Substrate processing method, method for manufacturing semiconductor device, substrate processing apparatus and program

Abstract

To control a place area capable of preventing an area easily advancing processing to a substrate.SOLUTION: A substrate processing method comprises performing predetermined times the first step of performing predetermined times (a1) the step of supplying, to the substrate, first modified gas for forming a first modified layer in at least a part on a substrate, and (a2) the step of supplying, to the substrate, first removal gas for removing a part of the first modified layer from the substrate; and the second step of performing predetermined times, following the first step (b1) the step of supplying, to the substrate, processing gas for preferentially processing an area without forming the first modified layer to an area having the first modified layer, and (b2) the step of supplying reactive gas to the substrate.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] As one step in a substrate processing process (a process for manufacturing a semiconductor device), a film is sometimes formed on the surface of a substrate using a substance that inhibits other substances from being adsorbed onto the substrate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-69407 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can control areas on a substrate where processing is likely to proceed and areas where processing is inhibited. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, (a1) supplying a first modifying gas to a substrate, the first modifying gas forming a first modified layer on at least a portion of the substrate; (a2) supplying a first removal gas to the substrate, the first removal gas removing a portion of the first modified layer from the substrate; a first step of performing the above a predetermined number of times; (b1) supplying a processing gas to the substrate, the processing gas being adapted to process a region where the first modified layer is not formed preferentially over a region where the first modified layer is present; (b2) supplying a reactive gas to the substrate; a second step of performing the above a predetermined number of times after the first step; A technique is provided for performing the above a predetermined number of times. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to control areas where processing on a substrate is likely to proceed and areas where processing is inhibited. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus, showing a processing furnace 202 in vertical cross section. [Figure 2] FIG. 2 is a schematic diagram of the vertical processing furnace of the substrate processing apparatus, showing an example of a cross section of the processing furnace 202 taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic diagram of the controller 121 of the substrate processing apparatus, and is a block diagram showing the control system of the controller 121. [Figure 4A] FIG. 4A is a diagram showing a processing sequence according to one embodiment of the present disclosure. [Figure 4B] FIG. 4B is a diagram showing an example of the procedure in step S10. [Figure 4C] FIG. 4C is a diagram showing an example of the procedure in step S12. [Figure 5] 5A to 5C are schematic diagrams of cross-sectional portions of the surface of wafer 200 obtained by performing each step of the processing sequence of FIG. [Figure 6] FIG. 6 is a schematic diagram of the vertical processing furnace of the substrate processing apparatus, showing an example of a cross section of the processing furnace 202 taken along line AA in FIG. 1 when gas is activated by plasma. [Figure 7A] FIG. 7A is a diagram showing an example of a processing sequence in the first modification. [Figure 7B] FIG. 7B is a diagram showing an example of step S30 in the first modification. [Figure 8]Figure 8 is a schematic diagram showing a cross-sectional portion of the surface of wafer 200 after steps S10-1, S10-2, and S30-1 have been performed when variant example 1 is performed using patterns (1) to (3) in which at least some of the processing conditions for each procedure are different from each other. [Figure 9A] FIG. 9A is a diagram showing a processing sequence in the second modification. [Figure 9B] FIG. 9B is a diagram showing an example of the procedure in step S40. [Figure 10] FIG. 10 is a diagram showing a processing sequence in the third modification. DETAILED DESCRIPTION OF THE INVENTION

[0008] <One aspect of the present disclosure> Hereinafter, one embodiment of the present disclosure will be described mainly with reference to Figures 1 to 5. Note that all drawings used in the following description are schematic, and the dimensional relationships between elements, the ratios of elements, etc. shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, etc. do not necessarily match between multiple drawings.

[0009] (1) Configuration of the substrate processing equipment 1, the processing furnace 202 has a heater 207. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) the gas by heat.

[0010] A reaction tube 203 is disposed inside the heater 207. A manifold 209 is disposed below the reaction tube 203, and an O-ring 220a is provided between the manifold 209 and the reaction tube 203. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed inside the processing vessel. The processing chamber 201 is configured to be able to accommodate wafers 200 as substrates. Processing of the wafers 200 is performed inside this processing chamber 201.

[0011] Nozzles 249a to 249c are provided in the processing chamber 201. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively.

[0012] 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.

[0013] 2, the nozzles 249a to 249c are each provided in a space between the inner wall of the reaction tube 203 and the wafer 200. The nozzles 249a and 249c are arranged on both sides of a straight line L that passes through the nozzle 249b and the center of the exhaust port 231a. The nozzles 249a to 249c are each provided with gas supply holes 250a to 250c that supply gas toward the wafer 200. A plurality of the gas supply holes 250a to 250c are provided from the bottom to the top of each of the nozzles 249a to 249c.

[0014] The first modifying gas is supplied into the processing chamber 201 via the gas supply pipe 232a, the MFC 241a, the valve 243a, and the nozzle 249a. The first modifying gas in this embodiment is a gas that inhibits the processing gas from being adsorbed onto the wafers 200.

[0015] The processing gas is supplied into the processing chamber 201 via the gas supply pipe 232b, the MFC 241b, the valve 243b, and the nozzle 249b. In this embodiment, the processing gas is a source gas that reacts with the reactive gas to form a processing layer 152 for forming (depositing) a desired film.

[0016] The first removal gas and the reactive gas are supplied into the processing chamber 201 via the gas supply pipe 232c, the MFC 241c, the valve 243c, and the nozzle 249c. The first removal gas is a gas that removes a part of the first modified layer 150 formed by the first modifying gas. The reactive gas is a gas that reacts with the processing layer 152 formed by the processing gas to form (deposit) a desired film (first layer 154).

[0017] The inert gas is supplied into the processing chamber 201 via the gas supply pipes 232d to 232f, the MFCs 241d to 241f, the valves 243d to 243f, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c. The inert gas acts as a purge gas, a carrier gas, a dilution gas, or the like.

[0018] The first modifying gas supply system is mainly composed of the gas supply pipe 232a, the MFC 241a, and the valve 243a. The process gas supply system is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. The first removal gas supply system and the reactive gas supply system are mainly composed of the gas supply pipe 232c, the MFC 241c, and the valve 243c. That is, the gas supply pipe 232c, the MFC 241c, and the valve 243c serve as both the first removal gas supply system and the reactive gas supply system. Note that, for example, the first removal gas supply system and the reactive gas supply system may be separated by providing a configuration similar to the gas supply pipe 232c, the MFC 241c, and the valve 243c. The inert gas supply system is mainly composed of the gas supply pipes 232d to 232f, the MFCs 241d to 241f, and the valves 243d to 243f. The nozzles connected to the gas supply pipes that constitute the various supply systems described above may be included in the respective supply systems.

[0019] Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which the valves 243a to 243f, the MFCs 241a to 241f, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232f, and is configured such that the supply operation of various substances (various gases) into the gas supply pipes 232a to 232f, that is, the opening and closing operation of the valves 243a to 243f and the flow rate adjustment operation by the MFCs 241a to 241f, are controlled by a controller 121, which will be described later.

[0020] An exhaust pipe 231 is connected to the lower sidewall of the reaction tube 203, and an exhaust port 231a is provided for exhausting the atmosphere inside the processing chamber 201. The exhaust pipe 231 is connected to a vacuum pump 246 as a vacuum exhaust device via a pressure sensor 245 as a pressure detector for detecting the pressure inside the processing chamber 201, an APC (Auto Pressure Controller) as a pressure regulator, and a valve 244. The APC valve 244 can evacuate and stop the vacuum evacuation inside the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. The APC valve 244 is further configured to adjust the pressure inside the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. The exhaust pipe 231, the APC valve 244, and the pressure sensor 245 mainly constitute an exhaust system. The vacuum pump 246 may be considered to be included in the exhaust system.

[0021] A seal cap 219 is provided below the manifold 209. An O-ring 220b is provided on the upper surface of the seal cap 219. A rotation mechanism 267 is provided below the seal cap 219. A rotation shaft 255 of the rotation mechanism 267 passes through the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the boat 217, thereby rotating the wafers 200. The boat elevator 115 is configured as a transfer device (transfer mechanism) that lifts and lowers the seal cap 219, thereby loading and unloading (transferring) the wafers 200 into and out of the processing chamber 201.

[0022] A shutter 219s is provided below the manifold 209, which can airtightly close the lower end opening of the manifold 209 when the boat 217 is unloaded from the processing chamber 201. An O-ring 220c is provided on the upper surface of the shutter 219s. The opening and closing operation (lifting and lowering operation, rotation operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0023] The boat 217, which serves as a substrate support, is configured to support, for example, 25 to 200 wafers 200 in a horizontal position in multiple stages. Note that in this specification, a numerical range such as "25 to 200" means that the range includes both the lower and upper limits. Therefore, for example, "25 to 200" means "25 to 200 wafers." The same applies to other numerical ranges. At the bottom of the boat 217, heat insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported in multiple stages.

[0024] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supplied to the heater 207 based on the temperature information detected by the temperature sensor 263, it is possible to achieve a desired temperature distribution in the processing chamber 201 or the wafer 200. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0025] As shown in FIG. 3, the controller 121, which is a control unit, 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 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. An external storage device 123 can also be connected to the controller 121. The substrate processing apparatus may be configured to include one or more control units. That is, control for performing the processing sequence described below may be performed using one control unit or multiple control units. Furthermore, the multiple control units may be configured as a control system connected to each other via a wired or wireless communication network, and control for performing the processing sequence described below may be performed by the entire control system. In this specification, when the term "control section" is used, it may include one control section, multiple control sections, or a control system configured by multiple control sections.

[0026] The storage device 121c is configured with, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. Control programs for controlling the operation of the substrate processing apparatus, process recipes describing procedures and conditions for substrate processing (described later), etc., are readably recorded and stored in the storage device 121c. The process recipe is a combination of procedures for substrate processing (described later) that are executed by the controller 121 in the substrate processing apparatus to obtain a predetermined result, and functions as a program. Hereinafter, the process recipes, control programs, etc. are collectively referred to simply as programs. The process recipes are also simply referred to as recipes. 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 (work area) for temporarily storing programs, data, etc. read by the CPU 121a.

[0027] 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, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, and the like.

[0028] 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 input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various substances (various gases) by the MFCs 241a to 241f, the opening and closing operations of the valves 243a to 243h, 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 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 boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the boat elevator 115, the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, and the like.

[0029] The controller 121 can be configured by installing the above-mentioned program recorded and 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, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory or an SSD. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to simply 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 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.

[0030] (2) Substrate processing process A method of processing a substrate as one step in the manufacturing process of a semiconductor device using the above-mentioned substrate processing apparatus, i.e., an example of a processing sequence for forming a film on wafer 200 as a substrate having recesses such as trenches, grooves, and holes, which are three-dimensional structures, formed on the surface, will be described mainly with reference to Figures 4A, 4B, 4C, and 5. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by controller 121.

[0031] In the processing sequence of this embodiment, (a1) supplying a first modifying gas to the wafer 200 to form a first modified layer 150 on at least a portion of the wafer 200; (a2) supplying a first removal gas onto the wafer 200 to remove a portion of the first modified layer 150 from the wafer 200; a first step of performing the above a predetermined number of times; (b1) supplying a processing gas to the wafer 200 to process a region where the first modified layer 150 is not formed, preferentially over a region where the first modified layer 150 is present; (b2) supplying a reaction gas to the wafer 200; a second step of performing the above a predetermined number of times after the first step; Repeat this a predetermined number of times.

[0032] That is, as shown in Fig. 4A, the first process is performed in step S10. In the first process, as shown in Fig. 4B, procedure (a1) is performed in step S10-1, and purging of the processing chamber 201 is performed in step S10-2. Procedure (a2) is performed in step S10-3, and purging of the processing chamber 201 is performed in step S10-4. In step S10-5, it is determined whether steps S10-1 to S10-4 have been performed a predetermined number of times, and if the determination is negative, the process returns to step S10-1, and if the determination is positive, the first process is terminated and the process proceeds to step S12, where the second process is performed.

[0033] 4C, in the second process, procedure (b1) is executed in step S12-1, and purging of the processing chamber 201 is executed in step S12-2. Procedure (b2) is executed in step S12-3, and purging of the processing chamber 201 is executed in step S12-4. In step S12-5, it is determined whether steps S12-1 to S12-4 have been executed a predetermined number of times. If the determination is negative, the process returns to step S12-1, and if the determination is positive, the second process is terminated and the process proceeds to step S14.

[0034] In step S14, it is determined whether the first and second steps have been performed a predetermined number of times, and if the determination is negative, the process returns to step S10, and if the determination is positive, the process ends.

[0035] 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".

[0036] As used herein, the term "layer" includes continuous and / or discontinuous layers. For example, a deposited layer may include a continuous layer, a discontinuous layer, or both.

[0037] In this specification, when we talk about the first source gas, the first adsorption inhibitory gas, the second source gas, the second adsorption inhibitory gas, and the reactive gas respectively adsorbing onto or reacting with the surface of the wafer 200, it may include not only situations in which they adsorb onto or react with the surface of the wafer 200 without being decomposed, but also situations in which they decompose or intermediates generated by the detachment of their ligands adsorb onto or react with the surface of the wafer 200.

[0038] (Wafer charge and boat load) A plurality of wafers 200 are loaded into the boat 217 (wafer charge). The shutter 219s is moved by the shutter opening / closing mechanism 115s, and the lower end opening of the manifold 209 is opened (shutter open). Thereafter, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). At this time, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b. In this way, the wafers 200 are prepared (provided) in the processing chamber 201, as shown in FIG. 1 .

[0039] (pressure and temperature regulation) After the boat loading is completed, the processing chamber 201, i.e., the space in which the wafers 200 are present, is evacuated (reduced pressure exhausted) by the vacuum pump 246 so that the interior of the processing chamber 201 is at a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Furthermore, the wafers 200 inside the processing chamber 201 are heated by the heater 207 so that the processing temperature is at a desired processing temperature. At this time, the power supplied to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the processing chamber 201 has a desired temperature distribution. Furthermore, the rotation mechanism 267 starts to rotate the wafers 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0040] (film formation process) Then, execute the following in sequence:

[0041] [a1] In this procedure, a first modifying gas is supplied to the wafer 200 in the processing chamber 201, in this embodiment, the wafer 200 having a recess on its surface, to form a first modified layer 150 on at least a portion of the wafer 200.

[0042] Specifically, the valve 243a is opened to allow a first modifying gas to flow into the gas supply pipe 232a. The flow rate of the first modifying gas is adjusted by the MFC 241a, and the first modifying gas is supplied into the processing chamber 201 through the nozzle 249a and exhausted from the exhaust port 231a. At this time, the first modifying gas is supplied to the wafer 200 from the side of the wafer 200 (first modifying gas supply). At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0043] The processing conditions for supplying the first reforming gas in this procedure are as follows: Treatment temperature: 350 to 700°C, preferably 500 to 600°C Treatment pressure: 1 to 10,000 Pa, preferably 10 to 1,333 Pa First reforming gas supply flow rate: 0.01 to 3 slm, preferably 0.1 to 1 slm First reforming gas supply time: 10 to 120 seconds, preferably 20 to 60 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm is exemplified.

[0044] 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. Furthermore, the supply flow rate refers to the flow rate of the gas supplied into the processing chamber 201. Furthermore, when the supply flow rate includes 0 slm, 0 slm means that the substance (gas) is not supplied into the processing chamber 201. These terms also apply to the following explanations.

[0045] By supplying the first modifying gas to the wafer 200 under the above-described processing conditions, the first modifying gas can be adsorbed to the adsorption sites present on the surface of the wafer 200 (see FIG. 5(a)). Specifically, this allows the first modifying gas to be discontinuously adsorbed on at least a portion of the upper surface and inner surface of the recess (the sidewall surface and bottom surface inside the recess) (see FIG. 5(a)). More specifically, this allows the first modifying gas to be adsorbed on the entire surface from the opening side to the deep side of the recess. Hereinafter, the "opening side of the recess" will be referred to as the "opening side," and the "deep side of the recess" will be referred to as the "deep side." In this specification, the "deep side of the recess" refers to a location, such as the bottom of the recess, that is more difficult for the gas supplied to the wafer 200 to reach than the opening side, and the surrounding area.

[0046] The first modifying gas may be a halogen-containing gas containing at least one of Cl, F, Br, or I. The halogen-containing gas has at least one halogen group, such as a Cl group, an F group, a Br group, or an I group, as a functional group. The first adsorption-inhibiting gas may be, for example, a simple halogen gas such as fluorine (F2) gas, chlorine (Cl2) gas, bromine (Br2) gas, or iodine (I2) gas; an interhalogen compound gas such as chlorine fluoride (ClF3) gas, bromine chloride (BrCl) gas, iodine chloride (ICl) gas, iodine fluoride (IF5) gas, bromine fluoride (BrF3) gas, or iodine bromide (IBr) gas; a hydrogen halide compound gas such as hydrogen chloride (HCl) gas, hydrogen fluoride (HF) gas, hydrogen bromide (HBr) gas, or hydrogen iodide (HI) gas; or a combination of these gases.

[0047] Furthermore, a gas containing an organic compound can be used as the first modifying gas. Examples of the gas containing an organic compound include a gas containing at least one selected from the group consisting of ether compounds, ketone compounds, amine compounds, organic hydrazine compounds, and compounds having a cyclic structure in their molecular structure. Examples of the gas containing an ether compound include a gas containing at least one of dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, isopropyl ether, furan, tetrahydrofuran, pyran, and tetrahydropyran. Examples of the gas containing a ketone compound include a gas containing at least one of dimethyl ketone, diethyl ketone, methyl ethyl ketone, and methyl propyl ketone. Examples of the gas containing an amine compound include a gas containing at least one of methylamine compounds such as monomethylamine, dimethylamine, and trimethylamine, ethylamine compounds such as monoethylamine, diethylamine, and triethylamine, and methylethylamine compounds such as dimethylethylamine and methyldiethylamine. The gas containing an organic hydrazine compound can be a gas containing at least one of methylhydrazine-based gases such as monomethylhydrazine, dimethylhydrazine, and trimethylhydrazine. The gas containing a compound having a cyclic structure can be a gas having a cyclic structure in its molecular structure that includes at least one of a cycloalkyl group, a benzene ring structure, and carbon, such as methoxycyclopentane, anisole, and trimethylene oxide. One or more of these can be used as the first adsorption inhibitory gas.

[0048] An alkyl group-containing gas containing an alkyl group can also be used. As the first modifying gas, methane (CH4) gas, ethane (C2H6) gas, propane (C3H8) gas, etc. can be used.

[0049] As the inert gas, nitrogen (N2) gas or a rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, or xenon (Xe) gas can be used. One or more of these can be used as the inert gas. This also applies to each step described below.

[0050] After the first modifying gas is adsorbed onto the surfaces of the wafers 200 (the upper and inner surfaces of the recesses), the valve 243a is closed to stop the supply of the first modifying gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gaseous substances remaining in the processing chamber 201. At this time, the valves 243d to 243f are opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c acts as a purge gas, thereby purging the space in which the wafers 200 exist, i.e., the processing chamber 201.

[0051] [a2] After step a1 is completed, a first removal gas is supplied to the wafer 200 in the processing chamber 201.

[0052] Specifically, the valve 243c is opened to allow a first removal gas to flow into the gas supply pipe 232c. The flow rate of the first removal gas is adjusted by the MFC 241c, and the first removal gas is supplied into the processing chamber 201 through the nozzle 249c and exhausted from the exhaust port 231a. At this time, the first removal gas is supplied to the wafers 200 (first removal gas supply). At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through each of the nozzles 249a to 249c.

[0053] The processing conditions for supplying the first removal gas in this procedure are as follows: Treatment temperature: 400 to 900°C, preferably 500 to 800°C Treatment pressure: 1 to 2666 Pa, preferably 10 to 1333 Pa Processing gas supply flow rate: 0.001 to 2 slm, preferably 0.01 to 1 slm Treatment gas supply time: 1 to 40 seconds, preferably 2 to 20 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm Other processing conditions may be the same as the processing conditions when the first modifying gas is supplied in step a1.

[0054] By supplying the first removal gas to the wafer 200 under the above-described processing conditions, it is possible to remove a portion of the first modified layer 150 on the surface of the wafer 200. For example, as shown in FIG. 5(b), it is possible to remove a portion of the first modified layer 150 on the upper surface of the recess and on the opening side of the recess.

[0055] The first removal gas may be, for example, a gas containing a reducing gas, an oxidizing gas, a nitriding gas, a sulfide gas, a selenide gas, a telluride gas, etc. One or more of these may be used as the reactive gas.

[0056] The reducing gas may be, for example, one or more of hydrogen (H) gas, deuterium (D) gas, borane (BH) gas, diborane (BH) gas, carbon monoxide (CO) gas, ammonia (NH) gas, monosilane (SiH) gas, disilane (SiH) gas, trisilane (SiH) gas, monogermane (GeH) gas, digermane (GeH) gas, etc. The reactive gas may be, for example, an oxidizing gas containing oxygen (O). The oxidizing gas may be, for example, one or more of gases containing oxygen (O), ozone (O), water vapor (H0), a mixed gas of H and O, hydrogen peroxide (H0), nitrous oxide (N0), etc. As the nitriding gas, for example, one or more of hydrogen nitride gases such as ammonia (NH3) gas, diazene (N2H2) gas, hydrazine (N2H4) gas, and N3H8 gas can be used. As the sulfide gas, for example, a gas containing sulfane (H2S), disulfane (H2S2), diammonium sulfide ((NH4)2S), dimethyl sulfide ((CH3)2S), etc. can be used. As the sulfide gas, for example, one or more of these can be used. As the selenide gas, for example, a gas containing selenium (H2Se), diselane (H2Se2), dimethylselenium ((CH3)2Se), etc. can be used. As the selenide gas, for example, one or more of these can be used. As the telluride gas, for example, a gas containing terane (H2Te), diterane (H2Te2), dimethylselenium ((CH3)2Te), etc. can be used. As the telluride gas, for example, one or more of these can be used.

[0057] After removing a portion of the first modified layer 150 on the surface of the wafer 200 (the upper surface and inner surface of the recess), the valve 243c is closed to stop the supply of the first removal gas into the processing chamber 201. Then, the processing chamber 201 is purged in the same procedure as the purging performed after completing step a1.

[0058] [Perform the specified number of times a] By performing the first process, which involves performing step a1, purging, step a2, and purging in this order, a predetermined number of times (n1 times, where n1 is an integer of 1 or greater), it is possible to form a first modified layer 150, from which a portion has been removed, on the surface of the wafer 200 (the inner surface of the recess). Note that the purging process may be omitted from the first process. Furthermore, steps a1 and a2 may be performed at least partially simultaneously.

[0059] [b1] A processing gas is supplied to the wafer 200 in the processing chamber 201. That is, the processing gas is supplied to the wafer 200 after the first modified layer 150 has been formed on the upper surface and inner surface of the recess and a portion of the first modified layer 150 has been removed.

[0060] Specifically, the valve 243b is opened to allow the processing gas to flow into the gas supply pipe 232b. The processing gas has a flow rate adjusted by the MFC 241b, is supplied into the processing chamber 201 through the nozzle 249b, and is exhausted from the exhaust port 231a. At this time, the processing gas is supplied to the wafer 200 (processing gas supply). At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0061] The processing conditions for supplying the processing gas in this procedure are as follows: Treatment temperature: 400 to 900°C, preferably 500 to 800°C Treatment pressure: 1 to 5000 Pa, preferably 10 to 1333 Pa Processing gas supply flow rate: 0.01 to 2 slm, preferably 0.1 to 1 slm Treatment gas supply time: 5 to 50 seconds, preferably 6 to 30 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm Other processing conditions may be the same as the processing conditions when the first modifying gas is supplied in step a1.

[0062] By supplying the processing gas to the wafer 200 under the above-mentioned processing conditions, the processing gas can be adsorbed to the area on the surface of the wafer 200 where the first modified layer 150 has been partially removed, thereby forming a processing layer 152 (see Figure 5(c)).

[0063] The processing gas may be, for example, a silane-based gas containing silicon (Si). The silane-based gas may be, for example, a gas containing Si and a halogen, i.e., a halosilane-based gas. Halogen includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), and the like. That is, the halosilane-based gas has at least one halogen group, such as a chloro (Cl) group, a fluoro (F) group, a bromo (Br) group, or an iodine (I) group, as a functional group.

[0064] The processing gas may be, for example, a chlorosilane-based gas such as monochlorosilane (SiH3Cl) gas, dichlorosilane (SiH2Cl2) gas, trichlorosilane (SiHCl3) gas, tetrachlorosilane (SiCl4) gas, hexachlorodisilane (Si2Cl6) gas, octachlorotrisilane (Si3Cl8) gas, etc. One or more of these may be used as the processing gas.

[0065] As the processing gas, in addition to chlorosilane-based gases, for example, fluorosilane-based gases such as tetrafluorosilane (SiF4) gas, trifluorosilane (SiHF3) gas, and difluorosilane (SiH2F2) gas, bromosilane-based gases such as tetrabromosilane (SiBr4) gas, tribromosilane (SiHBr3) gas, and dibromosilane (SiH2Br2) gas, and iodosilane-based gases such as tetraiodosilane (SiI4) gas, triiodosilane (SiHI3) gas, and diiodosilane (SiH2I2) gas can also be used. One or more of these can be used as the processing gas.

[0066] Furthermore, as the processing gas, for example, a gas having Si as the first element and an organic ligand can be used. As the gas having Si and an organic ligand, for example, an aminosilane-based gas such as tetrakis(dimethylamino)silane (Si[N(CH3)2]4) gas, tris(dimethylamino)silane (Si[N(CH3)2]3H) gas, bis(diethylamino)silane (Si[N(C2H5)2]2H2) gas, bis(tertiarybutylamino)silane (SiH2[NH(C4H9)]2) gas, or (diisopropylamino)silane (SiH3[N(C3H7)2]) gas can be used. As the processing gas, a gas having Si as the first element and a hydrogen (H) group can be used. As the gas having Si and an H group, for example, monosilane (SiH4) or disilane (Si2H6) can be used, and one or more of these can be used as the first source gas.

[0067] In addition to these, the processing gas may also be a gas containing Si and an alkyl group as an organic ligand, i.e., an alkylsilane gas. The alkyl group may be linear or branched. Examples of the alkyl group include methyl, ethyl, n-propyl, n-butyl, isopropyl, isobutyl, sec-butyl, and tert-butyl groups.

[0068] Furthermore, for example, one or more of tungsten (W), titanium (Ti), molybdenum (Mo), tantalum (Ta), cobalt (Co), yttrium (Y), ruthenium (Ru), hafnium (Hf), zirconium (Zr), aluminum (Al), boron (B), gallium (Ga), indium (In), phosphorus (P), carbon (C), etc. can be used.

[0069] The processing gas may be, for example, a gas containing a first element and a halogen element. Examples of such gases include hexachlorotungsten (WCl6), hexafluorotungsten (WF6), titanium tetrachloride (TiCl4), titanium tetrafluoride (TiF4), molybdenum pentachloride (MoCl5), molybdenum pentafluoride (MoF5), molybdenum dichloride dioxide (MoO2Cl2), molybdenum tetrachloride oxide (MoOCl4), tantalum pentachloride (TaCl5), tantalum pentafluoride (TaF5), cobalt difluoride (CoF2), and tungsten hexachloride (Tungsten hexafluoride). Examples of usable fluorides include cobalt trichloride (CoCl2), yttrium trifluoride (YF3), yttrium trichloride (YCl3), ruthenium trichloride (RuCl3), ruthenium trifluoride (RuF3), hafnium tetrachloride (HfCl4), hafnium tetrafluoride (HfF4), zirconium tetrachloride (ZrCl4), zirconium tetrafluoride (ZrF4), aluminum trichloride (AlCl3), aluminum trifluoride (AlF3), and the like. The first gas may be, for example, boron trifluoride (BF3), boron trichloride (BCl3), gallium trifluoride (GaF3), gallium trichloride (GaCl3), indium trifluoride (InF3), indium trichloride (InCl3), phosphorus trifluoride (PF3), phosphorus pentafluoride (PF5), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), carbon tetrafluoride (CF4), carbon tetrachloride (CCl4), trifluoromethane (CHF3), fluoromethane (CH3F), trichloromethane (CHCl3), chloromethane (CH3Cl), etc. The process gas may be, for example, a gas having the first element and a Br group, or a gas having the first element and an I group.

[0070] In addition, the processing gas may be, for example, a gas having a first element and an organic ligand, or a gas having a first element and a hydrogen group. The organic ligand may be, for example, an alkyl group, a cycloalkyl group, an alkoxide group, a phenyl group, or a cyclopentadienyl group. Examples of the first source gas include hexadimethylaminoditungsten (W2[N(CH3)2]6), bistertiarybutylimidobisdimethylamidotungsten ((t-C4H9NH)2W=(Nt-C4H9)2), tetrakisethylmethylaminotitanium (Ti[N(C2H5)(CH3)]4), bisethylcyclopentadienylruthenium (Ru(CH2CH3)Cp)2), biscyclopentadienylruthenium (Ru(Cp)2), tetrakisethylmethylaminohafnium (Hf[N(CH3)(CH2CH3)]4), tetrakisdiethylaminohafnium (Hf[N(CH2CH3)2]4), tetrakisdimethylaminohafnium (Hf[N(C H3)2]4), trisdimethylaminocyclopentadienylhafnium ((Cp)Hf[N(CH3)2]3), tetrakisethylmethylaminozirconium (Zr[N(CH3)Cp]4), tetrakisdiethylaminozirconium (Zr[N(CH2CH3)2]4), tetrakisdimethylaminozirconium (Zr[N(CH3)2]4), trisdimethylaminocyclopentadienylzirconium ((Cp)Zr[N(CH3)2]3), trimethylaluminum (Al(CH3)3), boron (BH3), trimethylgallium (Ga(CH3)3), trimethylindium (In(CH3)3), phosphine (PH3), methane (CH4), etc. can be used.

[0071] Here, the first modifying gas is a gas that inhibits the adsorption of the processing gas onto the wafer 200. Specifically, functional groups contained in the first modifying gas and formed (exposed) on the upper and inner surfaces of the recesses inhibit the adsorption of the processing gas onto the wafer 200 (the upper and inner surfaces of the recesses). As a result, the processing gas does not adsorb onto the first modified layer 150 on the surface of the wafer 200, but rather onto the portion of the first modified layer 150 from which a portion has been removed. For example, in this embodiment, as shown in FIG. 5(c), the processing gas adsorbs onto the upper surface and opening side of the recesses on the wafer 200. Generally, gas supplied to the wafer 200 easily reaches the upper surface and opening side of the recesses on the wafer 200, but has difficulty reaching the deeper portions of the recesses. Therefore, by adjusting the processing conditions of steps a1 and a2, and controlling the distribution of the first modified layer 150 formed on the wafer 200 or the distribution of the first modified layer 150 removed from the wafer 200, the position of the processing gas adsorbed onto the wafer 200 can be controlled.

[0072] Here, in this specification, "the processing gas does not adsorb onto the first modified layer 150" includes not only the case where the processing gas does not adsorb onto the first modified layer at all, but also the case where an extremely small amount of processing gas adsorbs onto the first modified layer, for example, the case where the processing gas adsorbs onto approximately 1% of the first modified layer on the wafer 200, and preferably onto less than 1% of the first modified layer.

[0073] By performing steps a1, a2, and b1, a layer in which the first modifying gas and the processing gas are adsorbed onto the adsorption sites provided on the surface of the wafer 200 can be formed.

[0074] After step b1, the valve 243b is closed to stop the supply of the processing gas into the processing chamber 201. Then, the processing chamber 201 is purged in the same manner as the purging performed after step a1.

[0075] [b2] After step b1 is completed, a reaction gas is supplied to the wafer 200.

[0076] Specifically, the valve 243c is opened to allow the reactive gas to flow into the gas supply pipe 232c. The reactive gas has a flow rate adjusted by the MFC 241c, is supplied into the processing chamber 201 through the nozzle 249c, and is exhausted from the exhaust port 231a. At this time, the reactive gas is supplied to the wafer 200 (reactive gas supply). At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0077] The processing conditions for supplying the reaction gas in this procedure are as follows: Treatment pressure: 1 to 4000 Pa, preferably 10 to 1000 Pa Reactant gas supply flow rate: 0.1 to 10 slm, preferably 1 to 5 slm Reaction gas supply time: 1 to 120 seconds, preferably 10 to 60 seconds Other processing conditions may be the same as the processing conditions when the first modifying gas is supplied in step a1.

[0078] By supplying the reactive gas to the wafer 200 under the above-described processing conditions, at least a portion of the processing layer 152 formed on the inner surface of the recess reacts with the reactive gas, thereby forming a first layer 154 (see FIG. 5(d)).

[0079] For example, the reactive gas may be a gas containing the above-mentioned reducing gas, oxidizing gas, nitriding gas, sulfide gas, selenide gas, telluride gas, or the like. One or more of these may be used as the reactive gas. Here, the first removal gas and the reactive gas may be gases having the same molecular structure. Alternatively, the first removal gas and the reactive gas may be gases having different molecular structures. In step b2, at least a portion of the first modified layer 150 on the wafer 200 may be removed by the reactive gas in parallel with the formation of the first layer 154.

[0080] After step b2, the valve 243c is closed to stop the supply of the reactive gas into the processing chamber 201. Then, the processing chamber 201 is purged in the same manner as the purging performed after step a1.

[0081] [Perform the specified number of times b] By performing the second process, which involves performing step b1, a purge process, step b2, and another purge process in this order, a predetermined number of times (n2 times, where n2 is an integer of 1 or greater), it is possible to form a first layer 154 of a predetermined thickness on the surface of the wafer 200 (the inner surface of the recess). The purge process may be omitted from the second process. Alternatively, steps b1 and b2 may be partially performed simultaneously to cause the process gas and the reactive gas to react in the gas phase. Alternatively, step b2 may be omitted and step b1 may be performed n2 times. In this case, it is possible to form a process layer 152 of a predetermined thickness on the surface of the wafer 200 (the inner surface of the recess).

[0082] [Perform the specified number of times] By performing the first cycle, which involves performing the first and second steps described above in this order, a predetermined number of times (n times, where n is an integer equal to or greater than 1), a film 160 having a desired composition can be formed on the upper surface of the wafer 200 and the opening side of the recess. For example, in step a1 of the second cycle, a first modified layer 150 is formed on the upper surface of the wafer 200 and the opening side of the recess, including the surface of the first layer 154, as shown in FIG. 5(e). In step a2, a portion of the first modified layer 150 on the upper surface of the wafer 200 and the opening side of the recess is removed as shown in FIG. 5(f). In step b1, a processed layer 152 is formed on the upper surface of the wafer 200 and the opening side of the recess, as shown in FIG. 5(g). In step b2, a thicker first layer 154 is formed on the upper surface of the wafer 200 and the opening side of the recess, as shown in FIG. 5(h). By further repeating the first cycle, the opening gradually narrows, allowing an air gap G to be formed as shown in FIG. 5(i).

[0083] (After purging and atmospheric pressure recovery) After the film formation process is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a to 249c into the process chamber 201 and exhausted from the exhaust port 231a. This purges the process chamber 201, and gases and reaction by-products remaining in the process chamber 201 are removed from the process chamber 201 (after-purge). Thereafter, the atmosphere in the process chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the process chamber 201 is returned to normal pressure (atmospheric pressure return).

[0084] (Boat unloading and wafer discharging) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the boat 217 is carried out of the reaction tube 203 (boat unloading). After the boat unloading, the shutter 219s is moved, and the lower end opening of the manifold 209 is sealed by the O-ring 220c and the shutter 219s (shutter close). Thereafter, the processed wafers 200 are taken out of the boat 217 (wafer discharging).

[0085] (3) Effects of this mode According to this aspect, in addition to the above-mentioned advantages, one or more of the following advantages can be obtained.

[0086] (a) By performing step a2 after step a1, it is possible to control the distribution of the first modified layer 150 in the recess of the wafer 200. This makes it possible to control the areas where processing is likely to proceed in the second step. For example, it is possible to form a first modified layer with the following distribution: (1) The density of the first modified layer formed in the center of the recess is higher than that in the opening and deep parts of the recess. (2) The density of the first modified layer formed in the deep part of the recess is higher than that in the opening part of the recess. (3) The density of the first modified layer is approximately uniform from the opening of the recess to the depth thereof.

[0087] (b) The first removal gas and the reactive gas may have the same molecular structure. In this case, a common system can be used as the reactive gas supply system and the first removal gas supply system. This simplifies the device configuration.

[0088] (c) The first removal gas and the reactive gas may have different molecular structures. In this case, gases with different reactivities may be used in steps a2 and b2. For example, when forming an oxide film as the film 160, O2 may be used as the first removal gas and O3, which is more reactive than O2, may be used as the reactive gas. Furthermore, when forming an oxynitride film as the film 160, NH3 may be used as the first removal gas and O3, which is more reactive than N2O, may be used as the reactive gas. In other words, a gas with a lower reactivity than the reactive gas may be used as the first removal gas. In these cases, excessive oxidation (modification) of the processing layer 152, first layer 154, and underlying film already formed on the wafer 200 can be suppressed.

[0089] On the other hand, for example, when an oxide film is formed as the film 160, O may be used as the first removal gas and O may be used as the reactive gas. Furthermore, when an oxynitride film is formed as the film 160, NH may be used as the first removal gas and O may be used as the reactive gas. That is, a gas with higher reactivity than the reactive gas may be used as the first removal gas. This allows oxidation (modification) of the processing layer 152 or the first layer 154 already formed on the wafer 200, or the underlying film of the processing layer 152 or the first layer 154, to proceed in step a2 as well.

[0090] (d) It is preferable to make the exposure amount of the reactive gas to the wafer 200 in step (b2) greater than the exposure amount of the first modifying gas to the wafer 200 in step (a2). This makes it easier for the reactive gas to reach the deeper part of the recess. Furthermore, when the first removal gas and the reactive gas have the same molecular structure, the reaction between the first removal gas (reactive gas) and the first modifying gas is more likely to occur. This makes it easier for the reaction to proceed sufficiently even in the deeper part of the recess, making it easier to perform uniform processing throughout the entire recess.

[0091] By satisfying at least one of the following conditions 1 to 6, the amount of reactive gas exposed to the wafer 200 in step (b2) can be made greater than the amount of first modifying gas exposed to the wafer 200 in step (a2).

[0092] 1. The reactant gas supply time in step b2 is set longer than the first modifying gas supply time in step a1. 2. The processing pressure in step b2 is set higher than the processing pressure in step a1. 3. The reactant gas supply flow rate in step b2 is set to be greater than the first modifying gas supply flow rate in step a1. 4. The inert gas supply flow rate in step b2 is set to be less than the inert gas supply flow rate in step a1. 5. The partial pressure of the reaction gas in the processing chamber 201 in step b2 is made higher than the partial pressure of the first modifying gas in the processing chamber 201 in step a1. 6. The molar fraction of the reactive gas in the gas inside the processing chamber 201 in step b2 is set to be greater than the molar fraction of the first modifying gas in step a1.

[0093] (e) The upper and inner surfaces of the recesses to which the first modifying gas is adsorbed are preferably in a state in which first functional groups derived from the first modifying gas are exposed, and in step (a2), at least a portion of the first functional groups constituting at least a portion of the first modified layer are preferably substituted with second functional groups having higher reactivity with the processing gas than the first functional groups. In this case, the first modified layer can be removed in a short time. Therefore, a decrease in the number of substrates that can be processed per unit time (throughput) can be suppressed.

[0094] (f) It is preferable that either (1) or (2) below be true: (1) The first modifying gas and the processing gas contain a halogen element. (2) The first modifying gas and the process gas are organic compounds or have organic ligands.

[0095] In such a case, the first modified layer is likely to inhibit the adsorption of the processing gas onto the wafer 200. This makes it possible to more precisely control the areas where processing is likely to proceed in the second step.

[0096] (g) When a film is formed on the wafer 200 in the second step, it is preferable that the first modifying gas does not contain a main constituent element of the film, which makes it easier to form a film preferentially on regions where the first modified layer is not formed compared to regions where the first modified layer is formed.

[0097] (h) The first removal gas may include a gas activated by plasma. An example of the configuration of the process furnace 202 in this case will be described with reference to FIG. 6. Elements that are substantially the same as those described in FIG. 1 are denoted by the same reference numerals, and their description will be omitted. FIG. 6 is an example of a cross-sectional view of the process furnace 202 taken along line AA of FIG. 1. A buffer chamber 237 partitioned by a partition wall 237a is provided within the reaction tube 203, and a nozzle 249c is disposed within the buffer chamber 237. Two rod-shaped electrodes 269 and 270, each made of a conductor, are provided within the buffer chamber 237, introduced into the buffer chamber 237 from the lower portion of the inner wall of the reaction tube 203 and extending upward toward the upper portion of the reaction tube 203 (the front side of the drawing). The rod-shaped electrodes 269 and 270 are each disposed parallel to the nozzle 249c. The rod-shaped electrodes 269 and 270 are covered from their upper to lower portions by an electrode protection tube 275. One of the rod-shaped electrodes 269, 270 is connected to a high-frequency power supply 273 via a matching box 272, and the other is connected to earth, which is a reference potential. By applying radio-frequency (RF) power between the rod-shaped electrodes 269, 270 from the high-frequency power supply 273, the first removal gas can be activated by plasma in a plasma generation region 224 between the rod-shaped electrodes 269, 270. The rod-shaped electrodes 269, 270 and the electrode protection tube 275 mainly constitute a plasma excitation unit (activation mechanism) that excites (activates) the gas into a plasma state.

[0098] When the first removal gas is activated by plasma, the reactivity of the first removal gas increases and decreases (deactivates) over time. This further increases the difference in the ease of removal of the first modified layer between areas that are easily reached by the first removal gas and areas that are difficult to reach. This makes it possible, for example, to make the first modified layer near the opening of the recess more easily removable and the first modified layer in the center or deeper part of the recess more difficult to remove. Therefore, the areas where the treatment is likely to proceed in the second step can be controlled more precisely.

[0099] (i) The number of times N that the first and second steps are repeated is preferably 2 or more. By repeating the steps 2 or more times, it is possible to facilitate the progress of the processing of the target position.

[0100] <Modification> The processing sequence in this embodiment can be modified as shown in the following modified examples. These modified examples can be combined as desired. Unless otherwise specified, the processing procedures and processing conditions in each step of each modified example can be the same as the processing procedures and processing conditions in each step of the above-described processing sequence.

[0101] (Variation 1) As shown in the process sequence of FIG. 7A, the third process (S30) is performed after the first process and before the second process. In the third process, as shown in FIG. 7B, procedure (c) is performed in step S30-1. Procedure (c) is a process of supplying a second modifying gas that forms a second modified layer 158 to at least a portion of the region on the wafer 200 where the first modified layer 150 is not formed. In step S30-2, a purge process is performed inside the process chamber 201. In step S30-3, it is determined whether procedure (c) has been performed a predetermined number of times. If the determination is negative, the process returns to step S30-1. If the determination is positive, the third process is terminated and the process proceeds to step S12, where the second process is performed.

[0102] (A) Effects of Modification 1 This modification also provides at least some of the effects of the above-described embodiment. Furthermore, this modification also provides one or more of the following effects.

[0103] (a) By carrying out the third step in this way, the distribution of the modified layer (one or both of the first modified layer and the second modified layer) within the pattern can be controlled in more detail. Specifically, for example, a modified layer having the following distribution can be formed.

[0104] (1) The densities of the first modified layer 150 and the second modified layer 158 can be made approximately uniform from the opening to the depth of the recess. In this case, the first modified layer 150 is formed deep into the recess in the first step (FIG. 8(1)(a)), and at least a portion of the first modified layer 150 on the opening side is removed (FIG. 8(1)(b)). In the third step, the second modified layer 158 is formed in the portion of the first modified layer 150 on the opening side from which at least a portion has been removed (FIG. 8(1)(c)).

[0105] (2) The densities of the first modified layer and the second modified layer formed in the opening and deep portions of the recess can be made higher than those in the center of the recess. In this case, the first modified layer 150 is formed deep into the recess in the first step (FIG. 8(2)(a)), and at least a portion of the first modified layer 150 is removed to a position deeper than the middle of the recess (FIG. 8(2)(b)), and the second modified layer 158 is formed on the opening side in the third step (FIG. 8(2)(c)).

[0106] (3) When the molecular structures of the first and second modifying gases are different, modified layers with different adsorption inhibition effects for the processing gas can be formed at the deeper side, the central area, and the opening side of the recess. For example, a second modified layer against the processing gas can be formed at the opening side, a first modified layer with a weaker adsorption inhibition effect than the second modified layer can be formed near the central area, and the first and second modified layers can be made difficult to form at the deeper side. In this case, the first modified layer 150 is formed deeper than the middle part of the recess (to the extent that it is not formed at the bottom) in the first step (FIG. 8(3)(a)), and at least a portion of the first modified layer 150 on the opening side is removed (FIG. 8(3)(b)). In the third step, a second modified layer 158 is formed in the portion of the first modified layer 150 on the opening side from which at least a portion has been removed (FIG. 8(3)(c)). This allows the ease of processing to gradually increase toward the deeper side of the recess, where the gas is less likely to reach. Therefore, the inside of the recess This allows the treatment at the first modified layer to proceed uniformly (facilitating the formation of a film of uniform thickness). For example, consider the case where the first modified layer and the second modified layer are formed as layers containing X1 and X2 groups, which are functional groups of different halogen elements X1 and X2, respectively. In this case, by making the atomic number of X2 smaller than that of X1 (for example, by using Cl and F as X1 and X2, respectively), the adsorption inhibition effect of the second modified layer can be made greater than that of the first modified layer.

[0107] (b) The exposure amount of the second modifying gas to the wafer 200 in step (c) is preferably smaller than the exposure amount of the first modifying gas to the wafer 200 in step (a1). In this case, the second modifying gas is supplied to the opening side of the recess after the first modified layer is removed in step (b2), so the first modified layer is less likely to inhibit the formation of the second modified layer. Therefore, the above-mentioned effect (control of the distribution of the modified film) can be easily achieved.

[0108] (c) When the first and second reforming gases have the same molecular structure, the first reforming gas supply system and the second reforming gas supply system can be made common, thereby simplifying the device configuration.

[0109] (d) In step (a2), it is preferable to replace at least a portion of the first functional groups on the wafer 200 as at least a portion of the first modified layer with second functional groups having a higher reactivity to the process gas than the first functional groups, and in step (c), to replace at least a portion of the second functional groups with third functional groups as at least a portion of the second modified layer having a lower reactivity to the process gas than the second functional groups. In this case, the removal of the first modified layer and the formation of the second modified layer can be completed in a short time. Therefore, a decrease in the number of substrates that can be processed per unit time (throughput) can be suppressed.

[0110] (e) It is preferable that either (1) or (2) below be true: (1) The first modifying gas, the processing gas, and the second modifying gas contain a halogen element. (2) The first modifying gas, the process gas, and the second modifying gas are organic compounds or have organic ligands.

[0111] In such a case, the first modified layer and the second modified layer are likely to inhibit the adsorption of the processing gas onto the wafer 200. This makes it possible to more precisely control the areas where processing is likely to proceed in the second step.

[0112] (f) When a film is formed on the wafer 200 in the second step, the first modifying gas and the second modifying gas preferably do not contain the main constituent elements of the film, which makes it easier to form the film preferentially on regions where at least one of the first modified layer and the second modified layer is not formed, compared to regions where at least one of the first modified layer and the second modified layer is formed.

[0113] (g) The first removal gas may include a gas activated by plasma. When the first removal gas is activated by plasma, the reactivity of the first removal gas increases and can be reduced (deactivated) over time. This can further increase the difference in the ease of removal of the first modified layer between areas that are easily reached by the first removal gas and areas that are difficult to reach. For example, the first modified layer near the opening of the recess can be made more easily removed, while the first modified layer in the center or deeper part of the recess can be made more difficult to remove. Therefore, the areas where treatment is likely to proceed in the second step can be controlled in more detail.

[0114] (Variation 2) As in the processing sequence shown in FIG. 9A, after the first and second processes are performed a predetermined number of times, the fourth process (S40) is performed. In the fourth process, as shown in FIG. 9B, procedure (d) is performed in step S40-1. Procedure (d) is a process of supplying a second removal gas that removes a portion of the first modified layer 150 from the wafer 200. In step S40-2, a purge process is performed inside the processing chamber 201. In step S40-3, it is determined whether or not process (c) has been performed a predetermined number of times. If the determination is negative, the process returns to step S40-1. If the determination is positive, the fourth process is terminated.

[0115] (A) Effect of Modification 2 This modification also provides at least some of the effects of the above-described aspects and modifications. Furthermore, this modification also provides one or more of the following effects.

[0116] (a) If the first modified layer 150 remains on the substrate after the second step, the processing in that area will be more difficult to perform in the second step than in other areas. This can lead to a decrease in the uniformity of the processing in the area on the wafer 200 where the processing is desired. For example, when a film is formed in step b, the uniformity of the formed film may be reduced due to the occurrence of areas where the film is not sufficiently formed (pinholes) or increased surface roughness of the film. In the fourth step, by supplying a second removal gas, at least a portion of the first modified layer remaining on the wafer 200 after the second step can be removed. This can improve the uniformity of the film (processing uniformity) in the area on the wafer 200 where the processing is desired.

[0117] (b) The first removal gas and the second removal gas may be gases with the same molecular structure. The second removal gas and the reactive gas may be gases with the same molecular structure. The first removal gas, the second removal gas, and the reactive gas may be gases with the same molecular structure. This allows two or more of the first removal gas supply system, the second removal gas supply system, and the reactive gas supply system to be standardized. This simplifies the device configuration.

[0118] (c) The first removal gas and the second removal gas may be gases with different molecular structures. The second removal gas and the reactive gas may be gases with different molecular structures. The first removal gas, the second removal gas, and the reactive gas may be gases with different molecular structures. This allows gases with different reactivities to be used in two or more of steps a2, b2, and d. This allows for control over the promotion or suppression of modification of the treatment layer 152, the first layer 154, and the base film.

[0119] (d) The amount of exposure of the wafer 200 to the second removal gas in step (d) is preferably greater than the amount of exposure of the wafer 200 to the first removal gas in step (a2). This makes it easier for the second removal gas to reach the deeper side of the recess. Also, the reaction between the second removal gas and the first modified layer 150 is more likely to occur. Therefore, removal of the first modified layer 150 can be more easily progressed even in the deeper side of the recess. This makes it easier to perform uniform processing throughout the entire recess.

[0120] (e) It is preferable to make the amount of exposure of the wafer 200 to the second removal gas in step (d) greater than the amount of exposure of the reaction gas to the wafer 200 in step (b2). This makes it easier for the second removal gas to reach the deeper side of the recess. Also, it makes it easier for the second removal gas to react with the first modified layer. Therefore, removal of the first modified layer 150 can be sufficiently facilitated even in the deeper side of the recess. This makes it easier to perform uniform processing throughout the entire recess.

[0121] (f) In step (a2), it is preferable to replace at least a portion of the first functional groups on the wafer 200 as at least a portion of the first modified layer 150 with second functional groups having a higher reactivity to the process gas than the first functional groups, and in step (c), to replace at least a portion of the second functional groups with third functional groups as at least a portion of the second modified layer 158 having a lower reactivity to the process gas than the second functional groups. By such replacement, the first modified layer 150 can be removed.

[0122] (Variation 3) 10, after the first, third, and second steps are performed a predetermined number of times, the fourth step (S40) is performed, and this is repeated a predetermined number of times to complete the process. In this modification 3, the second removal gas is a gas that removes at least a portion of the first modified layer 150 and at least a portion of the second modified layer 158.

[0123] (A) Effect of Modification 3 This modification also provides at least some of the effects of the above-described aspect and modifications 1 and 2. Furthermore, this modification also provides one or more of the following effects.

[0124] (a) As described in Modification 1, the distribution of one or both of the first modified layer and the second modified layer within the pattern can be controlled in more detail. In addition, as described in Modification 2, both fourth steps can improve the uniformity of the processing within the region on the wafer 200 where the processing is desired to proceed.

[0125] <Other Aspects of the Present Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0126] For example, in the above-described embodiment, a case where a film formation process is performed in step b has been described, but the present disclosure is not limited to this. By using the technology of the present disclosure, it is possible to control areas on the wafer 200 where the process is likely to proceed and areas where it is inhibited. For example, the technology of the present disclosure can also be applied when etching a film on the wafer 200 in step b. In such a case, it is possible to control areas where the etching process is likely to proceed and areas where it is inhibited by controlling the distribution of one or both of the first modified layer 150 and the second modified layer 158.

[0127] It is preferable that the recipes used for each process are individually prepared according to the process content and recorded and stored in the storage device 121c via an electric communication line or the external storage device 123. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from the multiple recipes recorded and stored in the storage device 121c. This makes it possible to form films with various film types, composition ratios, film qualities, and film thicknesses with good reproducibility using a single substrate processing apparatus. It also reduces the burden on the operator, prevents operational errors, and enables each process to be started quickly.

[0128] 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, for example. 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.

[0129] In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace. Furthermore, in the above-described embodiment, an example of activating a gas using heat or plasma has been described. However, the present disclosure is not limited thereto. For example, the present disclosure can be suitably applied to a case where a gas is activated by irradiating the gas with electromagnetic waves using a lamp or the like. Even when using these substrate processing apparatuses, each process can be performed using the same process procedures and conditions as in the above-described embodiment and modified examples, and the same effects as in the above-described embodiment and modified examples can be obtained.

[0130] 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]

[0131] 200 wafers (substrates)

Claims

1. (a1) supplying a first modifying gas to a substrate, the first modifying gas forming a first modified layer on at least a portion of the substrate; (a2) supplying a first removal gas to the substrate, the first removal gas removing a portion of the first modified layer from the substrate; a first step of performing the above a predetermined number of times; (b1) supplying a processing gas to the substrate to process a region where the first modified layer is not formed preferentially over a region where the first modified layer is present; (b2) supplying a reaction gas to the substrate; a second step of performing the above a predetermined number of times after the first step; a predetermined number of times.

2. the first removal gas and the reaction gas have the same molecular structure; The substrate processing method according to claim 1 .

3. the first removal gas and the reaction gas have molecular structures different from each other; The substrate processing method according to claim 1 .

4. The exposure amount of the first removal gas to the substrate in (a2) is set to be smaller than the exposure amount of the reaction gas to the substrate in (b2). The substrate processing method according to claim 1 .

5. After the first step and before the second step, (c) supplying a second modifying gas to the substrate, the second modifying gas forming a second modified layer in at least a part of an area on the substrate where the first modified layer is not formed; The method further comprises a third step comprising: The substrate processing method according to claim 1 .

6. (c) setting the exposure amount of the second modifying gas to the substrate to be smaller than the exposure amount of the first modifying gas to the substrate to be in (a1); The substrate processing method according to claim 5 .

7. The molecular structure of the second reforming gas is the same as the molecular structure of the first reforming gas. The substrate processing method according to claim 5 .

8. The second step is carried out multiple times, (d) supplying a second removal gas to the substrate, the second removal gas removing at least a portion of the first modified layer from the substrate; a fourth step, which is carried out after the second step is carried out a predetermined number of times; The method of claim 1 , further comprising:

9. After the first step, the third step, and the second step are performed a predetermined number of times, (d) supplying a second removal gas to the substrate, the second removal gas removing at least a portion of the first modified layer and at least a portion of the second modified layer from the substrate; The method of claim 5 further comprising:

10. The molecular structure of the second removal gas is the same as the molecular structure of the first removal gas. The substrate processing method according to claim 8 or 9.

11. The exposure amount of the second removal gas to the substrate in (d) is set to be greater than the exposure amount of the first removal gas to the substrate in (a2). The substrate processing method according to claim 8 or 9.

12. The molecular structure of the second removal gas is the same as the molecular structure of the reaction gas. The substrate processing method according to claim 8 or 9.

13. The exposure amount of the second removal gas to the substrate in (d) is set to be greater than the exposure amount of the reaction gas to the substrate in (b2). The substrate processing method according to claim 8 or 9.

14. (a1) forming the first modified layer includes forming a first functional group on the substrate; the removal of the first modified layer in (a2) includes substituting a portion of the first functional groups on the substrate with second functional groups having a higher reactivity with the processing gas than the first functional groups; The substrate processing method according to claim 1 .

15. (1) The first modifying gas and the processing gas contain a halogen element. (2) The first modifying gas and the processing gas are organic compounds or have organic ligands; 2. The substrate processing method according to claim 1, wherein (1) or (2) is satisfied.

16. In the second step, a film containing a predetermined element contained in the processing gas as a main constituent element is formed on the substrate, (a1) is carried out under conditions in which a substance containing the predetermined element is not formed on the substrate; The substrate processing method according to claim 1 .

17. the first removal gas includes a gas activated by plasma; The substrate processing method according to claim 1 .

18. (a1) supplying a first modifying gas to a substrate, the first modifying gas forming a first modified layer on at least a portion of the substrate; (a2) supplying a first removal gas to the substrate, the first removal gas removing a portion of the first modified layer from the substrate; a first step of performing the above a predetermined number of times; (b1) supplying a processing gas to the substrate to process an area where the first modified layer is not formed preferentially over an area where the first modified layer that forms a first substance on the substrate is present; (b2) supplying a reaction gas to the substrate; a second step of performing the above a predetermined number of times after the first step; a predetermined number of times.

19. a first modifying gas supply system that supplies a first modifying gas to form a first modified layer on at least a portion of the substrate; a first removal gas supply system that supplies a first removal gas that removes a portion of the first modified layer from above the substrate; a processing gas supply system that supplies a processing gas for processing a region where the first modified layer is not formed preferentially to a region where the first modified layer is present; a reaction gas supply system that supplies a reaction gas; (a1) supplying the first modifying gas to the substrate; (a2) supplying the first removal gas to the substrate; a first process including performing the above a predetermined number of times; (b1) supplying the process gas to the substrate; (b2) supplying the reaction gas to the substrate; a second process in which the above-mentioned step is performed a predetermined number of times after the first process; A process of performing the above a predetermined number of times; a control unit configured to be able to control the first modifying gas supply system, the first removal gas supply system, the process gas supply system, and the reactive gas supply system so that The substrate processing apparatus has:

20. (a1) supplying a first modifying gas to a substrate, the first modifying gas forming a first modified layer on at least a portion of the substrate; (a2) supplying a first removal gas to the substrate, the first removal gas removing a portion of the first modified layer from the substrate; a first procedure of performing the above a predetermined number of times; (b1) supplying a processing gas to the substrate for processing a region where the first modified layer is not formed preferentially over a region where the first modified layer is present; (b2) supplying a reactive gas to the substrate; a second procedure in which the above is performed a predetermined number of times after the first procedure; The procedure of performing the above a predetermined number of times is as follows: A program executed by a computer in a substrate processing apparatus.

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