Processing methods, manufacturing methods of semiconductor devices, programs and processing devices

Abstract

The present invention comprises a step of etching a film by repeating a cycle including the following steps (a) and (b) at least a portion thereof a predetermined number of times: (a) supplying a modifying gas to the film; (b) supplying an inert gas to the film; and (c) supplying an etching gas to the film.

Description

Technical Field

[0001] The present invention relates to a processing method, a manufacturing method of a semiconductor device, a program, and a processing device. Prior Art

[0002] As a step in the manufacturing process of a semiconductor device, there is a case where a substrate is etched (for example, refer to Patent Document 1). [Prior Art Documents] [Patent Documents]

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-136221 Summary of the Invention

[0004] (Problems to be Solved by the Invention)

[0005] The present invention provides a technique capable of improving the etching controllability of a substrate. (Technical Means for Solving the Problems)

[0006] According to one aspect of the present invention, there is provided a technique having a cycle including the following steps, repeating at least a part of the implementation period of (a) and the implementation period of (b) a predetermined number of times, thereby etching a film; (a) a step of supplying a modifying gas to the film; (b) a step of supplying an inert gas to the film; and (c) a step of supplying an etching gas to the film. (Effects Compared with the Prior Art)

[0007] According to the present invention, the etching controllability of the substrate can be improved. Brief Description of the Drawings

[0008] FIG. 1 is a schematic configuration diagram of a processing device used in one aspect, showing a part of the processing furnace 202 in a longitudinal sectional view. FIG. 2 is a schematic configuration diagram of a processing device used in one aspect, showing a part of the processing furnace 202 in a sectional view taken along line A-A of FIG. 1. FIG. 3 is a schematic configuration diagram of a controller 121 of a processing device used in one aspect, showing a control system of the controller 121 in a block diagram. FIG. 4 is a diagram showing a substrate processing timing of one aspect. FIG. 5(a) is an enlarged cross-sectional view of the surface of the wafer 200 with recesses formed by processing through a substrate processing step according to an aspect; FIG. 5(b) is an enlarged cross-sectional view of the wafer 200 according to an aspect after supplying a modifying gas to the film 200a formed on the surface of the recess; FIG. 5(c) is an enlarged cross-sectional view of the wafer 200 according to an aspect after supplying an inert gas to the film 200a; FIG. 5(d) is an enlarged cross-sectional view of the wafer 200 according to an aspect after supplying an etching gas to the film 200a. Embodiment

[0009] <An aspect of the present invention> An aspect of the present invention will be mainly described below with reference to FIGS. 1 to 4 and FIGS. 5(a) to 5(d). Also, the drawings used in the following description are schematic drawings, and the dimensional relationships of the respective elements shown in the drawings, the ratios of the respective elements, etc. are not necessarily the same as the actual ones. Also, the dimensional relationships of the respective elements and the ratios of the respective elements between the plurality of drawings are not necessarily the same.

[0010] (1) Configuration of the processing apparatus As shown in FIG. 1, the processing furnace 202 of the processing apparatus has a heater 207 as a temperature regulator (heating unit). The heater 207 has a cylindrical shape and is vertically erected supported by a holding plate. The heater 207 also has a function as an activation mechanism (excitation unit) for activating (exciting) a gas by heat.

[0011] Inside the heater 207, a reaction tube 203 is disposed concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO 2) or silicon carbide (SiC), and is formed in a cylindrical shape with an upper end closed and a lower end open. Below the reaction tube 203, a manifold 209 is disposed concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS), and is formed in a cylindrical shape with upper and lower ends open. At the upper end of the manifold 209, it is engaged with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a as a sealing member is provided between the manifold 209 and the reaction tube 203. The reaction tube 203 is vertically erected in the same manner as the heater 207. The processing container (reaction container) is mainly composed of the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the cylindrical hollow portion of the processing container. The processing chamber 201 is configured to be able to accommodate the wafer 200 as a substrate. The wafer 200 is processed in this processing chamber 201.

[0012] In the processing chamber 201, the nozzles 249a to 249c serving as the first to third supply units are respectively provided to penetrate the side wall of the manifold 209. The nozzles 249a to 249c are also respectively referred to as the first to third nozzles. The nozzles 249a to 249c are respectively made of a heat-resistant material such as quartz or SiC. Gas supply pipes 232a to 232c are respectively connected to the nozzles 249a to 249c. The nozzles 249a to 249c are different nozzles, and the nozzles 249b and 249c are respectively arranged adjacent to the nozzle 249a.

[0013] In the gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c belonging to a flow controller (flow control unit) and valves 243a to 243c belonging to a switching valve are respectively provided in sequence from the upstream side of the gas flow. On the more downstream side of the valve 243a in the gas supply pipe 232a, the gas supply pipe 232d is connected. On the more downstream side of the valve 243b in the gas supply pipe 232b, the gas supply pipe 232e is connected. In the gas supply pipes 232d and 232e, MFCs 241d and 241e and valves 243d and 243e are respectively provided in sequence from the upstream side of the gas flow. The gas supply pipes 232a to 232e are made of a metal material such as SUS, for example.

[0014] As shown in FIG. 2, the nozzles 249a to 249c are respectively arranged in a space that is annular in a plan view between the inner wall of the reaction tube 203 and the wafer 200, standing upright from the lower part to the upper part along the inner wall of the reaction tube 203 in the arrangement direction of the wafer 200 upward. That is, the nozzles 249a to 249c are respectively arranged along the wafer arrangement area in a region that horizontally surrounds the wafer arrangement area on the side of the wafer arrangement area where the wafer 200 is arranged. In a plan view, the nozzle 249a is arranged to face each other in a straight line with the center of the wafer 200 in the processing chamber 201 interposed therebetween with respect to the exhaust port 231a described later. The nozzles 249b and 249c are arranged to sandwich the straight line L passing through the centers of the nozzle 249a and the exhaust port 231a along the inner wall of the reaction tube 203 (the outer peripheral portion of the wafer 200). The straight line L is also a straight line passing through the nozzle 249a and the center of the wafer 200. That is, the nozzle 249c can also be arranged on the opposite side of the nozzle 249b while sandwiching the straight line L. The nozzles 249b and 249c are arranged symmetrically with respect to the straight line L as the axis of symmetry. 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 respectively opened to face (opposite surfaces) the exhaust port 231a in a plan view, and can supply gas to the wafer 200. The gas supply holes 250a to 250c are provided in plural from the lower part to the upper part of the reaction tube 203.

[0015] From the gas supply pipe 232a, the reforming gas is supplied into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0016] From the gas supply pipe 232b, the etching gas is supplied into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0017] From the gas supply pipes 232c to 232e, the inert gas is respectively supplied into the processing chamber 201 via the MFCs 241c to 241e, the valves 243c to 243e, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c. The inert gas functions as a purge gas, a carrier gas, a dilution gas, etc.

[0018] The reforming gas supply system (the first gas supply system) is mainly composed of the gas supply pipe 232a, the MFC 241a, and the valve 243a. The etching gas supply system (the third gas supply system) is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. The inert gas supply system (the second gas supply system) is mainly composed of the gas supply pipes 232c to 232e, the MFCs 241c to 241e, and the valves 243c to 243e.

[0019] In any of the above various supply systems, any one or all of the supply systems may also be configured as an integrated supply system 248 formed by integrating the valves 243a to 243e, the MFCs 241a to 241e, etc. The integrated supply system 248 is respectively connected to the gas supply pipes 232a to 232e. The supply operations of various substances (various gases) in the gas supply pipes 232a to 232e, that is, the opening and closing operations of the valves 243a to 243e or the flow rate adjustment operations performed by the MFCs 241a to 241e, etc., are configured to be controlled by the controller 121 described later. The integrated supply system 248 is configured as an integrated unit of an integral type or a split type, and can be disassembled and assembled for the gas supply pipes 232a to 232e, etc. according to the integrated unit unit, and is configured to perform maintenance, replacement, addition, etc. of the integrated supply system 248 according to the integrated unit unit.

[0020] Below the side wall of the reaction tube 203, an exhaust port 231a for exhausting the environment in the processing chamber 201 is provided. As shown in FIG. 2, the exhaust port 231a is provided at a position that faces (opposite surface) the nozzles 249a to 249c (gas supply holes 250a to 250c) while holding the wafer 200 in a plan view. The exhaust port 231a is provided along the side wall of the reaction tube 203 from the lower part to the upper part, that is, along the wafer alignment area. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is connected to a vacuum pump 246 serving as a vacuum exhaust device 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 is configured to open and close the valve in a state where the vacuum pump 246 is actuated, so that vacuum exhaust or vacuum exhaust stop in the processing chamber 201 can be performed. Further, in a state where the vacuum pump 246 is actuated, the valve opening degree is adjusted according to the pressure information detected by the pressure sensor 245, so that the pressure in the processing chamber 201 can be adjusted. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 can also be considered to be included in the exhaust system.

[0021] Below the manifold 209, a sealing lid 219 (hereinafter referred to as lid 219) serving as a furnace port lid for hermetically closing the lower end opening of the manifold 209 is provided. The lid 219 is made of a metal material such as SUS and is formed in a disk shape. On the upper surface of the lid 219, an O-ring 220b serving as a sealing member that abuts against the lower end of the manifold 209 is provided. Below the lid 219, a rotation mechanism 267 for rotating a susceptor 217 described later is provided. The rotation shaft 255 of the rotation mechanism 267 penetrates the lid 219 and is connected to the susceptor 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the susceptor 217. The lid 219 is configured to be lifted and lowered in the vertical direction by a susceptor lifter 115 (hereinafter referred to as lifter 115) serving as a lifting mechanism provided outside the reaction tube 203. The lifter 115 is a transfer device (transfer mechanism) configured to transfer (carry in and out) the wafer 200 in and out of the processing chamber 201 by lifting and lowering the lid 219.

[0022] Below the manifold 209, a shutter 219s serving as a furnace port cover is provided to airtightly seal the lower end opening of the manifold 209 in a state where the lid 219 is lowered and the susceptor 217 is carried out of the processing chamber 201. The shutter 219s is made of a metal material such as SUS, for example, and is formed in a disk shape. On the upper surface of the shutter 219s, an O-ring 220c serving as a sealing member that abuts against the lower end of the manifold 209 is provided. The opening and closing operation (lifting operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter switch mechanism 115s.

[0023] The susceptor 217 serving as a substrate support is configured to support a plurality of, for example, 25 to 200 wafers 200 in a horizontal posture and in a state where their centers are aligned with each other, and are vertically arranged in multiple stages, that is, arranged at intervals. The susceptor 217 is made of a heat-resistant material such as quartz or SiC, for example. Below the susceptor 217, heat insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported in multiple stages.

[0024] In the reaction tube 203, a temperature sensor 263 serving as a temperature detector is provided. The energization state of the heater 207 is adjusted according to the temperature information detected by the temperature sensor 263 so that the temperature in the processing chamber 201 becomes a desired temperature distribution. The temperature sensor 263 is provided along the inner wall of the reaction tube 203.

[0025] As shown in FIG. 3, the controller 121 belonging to the 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 configured as a touch panel, for example, is connected to the controller 121. Also, an external storage device 123 can be connected to the controller 121. Moreover, the processing device can be configured to have one control unit or can be configured to include a plurality of control units. That is, for controlling the processing sequence described later, one controller can be used, or a plurality of control units can be used. Also, a plurality of control units can also be configured as a control system connected to each other via a wired or wireless communication network, and the control of the processing sequence described later can also be performed by the entire control system. In this specification, when using the term control unit, in addition to including the case of one control unit, there are also cases including a plurality of control units or a control system composed of a plurality of control units.

[0026] The memory device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. A control program for controlling the operation of the control processing device, or a process recipe (recipe) etc. that describes the procedures or conditions of substrate processing described later, etc. are recordable and storable in a readable manner in the memory device 121c. The process recipe is combined in such a way that each procedure in the substrate processing described later is executed by the processing device via the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, as a general term for the process recipe, the control program, etc., it is also simply referred to as a program. Also, the process recipe is sometimes simply referred to as a recipe. In this specification, when the term "program" is used, it refers to the case of only including the recipe alone, the case of only including the control program alone, or the case of including both of them. The RAM 121b is configured as a memory area for temporarily storing the program or data etc. read by the CPU 121a.

[0027] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241e, valves 243a to 243e, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, susceptor elevator 115, shutter switch mechanism 115s, etc.

[0028] The CPU 121a is configured to read the control program from the memory device 121c and execute it, and read the recipe from the memory device 121c in accordance with the input of the operation instruction from the input / output device 122, etc. The CPU 121a is configured to control the flow rate adjustment operation of various substances (various gases) using the MFCs 241a to 241e, the opening and closing operations of the valves 243a to 243e, the opening and closing operation of the APC valve 244 and the pressure adjustment operation using the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the susceptor 217 by the rotation mechanism 267, the lifting operation of the susceptor 217 using the susceptor elevator 115, the opening and closing operation of the shutter 219s using the shutter switch mechanism 115s, etc.

[0029] The controller 121 is configured by installing the above-mentioned program recorded and stored in the external memory device 123 into the computer. The external memory device 123 includes magnetic disks such as HDDs, optical disks such as CDs, USB memories, semiconductor memories such as SSDs, and the like. The memory device 121c or the external memory device 123 is configured as a recording medium readable by the computer. Hereinafter, as a general term for these, it is simply referred to as a recording medium. In this specification, when the term recording medium is used, it refers to the case of including only the memory device 121c alone, the case of including only the external memory device 123 alone, or the case of including both of them. Moreover, for the program provision to the computer, it is also possible to use communication means such as a network or a dedicated line without using the external memory device 123.

[0030] (2) Substrate Processing Step As one of the manufacturing steps of using the above-mentioned processing device (substrate processing device) and semiconductor device, for the processing timing example of etching the wafer 200 as the substrate, it is mainly described with reference to FIGS. 4, 5(a) to 5(d). In the following description, the operations of each part constituting the processing device are controlled by the controller 121.

[0031] The wafer 200 processed by the substrate processing step of one aspect of the present invention can use, for example, a Si substrate made of single crystal silicon (Si). On the surface of the wafer 200, as shown in FIG. 5(a), concave portions such as grooves or holes are formed, and a natural oxide film 200a such as a silicon oxide film (SiO film) is formed on the surface. Hereinafter, the natural oxide film 200a may sometimes be simply referred to as the film 200a.

[0032] As shown in FIG. 4, the processing timing of this aspect has the following steps: including (a) Step A of supplying a modifying gas to the film 200a, (b) Step B of supplying an inert gas to the film 200a, and (c) Step C of supplying an etching gas to the film 200a are cycled a predetermined number of times (n times, n is an integer of 1 or more), thereby etching the film 200a; During the above cycle, at least a part of the implementation period of step A and the implementation period of step B are repeated.

[0033] Also, as shown in FIG. 4, the processing timing of this aspect starts step A before step B, and starts step B while continuously executing step A. In this aspect, the case where step B is performed in the latter half of the implementation period of step A is described.

[0034] Further, in this embodiment, as an example, the case where, after performing step C, a step of raising the temperature in the processing chamber 201 (hereinafter referred to as step D) is performed will be described.

[0035] In this specification, for convenience, the above substrate processing timing is represented as follows. The same notation is also used in the description of the following modified examples or other embodiments.

[0036] (Reforming gas + inert gas → etching gas → temperature increase) × n

[0037] In this specification, when the term "wafer" is used, it is intended to mean the case of the wafer itself, or the case of a laminate of the wafer and a predetermined layer or film formed on its surface. When the term "wafer surface" is used in this specification, it is intended to mean the surface of the wafer itself, or the surface of a predetermined layer formed on the wafer. When it is described in this specification that "a predetermined layer is formed on the wafer", it is intended to mean the case where the predetermined layer is directly formed on the surface of the wafer itself, or represents the case where the predetermined layer is formed on a layer formed on the wafer. When the term "substrate" is used in this specification, it has the same meaning as when the term "wafer" is used.

[0038] The term "substance" used in this specification includes at least any one of gaseous substances and liquid substances. Liquid substances include mist-like substances. That is, the substance may include gaseous substances, may include liquid substances such as mist-like substances, or may include both of these.

[0039] (Filling and susceptor loading) When loading a plurality of wafers 200 into the susceptor 217, the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209 (shutter open). Thereafter, as shown in FIG. 1, the susceptor 217 supporting the plurality of wafers 200 is lifted by the susceptor lifter 115 and carried into the processing chamber 201 (susceptor loading). In this state, the lid 219 makes the lower end of the manifold 209 sealed via the O-ring 220b. Thus, the wafers 200 are prepared in the processing chamber 201.

[0040] (Pressure adjustment and temperature adjustment) After the wafer loading is completed, evacuation (pressure reduction evacuation) is performed by the vacuum pump 246 so that the pressure (degree of vacuum) in the processing chamber 201, that is, the space where the wafer 200 exists, becomes the required pressure. At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled according to the measured pressure information. Also, the wafer 200 in the processing chamber 201 is heated by the heater 207 so that it becomes the required processing temperature. At this time, the energization state of the heater 207 is feedback-controlled according to the temperature information detected by the temperature sensor 263 so that the required temperature distribution is formed in the processing chamber 201. Also, the rotation of the wafer 200 is started by the rotation mechanism 267. Any one of the evacuation in the processing chamber 201, the heating of the wafer 200, and the rotation is continuously performed at least until the processing of the wafer 200 is completed.

[0041] (Etching) Thereafter, the following steps A to D are sequentially executed.

[0042] [Step A] In this step, a reforming gas is supplied to the wafer 200 in the processing chamber 201, that is, the film 200a formed on the surface of the wafer 200.

[0043] Specifically, the valve 243a is opened to allow the reforming gas to flow in the gas supply pipe 232a. The reforming gas is flow-adjusted by the MFC241a, supplied into the processing chamber 201 through the nozzle 249a, and exhausted from the exhaust port 231a. At this time, the reforming gas is supplied to the wafer 200 from a direction different from the bottom direction of the concave portion on the surface of the wafer 200 (reforming gas supply). In this specification, the bottom direction of the concave portion means the direction perpendicular to the upper surface of the concave portion. The direction different from the bottom direction of the concave portion means, for example, a direction substantially perpendicular to the bottom direction of the concave portion. Also, when the concave portion is formed to extend in the thickness direction of the wafer 200, the direction different from the bottom direction of the concave portion becomes a direction substantially parallel to the surface of the wafer 200. Also, when the concave portion is formed to extend in a direction substantially parallel to the surface of the wafer 200, the direction different from the bottom direction of the concave portion becomes a direction perpendicular to the surface of the wafer 200.

[0044] As the processing conditions when supplying the reforming gas in this step, the following can be exemplified: Processing temperature: 20 to 75 °C, preferably 25 to 70 °C Processing pressure: 1 to 10000 Pa, preferably 10 to 1333 Pa Reforming gas supply flow rate: 0.01 to 3 slm, preferably 0.1 to 1 slm Reforming gas supply time: 30 to 1800 seconds, preferably 50 to 1200 seconds. The processing pressure in this step is preferably higher than the processing pressure in step C described later. Also, in this step, preferably, the reforming gas is set to the above-mentioned processing pressure in an undecomposed state.

[0045] Moreover, in this specification, the notation of a numerical range such as "20 to 75 °C" means that the range includes the lower limit value and the upper limit value. Therefore, for example, "20 to 75 °C" means "20 °C or higher and 75 °C or lower". The same applies to other numerical ranges. Also, in this specification, the so-called processing temperature means the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure means the pressure inside the processing chamber 201, in other words, the pressure of the space where the wafer 200 exists. Also, the so-called processing time means the duration of the processing. Also, in the case where the supply flow rate includes 0 slm, 0 slm means the case where the substance (gas) is not supplied. The same applies to the following descriptions.

[0046] By supplying the reforming gas to the wafer 200 (film 200a) under the above-mentioned processing conditions, at least one of the reforming gas, a substance having a part of the molecular structure of the reforming gas, and a predetermined element contained in the reforming gas can be adsorbed on the surface of the film 200a (refer to Fig. 5(b)). Hereinafter, sometimes at least one of the reforming gas, a substance having a part of the molecular structure of the reforming gas, and a predetermined element contained in the reforming gas is referred to as the reforming gas. Also, in Figs. 5(b) to 5(d), the reforming gas is represented by the letter α.

[0047] By supplying the reforming gas to the wafer 200 (film 200a) under the above-mentioned processing conditions, the reforming gas is filled from the upper surface on the opening side (hereinafter referred to as the upper surface of the recess) to the inner bottom surface of the recess (hereinafter referred to as the bottom surface of the recess) formed in the wafer 200, and the reforming gas is adsorbed on the upper surface of the recess, the side surface and the bottom surface inside the recess (hereinafter referred to as the side surface and the bottom surface of the recess). At this time, compared with the side surface and the bottom surface of the recess, the reforming gas and the like are preferentially adsorbed on the upper surface of the recess. In other words, the amount of the reforming gas and the like adsorbed on the upper surface of the recess is larger than the amount of the reforming gas and the like adsorbed on the side surface and the bottom surface of the recess (refer to Fig. 5(b)).

[0048] As the reforming gas, NH group-containing gases such as ammonia (NH3) gas, hydrazine (N2H4) gas, pyridine (C5H5N) gas, pyrimidine (C4H4N2) gas, and picoline (C6H7N) gas can be used. One or more of these can be used as the reforming gas.

[0049] [Step B] After the start of Step A, if a predetermined time has elapsed and while Step A is being continuously executed, an inert gas is supplied to the wafer 200 in the processing chamber 201, that is, the film 200a adsorbed with the reforming gas (refer to FIG. 4).

[0050] Specifically, in the latter half of the implementation period of Step A, after the reforming gas is adsorbed on the entire surface of the concave portion, that is, on the upper surface, side surface, and bottom surface of the concave portion, with the reforming gas being continuously supplied, valves 243c to 243e are opened to allow the inert gas to flow through the gas supply pipes 232c to 232e. The inert gas is adjusted in flow rate by MFCs 241c to 241e, supplied into the processing chamber 201 via nozzles 249a to 249c, and exhausted from the exhaust port 231a. At this time, the inert gas is supplied to the wafer 200 from a direction different from the bottom direction of the concave portion (inert gas supply).

[0051] As the processing conditions when supplying the inert gas in this step, the following can be exemplified: Processing temperature: 20 to 75°C, preferably 25 to 70°C Processing pressure: 1 to 10000 Pa, preferably 10 to 1333 Pa Inert gas supply flow rate: 0.01 to 3 slm, preferably 0.1 to 1 slm Inert gas supply time: 10 to 300 seconds, preferably 20 to 60 seconds. The implementation time of this step (inert gas supply time) is preferably shorter than the implementation time of Step A (reforming gas supply time). Also, the supply amount of the inert gas in this step is preferably less than the supply amount of the reforming gas in Step A. Also, the supply amount of the gas can be obtained by multiplying the gas supply flow rate by the gas supply time.

[0052] By supplying an inert gas to the film 200a adsorbed with a reforming gas or the like under the above conditions, for example, from a direction different from the bottom direction of the concave portion, a part of the reforming gas or the like adsorbed (laminated) on the upper surface of the concave portion can be peeled off and removed (detached) from the upper surface of the concave portion (see FIG. 5(c)). On the other hand, by supplying the inert gas under the above conditions, the reforming gas or the like adsorbed on the side surface and the bottom surface of the concave portion is hardly peeled off. Thus, by adjusting the amount of the reforming gas or the like adsorbed on the surface of the concave portion, in this embodiment, the amount of the reforming gas or the like adsorbed on the upper surface of the concave portion can be made smaller than the amount of the reforming gas or the like adsorbed on the side surface and the bottom surface of the concave portion (see FIG. 5(c)). Further, in FIG. 5(c), the gas flow of the inert gas is indicated by an arrow.

[0053] As the inert gas, for example, nitrogen (N2) gas, or rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas can be used. One or more of these can be used as the inert gas. This is the same in each of the steps described later.

[0054] Thereafter, valves 243a, 243c to 243e are closed, and the supply of the reforming gas and the inert gas to the processing chamber 201 is stopped. Then, the inside of the processing chamber 201 is evacuated, and gaseous substances and the like remaining in the processing chamber 201 are exhausted from the processing chamber 201. At this time, valves 243c to 243e can also be maintained open, and an inert gas is supplied to the inside of the processing chamber 201 via nozzles 249a to 249c. The inert gas supplied from nozzles 249a to 249c acts as a purge gas, and thereby purges the space where the wafer 200 is present, that is, the inside of the processing chamber 201.

[0055] [Step C] After Steps A and B are completed, an etching gas is supplied to the wafer 200 in the processing chamber 201, that is, the film 200a adsorbed with a reforming gas or the like (see FIG. 4).

[0056] Specifically, valve 243b is opened to allow the etching gas to flow through the gas supply pipe 232b. The flow rate of the etching gas is adjusted by MFC241b, supplied to the inside of the processing chamber 201 via nozzle 249b, and exhausted from the exhaust port 231a. At this time, the etching gas is supplied to the wafer 200 (etching gas supply). At this time, valves 243c to 243e can also be opened to supply an inert gas to the inside of the processing chamber 201 via nozzles 249a to 249c, respectively.

[0057] As the processing conditions when supplying the etching gas in this step, the following can be exemplified: Processing temperature: 25 to 75 °C, preferably 25 to 70 °C Processing pressure: 1 to 10000 Pa, preferably 10 to 1333 Pa Etching gas supply flow rate: 0.01 to 3 slm, preferably 0.1 to 1 slm Etching 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.

[0058] By supplying an etching gas to the wafer 200 (film 200a) under the above processing conditions, at least one of the etching gas, a substance having a part of the molecular structure of the etching gas, and a predetermined element contained in the etching gas can be adsorbed on the surface of the film 200a such as a modifying gas (see Fig. 5(d)). Hereinafter, at least one of the etching gas, a substance having a part of the molecular structure of the etching gas, and a predetermined element contained in the etching gas may be referred to as the etching gas etc. Also, in Fig. 5(d), the etching gas etc. is indicated by the letter β.

[0059] By supplying an etching gas to the film 200a under the above processing conditions, the etching gas can reach from the upper surface of the concave portion formed in the wafer 200 to the bottom surface of the concave portion, and the etching gas can be adsorbed on the upper surface, side surface, and bottom surface of the concave portion. At this time, the etching gas etc. is preferentially adsorbed on the upper surface of the concave portion as compared with the side surface and the bottom surface of the concave portion. In other words, the amount of the etching gas etc. adsorbed on the upper surface of the concave portion is larger than the amount of the etching gas etc. adsorbed on the side surface and the bottom surface of the concave portion (see Fig. 5(d)).

[0060] As the etching gas, for example, a fluorine (F)-containing gas such as hydrogen fluoride (HF) gas, chlorine trifluoride (ClF3) gas, fluorine (F2), nitrogen trifluoride (NF3) gas, and carbon tetrafluoride (CF4) gas can be used. As the etching gas, one or more of these can be used.

[0061] After the etching gas etc. is adsorbed on the modifying gas etc. adsorbed on the surface of the film 200a, the valve 243d is closed, and the supply of the etching gas into the processing chamber 201 is stopped. Then, the inside of the processing chamber 201 is evacuated, and gaseous substances etc. remaining in the processing chamber 201 are exhausted from the processing chamber 201. At this time, the valves 243c to 243e are opened, and an inert gas is supplied into the processing chamber 201 via the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c acts as a purge gas, and thereby purges the space where the wafer 200 exists, that is, the inside of the processing chamber 201.

[0062] [Step D] Adjust the output of the heater 207 so that the temperature in the processing chamber 201, i.e., the temperature of the wafer 200, rises to a predetermined temperature. Also, perform vacuum exhaust by the vacuum pump 246 so that the space in the processing chamber 201, i.e., the space where the wafer 200 is located, becomes a predetermined pressure. In this step, it is preferably carried out in an inert gas environment. That is, when performing this step, it is preferably to open the valves 243c to 243e and supply an inert gas into the processing chamber 201 via the nozzles 249a to 249c to flush the inside of the processing chamber 201.

[0063] As the processing conditions in this step, the following can be exemplified: Processing temperature: 100 to 200 °C, preferably 150 to 200 °C Processing pressure: 1 to 10000 Pa, preferably 10 to 1333 Pa Processing time: 0.5 to 5 hours Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm.

[0064] By performing a temperature increase treatment (heat treatment) on the wafer 200 under the above processing conditions, the film 200a can be etched. Hereinafter, as an example of the process for etching the film 200a, the case where the film 200a formed on the surface of the concave portion is a SiO film, NH 3 gas is used as the modifying gas, and HF gas is used as the etching gas will be described. Under the above processing conditions, steps A and C are performed, and when NH 3 gas (modifying gas) and HF gas (etching gas) are supplied to the SiO film (film 200a), the NH 3 gas and HF gas are adsorbed on the surface of the wafer 200 and react with the SiO film. The SiO film reacted with the NH 3 gas and HF gas is modified into an ammonium hexafluorosilicate ((NH 4)SiF 6) film. Thereafter, step D is performed under the above processing conditions to perform a temperature increase treatment on the wafer 200, whereby the (NH 4)SiF 6 film sublimes and is removed (etched).

[0065] After etching the film 200a, perform vacuum exhaust on the inside of the processing chamber 201 to remove gaseous substances and the like remaining in the processing chamber 201 from the inside of the processing chamber 201. At this time, open the valves 243c to 243e and supply an inert gas into the processing chamber 201 via the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c acts as a flushing gas, whereby the space where the wafer 200 is located, i.e., the inside of the processing chamber 201, is flushed. At this time, if necessary, lower the temperature in the processing chamber 201 to the processing temperature of step A.

[0066] [Performed a predetermined number of times] By performing the cycle of sequentially performing the above steps A to D n times (n is an integer of 1 or more), the film 200a formed on the surface of the wafer 200 can be etched to a predetermined depth. The above cycle is preferably repeated a plurality of times. That is, preferably, the thickness of the film etched in each cycle is thinner than the required thickness, and the above cycle is repeated a plurality of times until the thickness of the film removed by etching becomes the required thickness.

[0067] (Rinsing and atmospheric pressure recovery) After the etching process is completed, an inert gas as a rinsing gas is supplied into the processing chamber 201 from the nozzles 249a to 249c, respectively, and exhausted from the exhaust port 231a. Thereby, the inside of the processing chamber 201 is rinsed, and the gas or reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201. Thereafter, the environment in the processing chamber 201 is replaced with an inert gas, and the pressure in the processing chamber 201 is restored to normal pressure (atmospheric pressure).

[0068] (Unloading and wafer removal) Thereafter, the cover 219 is lowered by the lifter 115 to open the lower end of the manifold 209. Then, the processed wafer 200 is unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 in a state supported by the boat 217. After unloading, the shutter 219s is moved to seal the lower end opening of the manifold 209 via the O-ring 220c by the shutter 219s. After the processed wafer 200 is unloaded to the outside of the reaction tube 203, it is taken out from the boat 217.

[0069] (3) Effects of this embodiment According to this embodiment, one or more of the following effects can be obtained.

[0070] (a) By making at least a part of the implementation period of step A overlap with the implementation period of step B, the amount of the modified gas or the like adsorbed on the surface of the film 200a can be adjusted. Thereby, the etching amount of the film 200a can be adjusted (controlled). Especially when there are recesses formed on the surface of the wafer 200, the amount of the modified gas present above the recesses can be made different from the amount of the modified gas present on the side surfaces and the bottom surface of the recesses. In other words, the amount of the modified gas present on the opening side of the recesses can be made different from the amount of the modified gas present on the bottom side of the recesses. Thereby, the etching amounts of the film 200a formed above the recesses and the film 200a formed on the side surfaces and the bottom surface of the recesses can be adjusted (controlled). The following will explain these. Moreover, the amount of the modified gas present refers to the amount of the molecules of the material itself constituting the modified gas or a part of the molecules. Also, the modified gas includes substances floating in the inner space of the recesses or substances adsorbed on the respective surfaces within the recesses.

[0071] For example, when supplying gas to the wafer 200 having recesses formed on its surface, there is a tendency for the supplied gas to be preferentially adsorbed on the upper surfaces of the recesses. That is, the amount of the modified gas or the etching gas adsorbed on the upper surfaces of the recesses is larger than the amount of the modified gas or the etching gas adsorbed on the side surfaces and the bottom surface of the recesses. Therefore, when etching the film 200a formed on the surface of the recesses, the upper surfaces of the recesses are etched more than the side surfaces and the bottom surface of the recesses, and it is difficult to etch the film 200a uniformly.

[0072] In this aspect, at least a part of the implementation period of step A is made to overlap with the implementation period of step B. Specifically, in the state where the modified gas is being supplied to the film 200a in step A, an inert gas is supplied to the film 200a in step B. Thereby, a part of the modified gas or the like adsorbed on the upper surfaces of the recesses can be removed (detached) by flowing the inert gas (refer to Fig. 5(c)). In this way, the amount of the modified gas or the like adsorbed (present) on the upper surfaces of the recesses can be reduced. Thereafter, when the etching gas is supplied to the film 200a in step C, although the etching gas is preferentially adsorbed on the upper surfaces of the recesses, since the amount of the modified gas or the like adsorbed on the upper surfaces of the recesses is smaller, the etching amount of the film 200a on the upper surfaces of the recesses is suppressed. On the other hand, the modified gas or the like adsorbed (present) on the side surfaces and the bottom surface of the recesses is hardly affected by the inert gas supplied in step B. Therefore, the amount of the modified gas or the like present on the side surfaces and the bottom surface of the recesses hardly decreases. Consequently, in step C, the film 200a formed on the side surfaces and the bottom surface of the recesses is etched hardly affected by the inert gas supplied in step B. In this way, the etching amounts of the film 200a on the upper surfaces of the recesses and the film 200a on the side surfaces and the bottom surface of the recesses can be adjusted (controlled). As a result, the film 200a can be etched uniformly.

[0073] (b) By making the pressure in the processing chamber 201 in step A higher than the pressure in the processing chamber 201 in step C, that is, performing step A under a higher pressure, the modification gas can fill the inside of the recess, and the modification gas can be uniformly adsorbed from the opening to the bottom surface of the recess.

[0074] (c) By performing step B in the latter half of the implementation period of step A, the amount of the modification gas or the like present on the upper surface of the recess can be made less than the amount of the modification gas or the like present on the side surface and the bottom surface of the recess. Specifically, by performing step B in the latter half of the implementation period of step A, after the modification gas fills from the upper surface to the bottom surface of the recess, an inert gas is supplied. Since the inert gas is preferentially supplied to the upper surface of the recess, the modification gas or the like present on the upper surface of the recess is removed (detached) by the inert gas. In contrast, since the modification gas or the like present on the side surface and the bottom surface of the recess is hardly affected by the inert gas, it remains in the recess. Thereby, the amount of the modification gas or the like present on the upper surface of the recess can be made less than the amount of the modification gas or the like present on the side surface and the bottom surface of the recess.

[0075] (d) By making the implementation time of step B shorter than the implementation time of step A, the controllability of the amount of the modification gas or the like adsorbed on the film 200a (remaining on the film 200a) can be improved. Specifically, by making the implementation time of step B shorter, since the inert gas can be supplied instantaneously only for a short time, the modification gas or the like present on the side surface and the bottom surface of the recess can be hardly reduced, and the modification gas or the like present on the upper surface of the recess can be reduced.

[0076] (e) By making the supply amount of the inert gas in step B less than the supply amount of the modification gas in step A, the controllability of the amount of the modification gas or the like adsorbed on the film 200a can be improved.

[0077] (4) Variation The processing timing of this aspect can be changed as in the following variations. These variations can be combined arbitrarily. Without special explanation, the processing procedures and processing conditions in each step of each variation can be set to be the same as those in each step of the above processing timing.

[0078] (Variation 1) Step B can also be performed in the middle (i.e., the middle stage, the middle period) of the implementation period of step A. In this variation, the same effect as the above aspect can be obtained.

[0079] (Variation 2) Steps A to D may also be carried out in the order of steps B, A, C, D, and while continuously supplying an inert gas in step B, step A may be started to supply a reforming gas. Specifically, step A may also be carried out in the latter half of the period of carrying out step B.

[0080] In this modification, at least a part of the effects described in the above aspect can be obtained. Also, in this modification, by further carrying out step A in the latter half of the period of carrying out step B, the amount of the reforming gas or the like present on the upper surface of the recess can be made larger than the amount of the reforming gas or the like present on the side surface and the bottom surface of the recess. This is because step A is carried out in the latter half of the period of carrying out step B, so the reforming gas is supplied after the inside of the recess is filled with the inert gas. Since the inside of the recess is filled with the inert gas, and then the reforming gas is preferentially supplied to the upper surface of the recess, most of the supplied reforming gas is adsorbed on the upper surface of the recess. Thus, the amount of the reforming gas or the like present on the upper surface of the recess can be made larger than the amount of the reforming gas or the like present on the side surface and the bottom surface of the recess. As a result, the film 200a formed on the upper surface of the recess can be etched preferentially. This modification is particularly useful when dealing with the process of expanding the opening of the recess.

[0081] (Modification 3) Steps A to D may also be carried out in the order of steps B, A, C, D, and while continuously supplying an inert gas in step B, step A may be started to supply a reforming gas. Specifically, step A may also be carried out in the middle (i.e., the middle stage, the middle period) of the period of carrying out step B.

[0082] In this modification, at least a part of the effects described in the above aspect can be obtained. Also, in this modification, by further carrying out step A in the middle of the period of carrying out step B, the amount of the reforming gas or the like present on the upper surface of the recess can be made larger than the amount of the reforming gas or the like present on the side surface and the bottom surface of the recess. The reason is that since step A is carried out in the middle of the period of carrying out step B, the reforming gas is supplied after the inside of the recess is filled with the inert gas to a certain extent. By filling the inside of the recess with the inert gas to a certain extent and then preferentially supplying the reforming gas to the upper surface of the recess, most of the supplied reforming gas is adsorbed on the upper surface of the recess. Thus, the amount of the reforming gas or the like present on the upper surface of the recess can be made larger than the amount of the reforming gas or the like present on the side surface and the bottom surface of the recess. As a result, the film 200a formed on the upper surface of the recess can be etched preferentially. This modification can be used when dealing with the process of expanding the opening of the recess.

[0083] (Modification 4) When processing the timing as shown below, it is also possible to further have a step E of supplying an inert gas to the film 200a during the implementation of step C. Specifically, it is also possible to start step E to supply the inert gas while continuously supplying the etching gas in step C. Step E can be carried out in the latter half of the implementation period of step C, or can be carried out in the middle (mid-stage, middle period) of the implementation period of step C. In this modification example, the implementation time of step E is preferably shorter than the implementation time of step C. Also, the supply amount of the inert gas in step E is preferably less than the supply amount of the etching gas in step C.

[0084] (Reforming gas + inert gas → etching gas + inert gas → temperature increase treatment) × n

[0085] In this modification example, the same effect as the above aspect can also be obtained. In this modification example, by further performing step E, since the flow of the etching gas present on the film 200a is made good, the controllability of the amount of the etching gas remaining on the film 200a can be improved. By performing step E in the latter half or the middle of the implementation period of step C, in particular, the controllability of the amount of the etching gas and the like present on the upper surface of the concave portion can be improved. By making the implementation time of step E shorter than the implementation time of step C, or making the supply amount of the inert gas in step E less than the supply amount of the etching gas in step C, in particular, the controllability of the amount of the etching gas and the like present on the upper surface of the concave portion can be improved.

[0086] <Other aspects of the present invention> The aspects of the present invention have been specifically described above. However, the present invention is not limited to the above aspects, and various changes can be made without departing from the gist thereof.

[0087] For example, the above aspect has been described by taking the case where the film 200a to be etched is formed on the surface of the wafer 200 as an example. However, the present invention is not limited to such an aspect. For example, the film 200a to be etched can also be formed on the reaction tube 203 or the like. In this aspect, the same effect as the above aspect can also be obtained.

[0088] For example, in the above aspect, the case of using the wafer 200 having concave portions formed on its surface has been described as an example. However, the present invention is not limited to such an aspect. For example, the wafer 200 having no concave portions formed on its surface can also be used. In this aspect, the same effect as the above aspect can also be obtained.

[0089] Although not specifically described in the above aspect, pulsed supply of an inert gas may also be performed in step B or step E. In this aspect, the same effects as those in the above aspect can also be obtained. In this aspect, the controllability of the amount of the modifying gas or the etching gas remaining on the film 200a can be further improved.

[0090] For example, in the above aspect, the case where a SiO film is formed on the surface of the concave portion is taken as an example for description. However, the present invention is not limited to such an aspect. For example, a silicon nitride film (SiN film) may also be formed. Further, a film containing a metal element may also be formed. Moreover, the film containing a metal element refers to a film of a single metal element or a film containing at least one of a metal element, oxygen, nitrogen, and carbon. In this aspect, the same effects as those in the above aspect can also be obtained.

[0091] The recipes used in each process are preferably prepared individually in accordance with the process content and stored in the memory device 121c in advance via a telecommunication path or an external memory device 123. Then, preferably, at the start of each process, the CPU 121a appropriately selects a suitable recipe from a plurality of recipes stored in the memory device 121c in accordance with the process content. Thereby, various films having different film types, composition ratios, film qualities, and film thicknesses can be etched with good reproducibility by the processing device. Further, the burden on the operator can be reduced, operation errors can be avoided, and each process can be started quickly.

[0092] The above recipes are not limited to being newly created. For example, they can also be prepared by changing the existing recipes already installed in the processing device. In the case of changing the recipe, the changed recipe can be installed in the processing device via a telecommunication path or a recording medium recording the recipe. Further, the input / output device 122 provided in the existing processing device can also be operated to directly change the existing recipe installed in the processing device.

[0093] In the above aspect, an example of etching a film using a batch processing device that processes a plurality of substrates at a time has been described. The present invention is not limited to the above aspect. For example, it can also be suitably applied to the case of etching a film using a single wafer processing device that processes one or several substrates at a time. Further, in the above aspect, an example of etching a film using a processing device having a hot wall type processing furnace has been described. The present invention is not limited to the above aspect and is also suitably applicable to the case of etching a film using a processing device having a cold wall type processing furnace.

[0094] Furthermore, in the above aspect, an example was described in which the above processing sequence is performed in-situ in the same processing chamber of the same processing device. The present invention is not limited to the above aspect. For example, any step of the above processing sequence and any other step may be performed ex-situ in different processing chambers of different processing devices, or may be performed in different processing chambers of the same processing device.

[0095] In the case of using these processing devices, each process can also be performed according to the same processing procedure and processing conditions as in the above aspect or modification example, and the same effects as in the above aspect or modification example can be obtained.

[0096] The above aspect or modification example can be used in appropriate combination. The processing procedure and processing conditions at this time can be set to be the same as, for example, the processing procedure and processing conditions in the above aspect or modification example.

[0097] 115: Cassette lifter 115s: Gate opening and closing mechanism 121: Controller 121a: CPU 121b: RAM 121c: Memory device 121d: I / O port 121e: Internal bus 122: Input / output device 123: External memory device 200: Wafer (substrate) 200a: Film 201: Processing chamber 202: Processing furnace 203: Reaction tube 207: Heater 209: Manifold 217: Cassette 218: Heat insulation plate 219: Sealing cover 219s: Gate 220a, 220b, 220c: O-ring 231: Exhaust pipe 231a: Exhaust port 232a, 232b, 232c, 232d, 232e: Gas supply pipe 241a, 241b, 241c, 241d, 241e: Mass flow controller (MFC) 243a, 243b, 243c, 243d, 243e: Valve 244: APC Valve 245: Pressure Sensor 246: Vacuum Pump 248: Integrated Supply System 249a, 249b, 249c: Nozzle 250a, 250b, 250c: Gas Supply Hole 255: Rotating Shaft 263: Temperature Sensor 267: Rotating Mechanism α: Reforming Gas β: Etching Gas

Claims

1. A processing method comprising the steps of etching a film by repeating a cycle comprising the following steps (a) and (b) at least a predetermined number of times; (a) supplying the film with a modified gas containing NH groups; (b) supplying the film with an inert gas to detach a portion of the modified gas adsorbed on the film; and (c) supplying the film with an etching gas; wherein a recess is provided on the surface of a substrate on which the film is formed.

2. A processing method comprising the steps of etching a film by repeating a cycle comprising the following steps (a) and (b) at least a predetermined number of times; (a) supplying the film with a modified gas containing NH groups; (b) supplying the film with an inert gas to detach a portion of the modified gas adsorbed on the film; and (c) supplying the film with an etching gas; wherein the execution time of (b) is shorter than the execution time of (a).

3. A processing method comprising the steps of etching a film by repeating a cycle comprising the following steps (a) and (b) at least a predetermined number of times; (a) supplying the film with a modified gas containing NH groups; (b) supplying the film with an inert gas to detach a portion of the modified gas adsorbed on the film; and (c) supplying the film with an etching gas; wherein, in (b), the inert gas is pulsed.

4. As in the processing method for request item 1, where, (b) shall be carried out in the latter half of the implementation period of (a).

5. As in the processing method for request item 1, wherein, (b) shall be carried out during the implementation period of (a).

6. As with the processing method for request item 1, wherein, The supply amount of the inert gas in (b) is less than the supply amount of the modified gas in (a).

7. As in the processing method of request item 1, wherein, (a) shall be carried out in the latter half of the implementation period of (b).

8. As in the processing method for request item 1, wherein, (a) shall be carried out during the implementation period of (b).

9. As in the processing method of request item 1, wherein, The step of supplying the inert gas to the membrane during the implementation of (e) in (c) is included.

10. As in the processing method of request item 9, wherein, The implementation time of (e) is shorter than that of (c).

11. As in the processing method of request item 9, wherein, In (e), the aforementioned inert gas is supplied in a pulse.

12. As in the processing method of request item 9, wherein, (e) shall be carried out in the latter half of the implementation period of (c).

13. As in the processing method of request item 9, wherein, (e) shall be carried out during the implementation period of (c).

14. The processing method as described in request item 13, wherein, The supply amount of the inert gas in (e) is less than the supply amount of the etching gas in (c).

15. As in the processing method of request item 1, wherein, The modified gas and the inert gas are supplied from a direction different from the bottom direction of the recess.

16. As in the processing method of request item 1, wherein, The pressure in the space where the substrate exists in (a) is higher than the pressure in the space where the substrate exists in (c).

17. A method for manufacturing a semiconductor device, comprising the steps of etching a film by repeating a cycle including the following steps at least a predetermined number of times during the implementation period of (a) and the implementation period of (b); (a) supplying the film with a modified gas containing NH groups; (b) supplying the film with an inert gas to detach a portion of the modified gas adsorbed on the film; and (c) supplying the film with an etching gas; wherein a recess is provided on the surface of a substrate on which the film is formed.

18. A program executed by a computer on a processing device, wherein the program executes a loop comprising the following steps, wherein at least a portion of the execution period of (a) and the execution period of (b) are repeated a predetermined number of times, thereby etching a film; (a) a process of supplying the film with a modified gas containing NH groups; (b) a process of supplying the film with an inert gas to detach a portion of the modified gas adsorbed on the film; and (c) a process of supplying the film with an etching gas; wherein a recess is provided on the surface of a substrate on which the film is formed.

19. A processing apparatus comprising: a first gas supply system for supplying a modified gas containing NH groups to a membrane; a second gas supply system for supplying an inert gas to the membrane; a third gas supply system for supplying an etching gas to the membrane; and a control unit configured to control the first gas supply system, the second gas supply system, and the third gas supply system to perform a cycle comprising the following processes, repeating at least a portion of the implementation period of (a) and the implementation period of (b) a predetermined number of times, thereby etching the membrane; (a) a process of supplying the modified gas to the membrane; (b) a process of supplying the inert gas to the membrane to detach a portion of the modified gas adsorbed on the membrane; and (c) a process of supplying the etching gas to the membrane; and a recess is provided on the surface of a substrate on which the membrane is formed.

20. A method for manufacturing a semiconductor device, comprising the steps of etching a film by repeating a cycle including the following steps at least a portion of the implementation period of (a) and the implementation period of (b) a predetermined number of times; (a) supplying the film with a modified gas containing NH groups; (b) supplying the film with an inert gas to detach a portion of the modified gas adsorbed on the film; and (c) supplying the film with an etching gas; wherein the implementation time of (b) is shorter than the implementation time of (a).

21. A program by means of a computer to execute a processing device, wherein the program executes a loop comprising the following procedures, wherein at least a portion thereof during the execution period of (a) and the execution period of (b) are repeated a predetermined number of times, thereby etching a film; (a) a procedure of supplying the film with a modified gas containing NH groups; (b) a procedure of supplying the film with an inert gas to detach a portion of the modified gas adsorbed on the film; and (c) a procedure of supplying the film with an etching gas; wherein the execution time of (b) is shorter than the execution time of (a).

22. A processing apparatus comprising: a first gas supply system for supplying a modified gas containing NH groups to a membrane; a second gas supply system for supplying an inert gas to the membrane; a third gas supply system for supplying an etching gas to the membrane; and a control unit configured to control the first gas supply system, the second gas supply system, and the third gas supply system to perform a cycle comprising the following processes, repeating at least a portion of the implementation period of (a) and the implementation period of (b) a predetermined number of times, thereby etching the membrane; (a) a process of supplying the modified gas to the membrane; (b) a process of supplying the inert gas to the membrane to detach a portion of the modified gas adsorbed on the membrane; and (c) a process of supplying the etching gas to the membrane; wherein the implementation time of (b) is shorter than the implementation time of (a).

23. A method for manufacturing a semiconductor device, comprising the steps of etching a film by repeating a cycle including the following steps at least a predetermined number of times during the implementation period of (a) and the implementation period of (b); (a) supplying the film with a modified gas containing NH groups; (b) pulsely supplying an inert gas to the film to detach a portion of the modified gas adsorbed on the film; and (c) supplying the film with an etching gas.

24. A program by means of a computer to execute a processing device, wherein the program executes a loop comprising the following procedures, wherein at least a portion of the execution period of (a) and the execution period of (b) are repeated a predetermined number of times, thereby etching a membrane; (a) a procedure of supplying the membrane with a modified gas containing NH groups; (b) a procedure of pulsely supplying an inert gas to the membrane to detach a portion of the modified gas adsorbed on the membrane; and (c) a procedure of supplying an etching gas to the membrane.

25. A processing apparatus comprising: a first gas supply system for supplying a modified gas containing NH groups to a membrane; a second gas supply system for supplying an inert gas to the membrane; a third gas supply system for supplying an etching gas to the membrane; and a control unit configured to control the first gas supply system, the second gas supply system, and the third gas supply system to perform a cycle comprising the following processes, repeating at least a portion of the implementation period of (a) and the implementation period of (b) a predetermined number of times, thereby etching the membrane; (a) a process of supplying the modified gas to the membrane; (b) a process of pulsely supplying the inert gas to the membrane to detach a portion of the modified gas adsorbed on the membrane; and (c) a process of supplying the etching gas to the membrane.

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