exists.

10. The substrate processing method as described in claim 1, wherein, Based on the aforementioned loop, it further includes: (c) supplying a modifier to the aforementioned substrate to convert at least a portion of the aforementioned first product into a third product containing the aforementioned element X and having a vapor pressure higher than that of the aforementioned first product.

11. The substrate processing method as described in claim 10, wherein, (c) is performed under the condition that at least a portion of the aforementioned substance Y can be removed from the aforementioned substrate when the aforementioned modifier is supplied to the aforementioned substance Y which does not have the aforementioned first halogen element on the surface.

12. The substrate processing method as described in claim 11, wherein, In (c), the conversion from the first product to the third product is carried out preferentially with respect to the removal of the aforementioned substance Y.

13. The substrate processing method as described in claim 11, wherein, The aforementioned modifier is more reactive to the aforementioned substance Y and the aforementioned first product than to the aforementioned second gas.

14. The substrate processing method as described in claim 11, wherein, The aforementioned modifier is a gas containing a third halogen element.

15. The substrate processing method as described in claim 14, wherein, The exposure amount of the gas containing the third halogen element in (c) to the aforementioned substrate is greater than the exposure amount of the second gas to the aforementioned substrate in (b1).

16. The substrate processing method as described in claim 1, wherein, The atomic number of the second halogen element is greater than that of the first halogen element.

17. The substrate processing method as described in claim 1, wherein, (b1) is performed under the condition that at least a portion of the substance Y is exposed at the opening side of the recess by removing the second product from the substrate.

18. A method for manufacturing a semiconductor device, comprising: The loops performed in the order of (a1) and (b1) are performed a predetermined number of times to remove at least a portion of the substance Y from the substrate; (a1) is a process of supplying a first gas containing a first halogen element to a substrate having a recess on its surface that exposes the substance Y containing element X, and forming a first product containing the first halogen element and the element X on the substrate; (b1) is a process of supplying a second gas containing a second halogen element to the substrate and converting a portion of the first product into a second product containing the element X and having a vapor pressure higher than that of the first product; wherein (b1) is performed under the condition that the second gas removes a portion of the substance Y when the substance Y does not have the first halogen element on its surface, and does not convert at least a portion of the first product formed on the deep side of the recess into the second product.

19. A substrate processing apparatus comprising: a first gas supply system for supplying a first gas containing a first halogen element; a second gas supply system for supplying a second gas containing a second halogen element; and a control unit configured to control the first gas supply system and the second gas supply system to perform a process comprising removing at least a portion of a substance Y from a substrate by performing a predetermined number of cycles in sequence (a1) and (b1), (a1) supplying the first gas to a substrate having a recess on its surface in which the substance Y containing element X is exposed, thereby forming a first product containing the first halogen element and the element X on the substrate, and (b1) supplying the second gas to the substrate to convert a portion of the first product into a second product containing the element X and having a vapor pressure higher than that of the first product, wherein... (b1) is performed when the aforementioned second gas is supplied to the aforementioned substance Y, which does not contain the aforementioned first halogen element on the surface, and the aforementioned second gas removes a portion of the aforementioned substance Y and does not convert at least a portion of the aforementioned first product formed on the deep side of the aforementioned recess into the aforementioned second product.

20. A program for causing a substrate processing apparatus to perform the following steps, the steps including: The loops performed in the order of (a1) and (b1) are performed a predetermined number of times to remove at least a portion of the substance Y from the substrate; (a1) is a step of supplying a first gas containing a first halogen element to a substrate having a recess on its surface in which the substance Y containing element X is exposed, and forming a first product containing the first halogen element and the element X on the substrate; (b1) is a step of supplying a second gas containing a second halogen element to the substrate and converting a portion of the first product into a second product containing the element X and having a vapor pressure higher than that of the first product; wherein (b1) is performed when the second gas removes a portion of the substance Y when the first halogen element is supplied to the substance Y on the surface where the first halogen element is not present, and at least a portion of the first product formed on the deep side of the recess is not converted into the second product.

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