Etching method, semiconductor device manufacturing method, processing apparatus, and program

Abstract

The present invention performs a cycle for a predetermined number of times, said cycle including: (a) a step for forming an inhibitor layer on the surface of a second substrate by supplying a modifier to the substrate having the first substrate and the second substrate on the surface thereof; (b) supplying a modifying agent having a molecular structure different from that of the modifying agent to the substrate, thereby modifying at least a portion of the first substrate; and (c) etching at least a portion of the modified portion in the first substrate by supplying an etchant to the substrate.

Description

Technical Field

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

[0002] As one of the manufacturing processes of a semiconductor device, a process of removing a substrate exposed on the surface of a substrate by etching (for example, refer to Japanese Patent Application Laid-Open No. 2021-082774, Japanese Patent Application Laid-Open No. 2021-082774) is sometimes performed. Summary of the Invention

[0003] Problems to be Solved by the Invention

[0004] However, depending on the combination of the etchant used during etching and the etching target film, stable etching may not be performed with good controllability.

[0005] The present disclosure provides a technique capable of performing stable etching with good controllability.

[0006] Means for Solving the Problems

[0007] According to one aspect of the present disclosure, a technique is provided in which the following steps are cycled a specified number of times:

[0008] (a) A modifier is supplied to a substrate having a first substrate and a second substrate on its surface, whereby an inhibitor layer is formed on the surface of the second substrate;

[0009] (b) A deteriorating agent having a molecular structure different from that of the modifier is supplied to the substrate, whereby at least a part of the first substrate is deteriorated; and

[0010] (c) By supplying an etchant to the substrate, at least a part of the deteriorated portion of the first substrate is etched.

[0011] Advantages of the Invention

[0012] According to the present disclosure, stable etching can be performed with good controllability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural view of a vertical processing furnace of a processing apparatus preferably used in one aspect of the present disclosure, and is a view showing a part of the processing furnace 202 in a longitudinal sectional view.

[0014] Figure 2 It is a schematic structural view of a vertical processing furnace of a processing apparatus preferably used in one aspect of the present disclosure, and is Figure 1 a view showing a part of the processing furnace 202 in a sectional view taken along line A-A.

[0015] Figure 3This is a schematic structural diagram of a controller 121 of a processing device preferably used in one aspect of the present disclosure, and is a diagram showing the control system of the controller 121 in a block diagram.

[0016] Figure 4 (a) of is a schematic cross-sectional view showing a wafer surface portion having a first substrate and a second substrate on the surface. In addition, Figure 4 (a) of shows an example in which the first substrate and the second substrate are alternately stacked adjacent to each other and are respectively adjacent to the third substrate. Figure 4 (b) of is a schematic cross-sectional view showing a wafer surface portion after an inhibitor layer is formed on the surface of the second substrate by performing step A from the state of (a) of Figure 4 . Figure 4 (c) of is a schematic cross-sectional view showing a wafer surface portion after at least a part of the first substrate is deteriorated by performing step B from the state of (b) of Figure 4 . Figure 4 (d) of is a schematic cross-sectional view showing a wafer surface portion after at least a part of the deteriorated portion in the first substrate is etched by performing step C from the state of (c) of Figure 4 .

[0017] Figure 5 (a) of is a schematic cross-sectional view showing a wafer surface portion after an inhibitor layer is formed on the exposed surface of the second substrate by performing step A from the state of (d) of Figure 4 . Figure 5 (b) of is a schematic cross-sectional view showing a wafer surface portion after at least a part of the first substrate is deteriorated by performing step B from the state of (a) of Figure 5 . Figure 5 (c) of is a schematic cross-sectional view showing a wafer surface portion after at least a part of the deteriorated portion in the first substrate is etched by performing step C from the state of (b) of Figure 5 . Figure 5 (d) of is a schematic cross-sectional view showing a wafer surface portion after the inhibitor layer remaining on the surface of the second substrate is removed by performing step D from the state of (c) of Figure 5 . Detailed Description of the Invention

[0018] <One Aspect of the Present Disclosure>

[0019] Hereinafter, mainly referring to Figures 1 to 3 , Figure 4 (a) to Figure 4 (d) of, Figure 5 (a) to Figure 5Part (d) of this disclosure will be described. In addition, the drawings used in the following description are all schematic, and the dimensional relationships and ratios of the respective elements shown in the drawings do not necessarily match the actual situation. Also, the dimensional relationships and ratios of the respective elements are not necessarily the same among multiple drawings.

[0020] (1) Structure of the processing device

[0021] As Figure 1 shown, the processing furnace 202 of the processing device has a heater 207 as a temperature adjuster (heating unit). The heater 207 has a cylindrical shape and is vertically installed by being supported on a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) a gas using heat.

[0022] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), for example, and is formed in a cylindrical shape with a closed upper end and an open lower end. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS), for example, and is formed in a cylindrical shape with open upper and lower ends. The upper end portion of the manifold 209 is engaged with the lower end portion 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 installed vertically like 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 a wafer 200 as a substrate. Processing of the wafer 200 is performed inside this processing chamber 201.

[0023] Inside the processing chamber 201, nozzles 249a to 249c as the first to third supply portions are respectively provided so as 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 made of a heat-resistant material such as quartz or SiC, for example. 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 249a and 249c are respectively provided adjacent to the nozzle 249b.

[0024] Mass flow controllers (MFCs) 241a to 241c, which are flow controllers (flow control units), and valves 243a to 243c, which are on-off valves, are respectively provided in the gas supply pipes 232a to 232c in order from the upstream side of the gas flow. Gas supply pipes 232d and 232f are respectively connected to positions on the downstream side of the valve 243a in the gas supply pipe 232a. Gas supply pipes 232e and 232g are respectively connected to positions on the downstream side of the valve 243b in the gas supply pipe 232b. The gas supply pipe 232h is connected to a position on the downstream side of the valve 243c in the gas supply pipe 232c. MFCs 241d to 241h and valves 243d to 243h are respectively provided in the gas supply pipes 232d to 232h in order from the upstream side of the gas flow. The gas supply pipes 232a to 232h are made of a metal material such as SUS, for example.

[0025] As Figure 2 shown, in a space that is annular in a plan view between the inner wall of the reaction tube 203 and the wafer 200, nozzles 249a to 249c are respectively provided so as to stand up from the lower part of the inner wall of the reaction tube 203 along the upper part in the arrangement direction of the wafer 200 upward. That is, in a region that is laterally adjacent to the wafer arrangement region where the wafer 200 is arranged and horizontally surrounds the wafer arrangement region, the nozzles 249a to 249c are respectively provided along the wafer arrangement region. In a plan view, the nozzle 249b is arranged to be opposed to the exhaust port 231a described later in a straight line across the center of the wafer 200 in the processing chamber 201. The nozzles 249a and 249c are arranged to sandwich the straight line L passing through the centers of the nozzle 249b and the exhaust port 231a from both sides 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 centers of the nozzle 249b and the wafer 200. That is, the nozzle 249c may also be provided on the opposite side of the nozzle 249a across the straight line L. The nozzles 249a 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 so as to be opposed (face to face) to the exhaust port 231a in a plan view, so that gas can be supplied to the wafer 200. A plurality of gas supply holes 250a to 250c are provided from the lower part to the upper part of the reaction tube 203.

[0026] A modifier is supplied into the processing chamber 201 from the gas supply pipe 232a via the MFC 241a, the valve 243a, and the nozzle 249a.

[0027] An oxidant is supplied into the processing chamber 201 from the gas supply pipe 232b via the MFC 241b, the valve 243b, and the nozzle 249b. The oxidant is used as a kind of metamorphic agent.

[0028] A catalyst is supplied into the processing chamber 201 from the gas supply pipe 232c via the MFC 241c, the valve 243c, and the nozzle 249c. The catalyst serves as a kind of metamorphic agent.

[0029] An etchant is supplied into the processing chamber 201 from the gas supply pipe 232d via the MFC 241d, the valve 243d, the gas supply pipe 232a, and the nozzle 249a.

[0030] An invalidator is supplied into the processing chamber 201 from the gas supply pipe 232e via the MFC 241e, the valve 243e, the gas supply pipe 232b, and the nozzle 249b.

[0031] An inert gas is supplied into the processing chamber 201 from the gas supply pipes 232f to 232h via the MFCs 241f to 241h, the valves 243f to 243h, 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, etc.

[0032] The modifier supply system is mainly composed of the gas supply pipe 232a, the MFC 241a, and the valve 243a. The oxidant supply system is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. The catalyst supply system is mainly composed of the gas supply pipe 232c, the MFC 241c, and the valve 243c. The etchant supply system is mainly composed of the gas supply pipe 232d, the MFC 241d, and the valve 243d. The invalidator supply system is mainly composed of the gas supply pipe 232e, the MFC 241e, and the valve 243e. The inert gas supply system is mainly composed of the gas supply pipes 232f to 232h, the MFCs 241f to 241h, and the valves 243f to 243h. The oxidant supply system and the catalyst supply system are each or all also referred to as the metamorphic agent supply system.

[0033] Any one or all of the above various supply systems may also be configured as an integrated supply system 248 in which the valves 243a to 243h, the MFCs 241a to 241h, etc. are integrated. The integrated supply system 248 is respectively connected to the gas supply pipes 232a to 232h, and the supply operation of various substances (various gases) into the gas supply pipes 232a to 232h, that is, the opening and closing operations of the valves 243a to 243h, the flow rate adjustment operations performed by the MFCs 241a to 241h, etc. are 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 loaded and unloaded with respect to the gas supply pipes 232a to 232h, etc. in units of the integrated unit, and maintenance, replacement, addition, etc. of the integrated supply system 248 can be performed in units of the integrated unit.

[0034] An exhaust port 231a for exhausting the atmosphere in the processing chamber 201 is provided below the side wall of the reaction tube 203. As Figure 2 shown, in a plan view, the exhaust port 231a is provided at a position facing (face to face) the nozzles 249a to 249c (gas supply holes 250a to 250c) across the wafer 200. The exhaust port 231a may also be provided along the upper part from the lower part of the side wall of the reaction tube 203, that is, along the wafer arrangement area. The 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 operating, thereby enabling vacuum exhaust and stopping of vacuum exhaust in the processing chamber 201, and to adjust the valve opening according to the pressure information detected by the pressure sensor 245 in a state where the vacuum pump 246 is operating, thereby enabling adjustment of the pressure in the processing chamber 201. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may also be included in the exhaust system.

[0035] A seal cover 219 serving as a furnace port cover for hermetically closing the lower end opening of the manifold 209 is provided below the manifold 209. The seal cover 219 is made of a metal material such as SUS, for example, and is formed in a disc shape. An O-ring 220b serving as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the seal cover 219. A rotation mechanism 267 for rotating a boat 217 (to be described later) is provided below the seal cover 219. The rotation shaft 255 of the rotation mechanism 267 passes through the seal cover 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the boat 217. The seal cover 219 is configured to be lifted and lowered in the vertical direction by a boat elevator 115 serving as a lifting mechanism provided outside the reaction tube 203. The boat elevator 115 is a transfer device (transfer mechanism) configured to transfer (load and unload) the wafer 200 into and out of the processing chamber 201 by lifting and lowering the seal cover 219.

[0036] Provided below the manifold 209 is a gate 219s as a furnace port cover that can hermetically seal the lower end opening of the manifold 209 in a state where the sealing cover 219 is lowered and the susceptor 217 is carried out from the processing chamber 201. The gate 219s is made of a metal material such as SUS, for example, and is formed in a disk shape. An O-ring 220c as a sealing member is provided on the upper surface of the gate 219s to abut against the lower end of the manifold 209. The opening and closing operation (lifting operation, rotating operation, etc.) of the gate 219s is controlled by a gate opening and closing mechanism 115s.

[0037] The susceptor 217 as a substrate support is configured to support multiple wafers 200, for example, 25 to 200 wafers, in a vertically arranged manner in a horizontal posture and with their centers aligned with each other, that is, arranged at intervals. The susceptor 217 is made of a heat-resistant material such as quartz or SiC, for example. An insulating plate 218 made of a heat-resistant material such as quartz or SiC is supported in multiple stages at the lower part of the susceptor 217.

[0038] A temperature sensor 263 as a temperature detector is provided in the reaction tube 203. The energization condition of the heater 207 is adjusted according to the temperature information detected by the temperature sensor 263, whereby 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.

[0039] As Figure 3 shown, a controller 121 as a control unit (control unit) is configured as a computer having the following parts: 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 perform data exchange with the CPU 121a via an internal bus 121e. An input / output device 122 configured as a touch panel, etc., is connected to the controller 121. In addition, an external storage device 123 can be connected to the controller 121. Furthermore, the processing device can be configured to have one control unit or multiple control units. That is, the control of the processing sequence described later can be performed using one control unit or multiple control units. In addition, multiple control units can be configured as a control system connected to each other through a wired or wireless communication network, and the control for performing the processing sequence described later can be performed through the entire control system. In this specification, when the term control unit is used, in addition to the case of including one control unit, there are also cases of including multiple control units and cases of including a control system composed of multiple control units.

[0040] The storage device 121c is constituted by, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. In the storage device 121c, a control program for controlling the operation of the processing device, a process recipe such as the process or conditions of the substrate processing described later, etc. are recorded and stored in a readable manner. The process recipe is combined in such a way that the processing device can execute each process in the substrate processing (etching process) described later by the controller 121 and obtain a prescribed result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are also collectively referred to as a program. In addition, the process recipe is also simply referred to as a recipe. In this specification, when the term program is used, there are cases where it includes only the recipe alone, cases where it includes only the control program alone, or cases where it includes both. The RAM 121b is configured as a storage area (work area) for temporarily holding programs or data, etc. read out by the CPU 121a.

[0041] The I / O port 121d is connected to the above-described MFCs 241a to 241h, valves 243a to 243h, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, susceptor elevator 115, gate opening / closing mechanism 115s, etc.

[0042] The CPU 121a is configured to be able to read out the control program from the storage device 121c and execute it, and to read out the recipe from the storage device 121c based on the input of an operation command from the input / output device 122, etc. The CPU 121a is configured to be able to control the following operations according to the read recipe content: the flow rate adjustment operations of various substances (various gases) performed by the MFCs 241a to 241h, the opening / closing operations of the valves 243a to 243h, the opening / closing operations of the APC valve 244 and the pressure adjustment operations performed by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operations of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operations of the susceptor 217 performed by the rotation mechanism 267, the lifting operations of the susceptor 217 performed by the susceptor elevator 115, the opening / closing operations of the gate 219s performed by the gate opening / closing mechanism 115s, etc.

[0043] The controller 121 can be formed by installing the above program recorded and stored in the external storage device 123 on a computer. The external storage device 123 includes, for example, magnetic disks such as HDDs, optical discs such as CDs, magneto-optical discs such as MOs, USB memories, semiconductor memories such as SSDs, and the like. The storage device 121c and the external storage device 123 are configured as computer-readable storage media. Hereinafter, they are also collectively referred to as storage media. In this specification, when the term storage medium is used, there are cases where it includes only the storage device 121c alone, only the external storage device 123 alone, or both of them. In addition, instead of using the external storage device 123, a communication unit such as the Internet or a dedicated line can be used to provide the program to the computer.

[0044] (2) Processing steps

[0045] Using the above processing device, as one step of the manufacturing process (manufacturing method) of the semiconductor device, mainly using Figure 4 of (a) to Figure 4 of (d), Figure 5 of (a) to Figure 5 of (d), an example of the processing sequence for selectively etching the first substrate of the first substrate and the second substrate on the surface of the wafer 200 as the substrate is described. In the following description, the operations of the respective parts constituting the processing device are controlled by the controller 121. In addition, the processing device is also referred to as a substrate processing device, an etching processing device, or an etching device. In addition, the processing method is also referred to as a substrate processing method, an etching processing method, or an etching method.

[0046] In the processing sequence of this embodiment, a cycle including the following steps is repeated a specified number of times (n times, where n is an integer of 1 or more):

[0047] (a) Step A: A modifier is supplied to the wafer 200 having the first substrate and the second substrate on its surface, whereby an inhibitor layer is formed on the surface of the second substrate;

[0048] (b) Step B: A deteriorating agent having a molecular structure different from that of the modifier is supplied to the wafer 200, whereby at least a part of the first substrate is deteriorated; and

[0049] (c) Step C: By supplying an etchant to the wafer 200, at least a part of the deteriorated part of the first substrate is etched.

[0050] Thus, a specified amount of the first substrate can be etched.

[0051] In the following examples, a case where the following steps are further performed is described: (d) Step D, after etching, at least one of removal and invalidation is performed, where removal means removing the inhibitor layer remaining on the surface of the second substrate, and invalidation means invalidating the inhibitor layer. In Step D, an invalidating agent is supplied to the wafer 200, for example. However, Step D may be omitted when it is not necessary to remove or invalidate the inhibitor layer remaining on the surface of the second substrate after etching, or when no inhibitor layer remains on the surface of the second substrate after etching.

[0052] In this specification, for convenience, the above processing sequence is sometimes expressed as follows. In addition, in the description of the following modification examples and the like, the same expression may sometimes be used.

[0053] (Modifier → Degradant → Etchant) × n

[0054] (Modifier → Degradant → Etchant) × n → Invalidation agent

[0055] In addition, in the following examples, a case where an oxidizing agent and a catalyst are supplied to the wafer 200 as a degradant in Step B is described. However, the supply of the catalyst may be omitted depending on the processing conditions.

[0056] In addition, preferably, the reactivity of the modifier with the second substrate is higher than the reactivity of the modifier with the first substrate. Also, preferably, the reactivity of the degradant with the first substrate is higher than the reactivity of the degradant with the inhibitor layer. Also, preferably, the reactivity of the degradant with the first substrate is higher than the reactivity of the degradant with the second substrate. Also, preferably, the reactivity of the etchant with the modified portion of the first substrate is higher than the reactivity of the etchant with the inhibitor layer. Also, preferably, the reactivity of the etchant with the modified portion of the first substrate is higher than the reactivity of the etchant with the second substrate.

[0057] The term "wafer" used in this specification sometimes refers to the wafer itself and sometimes refers to a laminate of the wafer and a specified layer or film formed on its surface. The term "wafer surface" used in this specification sometimes refers to the surface of the wafer itself and sometimes refers to the surface of a specified layer or the like formed on the wafer. When it is described in this specification that "a specified layer is formed on the wafer", sometimes it means that the specified layer is directly formed on the surface of the wafer itself, and sometimes it means that the specified layer is formed on a layer or the like formed on the wafer. When the term "substrate" is used in this specification, it is synonymous with the case where the term "wafer" is used.

[0058] The term "agent" used in this specification includes at least one of gaseous substances and liquid substances. The liquid substances include aerosol substances. That is, the modifier, the deteriorating agent (oxidizing agent, catalyst), the etchant, and the invalidating agent can each include a gaseous substance, can also include a liquid substance such as an aerosol substance, or can also include both of them.

[0059] The term "layer" used in this specification includes at least one of a continuous layer and a discontinuous layer. For example, the inhibitor layer can include a continuous layer, a discontinuous layer, or both as long as it can produce a reaction inhibition effect (deterioration inhibition effect, etching inhibition effect). Additionally, for example, the deteriorating layer can include a continuous layer, a discontinuous layer, or both as long as it is a layer in which at least a part of the first substrate has deteriorated.

[0060] (Wafer Loading and Cassette Loading)

[0061] When loading multiple wafers 200 (wafer loading) into the cassette 217, the gate 219s is moved by the gate opening / closing mechanism 115s, and the lower end opening of the manifold 209 is opened (gate opened). After that, as Figure 1 shown, the cassette 217 supporting multiple wafers 200 is lifted by the cassette elevator 115 and carried into the processing chamber 201 (cassette loading). In this state, the seal cover 219 is in a state of sealing the lower end of the manifold 209 via the O-ring 220b. In this way, the wafers 200 are prepared in the processing chamber 201.

[0062] In addition, as Figure 4 (a) of shows, the wafers 200 loaded in the cassette 217 have a first substrate, which is an object to be etched, and a second substrate, which is a non-etching object, on their surfaces. As Figure 4 (a) of shows, the first substrate and the second substrate are alternately stacked adjacent to each other and are each adjacent to the third substrate. In Figure 4In (a) thereof, an example is shown in which a plurality of first substrates and second substrates are alternately stacked adjacent to each other and are in contact with each other, and the first substrate and the second substrate are each in contact with a third substrate. The first substrate contains a substance that has low reactivity with an etchant and cannot be directly etched by the etchant alone, or a substance that is difficult to be directly etched by the etchant alone. The first substrate contains, for example, silicon (Si). As the first substrate, for example, an oxygen (O)-free film such as a silicon film (Si film) can be used. The second substrate contains a substance whose reactivity with the etchant is lower than the reactivity of the etchant with the deteriorated portion of the first substrate. The second substrate contains, for example, silicon (Si) and oxygen (O). Preferably, the second substrate further contains carbon (C). As the second substrate, for example, an oxygen (O)-containing film such as a silicon oxycarbide film (SiOC film) can be used. As described above, the materials, components, compositions, and molecular structures of the first substrate and the second substrate are different. In addition, as the third substrate, for example, a material having a different material from the first substrate can be used. For example, a material having the same material as the second substrate can also be used, and a material having a different material from the second substrate can also be used.

[0063] As the first substrate and the second substrate, for example, a film (CVD film) formed by chemical vapor deposition (CVD method) can be used. As the CVD method, a thermal CVD method, a plasma CVD method, a photo CVD method, etc. can be used. As the processing temperature when forming the film, for example, 350 to 800 °C is exemplified, and preferably 450 to 700 °C.

[0064] (Pressure adjustment and temperature adjustment)

[0065] After the loading of the susceptor is completed, vacuum exhaust (pressure reduction exhaust) is performed by a vacuum pump 246 so that the pressure (vacuum degree) in the processing chamber 201, that is, the space where the wafer 200 exists, becomes a desired pressure. At this time, the pressure in the processing chamber 201 is measured by a pressure sensor 245, and feedback control is performed on the APC valve 244 based on the measured pressure information. In addition, heating is performed by a heater 207 so that the wafer 200 in the processing chamber 201 becomes a desired processing temperature. At this time, feedback control is performed on the energization of the heater 207 based on the temperature information detected by a temperature sensor 263 so that a desired temperature distribution is obtained in the processing chamber 201. In addition, rotation of the wafer 200 by a rotation mechanism 267 is started. Exhaust in the processing chamber 201, heating of the wafer 200, and rotation are continuously performed at least until the processing of the wafer 200 is completed.

[0066] (Step A)

[0067] Thereafter, by supplying a modifier (modifying gas) to the wafer 200, an inhibitor layer is formed on the surface of the second substrate.

[0068] Specifically, valve 243a is opened to allow the modifier to flow into gas supply pipe 232a. The flow rate of the modifier is adjusted by MFC241a and supplied into processing chamber 201 via nozzle 249a, and exhausted from exhaust port 231a. At this time, the modifier is supplied to wafer 200 from the side of wafer 200 (modifier supply). At this time, valves 243f to 243h may also be opened to supply inert gas into processing chamber 201 via nozzles 249a to 249c, respectively.

[0069] By supplying the modifier to wafer 200 under the processing conditions described below, at least a part of the molecular structure of the molecules constituting the modifier, i.e., inhibitor molecules, is selectively chemisorbed on the surface (exposed surface) of the second substrate of wafer 200. As shown in (b) of Figure 4 an inhibitor layer can be selectively formed on the surface of the second substrate. The inhibitor layer can exert an effect of inhibiting or hindering the reaction with the denaturant of the second substrate and the reaction with the etchant of the second substrate. Therefore, it can also be said to be a reaction inhibition layer (denaturation inhibition layer, etching inhibition layer) or a reaction hindrance layer (denaturation hindrance layer, etching hindrance layer). In addition, the inhibitor molecules can also be said to be reaction inhibition molecules or reaction hindrance molecules. The inhibitor layer formed in this step contains residues from the modifier, i.e., at least a part of the molecular structure of the molecules constituting the modifier. The inhibitor layer prevents the denaturant from contacting the surface of the second substrate in step B, inhibiting or hindering the denaturation of the second substrate. In addition, the inhibitor layer is a layer covering the surface of the second substrate and can also prevent the etchant from contacting the surface of the second substrate in step C, inhibiting or hindering the etching of the second substrate. That is, the inhibitor layer can also be said to be a protective layer that protects the surface (exposed surface) of the second substrate.

[0070] At least a part of the molecular structure of the molecule serving as a modifier, that is, an inhibitor molecule, can be exemplified by trialkylsilyls such as trimethylsilyl (-SiMe3) and triethylsilyl (-SiEt3). Trialkylsilyls contain an alkyl group, which is a type of hydrocarbon group. When the inhibitor molecule contains them, Si of trimethylsilyl or triethylsilyl adsorbs to the adsorption sites on the surface of the second substrate of the wafer 200. When the second substrate is, for example, a SiOC film, the surface of the second substrate contains OH terminations (OH groups) as adsorption sites, and Si of trimethylsilyl or triethylsilyl bonds to O of the OH termination (OH group) on the surface of the second substrate, and the surface of the second substrate is terminated with an alkyl group such as a methyl group or an ethyl group. The hydrocarbon group represented by an alkyl group (alkylsilyl) such as a methyl group (trimethylsilyl) or an ethyl group (triethylsilyl) that terminates the surface of the second substrate forms an inhibitor layer, and in step B, it is possible to prevent the modifier from contacting the surface of the second substrate, and it is possible to inhibit or impede the deterioration of the second substrate, that is, it is possible to inhibit or impede the deterioration reaction of the second substrate. In addition, the hydrocarbon group that terminates the surface of the second substrate can also prevent the etchant from contacting the surface of the second substrate in step C, and inhibit or impede the etching of the second substrate, that is, inhibit or impede the etching reaction of the second substrate.

[0071] When the inhibitor molecule adsorbed to the adsorption sites on the surface of the second substrate is a trialkylsilyl such as trimethylsilyl (-SiMe3) or triethylsilyl (-SiEt3), the inhibitor molecule contains an alkyl group (alkylsilyl), and the inhibitor layer contains an alkyl group (alkylsilyl) termination. When the inhibitor layer contains a hydrocarbon group termination such as an alkyl group (alkylsilyl) termination, an appropriate reaction hindrance effect (deterioration inhibition effect, etching inhibition effect) can be obtained. In addition, the alkyl group (alkylsilyl) termination and the hydrocarbon group termination are also referred to as an alkyl group (alkylsilyl) termination and a hydrocarbon termination, respectively.

[0072] In addition, in this step, sometimes at least a part of the molecular structure of the molecules constituting the modifier is also adsorbed on a part of the first substrate surface of the wafer 200, but the adsorption amount is very small, and the adsorption amount of the wafer 200 onto the second substrate surface is overwhelmingly large. Such selective (preferential) adsorption can be achieved because the reactivity of the modifier with the second substrate is higher than that with the first substrate. For example, this is because, as in the case where the second substrate is a SiOC film and the first substrate is a Si film, the entire region of the second substrate surface is capped with OH, while many regions of the first substrate surface are not capped with OH. Additionally, it is because the processing conditions in this step are set such that the modifier does not undergo gas-phase decomposition in the processing chamber 201. Thus, in this step, at least a part of the molecular structure of the molecules constituting the modifier does not multi-stack on the surfaces of the first substrate and the second substrate, and at least a part of the molecular structure of the molecules constituting the modifier is selectively adsorbed on the second substrate surface among the surfaces of the first substrate and the second substrate. As a result, the surface of the second substrate is selectively capped with at least a part of the molecular structure of the molecules constituting the modifier.

[0073] As the processing conditions when supplying the modifier in step A, examples are:

[0074] Processing temperature: room temperature (25 °C) to 500 °C, preferably room temperature to 250 °C

[0075] Processing pressure: 5 to 2000 Pa, preferably 10 to 1000 Pa

[0076] Modifier supply flow rate: 0.001 to 3 slm, preferably 0.001 to 0.5 slm

[0077] Modifier supply time: 1 to 300 seconds, preferably 5 to 120 seconds

[0078] Inert gas supply flow rate (for each gas supply pipe): 0 to 20 slm.

[0079] In addition, the expression of the numerical range such as "25 to 500 °C" in this specification means that the lower limit value and the upper limit value are included in this range. Therefore, for example, "25 to 500 °C" means "25 °C or higher and 500 °C or lower". The same applies to other numerical ranges. Additionally, the processing temperature in this specification refers to the temperature of the wafer 200 or the temperature in the processing chamber 201, the processing pressure refers to the pressure in the processing chamber 201. Additionally, the processing time refers to the duration of this processing. Additionally, when the supply flow rate includes 0 slm, 0 slm means the case where this substance (gas) is not supplied. The same applies to the following descriptions.

[0080] After the inhibitor layer is selectively formed on the second substrate surface of the wafer 200, the valve 243a is closed to stop supplying the modifier into the processing chamber 201. Then, the inside of the processing chamber 201 is evacuated, and gaseous substances remaining in the processing chamber 201 are exhausted from the processing chamber 201. At this time, the valves 243f to 243h are opened, and an inert gas is supplied into the processing chamber 201 through the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c functions as a purge gas, whereby the inside of the processing chamber 201 is purged.

[0081] As the processing conditions during the purge in step A, examples are:

[0082] Processing pressure: 1 to 30 Pa

[0083] Processing time: 1 to 120 seconds, preferably 1 to 60 seconds

[0084] Inert gas supply flow rate (for each gas supply pipe): 0.5 to 20 slm.

[0085] In addition, the processing temperature during the purge in this step is preferably set to the same temperature as the processing temperature when supplying the modifier.

[0086] The modifier preferably contains an organic substance. In addition, the modifier preferably contains at least one of an alkyl group and an amino group. As the modifier, for example, a compound having a structure in which an amino group is directly bonded to Si, a compound having a structure in which an alkyl group is directly bonded to Si, or a compound having a structure in which an amino group and an alkyl group are directly bonded to Si can be used. As the amino group in these compounds, a substituted amino group substituted with an alkyl group such as a methyl group or an ethyl group is preferred.

[0087] As a modifier, for example, bis(dipropylamino)dimethylsilane ([(C3H7)2N]2Si(CH3)2), bis(dipropylamino)diethylsilane ([(C3H7)2N]2Si(C2H5)2), bis(dimethylamino)dimethylsilane ([(CH3)2N]2Si(CH3)2), bis(diethylamino)diethylsilane ([(C2H5)2N]2Si(C2H5)2), bis(dimethylamino)diethylsilane ([(CH3)2N]2Si(C2H5)2), bis(diethylamino)dimethylsilane ([(C2H5)2N]2Si(CH3)2), bis(dimethylamino)silane ([(CH3)2N]2SiH2), bis(diethylamino)silane ([(C2H5)2N]2SiH2), bis(dimethylaminodimethylsilyl)ethane ([(CH3)2N(CH3)2Si]2C2H6), bis(dipropylamino)silane ([(C3H7)2N]2SiH2), bis(dibutylamino)silane ([(C4H9)2N]2SiH2), (dimethylsilyl)diamine ((CH3)2Si(NH2)2), (diethylsilyl)diamine ((C2H5)2Si(NH2)2), (dipropylsilyl)diamine ((C3H7)2Si(NH2)2), bis(dimethylaminodimethylsilyl)methane ([(CH3)2N(CH3)2Si]2CH2), bis(dimethylamino)tetramethyldisilane ([(CH3)2N]2(CH3)4Si2), etc. can also be used. As the modifier, one or more of them can be used.

[0088] In addition, as a modifier, for example, (dipropylamino)trimethylsilane ((C3H7)2NSi(CH3)3), (dibutylamino)trimethylsilane ((C4H9)2NSi(CH3)3), (dimethylamino)trimethylsilane ((CH3)2NSi(CH3)3), (diethylamino)triethylsilane ((C2H5)2NSi(C2H5)3), (dimethylamino)triethylsilane ((CH3)2NSi(C2H5)3), (diethylamino)trimethylsilane ((C2H5)2NSi(CH3)3), (trimethylsilyl)amine ((CH3)3SiNH2), (triethylsilyl)amine ((C2H5)3SiNH2), (dimethylamino)silane ((CH3)2NSiH3), (diethylamino)silane ((C2H5)2NSiH3), (dipropylamino)silane ((C3H7)2NSiH3), (dibutylamino)silane ((C4H9)2NSiH3), etc. can be used. As the modifier, one or more of them can be used.

[0089] As the inert gas, noble gases such as nitrogen (N2) gas, argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, etc. can be used. As the inert gas, one or more of them can be used. This is the same in each of the steps described later.

[0090] (Step B)

[0091] After the end of Step A, to the wafer 200, that is, the wafer 200 after the inhibitor layer is formed on the second substrate surface, a denaturant (denaturing gas) having a molecular structure different from that of the modifier is supplied, whereby at least a part of the first substrate is denatured. Here, an example of supplying an oxidizing agent (oxidizing gas) and a catalyst (catalyst gas) as the denaturant will be described.

[0092] Specifically, valves 243b and 243c are opened so that the oxidizing agent and the catalyst flow into the gas supply pipes 232b and 232c, respectively. The flow rates of the oxidizing agent and the catalyst are adjusted by MFCs 241b and 241c, respectively, and are supplied into the processing chamber 201 via nozzles 249b and 249c, mixed in the processing chamber 201, and exhausted from the exhaust port 231a. At this time, the oxidizing agent and the catalyst are supplied to the wafer 200 from the side of the wafer 200 (oxidizing agent + catalyst supply). At this time, valves 243f to 243h can also be opened to supply inert gas into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0093] By supplying the oxidizing agent and the catalyst to the wafer 200 under the processing conditions described later, it is possible to suppress the denaturation of the second substrate and selectively denature at least a part of the first substrate. That is, it is possible to suppress the oxidation of the second substrate and selectively oxidize at least a part of the first substrate. Thus, as Figure 4 shown in (c), a denatured layer formed by denaturing the first substrate, that is, an oxidized layer formed by oxidizing the first substrate, is formed in at least a part of the surface side (exposed surface side) of the first substrate. When the first substrate is, for example, a Si film, the denatured layer, that is, the oxidized layer, becomes a layer containing at least Si and O. In this step, by supplying the catalyst together with the oxidizing agent, the above oxidation reaction can be carried out under low temperature conditions as described later.

[0094] In addition, in this step, it is possible to selectively (preferably) denature at least a part of the first substrate among the first substrate and the second substrate because the reactivity of the denaturant with the first substrate is higher than the reactivity of the denaturant with the inhibitor layer. Also, because the reactivity of the denaturant with the first substrate is higher than the reactivity of the denaturant with the second substrate. Thus, in this step, the reaction of the denaturant with the first substrate is selectively carried out, and at least a part of the first substrate is selectively denatured.

[0095] As the processing conditions for supplying the metamorphic agent (oxidizing agent and catalyst) in step B, examples are as follows:

[0096] Processing temperature: room temperature (25 °C) to 500 °C, preferably room temperature to 200 °C, more preferably room temperature to 150 °C; Processing pressure: 1 to 13332 Pa, preferably 133 to 1333 Pa

[0097] Supply flow rate of the oxidizing agent: 0.001 to 5 slm, preferably 0.001 to 2 slm

[0098] Supply flow rate of the catalyst: 0 to 2 slm, preferably 0.001 to 2 slm

[0099] Supply flow rate of the inert gas (for each gas supply pipe): 0 to 20 slm

[0100] Supply time of each substance: 1 to 300 seconds, preferably 5 to 120 seconds.

[0101] After at least a part of the first substrate is metamorphosed, valves 243b and 243c are closed, and the supply of the oxidizing agent and the catalyst into the processing chamber 201 is stopped respectively. Then, through the same processing procedure and processing conditions as the purge in step A, the gaseous substances remaining in the processing chamber 201 are exhausted from the processing chamber 201 (purge). In addition, the processing temperature during the purge in this step is preferably set to the same temperature as the processing temperature when supplying the metamorphic agent.

[0102] As the oxidizing agent of the metamorphic agent, a gas containing hydrogen (H) and oxygen (O) as an oxidizing gas can be used. As the gas containing H and O, for example, hydrogen peroxide (H2O2) gas, water vapor (H2O gas), hydrogen (H2) gas + oxygen (O2) gas, H2 gas + ozone (O3) gas, etc. can be used. That is, as the gas containing H and O, a gas containing H + a gas containing O (reducing gas + oxidizing gas) can also be used. In this case, as the gas containing H, that is, the reducing gas, deuterium (D2) gas can also be used instead of H2 gas. In addition, as the oxidizing agent, an O2 gas, a nitrous oxide (N2O) gas, a nitric oxide (NO) gas, a nitrogen dioxide (NO2) gas, a carbon dioxide (CO2) gas, a carbon monoxide (CO) gas, etc., a gas containing O, a gas containing N and O, a gas containing C and O, etc. can also be used. Thus, as the metamorphic agent, for example, a substance containing H and O, a substance containing D and O, a substance containing O, a substance containing N and O, a substance containing C and O, etc. can be used. As the oxidizing agent of the metamorphic agent, one or more of them can be used.

[0103] In addition, the combined description of two gases such as "H2 gas + O2 gas" in this specification means a mixed gas of H2 gas and O2 gas. When supplying the mixed gas, the two gases can be mixed (pre-mixed) in the supply pipe and then supplied into the processing chamber 201, or the two gases can be separately supplied into the processing chamber 201 from different supply pipes and mixed in the processing chamber 201 (post-mixed).

[0104] As a catalyst for the dopant, for example, an amine-based gas (amine-based substance) containing carbon (C), nitrogen (N), and hydrogen (H) can be used. As the amine-based gas, a cyclic amine-based gas (cyclic amine-based substance) or a linear amine-based gas (linear amine-based substance) can be used. As the catalyst, for example, aminopyridine (C5H6N2), picoline (C6H7N), dimethylpyridine (C7H9N), pyrimidine (C4H4N2), pyridine (C5H5N), quinoline (C9H7N), piperazine (C4H 10 N2), piperidine (C5H 11 N), aniline (C6H7N) and other cyclic amines can be used. In addition, as the catalyst, for example, triethylamine ((C2H5)3N), diethylamine ((C2H5)2NH), monoethylamine ((C2H5)NH2), trimethylamine ((CH3)3N), dimethylamine ((CH3)2NH), monomethylamine ((CH3)NH2) and other linear amines can be used. In addition, ammonia (NH3) can also be used as the catalyst. As the catalyst for the dopant, one or more of them can be used. In addition, as described above, the supply of the catalyst can also be omitted depending on the processing conditions.

[0105] When the doped layer formed by doping at least a part of the surface side of the above-mentioned first substrate is etched in step C, a specific substance that reacts with the etchant but does not contribute to etching alone can be generated. In step C, when etching starts, when at least a part of the doped layer is etched, a mixture of the specific substance generated from the doped layer and the etchant can be used to etch at least a part of the remaining doped layer. The specific substance generated from the doped layer can promote and accelerate the etching of the remaining doped layer by reacting with the etchant. That is, the doped layer can be said to be an etching promoting layer for the doped layer itself.

[0106] For example, by using the above-described oxidizing agent and catalyst as modifiers, a modified layer containing H and O can be formed on at least a part of the surface side of the first substrate. H and O in the modified layer are preferably contained in the modified layer as a compound containing H and O. That is, the modified layer preferably contains a compound containing H and O. The modified layer containing H and O preferably contains H2O as a compound containing H and O, for example. That is, the modified layer may contain H and O, preferably may contain a compound containing H and O, and more preferably may contain H2O. Since the modified layer contains H and O and preferably contains H2O, when the modified layer is etched in step C, a specific substance that reacts with the etchant but does not contribute to etching alone can be effectively generated.

[0107] As described above, in the case where the modified layer contains H2O as a compound containing H and O, the H2O molecules contained in the modified layer are retained in the modified layer, for example, by forming hydrogen bonds with other components (molecules) in the modified layer. Therefore, it can be considered that when the modified layer in which the H2O molecules are retained is etched, the above-described hydrogen bonds are broken, and the H2O molecules become gaseous, for example, and escape from the modified layer and are released. Thus, when the modified layer is etched in step C, the H2O contained in the modified layer is generated from the modified layer as a specific substance. That is, when the modified layer containing H2O is etched, H2O is generated as a specific substance. In addition, when the modified layer is etched or otherwise, the H2O molecules in the modified layer sometimes exude to the surface of the modified layer as a liquid.

[0108] In this step, by adjusting the processing time when forming the modified layer, a modified layer with a desired thickness can be obtained. And the etching amount of the first substrate in step C can be controlled by using the thickness of the modified layer formed in this step. This is because the first substrate contains a substance that has low reactivity with the etchant and cannot be directly etched by the etchant alone, or a substance that is difficult to be directly etched by the etchant alone, while the modified layer contains a substance that has high reactivity with the etchant and is easily etched by the etchant. Thus, the reactivity of the etchant with the modified layer is much higher than the reactivity of the etchant with the first substrate, and thereby, the etching amount of the first substrate can be controlled by the thickness of the modified layer. As a result, the controllability and uniformity of the etching amount of the first substrate can be improved.

[0109] (Step C)

[0110] After the completion of step B, an etchant (etching gas) is supplied to the wafer 200, i.e., the wafer 200 in which at least a part of the first substrate has deteriorated. Thereby, at least a part of the deteriorated portion in the first substrate, i.e., the deteriorated layer, is etched. As described above, in this step, when etching the deteriorated layer, a specific substance that reacts with the etchant but does not contribute to etching alone is generated. A mixture of the specific substance and the etchant can be used to etch the deteriorated layer. Hereinafter, the case where this specific substance is generated during etching to promote the etching reaction will be described.

[0111] Specifically, the valve 243d is opened to allow the etchant to flow into the gas supply pipe 232d. The flow rate of the etchant is adjusted by the MFC241d, supplied into the processing chamber 201 via the gas supply pipe 232a and the nozzle 249a, and exhausted from the exhaust port 231a. At this time, the etchant is supplied to the wafer 200 from the side of the wafer 200 (etchant supply). At this time, the valves 243f to 243h may also be opened to supply inert gas into the processing chamber 201 via the nozzles 249a to 249c, respectively.

[0112] By supplying the etchant to the wafer 200 under the processing conditions described below, etching of the second substrate can be suppressed, and at least a part of the deteriorated layer formed on the surface side of the first substrate can be selectively etched. At this time, when the etching of the deteriorated layer starts, a specific substance is released from the deteriorated layer as a gas, for example, and the released specific substance is mixed with the etchant. In the mixture of the specific substance and the etchant thus obtained, the specific substance reacts with the etchant to generate an activated etchant, whereby the remaining deteriorated layer is etched. By continuously etching the mixture of the specific substance and the etchant, as Figure 4 shown in (d) of, at least a part of the deteriorated portion in the first substrate is etched. In addition, Figure 4 (d) of shows an example in which all of the deteriorated portion in the first substrate, i.e., the entire deteriorated layer, is etched.

[0113] In addition, the specific substance is a substance that, although it does not contribute to etching alone, can promote etching by reacting with the etchant. That is, the specific substance can be said to be a substance that promotes etching by reacting with the etchant, or a substance that activates the etchant. In addition, the specific substance sometimes contains a liquid in addition to the case where it is a gas released from the deteriorated layer. For example, when the specific substance oozes out to the surface of the deteriorated layer as a liquid during etching of the deteriorated layer, by using a mixture of the specific substance as the liquid and the etchant, at least a part of the deteriorated layer can be etched efficiently and effectively. In addition, at this time, etching of at least a part of the deteriorated layer can also be started rapidly.

[0114] In this step, the specific substances generated during the etching of the deteriorated layer may contain H and O, and preferably may contain H2O. Since the specific substances contain H and O, and preferably contain H2O, the etchant can be effectively activated, and the etching of the deteriorated layer can be further promoted. As a result, the etching of the deteriorated layer can be performed more stably.

[0115] In addition, in this step, it is possible to selectively (preferably) etch at least a part of the deteriorated portion in the first substrate because: the reactivity of the etchant with the deteriorated portion of the first substrate is higher than at least one of the reactivity of the etchant with the inhibitor layer and the reactivity of the etchant with the second substrate.

[0116] When the reactivity of the etchant with the deteriorated portion of the first substrate is higher than the reactivity of the etchant with the inhibitor layer, the etching of the inhibitor layer can be suppressed, and the deteriorated layer can be selectively etched. At this time, since the etching of the inhibitor layer can be suppressed, the state in which the surface of the second substrate is protected by the inhibitor layer can be maintained. As a result, the etching of the second substrate can be suppressed.

[0117] When the reactivity of the etchant with the deteriorated portion of the first substrate is higher than the reactivity of the etchant with the second substrate, the etching of the second substrate can be suppressed, and the deteriorated layer can be selectively etched. At this time, assuming that at least a part of the inhibitor layer is etched and the portion of the second substrate covered by the inhibitor layer is exposed, and this exposed surface is exposed to the etchant, even in this case, the etching of the second substrate can be suppressed. In addition, when the deteriorated layer is etched, the portion of the second substrate in contact with the deteriorated layer is exposed, and this exposed surface is exposed to the etchant, even in this case, the etching of the second substrate can be suppressed. Thus, when the reactivity of the etchant with the deteriorated portion of the first substrate is higher than the reactivity of the etchant with the second substrate, assuming that the surface of the second substrate is exposed and this exposed surface is exposed to the etchant, even in this case, the etching of the second substrate can be suppressed.

[0118] In addition, in this step, it is possible to selectively (preferably) etch at least a part of the deteriorated portion in the first substrate because: the reactivity of the etchant with the deteriorated portion of the first substrate is much higher than the reactivity of the etchant with the non-deteriorated portion (non-deteriorated part) of the first substrate. Thereby, the etching of the non-deteriorated portion of the first substrate can be suppressed, and the deteriorated layer of the first substrate can be selectively etched.

[0119] As the processing conditions when supplying the etchant in step C, examples are as follows:

[0120] Processing temperature: room temperature (25 °C) to 300 °C, preferably room temperature to 200 °C

[0121] Processing pressure: 133 to 13332 Pa, preferably 1 to 1333 Pa

[0122] Etchant supply flow rate: 0.001 - 2 slm

[0123] Etchant supply time: 1 - 300 seconds, preferably 5 - 120 seconds

[0124] Inert gas supply flow rate (for each gas supply pipe): 0 - 20 slm.

[0125] After the etching of at least a part of the deteriorated portion in the first substrate is completed, valve 243d is closed to stop the supply of the etchant into the processing chamber 201. Then, the gaseous substances remaining in the processing chamber 201, etc. are exhausted from the processing chamber 201 (purged) through the same processing procedure and processing conditions as the purge in step A. In addition, the processing temperature during the purge in this step is preferably set to the same temperature as the processing temperature when supplying the etchant.

[0126] In addition, the processing temperature in step C can also be the same as the processing temperature in step A and the processing temperature in step B. In this case, the time required to change the processing temperature can be reduced, and the productivity of substrate processing can be improved.

[0127] As the etchant, a fluorine-based substance can be used. For example, a fluorine-containing (F) gas can be used. As the F-containing gas, for example, a chlorine trifluoride (ClF3) gas, a chlorine fluoride (ClF) gas, a nitrogen trifluoride (NF3) gas, a hydrogen fluoride (HF) gas, a fluorine (F2) gas, etc., which are Cl- and F-containing gases, N- and F-containing gases, H- and F-containing gases, etc. can be used. As described above, as the etchant, for example, a Cl- and F-containing substance, an N- and F-containing substance, an H- and F-containing substance, an F-containing substance, etc. can be used. That is, as the etchant, for example, an interhalogen compound, a nitrogen halide, a hydrogen halide, a halogen monomer, etc. can be used. One or more of them can be used as the etchant.

[0128] In addition, as the etchant, a gas such as ammonia (NH3) gas, H2 gas, H2O gas, isopropyl alcohol ((CH3)2CHOH) gas, methanol (CH3OH) gas, or a mixed gas thereof can also be added to these F-containing gases. In addition, when a solid by-product (complex, etc.) is generated by adding at least one of them to the F-containing gas, a step of sublimating the solid by-product, such as a heat treatment (annealing) step, etc., is preferably appropriately added. At this time, the heat treatment step is performed at a temperature equal to or higher than the processing temperature when supplying the etchant, preferably a temperature higher than the processing temperature when supplying the etchant, so that the solid by-product can be effectively sublimated.

[0129] When the etchant is a fluorine-containing substance, a specific substance can be effectively generated during the etching of the deteriorated layer. Additionally, when the etchant is a substance containing H and F, during the etching of the deteriorated layer, in addition to effectively generating a specific substance, a specific substance can also be formed through the chemical reaction between the etchant and the deteriorated layer during etching. Furthermore, the above-mentioned deteriorated layer sometimes contains H and O, sometimes contains H2O, sometimes is an oxide layer, and sometimes is an oxide layer containing H2O. For example, when the etchant is a substance containing H and F, during the etching of the deteriorated layer which is an oxide layer containing H2O, in addition to being able to effectively generate H2O as a specific substance by detaching it from the deteriorated layer, H2O as a specific substance can also be formed through the chemical reaction between the etchant and the deteriorated layer during etching.

[0130] (The number of times of implementation regulations)

[0131] By performing the cycle including the above-mentioned Step A, Step B, and Step C, that is, the cycle of sequentially performing each step non-simultaneously, a specified number of times (n times, where n is an integer of 1 or more), a specified amount of etching can be performed on the first substrate to be etched. It is preferred that the above cycle be repeated multiple times. That is, preferably, the thickness of the first substrate etched in each cycle is thinner than the desired etching thickness (specified amount) of the first substrate, and the above cycle is repeated multiple times until the etching thickness of the first substrate becomes the desired thickness (depth). By repeating the above cycle multiple times, the entire first substrate can also be etched.

[0132] In addition, when etching the deteriorated layer in Step C, as Figure 4 shown in (d), sometimes a part of the second substrate will be exposed. For example, when etching the deteriorated layer, the part of the second substrate in contact with the etched deteriorated layer and the part where the inhibitor layer is removed may be exposed. Even in this case, by performing Step A in the next cycle, an inhibitor layer can be formed on the exposed part of the second substrate as shown in Figure 5 (a), and the surface (exposed surface or exposed part) of the second substrate can be protected. For example, an inhibitor layer can be newly formed on the exposed part of the second substrate in contact with the etched deteriorated layer, and in addition, an inhibitor layer can be re-formed on the exposed part of the part of the second substrate where the inhibitor layer has been removed to repair and strengthen the inhibitor layer. Thus, when performing Step B later, as Figure 5 shown in (b), deterioration of the second substrate can be inhibited, and at least a part of the first substrate can be selectively deteriorated. Additionally, when performing Step C later, as Figure 5As shown in (c), etching of the second substrate can be suppressed and the deteriorated layer can be selectively etched. That is, even after the second cycle (the second cycle), reactions the same as those in the first cycle (the first cycle) can be generated in each step, and the same reactions as those in the first cycle (the first cycle) can be carried out.

[0133] (Step D)

[0134] After etching of a predetermined amount of the first substrate is completed, an invalidating agent (invalidating gas) is supplied to the wafer 200, whereby at least one of removal and invalidation is carried out after etching. Here, removal means removing the inhibitor layer remaining on the surface of the second substrate, and invalidation means invalidating the inhibitor layer.

[0135] Specifically, the valve 243e is opened to allow the invalidating agent to flow into the gas supply pipe 232e. The flow rate of the invalidating agent is adjusted by the MFC241e, and is supplied into the processing chamber 201 via the gas supply pipe 232b and the nozzle 249b, and exhausted from the exhaust port 231a. At this time, the invalidating agent is supplied to the wafer 200 from the side of the wafer 200 (invalidating agent supply). At this time, the valves 243f to 243h may also be opened to supply inert gas into the processing chamber 201 via the nozzles 249a to 249c, respectively.

[0136] By supplying the invalidating agent to the wafer 200 under the processing conditions described below, as Figure 5 shown in (d), at least one of removal and invalidation of the inhibitor layer remaining on the surface of the second substrate can be carried out after etching a predetermined amount of the first substrate. In addition, removal of the inhibitor layer means that inhibitor molecules as reaction-inhibiting molecules or reaction-impeding molecules detach from the surface of the second substrate, etc., and the inhibitor layer as a reaction-inhibiting layer or reaction-impeding layer disappears from the surface of the second substrate. In addition, invalidation of the inhibitor layer means that the function of the inhibitor molecules contained in the inhibitor layer as reaction-inhibiting molecules or reaction-impeding molecules is inactivated due to changes in its molecular structure or atomic arrangement structure, etc., and the inhibitor layer formed on the surface of the second substrate loses its function as a reaction-inhibiting layer or reaction-impeding layer. In addition, Figure 5 (d) shows an example in which the inhibitor layer remaining on the surface of the second substrate has been removed.

[0137] Examples of the processing conditions when supplying the invalidating agent in Step D are as follows:

[0138] Processing temperature: 200 to 1000 °C, preferably 400 to 700 °C

[0139] Processing pressure: 1 to 120000 Pa

[0140] Processing time: 1 to 18000 seconds

[0141] Flow rate of the deactivator supply: 0 - 50 slm

[0142] Flow rate of the inert gas supply (for each gas supply pipe): 0 - 20 slm

[0143] RF power: 0 - 10000 W.

[0144] In addition, the RF power is the power applied to generate plasma in the case of performing plasma treatment using the deactivator. Additionally, a deactivator supply flow rate of 0 slm means the case where no deactivator is supplied. That is, at least one of the removal and deactivation of the inhibitor layer remaining on the surface of the second substrate can also be performed using the thermal energy generated by heating, for example, without supplying the deactivator.

[0145] After performing at least one of the removal and deactivation of the inhibitor layer remaining on the surface of the second substrate, valve 243e is closed, and the supply of the deactivator to the processing chamber 201 is stopped. Then, the gaseous substances and the like remaining in the processing chamber 201 are exhausted from the processing chamber 201 (purge) through the same processing procedure and processing conditions as the purge in step A. In addition, the processing temperature during the purge in this step is preferably set to the same temperature as the processing temperature when supplying the deactivator.

[0146] As the deactivator, various oxidants, NH3 gas, diazene (N2H2) gas, hydrazine (N2H4) gas, H2 gas, D2 gas, and other reactive gases, He gas, Ar gas, N2 gas, and other inert gases, and their mixed gases can be used. As the deactivator, these gases can be supplied by exciting them into a plasma state, or they can be supplied by exciting them using heat. One or more of them can be used as the deactivator.

[0147] In addition, as described above, in the case where it is not necessary to remove the inhibitor layer remaining on the surface of the second substrate or to deactivate it after etching, or in the case where the inhibitor layer does not remain on the surface of the second substrate after etching, step D can also be omitted.

[0148] (Post - purge and atmospheric pressure recovery)

[0149] After step D is completed, inert gas as the purge gas is supplied into the processing chamber 201 from nozzles 249a - 249c respectively, and exhausted from the exhaust port 231a. Thereby, the processing chamber 201 is purged, and the gases, reaction by - products, etc. remaining in the processing chamber 201 are removed from the processing chamber 201 (post - purge). After that, the atmosphere in the processing chamber 201 is replaced with inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to atmospheric pressure (atmospheric pressure recovery).

[0150] (Cassette unloading and wafer unloading)

[0151] Thereafter, the sealing cover 219 is lowered by the cassette elevator 115, and the lower end of the manifold 209 opens. Then, the processed wafer 200 is carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 while being supported on the cassette 217 (cassette unloading). After the cassette unloading, the shutter 219s is moved, and the lower end opening of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter closing). After the processed wafer 200 is carried out to the outside of the reaction tube 203, it is taken out from the cassette 217 (wafer unloading).

[0152] Preferably, at least step A, step B, and step C are carried out in the same processing chamber (in-situ). Thus, after forming the inhibitor layer on the first substrate surface of the wafer 200 in step A, step B and step C can be carried out without exposing the wafer 200 to the atmosphere, that is, while keeping the surface of the wafer 200 clean, and the etching of the first substrate, which is the object to be etched, can be appropriately carried out.

[0153] (3) Effects of this method

[0154] According to this method, one or more of the following effects are obtained.

[0155] By performing the cycle including step A, step B, and step C a specified number of times, the deterioration and etching of the second substrate, which is the non-etching object in the first substrate and the second substrate, can be suppressed, and at least a part of the etching object, that is, the first substrate, can be selectively deteriorated and etched. In addition, the etching of the etching object, that is, the first substrate, can be promoted, and the etching of the first substrate can be carried out stably. In addition, the etching object, that is, the first substrate, can be etched with good controllability, and the controllability and uniformity of the etching amount can also be improved. Thus, in addition to the etching in the depth direction, that is, the etching in the direction perpendicular to the wafer surface, the lateral etching, that is, the etching in a direction other than the direction perpendicular to the wafer surface, for example, the etching in the direction parallel to the wafer surface, can be carried out with high controllability and uniformity. In addition, even when the reactivity of the etchant with the first substrate is low and the first substrate cannot be directly etched with the etchant, the first substrate can be etched. Furthermore, since the cycle includes sequentially performing step A, step B, and step C, these effects can be more effectively produced.

[0156] In this case, it is preferable that the reactivity of the modifier with the second substrate is higher than the reactivity of the modifier with the first substrate. Thus, the selective formation of the inhibitor layer on the surface of the non-etching object, that is, the second substrate, can be effectively carried out.

[0157] In addition, at this time, it is preferable that the reactivity of the modifier with the first substrate is higher than the reactivity of the modifier with the inhibitor layer. In addition, at this time, it is preferable that the reactivity of the modifier with the first substrate is higher than the reactivity of the modifier with the second substrate. Thus, selective modification of at least a part of the first substrate, which is the object to be etched, can be effectively performed.

[0158] In addition, at this time, it is preferable that the reactivity of the etchant with the modified portion of the first substrate is higher than the reactivity of the etchant with the inhibitor layer. In addition, at this time, it is preferable that the reactivity of the etchant with the modified portion of the first substrate is higher than the reactivity of the etchant with the second substrate. Thus, selective etching of at least a part of the first substrate, which is the object to be etched, can be effectively performed.

[0159] In addition, at this time, the modifier preferably contains an organic substance. In addition, the modifier preferably contains at least one of an alkyl group and an amino group. Thus, modification and etching of the second substrate can be suppressed, and selective modification and etching of at least a part of the first substrate can be effectively performed.

[0160] In addition, at this time, it is preferable that the modifier contains an oxidizing agent to oxidize a part of the first substrate in step B. In addition, the modifier preferably further contains a catalyst. Thus, selective modification of at least a part of the first substrate can be effectively performed. In addition, etching of the second substrate can be suppressed later, and selective etching of at least a part of the modified portion in the first substrate can be effectively performed. Furthermore, since the modifier also contains a catalyst, the processing temperature can be reduced, oxidation of the inhibitor layer can be suppressed, and the function of the inhibitor layer can be effectively maintained.

[0161] In addition, at this time, the etchant preferably contains a fluorine-based substance. In addition, the etchant preferably contains fluorine and hydrogen. Thus, etching of the second substrate can be suppressed, and selective etching of at least a part of the modified portion in the first substrate can be effectively performed.

[0162] In addition, at this time, it is preferable that the materials of the first substrate and the second substrate are different. In addition, it is preferable that the first substrate and the second substrate are alternately laminated adjacent to each other. In addition, it is preferable that the first substrate contains silicon, the second substrate contains silicon and oxygen, and preferably, the second substrate further contains carbon. Thus, the above effects can be more effectively produced. In particular, since the second substrate contains carbon, the reactivity of the etchant with the second substrate can be effectively reduced compared with the reactivity of the modified portion of the first substrate and the etchant, and the selectivity of selective etching of the modified portion of the first substrate can be further improved.

[0163] After performing a cycle including step A, step B, and step C a specified number of times, the reaction is inhibited at the portion where the inhibitor layer remains on the surface of the second substrate after etching. In the surface of the second substrate, the subsequent processes (film formation, etching, etc.) may not proceed uniformly. At this time, by performing step D, the surface of the second substrate can be reset, the unevenness of the subsequent processes on the surface of the second substrate can be prevented, and the surface of the second substrate can be uniformly processed.

[0164] (4) Variation

[0165] The processing sequence in this method can be changed as in the following variations. These variations can be combined arbitrarily. Unless otherwise specified, the processing procedures and conditions in each step of each variation can be the same as those in each step of the above processing sequence.

[0166] (Variation 1)

[0167] As in the following processing sequence, the above cycle can include successively performing: a process of alternately performing step A and step B a specified number of times (m1 times, where m1 is an integer of 1 or more), and a process of performing step C. In this variation, the same effect as the above method can also be obtained. Additionally, according to this variation, the variable mass or etching amount of at least a part of the first substrate, which is the object to be etched, can be finely adjusted.

[0168] [(Modifier → Degradant) × m1 → Etchant] × n

[0169] [(Modifier → Degradant) × m1 → Etchant] × n → Inactivator

[0170] (Variation 2)

[0171] As in the following processing sequence, the above cycle can include successively performing: a process of performing step A, and a process of alternately performing step B and step C a specified number of times (m2 times, where m2 is an integer of 1 or more). In this variation, the same effect as the above method can also be obtained. Additionally, according to this variation, the variable mass or etching amount of at least a part of the first substrate, which is the object to be etched, can be finely adjusted.

[0172] [Modifier → (Degradant → Etchant) × m2] × n

[0173] [Modifier → (Degradant → Etchant) × m2] × n → Inactivator

[0174] (Variation 3)

[0175] As in the processing sequence shown below, before performing step A, step E of cleaning the surface of the wafer 200 with a cleaning agent can also be carried out.

[0176] Cleaning agent → (Modifier → Degradant → Etchant) × n

[0177] Cleaning agent → (Modifier → Degradant → Etchant) × n → Inactivator

[0178] Cleaning agent → [(Modifier → Degradant) × m1 → Etchant] × n

[0179] Cleaning agent → [(Modifier → Degradant) × m1 → Etchant] × n → Inactivator

[0180] Cleaning agent → [Modifier → (Degradant → Etchant) × m2] × n

[0181] Cleaning agent → [Modifier → (Degradant → Etchant) × m2] × n → Inactivator

[0182] The cleaning agent can be a gaseous substance or a liquid substance. In addition, the cleaning agent can also be a liquid substance such as a mist-like substance. As the cleaning agent, for example, the above-mentioned F-containing gas, acetic acid (CH3COOH) gas, formic acid (HCOOH) gas, hexafluoroacetylacetone (C5H2F6O2) gas, H2 gas, etc. can be used. In addition, as the cleaning agent, an acetic acid aqueous solution, a formic acid aqueous solution, various cleaning liquids described later, etc. can also be used. As the cleaning agent, one or more of them can be used.

[0183] For example, in step E, an HF aqueous solution can be used as the cleaning agent to perform DHF cleaning on the wafer 200. In addition, for example, in step E, a cleaning liquid containing ammonia water, hydrogen peroxide water, and pure water can be used as the cleaning agent to perform SC-1 cleaning (APM cleaning) on the wafer 200. In addition, for example, in step E, a cleaning liquid containing hydrochloric acid, hydrogen peroxide water, and pure water can be used as the cleaning agent to perform SC-2 cleaning (HPM cleaning) on the wafer 200. In addition, for example, in step E, a cleaning liquid containing sulfuric acid and hydrogen peroxide water can be used as the cleaning agent to perform SPM cleaning on the wafer 200.

[0184] In this modified example, the same effects as those in the above-described manner can also be obtained. Additionally, according to this modified example, by performing step E, it is possible to remove contaminants such as a natural oxide film formed on the surface of the wafer 200 before etching, and it is possible to remove a film formed on the surface of the wafer 200 in an uncontrolled state (a film formed under non-control) before etching. As a result, it is possible to more appropriately form an inhibitor layer on the surface of the second substrate with higher controllability and uniformity, and it is possible to more appropriately form a modified layer on the surface of the first substrate with higher controllability and uniformity. Consequently, it is possible to more appropriately perform selective etching of the first substrate with higher controllability and uniformity.

[0185] <Other aspects of the present disclosure>

[0186] As described above, the aspects of the present disclosure have been specifically described. However, the present disclosure is not limited to the above-described aspects, and various modifications can be made without departing from its spirit.

[0187] For example, as described above, the wafer 200 may have a non-O film such as a Si film as the first substrate, which is the object to be etched. The Si film can be in any of an amorphous (non-crystalline) state, a polycrystalline (polycrystalline) state, a mixed crystal state of amorphous and polycrystalline, or a single crystal state. That is, the Si film can be any of an amorphous Si film, a polycrystalline Si film, a mixed crystal Si film of amorphous and polycrystalline, or an epitaxial Si film.

[0188] In addition, the wafer 200 may have a film on its surface on which it is difficult to form an inhibitor layer as the first substrate, which is the object to be etched. Preferably, the wafer 200 has a film on its surface on which it is difficult to form an inhibitor layer compared to the second substrate as the first substrate. For example, preferably, the wafer 200 has a film that does not contain more OH groups on its surface compared to the second substrate, that is, a film that is difficult to adsorb at least a part of the molecular structure of the molecules constituting the modifier compared to the second substrate, as the first substrate. For example, in addition to the above-described Si film, the wafer 200 may have a non-O film (non-oxide film) containing semiconductor elements such as a silicon nitride film (SiN film), a silicon carbide film (SiC film), a silicon carbonitride film (SiCN film), a silicon boron nitride film (SiBN film), a silicon boron carbonitride film (SiBCN film), a silicon boron carbide film (SiBC film), a germanium film (Ge film), or a silicon germanium film (SiGe film) as the first substrate. Additionally, for example, the wafer 200 may have multiple regions with different materials as the first substrate. In this aspect, the same effects as those in the above-described aspect can also be obtained.

[0189] In addition, for example, the wafer 200 may have a film on its surface where an inhibitor layer can be easily formed, serving as a second substrate that is not an object to be etched. Preferably, the wafer 200 has a film on its surface where an inhibitor layer can be more easily formed compared to the first substrate, as the second substrate. For example, preferably, the wafer 200 has a film that contains more OH groups on its surface compared to the first substrate, that is, a film that can more easily adsorb at least a part of the molecular structure of the molecules constituting the modifier compared to the first substrate, as the second substrate. For example, in addition to the above-mentioned SiOC film, the wafer 200 may also have an oxygen carbonitride film (SiOCN film), an oxynitride film (SiON film), a boron oxygen carbonitride film (SiBOCN film), a boron oxynitride film (SiBON film), etc., which are O-containing films (oxide films) containing semiconductor elements, as the second substrate. In addition, for example, the wafer 200 may also have multiple regions with different materials as the second substrate. In this mode, the same effects as those in the above mode can also be obtained.

[0190] In addition, for example, as a combination of the first substrate (object to be etched) and the second substrate (object not to be etched) that the wafer 200 has, it can be a combination of at least one of various films exemplified as the first substrate and at least one of various films exemplified as the second substrate. In this case, it is preferable that an inhibitor layer can be more easily formed on the surface of the second substrate than on the surface of the first substrate. In this mode, the same effects as those in the above mode can also be obtained.

[0191] Preferably, the processes used in each process are prepared separately according to the processing content and stored in the storage device 121c via an electrical communication line or an external storage device 123. And preferably, when starting each process, the CPU 121a appropriately selects an appropriate process from the multiple processes stored in the storage device 121c according to the processing content. Thereby, it is possible to reproduce the etching process of the film for various film types, composition ratios, film qualities, and film thicknesses well by the processing device. In addition, the burden on the operator can be reduced, operation errors can be avoided, and each process can be started quickly.

[0192] It is not limited to the case of newly creating the above processes. For example, it can also be prepared by changing the existing processes already installed in the processing device. In the case of changing the processes, the changed processes can be installed in the processing device via an electrical communication line or a storage medium that records the processes. In addition, the input / output device 122 of the existing processing device can also be operated to directly change the existing processes already installed in the processing device.

[0193] In the above method, an example of performing an etching process on a batch processing apparatus that processes multiple substrates at once has been described. The present disclosure is not limited to the above method, and for example, it can also be suitably applied when performing an etching process using a single wafer processing apparatus that processes one or more substrates at once. Additionally, in the above method, an example of performing an etching process using a processing apparatus having a hot wall type processing furnace has been described. The present disclosure is not limited to the above method, and it can also be suitably applied when performing an etching process using a processing apparatus having a cold wall type processing furnace.

[0194] Furthermore, in the above method, an example of performing the above processing sequence in the same processing chamber (in-situ) of the same processing apparatus has been described. The present disclosure is not limited to the above method, and for example, a certain step and another certain step of the above processing sequence can be performed in different processing chambers (ex-situ) of different processing apparatuses, or a certain step and another certain step of the above processing sequence can be performed in different processing chambers of the same processing apparatus, respectively.

[0195] When using these processing apparatuses, each process can also be performed with the same processing procedure and processing conditions as in the above method or the modified example, and the same effects as in the above method or the modified example can be obtained.

[0196] The above method or modified example can be used in appropriate combination. The processing procedure and processing conditions at this time can be the same as those of, for example, the above method or modified example.

[0197] 200 wafers (substrates).

Claims

1. An etching method, characterized in that: A cycle including the following processes is performed a specified number of times: (a) A modifier is supplied to a substrate having a first substrate and a second substrate on its surface, whereby an inhibitor layer is formed on the surface of the second substrate; (b) A deteriorating agent having a molecular structure different from that of the modifier is supplied to the substrate, whereby at least a part of the first substrate is deteriorated; And (c) By supplying an etchant to the substrate, at least a part of the deteriorated portion in the first substrate is etched.

2. The etching method according to claim 1, characterized in that: The reactivity of the modifier with the second substrate is higher than the reactivity of the modifier with the first substrate.

3. The etching method according to claim 1, characterized in that: The reactivity of the deteriorating agent with the first substrate is higher than the reactivity of the deteriorating agent with the inhibitor layer.

4. The etching method according to claim 1, characterized in that: The reactivity of the etchant with the deteriorated portion of the first substrate is higher than the reactivity of the etchant with the inhibitor layer.

5. The etching method according to claim 1, characterized in that: The reactivity of the etchant with the deteriorated portion of the first substrate is higher than the reactivity of the etchant with the second substrate.

6. The etching method according to claim 1, characterized in that: The modifier contains an organic substance.

7. The etching method according to claim 6, characterized in that: The modifier contains at least one of an alkyl group and an amino group.

8. The etching method according to claim 1, characterized in that: The deteriorating agent contains an oxidizing agent, and in (b), a part of the first substrate is oxidized.

9. The etching method according to claim 8, characterized in that: The deteriorating agent further contains a catalyst.

10. The etching method according to claim 1, characterized in that: The etchant contains a fluorine-based substance.

11. The etching method according to claim 10, characterized in that: The etchant contains fluorine and hydrogen.

12. The etching method according to claim 1, characterized in that: The cycle includes sequentially performing (a), (b), and (c).

13. The etching method according to claim 1, characterized in that: The cycle includes sequentially performing: a process of alternately performing (a) and (b) a specified number of times, a process of performing (c), or The cycle includes sequentially performing: a process of performing (a), a process of alternately performing (b) and (c) a specified number of times.

14. The etching method according to claim 1, characterized in that: The etching method further includes the following process: (d) After etching, at least one of removal and invalidation is performed, where the removal refers to removing the inhibitor layer remaining on the surface of the second substrate, and the invalidation refers to invalidating the inhibitor layer.

15. The etching method according to any one of claims 1 to 14, characterized in that: The materials of the first substrate and the second substrate are different.

16. The etching method according to claim 15, characterized in that: The first substrate and the second substrate are alternately stacked adjacent to each other.

17. The etching method according to claim 15, wherein the first substrate contains silicon, and the second substrate contains silicon and oxygen.

18. The etching method according to claim 17, wherein the second substrate further contains carbon.

19. A method for manufacturing a semiconductor device, wherein it has a process of performing a cycle including the following processes a prescribed number of times: (a) A modifier is supplied to a substrate having a first substrate and a second substrate on its surface, whereby an inhibitor layer is formed on the surface of the second substrate; (b) A denaturant having a molecular structure different from that of the modifier is supplied to the substrate, whereby at least a part of the first substrate is denatured; and (c) By supplying an etchant to the substrate, at least a part of the denatured portion in the first substrate is etched.

20. A processing device, characterized in that, It has: a modifier supply system that supplies a modifier to a substrate; a denaturant supply system that supplies a denaturant to the substrate, wherein the molecular structure of the denaturant is different from that of the modifier; an etchant supply system that supplies an etchant to the substrate; and a control unit configured to be able to control the modifier supply system, the modifier supply system, and the etchant supply system, and perform a cycle including the following processes a prescribed number of times: (a) A modifier is supplied to a substrate having a first substrate and a second substrate on its surface, whereby an inhibitor layer is formed on the surface of the second substrate; (b) The denaturant is supplied to the substrate, whereby at least a part of the first substrate is denatured; and (c) By supplying an etchant to the substrate, at least a part of the denatured portion in the first substrate is etched.

21. A program, wherein the program causes a processing device to execute a process of performing a cycle including the following processes a prescribed number of times: (a) A modifier is supplied to a substrate having a first substrate and a second substrate on its surface, whereby an inhibitor layer is formed on the surface of the second substrate; (b) A denaturant having a molecular structure different from that of the modifier is supplied to the substrate, whereby at least a part of the first substrate is denatured; and (c) By supplying an etchant to the substrate, at least a part of the denatured portion in the first substrate is etched.

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