Processing method, semiconductor device manufacturing method, program, and processing device

Abstract

To provide a technique that enables selective etching of specific areas.SOLUTION: A method including a step (a) of supplying an inhibitor to an object having a first surface and a second surface, thereby adsorbing the inhibitor onto the second surface, a step (b) of supplying a first halogen element-containing gas to the first surface, a step (c) of supplying a second halogen element-containing gas to the first surface, and a step (d) of performing the steps (b) and (c) N times to remove at least a portion of the first surface.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a processing method, a method for manufacturing a semiconductor device, a program, and a processing device. [Background technology]

[0002] BACKGROUND ART As one of the steps of a substrate processing process (a process for manufacturing a semiconductor device), a film may be etched by performing a cycle of supplying different types of gases a predetermined number of times (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-158142 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it can be difficult to selectively etch specific areas.

[0005] The present disclosure provides a technique that allows selective etching of specific areas. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, (a) providing an inhibitor to an object having a first surface and a second surface, thereby adsorbing the inhibitor to the second surface; (b) supplying a first halogen-containing gas to the first surface; (c) supplying a second halogen-containing gas to the first surface; (d) performing (b) and (c) N times to remove at least a portion of the first surface; The present invention provides a technique having the following. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to selectively etch specific areas. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a longitudinal sectional view showing an outline of a substrate processing apparatus according to one embodiment. [Figure 2] FIG. 2 is a schematic diagram of a controller of a substrate processing apparatus according to one embodiment, showing a control system of the controller in a block diagram. [Figure 3] FIG. 3 is a flow chart illustrating a substrate processing process according to one embodiment. [Figure 4] Fig. 4(A) is an image diagram of a substrate having a first film 300 and a second film 400 formed on its surface. Fig. 4(B) is an image diagram of a substrate having an inhibition film 500 formed on the second film 400. Fig. 4(C) is an image diagram of the substrate after etching. [Figure 5] Figure 5(A) is an image of the aluminum oxide film surface before the inhibitor is supplied. Figure 5(B) is an image of the aluminum oxide film surface after the inhibitor is supplied. Figure 5(C) is an image of the titanium nitride film surface before the inhibitor is supplied. Figure 5(D) is an image of the titanium nitride film surface after the inhibitor is supplied. [Figure 6] Fig. 6(A) is an image diagram of a substrate having a first film 300 and a second film 400 formed on its surface, and Fig. 6(B) is an image diagram of the substrate after etching processing. [Figure 7] FIG. 7 is a diagram showing a comparison of etching rates of a titanium nitride film, an aluminum oxide film, a silicon nitride film, a silicon oxide film, and a silicon film. [Figure 8] FIG. 8 is a flowchart showing a substrate processing process according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, one embodiment of the present disclosure will be described mainly with reference to FIGS. 1 to 8. It should be noted that the drawings used in the following description are all schematic, and the dimensional relationships, ratios, etc. of the elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships, ratios, etc. of the elements do not necessarily correspond between multiple drawings. Furthermore, substantially identical elements are denoted by the same reference numerals between multiple drawings, and each element is described in the drawing in which it first appears, and its description is omitted in subsequent drawings unless particularly necessary. Furthermore, the present disclosure is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the present disclosure.

[0010] (1) Configuration of the substrate processing equipment As shown in FIG. 1, a processing furnace 202 serving as a processing apparatus and a substrate processing apparatus has a heater 207 as a heating mechanism (temperature adjustment unit). The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas with heat. A reaction tube 203 is disposed inside the heater 207. A processing chamber 201 capable of accommodating wafers 200 serving as substrates is formed in a cylindrical hollow portion of the reaction tube 203. The wafers 200 are processed in this processing chamber 201. Nozzles 249a to 249c are provided inside the processing chamber 201 so as to penetrate a lower sidewall of the reaction tube 203. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively.

[0011] Gas supply pipes 232a-232c are respectively provided with mass flow controllers (MFCs) 241a-241c, which are flow rate control devices (flow rate control parts), and valves 243a-243c, which are on-off valves, in order from the upstream side of the gas flow. Gas supply pipe 232d is connected to gas supply pipe 232a downstream of valve 243a. Gas supply pipe 232e is connected to gas supply pipe 232b downstream of valve 243b. Gas supply pipe 232f is connected to gas supply pipe 232c downstream of valve 243c. Gas supply pipes 232d-232f are respectively provided with MFCs 241d-241f and valves 243d-243f in order from the upstream side of the gas flow.

[0012] The nozzles 249a to 249c are respectively provided in the annular space between the inner wall of the reaction tube 203 and the wafers 200, extending from the bottom to the top of the inner wall of the reaction tube 203 and rising upward in the arrangement direction of the wafers 200. Gas supply holes 250a to 250c for supplying gas are respectively provided on the side surfaces of the nozzles 249a to 249c. The gas supply holes 250a to 250c are each open toward the center of the reaction tube 203 and are configured to be able to supply gas toward the wafers 200. A plurality of the gas supply holes 250a to 250c are provided from the bottom to the top of the reaction tube 203.

[0013] As described above, in this embodiment, gas is transported (supplied) via the nozzles 249a to 249c into a space defined by the inner wall of the reaction tube 203 and the edges (peripheries) of the plurality of wafers 200 arranged in the reaction tube 203. Then, gas is supplied toward the wafers 200 in the reaction tube 203 from gas supply holes 250a to 250c opened in the nozzles 249a to 249c, respectively.

[0014] An inhibitor that inhibits etching of the underlying film by forming a film with a lower removal rate (hereinafter referred to as etching rate) than the etching target is supplied from the gas supply pipe 232a into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0015] The term "agent" as used herein includes at least one of a gaseous substance and a liquid substance. Note that liquid substances include mist-like substances. That is, the inhibitor may contain a gaseous substance, a liquid substance such as a mist-like substance, or both.

[0016] A first halogen element-containing gas containing a first halogen element is supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0017] A second halogen element-containing gas containing a second halogen element is supplied from the gas supply pipe 232c into the processing chamber 201 via the MFC 241c, the valve 243c, and the nozzle 249c.

[0018] Inert gases are supplied from the gas supply pipes 232d to 232f through the MFCs 241d to 241f, the valves 243d to 243f, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c into the processing chamber 201. The inert gases act as purge gases, carrier gases, dilution gases, etc.

[0019] The gas supply pipe 232a, MFC 241a, and valve 243a mainly constitute a first supply unit (also referred to as an inhibitor supply unit) that supplies an inhibitor. The gas supply pipe 232b, MFC 241b, and valve 243b mainly constitute a second supply unit (also referred to as a first halogen element-containing gas supply unit) that supplies a first halogen element-containing gas. The gas supply pipe 232c, MFC 241c, and valve 243c mainly constitute a third supply unit (also referred to as a second halogen element-containing gas supply unit) that supplies a second halogen element-containing gas. The gas supply pipes 232d to 232f, MFCs 241d to 241f, and valves 243d to 243f mainly constitute an inert gas supply unit that supplies an inert gas.

[0020] An exhaust pipe 231 for exhausting gas from the processing chamber 201 is connected to the lower sidewall of the reaction tube 203. A vacuum pump 246 (hereinafter referred to as pump 246) serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 can evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the pump 246 is operating. Furthermore, while the pump 246 is operating, the valve opening degree can be adjusted based on pressure information detected by the pressure sensor 245, thereby adjusting the pressure in the processing chamber 201. The exhaust pipe 231, the pressure sensor 245, and the APC valve 244 mainly constitute an exhaust system. The pump 246 may be included in the exhaust system.

[0021] A seal cap 219 (hereinafter referred to as the cap 219) capable of airtightly closing the lower end opening of the reaction tube 203 is provided below the reaction tube 203. A rotation mechanism 267 for rotating a boat 217 (described later) is provided below the cap 219. A rotation shaft 255 of the rotation mechanism 267 penetrates the cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The cap 219 is configured to be raised and lowered in the vertical direction by a boat elevator 115 (hereinafter referred to as the elevator 115) serving as an elevating mechanism installed outside the reaction tube 203. The elevator 115 is configured as a transfer device (transfer mechanism) that raises and lowers the cap 219 to load and unload (transfer) the wafers 200 into and out of the process chamber 201.

[0022] The boat 217, which serves as a substrate support, is configured to support multiple wafers 200, for example, 25 to 200, in multiple stages in a horizontal position. Heat insulating plates 218 are supported in multiple stages in a horizontal position below the boat 217. Note that in this disclosure, a numerical range such as "25 to 200 wafers" means that the range includes both the lower and upper limits. Therefore, "25 to 200 wafers" means "25 or more and 200 or less." The same applies to other numerical ranges.

[0023] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 is configured to have a desired temperature distribution.

[0024] As shown in FIG. 2, the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage 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, such as a touch panel, is connected to the controller 121. The controller 121 is also configured to be able to connect to an external storage device 123. The substrate processing apparatus may include one or more control units. That is, control for performing the substrate processing steps described below may be performed using one control unit or multiple control units. When the term "control unit" is used in this specification, it may include not only one control unit but also multiple control units.

[0025] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), etc. The storage device 121c readably stores a control program for controlling the operation of the substrate processing apparatus, a process recipe describing the procedure and conditions of an etching process (described later), etc. The process recipe is a combination of procedures in an etching process (described later) that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. The process recipe is also simply referred to as a recipe. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area for temporarily storing programs, data, etc. read by the CPU 121a.

[0026] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241f, valves 243a to 243f, pressure sensor 245, APC valve 244, pump 246, heater 207, temperature sensor 263, rotation mechanism 267, elevator 115, and the like.

[0027] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a recipe from the storage device 121c in response to an input of an operation command from the input / output device 122. The CPU 121a is configured to be able to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 241a to 241f, the opening and closing operations of the valves 243a to 243f, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the 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 boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the elevator 115, and the like.

[0028] The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, or a semiconductor memory such as a USB memory. The storage device 121c and the external storage device 123 are configured as computer-readable recording media on which the program is recorded. Hereinafter, these will be collectively referred to as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program (program product) may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0029] (2) Substrate processing process (processing method) An example of removing (also referred to as etching) at least a portion of first film 300 of wafer 200 having first film 300, which is a first surface and a first film, and second film 400, which is a second surface and a second film, using the above-described processing furnace 202 as one step in a semiconductor device manufacturing process will be described mainly with reference to Figures 3 to 7. In the following description, the operation of each component of processing furnace 202 is configured to be controllable by controller 121.

[0030] The first film 300 to be etched is, for example, an O-containing film (also referred to as an oxide film) containing oxygen (O). Examples of the O-containing film include metal elements such as aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), gallium (Ga), indium (In), and zinc (Zn). Preferably, a film containing a non-transition metal element such as Al, Ga, In, or Zn, and O can be used. The O-containing film may also be an oxide film containing two or more of these metal elements. That is, the technology of the present disclosure can be suitably applied to etching a high-k film (high-dielectric-constant film) such as an aluminum oxide (Al2O3, hereinafter referred to as AlO), titanium oxide (TiO2), zirconium oxide (ZrO2), or hafnium oxide (HfO2).

[0031] The second film 400, which is not the etching target, is an N-containing film (also called a nitride film) containing, for example, nitrogen (N). The N-containing film may be a film containing a metal element such as Al, Ti, Zr, Hf, Ga, In, or Zn, preferably a film containing a transition metal element such as Ti, Zr, or Hf, and N. The N-containing film may also be a nitride film containing two or more of these metal elements. That is, the second film 400 may be, for example, an aluminum nitride (AlN) film, a titanium nitride (TiN) film, a zirconium nitride (ZrN) film, or a hafnium nitride (HfN) film.

[0032] A first film 300 and a second film 400 are formed on the wafer 200. The first film 300 and the second film 400 are made of materials that can be removed by etching processes in steps S2 to S4, which will be described later. The etching rate of the first film 300 is lower than the etching rate of the second film 400.

[0033] 6A and 6B are diagrams illustrating the state of the surface of a wafer 200 when the wafer 200, having a first film 300 and a second film 400 formed thereon, is subjected to the etching process of steps S2 to S4 (described later). FIG. 7 is a diagram comparing the etching rates when the etching process of steps S2 to S4 (described later) is performed on a TiN film, an AlO film, a SiN film, a SiO film, and a Si film. For a wafer 200 having an AlO film (an example of the first film 300) and a TiN film (an example of the second film 400) formed thereon, as shown in FIG. 6A, it is sometimes desired to etch only the AlO film without etching the TiN film. However, when the wafer 200 having an AlO film and a TiN film formed thereon is subjected to the etching process of steps S2 to S4, the TiN film (an example of the second film 400) may be etched more than the AlO film (an example of the first film 300), as shown in FIG. 6B. This is because the etching rate of the AlO film is lower than that of the TiN film, as shown in Figure 7. Also, as shown in Figure 7, the etching rate of the AlO film is higher than that of silicon (Si)-containing films such as a silicon (Si) film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film.

[0034] In this embodiment, for example, a Si-containing film having an etching rate lower than that of an AlO film is formed on a TiN film having an etching rate higher than that of the AlO film. This allows only the AlO film to be etched without etching the TiN film. In other words, even if the etching target has a lower etching rate than the non-etching target film, the etching target can be etched without etching the non-etching target film.

[0035] In this specification, for convenience, the substrate processing sequence shown in Fig. 3 may be expressed as follows: Similar notations will be used in the following description.

[0036] [Inhibitor → (First halogen-containing gas → Second halogen-containing gas) × N] × M N and M are integers of 1 or 2 or more

[0037] The term "wafer" used in this specification may refer to the wafer itself or to a laminate of the 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 to the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0038] (Wafer loading) 4(A), a plurality of wafers 200 having a first film 300 and a second film 400 on their surfaces are loaded into a boat 217. Thereafter, the boat 217 supporting the plurality of wafers 200 is lifted by an elevator 115 and carried into a processing chamber 201.

[0039] (pressure and temperature regulation) The pump 246 evacuates (depressurizes) the processing chamber 201, i.e., the space in which the wafer 200 is present, to a desired processing pressure (vacuum level). The heater 207 heats the wafer 200 in the processing chamber 201 to a desired processing temperature. The rotation mechanism 267 starts rotating the wafer 200. The operation of the pump 246 and the heating and rotation of the wafer 200 continue at least until the processing of the wafer 200 is completed.

[0040] In this specification, the processing temperature refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure refers to the pressure inside the processing chamber 201. Furthermore, the processing time refers to the time the processing continues. These terms also apply to the following explanations.

[0041] Thereafter, the wafer 200 having the first film 300 and the second film 400 on its surface is subjected to the following steps S1 to S5.

[0042] (Inhibitor supply step, step S1) The valve 243a is opened to allow the inhibitor to flow into the gas supply pipe 232a. The inhibitor has its flow rate adjusted by the MFC 241a, is supplied into the processing chamber 201 through the nozzle 249a, and is 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.

[0043] After a predetermined time has elapsed since the start of the supply of the inhibitor, the valve 243a is closed to stop the supply of the inhibitor. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated to a vacuum by the pump 246. This removes residual gases, such as unreacted inhibitors and reaction by-products remaining on the wafer 200 and / or in the processing chamber 201, from the processing chamber 201. At this time, the valves 243d to 243f may be left open to continue supplying an inert gas into the processing chamber 201, thereby purging the processing chamber 201. The inert gas acts as a purge gas, and can enhance the effect of removing residual gases from above the wafer 200.

[0044] The treatment conditions for supplying the inhibitor in this step are as follows: Processing temperature: 300~500℃ Processing pressure: 0.1 to 3990 Pa Each gas supply time: 0.01 to 30 seconds Inhibitor treatment partial pressure: 0.1 to 3990 Pa The processing temperature is set to be substantially the same in all steps described below.

[0045] In this disclosure, the supply time of a certain gas refers to the time during which the gas is supplied to the wafer 200 or the inside of the processing chamber 201. Furthermore, the processing partial pressure of a certain gas refers to the partial pressure of the gas in the processing chamber 201. These terms also apply to the following explanations.

[0046] As the inhibitor, for example, a gas containing a halogen can be used. As the gas containing a halogen, for example, a gas containing chlorine (Cl) can be used. As the gas containing a halogen, a gas further containing a Group 14 element can be used. As the gas containing a halogen and a Group 14 element, for example, a halosilane gas such as Si2Cl6 gas (abbreviated as HCDS gas) or SiH2Cl2 gas (abbreviated as DCS gas) can be used.

[0047] The inhibitor may be, for example, a gas containing a Group 14 element. Examples of the Group 14 element-containing gas include a Si-containing gas. Examples of the Si-containing gas include silane-based gases such as HCDS gas, DCS gas, SiH4 gas, Si2H6 gas, and Si3H8 gas.

[0048] As the inhibitor, one or more of these can be used.

[0049] As the inert gas, in addition to N2 gas, rare gases such as Ar, He, Ne, and Xe can be used. One or more of these can be used as the inert gas. This also applies to other inert gases described later.

[0050] In this step, an inhibitor is supplied to the wafer 200 having the first film 300 and the second film 400, so that at least a portion of the inhibitor is adsorbed onto the second film 400 of the wafer 200. That is, as shown in FIG. 4(B), an inhibitor film 500 that inhibits etching of the second film 400 is formed on the second film 400 of the wafer 200. At this time, the inhibitor film 500 is not formed on the first film 300.

[0051] Here, the mechanism by which the inhibitor film 500 is formed on the second film 400 without being formed on the first film 300 will be described with reference to FIGS. 5(A) to 5(D).

[0052] 5(A), OH terminations are adsorbed on the surface of an AlO film, which is an example of the first film 300, by forming the film from, for example, Al(CH3)3 gas and water vapor (HO) or O3 gas. As shown in FIG. 5(B), when DCS gas is used as the inhibitor, Si, a Group 14 element contained in DCS gas, does not easily react with the OH terminations, and Si is not adsorbed or substituted by the OH terminations.

[0053] 5(C), an NH termination is adsorbed on the surface of a TiN film, which is an example of the second film 400, by forming the film using, for example, TiCl4 gas and NH3 gas. As shown in FIG. 5(D), when DCS gas is used as an inhibitor, Si contained in the DCS gas easily reacts with the NH termination, and Si is easily adsorbed or substituted by the NH termination.

[0054] That is, because the first film 300 has OH terminations and the second film 400 has NH terminations, atoms, molecules, or portions of molecules contained in the inhibitor are more easily adsorbed onto the second film 400 than onto the first film 300. In this step, at least a portion of the NH terminations of the second film 400 is adsorbed or replaced with at least a portion of the inhibitor, which is a Group 14 element or a molecule containing a Group 14 element, and the NH terminations of the second film 400 are replaced with terminations containing a Group 14 element. Furthermore, the OH terminations of the first film 300 are not replaced with terminations containing a Group 14 element. Therefore, an inhibitor film 500 containing a Group 14 element is less likely to form on the first film 300, but an inhibitor film 500 containing a Group 14 element is formed on the second film 400.

[0055] When a gas containing a halogen and a Group 14 element is used as the inhibitor, the supply of the inhibitor causes the Group 14 element contained in the inhibitor and a group containing a halogen to be adsorbed onto the second film 400. As a result, an inhibitor film 500 containing a Group 14 element such as Si, adsorbed onto the second film 400, is formed. That is, the inhibitor film 500 is a film containing a Group 14 element such as Si, and is, for example, a Si-containing film. Examples of the Si-containing film include a Si film, a SiN film, and a SiO film. As described above, Si-containing films such as a Si film, a SiN film, and a SiO film, which are examples of the inhibitor film 500, have a lower etching rate than the first film 300.

[0056] (First halogen element-containing gas supply process, step S2) The valve 243b is opened to allow a first halogen element-containing gas to flow into the gas supply pipe 232b. The flow rate of the first halogen element-containing gas is adjusted by the MFC 241b, and the gas is 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 an inert gas to flow into the gas supply pipes 232d to 232f.

[0057] After a predetermined time has elapsed since the start of the supply of the first halogen element-containing gas, the valve 243b is closed to stop the supply of the first halogen element-containing gas. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated to a vacuum by the pump 246. This removes residual gases, such as unreacted first halogen element-containing gas and reaction by-products remaining on the wafer 200 and / or in the processing chamber 201, from the processing chamber 201. At this time, the valves 243d to 243f may be left open to maintain the supply of an inert gas into the processing chamber 201, thereby purging the processing chamber 201.

[0058] The processing conditions for supplying the first halogen element-containing gas in this step are as follows: Processing pressure: 1 to 7000 Pa Each gas supply time: 10 to 1000 seconds Treatment partial pressure of first halogen element-containing gas: 10 to 4000 Pa is exemplified.

[0059] The first halogen-containing gas may be a gas containing a halogen element such as fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), and preferably an F-containing gas containing F may be used. The F-containing gas may be, for example, at least one of F2, NF3, HF, CF4, WF6, ClF3, SF4, or XeF2. The F-containing gas may be one or more of these. Furthermore, it is preferable to use a gas that does not contain metal elements as the F-containing gas. This reduces the likelihood of impurities from the F-containing gas being contained in the film, thereby improving the electrical properties of the film. Furthermore, it is preferable to use a gas that contains F and an element that does not constitute a film by itself, such as F2, NF3, HF, or XeF2. This further reduces the amount of impurity elements contained in the film, thereby preventing the electrical properties of the film from deteriorating.

[0060] In this step, a first halogen-containing gas is supplied to a wafer 200 having a first film 300 to be etched and a second film 400 having an inhibitor film 500 formed on its surface. The first halogen-containing gas undergoes a substitution reaction with at least a portion of the first film 300. That is, oxygen atoms (O) in the first film 300 react with the halogen atoms contained in the first halogen-containing gas, desorb from the first film 300, and are discharged from the processing chamber 201 as reaction by-products. As a result, as shown in FIGS. 4B and 4C, at least a portion of the first film 300 is removed (etched). Furthermore, since an inhibitor film 500 having a lower etching rate than the first film 300 is formed on the second film 400, the second film 400 is difficult to remove. Specifically, as described above, the inhibition film 500 such as a Si film, a SiN film, or a SiO film has a lower etching rate than the first film 300 such as an AlO film, and therefore the first film 300 such as an AlO film is preferentially (i.e., selectively) etched over the inhibition film 500.

[0061] (Second halogen element-containing gas supply process, step S3) The valve 243c is opened to allow a second halogen element-containing gas to flow into the gas supply pipe 232c. The flow rate of the second halogen element-containing gas is adjusted by the MFC 241c, and the gas is supplied into the processing chamber 201 through the nozzle 249c and exhausted from the exhaust pipe 231. At this time, the valves 243d to 243f are opened to allow an inert gas to flow into the gas supply pipes 232d to 232f.

[0062] After a predetermined time has elapsed since the start of the supply of the second halogen element-containing gas, the valve 243c is closed to stop the supply of the second halogen element-containing gas. At this time, the APC valve 244 of the exhaust pipe 231 is left open, and the processing chamber 201 is evacuated to a vacuum by the pump 246. This removes residual gases, such as unreacted second halogen element-containing gas remaining on the wafer 200 and / or in the processing chamber 201, and reaction by-products from the processing chamber 201. At this time, the valves 243d to 243f may be left open to maintain the supply of an inert gas into the processing chamber 201, thereby purging the processing chamber 201.

[0063] The processing conditions for supplying the second halogen element-containing gas in this step are as follows: Processing pressure: 10~10000Pa Each gas supply time: 10 to 1200 seconds Processing partial pressure of second halogen element-containing gas: 10 to 5000 Pa is exemplified.

[0064] The second halogen-containing gas may be, for example, a gas containing a halogen element such as F, Cl, Br, or I, and preferably a Cl-containing gas containing Cl. The Cl-containing gas may be, for example, at least one of Cl2 gas, HCl gas, or BCl3 gas. The Cl-containing gas may be one or more of these. Furthermore, it is preferable to use a gas that does not contain metal elements as the Cl-containing gas. This reduces the likelihood of impurities from the Cl-containing gas being contained in the film, thereby improving the electrical properties of the film.

[0065] In this step, a second halogen-containing gas is supplied to the wafer 200, which has a first film 300 to be etched and a second film 400 having an inhibitor film 500 formed on its surface. The second halogen-containing gas then undergoes a substitution reaction with at least a portion of the first film 300. That is, O in the first film 300 reacts with the second halogen element contained in the second halogen-containing gas, desorbs from the first film 300, and is discharged from the processing chamber 201 as a reaction by-product. This removes (etches) at least a portion of the first film 300. Furthermore, as described above, the inhibitor film 500, which has a low etching rate, is formed on the second film 400, making it difficult to remove.

[0066] (Performed a predetermined number of times, step S4) By repeating the cycle of performing the above-described steps S2 and S3 in this order a predetermined number of times (N times, where N is an integer of 1 or 2 or more), at least a portion of the first film 300 to be etched is removed.

[0067] (Performed a predetermined number of times, step S5) After repeating the cycle of performing the above-described steps S2 and S3 in this order a predetermined number of times (N times, where N is an integer of 1 or 2 or more), the process returns to step S1, and repeats the cycle of performing steps S1 to S4 in this order a predetermined number of times (M times, where M is an integer of 1 or 2 or more). As a result, at least a portion of the first film 300, which is the etching target, is etched until it reaches a predetermined film thickness (also referred to as depth).

[0068] In this way, even if the inhibitor film 500 on the second film 400 is etched by performing steps S2 and S3 a predetermined number of times, the inhibitor film 500 can be formed on the second film 400 before all of the inhibitor film 500 on the second film 400 is etched, and the first film 300 can be selectively etched until it reaches a predetermined film thickness.

[0069] (After purging and atmospheric pressure recovery) An inert gas is supplied into the processing chamber 201 from each of the gas supply pipes 232d to 232f and exhausted from the exhaust pipe 231. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201. Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas, and the pressure in the processing chamber 201 is returned to normal pressure.

[0070] (Wafer removal) Thereafter, the cap 219 is lowered by the elevator 115 to open the bottom end of the reaction tube 203. Then, the processed wafers 200, supported by the boat 217, are carried out from the bottom end of the reaction tube 203 to the outside of the reaction tube 203. The processed wafers 200 are taken out of the boat 217.

[0071] (3) Effects of this mode According to this embodiment, one or more of the following effects can be obtained. (a) By supplying an inhibitor, the inhibitor film 500 that inhibits etching of the second film 400 can be formed only on the second film 400 without being formed on the first film 300 . (b) On a wafer 200 having a first film 300 and a second film 400 on its surface, the first film 300 on which the inhibition film 500 is not formed can be selectively etched.

[0072] (4) Other aspects The above describes the embodiments of the present disclosure in detail. However, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present disclosure. In the following modifications, only the differences from the above embodiments will be described in detail.

[0073] (Variation) 8, in this modification, between the inhibitor supply step (S1) and the first halogen-containing gas supply step (S2) in the substrate processing process described above, step S11, a step of supplying a gas containing at least one of O and N, and step S12, a step of performing the process a predetermined number of times (X times, where X is an integer of 1 or 2 or more), are performed. That is, in this modification, the process furnace 202 described above is provided with a gas supply unit that supplies a gas containing at least one of O and N, and before performing the first halogen-containing gas supply step (S2), an inhibitor and a gas containing at least one of O and N are supplied a predetermined number of times to form an inhibitor film 500 on the second film 400. In other words, as the inhibitor film formation process for forming the inhibitor film 500, the inhibitor supply step (S1), step S11, a step of supplying a gas containing at least one of O and N, and step S12, a step of performing the process a predetermined number of times (X times, where X is an integer of 1 or 2 or more). The substrate processing process of this modification can also be expressed as follows.

[0074] [(inhibitor → gas containing at least one of O and N) × X → (first halogen-containing gas → second halogen-containing gas) × N] × M X, N, and M are integers of 1 or more.

[0075] In this modification, a Group 14 element-containing film is formed as the inhibitor film 500, which contains a Group 14 element and at least one of O and N. That is, a silicon-containing compound film, such as an SiO film, SiN film, or silicon oxynitride (SiON) film, which has a lower etching rate than the first film 300, is formed on the second film 400 as the inhibitor film 500. In this modification, the same effects as those of the above-described embodiment can be obtained.

[0076] In this modification, the inhibitor supply step of step S1 and the step of supplying a gas containing at least one element of O and N of step S11 may not necessarily be performed a predetermined number of times in step S12. The inhibitor supply step of step S1 and the step of supplying a gas containing at least one element of O and N of step S11 may also be performed simultaneously. That is, the inhibitor and the gas containing at least one element of O and N may be supplied simultaneously. Even in this case, the same effect as in the above embodiment can be obtained.

[0077] In the above description, the etching target is a film formed on the wafer 200. However, the present disclosure is not limited to this. For example, the technology of the present disclosure can be suitably applied to a case where the etching target is a film formed on the inner wall of the processing chamber 201 or on the surfaces of walls or components inside the reaction tube 203, such as the boat 217, the nozzles 249a to 249c, and the cap 219. Furthermore, the technology of the present disclosure can be suitably applied to a case where a process for forming a film on the wafer 200 is performed in the processing chamber 201 and the film is etched in the processing chamber 201. In these embodiments, the same effects as those of the above embodiment can be obtained.

[0078] In the above, the first halogen element used in the first halogen-element-containing gas supply step (S2) and the second halogen element used in the second halogen-element-containing gas supply step (S3) may be the same halogen element or different halogen elements. Furthermore, the first halogen-element-containing gas used in the first halogen-element-containing gas supply step (S2) and the second halogen-element-containing gas used in the second halogen-element-containing gas supply step (S3) may be the same gas or different gases. In either embodiment, the same effects as those of the above embodiment can be obtained. When the same gas (gas having the same molecular structure) is used as the first halogen-element-containing gas and the second halogen-element-containing gas, the gas supply system and processing sequence can be simplified.

[0079] It is preferable that recipes used for substrate processing are individually prepared according to the processing contents and stored in the storage device 121c via an electric communication line or the external storage device 123. Then, when starting substrate processing, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the processing contents from among the multiple recipes stored in the storage device 121c. This enables the substrate processing device to process films of various film types, composition ratios, film qualities, and film thicknesses with good reproducibility. It also reduces the burden on the operator, prevents operational errors, and allows substrate processing to be started promptly.

[0080] The above-mentioned recipes do not necessarily have to be newly created, but may be prepared by modifying an existing recipe already installed in the substrate processing apparatus. When modifying a recipe, the modified recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the modified recipe is recorded. Alternatively, an existing recipe already installed in the substrate processing apparatus may be directly modified by operating the input / output device 122 provided in the existing substrate processing apparatus.

[0081] In the above-described embodiment, an example has been described in which a batch-type substrate processing apparatus that processes multiple substrates at a time is used. The present disclosure is not limited to the above-described embodiment. For example, the present disclosure can be suitably applied to a case in which a single-wafer type substrate processing apparatus that processes one or several substrates at a time is used. Furthermore, in the above-described embodiment, an example has been described in which a substrate processing apparatus having a hot-wall type processing furnace is used. The present disclosure is not limited to the above-described embodiment. For example, the present disclosure can be suitably applied to a case in which a substrate processing apparatus having a cold-wall type processing furnace is used.

[0082] When using these substrate processing apparatuses, processing can be performed under the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0083] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and processing conditions in such a case may be the same as those of the above-described embodiments and modifications, for example. [Explanation of symbols]

[0084] 300··· First membrane (first surface), 400··· Second membrane (second surface)

Claims

1. (a) providing an inhibitor to an object having a first surface and a second surface, thereby adsorbing the inhibitor to the second surface; (b) supplying a first halogen-containing gas to the first surface; (c) supplying a second halogen-containing gas to the first surface; (d) performing (b) and (c) N times to remove at least a portion of the first surface; A processing method comprising:

2. 2. The method of claim 1, further comprising the step of removing at least a portion of the first surface by performing (a) and (d) M times.

3. The processing method according to claim 1 , wherein the first surface and the second surface are each made of a material that can be removed by (d).

4. The method of claim 1 , wherein the removal rate of the first surface is lower than the removal rate of the second surface.

5. The method of claim 1 , wherein the first surface comprises oxygen.

6. The method of claim 1 , wherein the second surface comprises nitrogen.

7. The method of claim 1 , wherein the first surface comprises a non-transition metal element and the second surface comprises a transition metal element.

8. 10. The method of claim 1, wherein the first surface has an OH termination and the second surface has an NH termination.

9. the inhibitor comprises a Group 14 element; 9. The processing method according to claim 8, wherein in (a), at least a portion of the NH terminations are replaced with terminations containing the Group 14 element, and the OH terminations are not replaced with terminations containing the Group 14 element.

10. 2. The processing method according to claim 1, wherein in (a), a gas containing at least one element selected from oxygen and nitrogen is further supplied.

11. 11. The treatment method according to claim 10, wherein in (a), the inhibitor and the gas containing at least one element selected from oxygen and nitrogen are supplied a predetermined number of times.

12. 10. The method of claim 1, wherein the inhibitor comprises a halogen.

13. the inhibitor further comprises a Group 14 element; The processing method according to claim 12 , wherein in (a), the Group 14 element and the halogen-containing group are adsorbed onto the second surface.

14. The method of claim 1 , wherein the first surface is a first film and the second surface is a second film.

15. The processing method of claim 14 , wherein the first film and the second film are formed on a substrate.

16. (a) supplying an inhibitor to a substrate having a first surface and a second surface, thereby adsorbing the inhibitor onto the second surface; (b) supplying a first halogen-containing gas to the first surface; (c) supplying a second halogen-containing gas to the first surface; (d) performing (b) and (c) N times to remove at least a portion of the first surface; A method for manufacturing a semiconductor device having the above structure.

17. (a) supplying an inhibitor to an object having a first surface and a second surface, thereby adsorbing the inhibitor to the second surface; (b) supplying a first halogen-containing gas to the first surface; (c) supplying a second halogen-containing gas to the first surface; (d) performing (b) and (c) N times to remove at least a portion of the first surface; and A program that causes a processing device to execute the above by a computer.

18. a first supply unit that supplies an inhibitor to a target having a first surface and a second surface; a second supply unit that supplies a first halogen-containing gas to the first surface; a third supply unit that supplies a second halogen-containing gas to the first surface; (a) supplying the inhibitor to the target, thereby adsorbing the inhibitor onto the second surface; (b) supplying the first halogen-containing gas to the first surface; (c) supplying the second halogen-containing gas to the first surface; (d) a control unit configured to be able to control the first supply unit, the second supply unit, and the third supply unit to perform a process of removing at least a portion of the first surface by performing (b) and (c) N times; and A processing device having:

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