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

Abstract

A technique is provided that can significantly reduce the processing time when selectively removing a specific material on the surface of a substrate. [Solution] A cycle including the steps of: (a) exposing a substrate having a first material and a third material formed on a second material on its surface to a modifier, thereby adsorbing an inhibitor contained in the modifier onto the surface of the first material; (b) exposing the substrate to a reactant, thereby reacting at least a portion of the third material with the reactant to produce a reaction product; and (c) applying energy to the substrate, thereby simultaneously removing the reaction product and at least one of removing and neutralizing the inhibitor, is performed a predetermined number of times.

Description

[Technical Field]

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

[0002] As one step in the manufacturing process of a semiconductor device, a process of removing a specific material from the surface of a substrate is sometimes performed (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-082774 [Patent Document 2] Japanese Patent Publication No. 2022-018973 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can significantly reduce processing time when selectively removing specific materials from the surface of a substrate. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, A process for preparing a substrate that has undergone the following processes: (a) exposing the substrate, the substrate having a surface comprising a first material and a third material formed on a second material, to a modifier, thereby causing an inhibitor contained in the modifier to be adsorbed onto the surface of the first material; and (b) exposing the substrate to a reactant, thereby causing at least a portion of the third material to react with the reactant to generate a reaction product. (c) applying energy to the substrate to simultaneously remove the reaction product and remove and / or neutralize the inhibitor; a predetermined number of cycles including the steps of: removing the third material; [Effects of the Invention]

[0006] According to the present disclosure, it is possible to significantly reduce the processing time required to selectively remove a specific material from the surface of a substrate. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of a vertical processing furnace of a processing apparatus suitably used in one embodiment of the present disclosure, showing a processing furnace 202 portion in vertical cross section. [Figure 2] FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a processing apparatus suitably used in one embodiment of the present disclosure, and is a cross-sectional view of the processing furnace 202 portion taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic configuration diagram of the controller 121 of the processing device suitably used in one embodiment of the present disclosure, and is a block diagram showing the control system of the controller 121. [Figure 4] FIG. 4(a) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to an embodiment of the present disclosure, the surface of which has a first material and a third material formed on the second material. FIG. 4(b) is a partial cross-sectional enlarged view showing a surface portion of the substrate according to an embodiment of the present disclosure after the substrate has been exposed to a modifier from the state shown in FIG. 4(a) to adsorb an inhibitor to the surface. FIG. 4(c) is a partial cross-sectional enlarged view showing a surface portion of the substrate according to an embodiment of the present disclosure after the substrate has been exposed to a reactant from the state shown in FIG. 4(b) to convert a portion of the third material into a reaction product. FIG. 4(d) is a partial cross-sectional enlarged view showing a surface portion of the substrate according to an embodiment of the present disclosure after the substrate has been exposed to a reactant from the state shown in FIG. 4(c) to convert the entire third material into a reaction product. FIG. 4(e) is a partial cross-sectional enlarged view showing a surface portion of the substrate according to an embodiment of the present disclosure after the inhibitor and reaction product have been removed from the surface by applying energy from the state shown in FIG. 4(d). [Figure 5]FIG. 5(a) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to a modified example of the present disclosure before the first cycle is performed. FIG. 5(b) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to a modified example of the present disclosure after the substrate has been exposed to a modifier to adsorb an inhibitor to the surface, as shown in FIG. 5(a). FIG. 5(c) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to a modified example of the present disclosure after the substrate has been exposed to a reactant to convert a portion of the third material into a reaction product, as shown in FIG. 5(b). FIG. 5(d) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to a modified example of the present disclosure after the inhibitor and reaction product have been removed from the surface by applying energy, as shown in FIG. 5(c). FIG. 5(e) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to a modified example of the present disclosure before the second cycle is performed. FIG. 5(f) is a partial cross-sectional enlarged view showing a surface portion of a substrate according to a modified example of the present disclosure after the substrate has been exposed to a modifier to adsorb an inhibitor to the surface, as shown in FIG. 5(e). Figure 5(g) is a partial enlarged cross-sectional view of a surface portion of a substrate according to a modification of the present disclosure after being exposed to a reactant to convert the entire remainder of the third material into a reaction product from the state of Figure 5(f). Figure 5(h) is a partial enlarged cross-sectional view of a surface portion of a substrate according to a modification of the present disclosure after being exposed to energy to remove the inhibitor and reaction product from the surface from the state of Figure 5(g). DETAILED DESCRIPTION OF THE INVENTION

[0008] <One aspect of the present disclosure> Hereinafter, one embodiment of the present disclosure will be described mainly with reference to Figures 1 to 3 and 4(a) to 4(e). Note that the drawings used in the following description are all schematic, and the dimensional relationships between elements, the ratios of elements, etc. shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, etc. do not necessarily match between multiple drawings.

[0009] (1) Configuration of the processing device As shown in Figure 1, the processing furnace 202 of the processing apparatus has a heater 207 as a temperature regulator (heating unit). The heater 207 is cylindrical and is installed vertically by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas with heat. The heater 207 also functions as an energy imparting device that imparts thermal energy to the substrate.

[0010] A reaction tube 203 is disposed concentrically with the heater 207 inside the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and has a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is disposed concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) and has a cylindrical shape with open upper and lower ends. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing member. The reaction tube 203 is installed vertically, similar to the heater 207. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to be able to accommodate wafers 200 as substrates. In the processing chamber 201, processing of the wafers 200 is performed.

[0011] Nozzles 249a to 249c serving as first to third supply units are respectively provided in the processing chamber 201 so as to penetrate the sidewall of the manifold 209. The nozzles 249a to 249c are also referred to as first to third nozzles, respectively. The nozzles 249a to 249c are made of a heat-resistant material such as quartz or SiC. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively. The nozzles 249a to 249c are different nozzles, and each of the nozzles 249a and 249c is provided adjacent to the nozzle 249b.

[0012] Gas supply pipes 232a-232c are respectively provided with mass flow controllers (MFCs) 241a-241c, which are flow rate control devices (flow rate control parts), and valves 243a-243c, which are on-off valves, in order from the upstream side of the gas flow. Gas supply pipe 232d is connected to gas supply pipe 232a downstream of valve 243a. Gas supply pipe 232e is connected to gas supply pipe 232b downstream of valve 243b. Gas supply pipe 232f is connected to gas supply pipe 232c downstream of valve 243c. Gas supply pipes 232d-232f are respectively provided with MFCs 241d-241f and valves 243d-243f in order from the upstream side of the gas flow. Gas supply pipes 232a-232f are made of a metal material, for example, SUS.

[0013] As shown in FIG. 2, the nozzles 249a to 249c are respectively provided in an annular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, extending from the lower part to the upper part of the inner wall of the reaction tube 203 and rising upward in the arrangement direction of the wafers 200. That is, the nozzles 249a to 249c are respectively provided in regions horizontally surrounding the wafer arrangement region on the sides of the wafer arrangement region where the wafers 200 are arranged, and extending along the wafer arrangement region. In a plan view, the nozzle 249b is disposed so as to face an exhaust port 231a (described later) on a straight line across the center of the wafer 200 in the processing chamber 201. The nozzles 249a and 249c are disposed so as to sandwich a line L passing through the nozzle 249b and the center of the exhaust port 231a along the inner wall of the reaction tube 203 (the outer periphery of the wafers 200) from both sides. The line L also passes through the nozzle 249b and the center of the wafer 200. In other words, the nozzle 249c can be said to be provided on the opposite side of the nozzle 249a across the line L. The nozzles 249a and 249c are arranged symmetrically with respect to the line L as the axis of symmetry. Gas supply holes 250a to 250c for supplying gas are provided on the side surfaces of the nozzles 249a to 249c, respectively. Each of the gas supply holes 250a to 250c opens to face (face) the exhaust port 231a in a plan view, and is able to supply gas toward the wafers 200. A plurality of the gas supply holes 250a to 250c are provided from the bottom to the top of the reaction tube 203.

[0014] The modifying agent is supplied from the gas supply pipe 232a into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0015] A first reactant serving as a reactant is supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0016] A second reactant and a remover serving as reactants are supplied from the gas supply pipe 232c into the processing chamber 201 via the MFC 241c, the valve 243c, and the nozzle 249c.

[0017] Inert gases are supplied from the gas supply pipes 232d to 232f through the MFCs 241d to 241f, the valves 243d to 243f, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c into the processing chamber 201. The inert gases act as purge gases, carrier gases, dilution gases, etc.

[0018] The modifying agent supply system (modifying agent exposure system) is mainly constituted by the gas supply pipe 232a, the MFC 241a, and the valve 243a. The first reactant supply system (first reactant exposure system) is mainly constituted by the gas supply pipe 232b, the MFC 241b, and the valve 243b. The second reactant supply system (second reactant exposure system) and the remover supply system (removal agent exposure system) are mainly constituted by the gas supply pipe 232c, the MFC 241c, and the valve 243c. The inert gas supply system is mainly constituted by the gas supply pipes 232d to 232f, the MFCs 241d to 241f, and the valves 243d to 243f. Either or all of the first reactant supply system and the second reactant supply system are also referred to as the reactant supply system (reactant exposure system). The remover supply system can also supply a remover excited into a plasma state, and functions as an energy imparting device that imparts plasma energy as energy to the substrate. The remover supply system can also supply a heated remover, and functions as an energy imparting device that imparts thermal energy as energy to the substrate. The remover supply system also functions as an energy imparting device that imparts kinetic energy as energy to the substrate by supplying the remover.

[0019] Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which valves 243a-243f, MFCs 241a-241f, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a-232f, and is configured so that the supply operation of various substances (various gases) into the gas supply pipes 232a-232f, i.e., the opening and closing operation of the valves 243a-243f and the flow rate adjustment operation by the MFCs 241a-241f, etc., are controlled by a controller 121, which will be described later. The integrated supply system 248 is configured as an integrated or separate integrated unit, and can be attached and detached to and from the gas supply pipes 232a-232f, etc., so that maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed on an integrated unit basis.

[0020] An exhaust port 231a for exhausting the atmosphere inside the processing chamber 201 is provided at the bottom of the sidewall of the reaction tube 203. As shown in FIG. 2, the exhaust port 231a is provided at a position facing (opposite) the nozzles 249a-249c (gas supply holes 250a-250c) across the wafer 200 in a plan view. The exhaust port 231a may be provided along the sidewall of the reaction tube 203 from the bottom to the top, i.e., along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246 serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure inside 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 be able to evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating, and further, to be able to adjust the pressure inside the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

[0021] Below the manifold 209, a seal cap 219 is provided as a furnace port cover capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is made of a metal material such as SUS and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a sealing member that abuts against the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 is provided to rotate the boat 217 (described later). A rotation shaft 255 of the rotation mechanism 267 penetrates the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the boat 217, thereby rotating the wafers 200. The seal cap 219 is configured to be vertically raised and lowered by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the wafers 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219.

[0022] A shutter 219s is provided below the manifold 209 as a furnace port cover that can airtightly close the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is removed from the processing chamber 201. The shutter 219s is made of a metal material such as SUS and has a disk shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a sealing member that abuts against the lower end of the manifold 209. The opening and closing operation (lifting and lowering operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0023] The boat 217 as a substrate support is configured to support a plurality of wafers 200, for example, 25 to 200 wafers 200, in a horizontal position and aligned vertically with their centers aligned, i.e., arranged at intervals, in multiple stages. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, heat insulating plates 218, also made of a heat-resistant material such as quartz or SiC, are supported in multiple stages.

[0024] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 can be adjusted to a desired temperature distribution. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0025] As shown in FIG. 3, the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, such as a touch panel, is connected to the controller 121. An external storage device 123 can also be connected to the controller 121. The processing device may be configured to include one or more control units. That is, control for performing the processing sequence described below may be performed using one control unit or multiple control units. The multiple control units may be configured as a control system connected to each other via a wired or wireless communication network, and control for performing the processing sequence described below may be performed by the entire control system. In this specification, when the term "control section" is used, it may include one control section, multiple control sections, or a control system configured by multiple control sections.

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

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

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

[0029] The controller 121 can be configured by installing the above-mentioned program recorded and stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, or a semiconductor memory such as a USB memory or an SSD. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0030] (2) Treatment process An example of a method (processing method) for processing a substrate as one step in a semiconductor device manufacturing process (manufacturing method) using the processing apparatus described above, i.e., a processing sequence for selectively removing the third material from the first material, the second material, and the third material on the surface of a wafer 200 as a substrate, will be described mainly with reference to Figures 4(a) to 4(e). In the following description, the operation of each part constituting the processing apparatus is controlled by a controller 121.

[0031] The processing apparatus is also referred to as a substrate processing apparatus, an etching processing apparatus, or an etching apparatus. The processing method is also referred to as a substrate processing method, an etching processing method, or an etching method. Each or all of the parts of the processing apparatus used when performing steps A and B described below are also referred to as an apparatus for preparing a substrate. Each of the parts of the processing apparatus used when performing step C described below, i.e., any or all of the heater 207 and the remover supply system described above, are also referred to as an energy application apparatus for applying energy to the substrate.

[0032] In the processing sequence of this embodiment, (a) a step A of exposing a wafer 200 having a first material and a third material formed on the second material on its surface to a modifier, thereby causing an inhibitor contained in the modifier to adsorb onto the surface of the first material; and (b) a step B of exposing the wafer 200 to a reactant, thereby causing at least a portion of the third material to react with the reactant to generate a reaction product, to prepare a wafer 200 that has undergone the steps of: (c) Step C of applying energy to the wafer 200 to remove the reaction products and remove and / or neutralize the inhibitors in parallel; The third material is removed by performing a cycle including the steps a predetermined number of times (n times, where n is an integer of 1 or greater than 2). This series of processes is also called an etching process.

[0033] In the following example, a case where a cycle including steps A to C is performed once will be described.

[0034] In addition, in the processing sequence of this embodiment, the reactants used in step B include a first reactant and a second reactant that reacts with the first reactant, and step B includes at least one of a period in which the wafer 200 is alternately exposed to the first reactant and the second reactant and a period in which the wafer 200 is simultaneously exposed to the first reactant and the second reactant.

[0035] In the following example, a cycle including step B1 of exposing wafer 200 to a first reactant and step B2 of exposing wafer 200 to a second reactant is performed a predetermined number of times (m times, where m is an integer of 1 or greater), i.e., wafer 200 is alternately exposed to the first reactant and the second reactant.

[0036] In this specification, the above-described processing sequence may be referred to as follows for convenience. In the following, "P" refers to a process of purging the space in which the wafer 200 is present, i.e., the processing chamber 201. Also, "parallel removal" refers to a process performed in step C, i.e., a process of simultaneously performing in parallel the removal of reaction products generated on the surface of the wafer 200 in step B and at least one of the removal and neutralization of inhibitors adsorbed on the surface of the wafer 200 in step A. In this disclosure, this parallel process performed in step C is also referred to as "parallel removal." Similar notations may be used in the following explanations of modified examples, etc. In this specification, "neutralizing an inhibitor" refers to the neutralization of the inhibitor's action, i.e., the inhibitor effect described below.

[0037] [Modifier → P → (First reactant → Second reactant) × m → Parallel removal] × n

[0038] The term "wafer" used herein may refer to the wafer itself or to a laminate of the wafer and a predetermined layer or film (material) formed on its surface. The term "surface of a wafer" used herein may refer to the surface of the wafer itself or to the surface of a predetermined layer or the like formed on the wafer. When used herein, the phrase "forming a predetermined layer on the surface of a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. Furthermore, when used herein, the phrase "applying energy to a wafer" may mean applying energy to the wafer itself or to applying energy to a reaction product generated on the surface of the wafer or an inhibitor adsorbed on the surface of the wafer. When used herein, the term "substrate" is synonymous with the term "wafer."

[0039] The terms "agent" and "substance" used in this specification include at least one of a gaseous substance and a liquid substance. A liquid substance includes a mist substance. That is, each of the modifying agent, the reacting agent (first and second reacting agents), and the removing agent may contain a gaseous substance, a liquid substance such as a mist substance, or both.

[0040] (Wafer charge and boat load) When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s, and the lower end opening of the manifold 209 is opened (shutter open). Thereafter, as shown in FIG. 1 , the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b. In this manner, the wafers 200 are prepared in the processing chamber 201.

[0041] 4(a), the wafers 200 loaded into the boat 217 have a first material and a third material formed on the second material on their surfaces. The first material, the second material, and the third material are also referred to as a first base layer, a second base layer, and a third base layer, respectively. The surfaces of the first material, the second material, and the third material are also referred to as a first surface, a second surface, and a third surface, respectively.

[0042] The third material may contain the same elements as the elements constituting the first material. The first material and the third material may both contain the same elements, with the first material having a first composition and the third material having a second composition different from the first composition. Also, the first material and the third material may both contain the same elements, with the first composition including a stoichiometric composition and the second composition including a non-stoichiometric composition.

[0043] The density of the third material may be lower than the density of the first material. When both the first material and the third material contain a first element and a second element, the atomic concentration of the second element contained in the third material may be lower than the atomic concentration of the second element contained in the first material.

[0044] Furthermore, the density of adsorption sites on the surface of the third material may be lower than the density of adsorption sites on the surface of the first material, i.e., the density of hydroxyl group terminations (OH terminations) on the surface of the third material may be lower than the density of OH terminations on the surface of the first material.

[0045] The first material may include at least one of a thermal oxide film and a deposited oxide film, and the third material may include at least one of a native oxide film and a chemical oxide film. Here, a thermal oxide film refers to an oxide film formed by a thermal oxidation method. A deposited oxide film refers to an oxide film formed (deposited) by a method such as a CVD (chemical vapor deposition) method. A native oxide film refers to an oxide film formed on the surface of the wafer 200 by leaving the wafer 200 in the atmosphere. A chemical oxide film refers to an oxide film formed on the surface of the wafer 200 by performing a predetermined cleaning process (SC-1, SC-2, etc.) using a cleaning solution on the wafer 200.

[0046] The elements constituting the second material and the composition of the second material are not particularly limited. The second material may contain the same elements as the elements constituting the first material and the third material, or may contain elements different from the elements constituting the first material and the third material. Furthermore, the second material may have the same composition as the first material and the third material, or may have a different composition from the first material and the third material.

[0047] Hereinafter, an example will be described in which the first material is a thermal oxide film, the second material is a nitride film, and the third material is a native oxide film. Specifically, in this example, the first material and the third material each contain silicon (Si) as a first element and oxygen (O) as a second element, and the first material contains a silicon oxide film (SiO2 film) of a first composition (Si:O=1:2), and the third material contains a silicon oxide film (SiO2 film) of a second composition (Si:O=1:x) different from the first composition. x where the first composition is stoichiometric and the second composition is non-stoichiometric, and the SiO xwhere x is a real number less than 2. The density of the third material is lower than that of the first material, the concentration of O contained in the third material is lower than that of the first material, and the density of adsorption sites (OH terminations) on the surface of the third material is lower than the density of adsorption sites (OH terminations) on the surface of the first material. In this example, the second material includes Si as the first element and nitrogen (N) as the third element, and includes a silicon nitride film (SiN film) with a third composition (Si:N=3:4). That is, in this example, the constituent elements, composition, and material of the second material are different from those of the first material and the third material.

[0048] (pressure and temperature regulation) After the boat loading is completed, the processing chamber 201 is evacuated (reduced pressure exhausted) by the vacuum pump 246 so that the interior of the processing chamber 201 reaches a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Furthermore, the wafers 200 inside the processing chamber 201 are heated by the heater 207 so that the wafers 200 reach a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the interior of the processing chamber 201 has a desired temperature distribution. Furthermore, the rotation mechanism 267 starts to rotate the wafers 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0049] (Step A) The wafer 200 is then exposed to a modifying agent.

[0050] Specifically, the valve 243a is opened to allow the modifying agent to flow into the gas supply pipe 232a. The flow rate of the modifying agent is adjusted by the MFC 241a, and the modifying agent is supplied into the processing chamber 201 through the nozzle 249a and exhausted from the exhaust port 231a. At this time, the modifying agent is supplied to the wafer 200 from the side of the wafer 200, and the wafer 200 is exposed to the modifying agent (modifying agent supply, exposure). At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0051] By exposing the wafer 200 to a modifier under processing conditions described below, as shown in FIG. 4(b), the inhibitor contained in the modifier is adsorbed onto the surface of the first material, selectively forming a first inhibitor layer on the surface of the first material among the first material and the third material. The inhibitor contains at least a portion of the molecular structure of the molecule constituting the modifier, i.e., a residue derived from the modifier contained in the modifier. The first inhibitor layer is an aggregate of inhibitors and includes a dense layer that densely covers the surface of the first material. The first inhibitor layer may also include a layer that continuously covers the surface of the first material, i.e., a continuous layer. The first inhibitor layer functions to prevent contact of the reactant with the surface of the first material and to suppress or inhibit (block) the progress of the reaction between the first material and the reactant in Step B described below. That is, the first inhibitor layer functions as a protective layer that protects the first material in Step B described below. The above-described effect of the first inhibitor layer is also referred to as the inhibitor effect (reaction suppression effect, reaction inhibition effect). Note that the first inhibitor layer does not need to be a continuous layer and may be a discontinuous layer as long as it has the inhibitor effect. Even if the first inhibitor layer is a discontinuous layer, the inhibitor effect can be produced by making the gaps in the discontinuous parts of the discontinuous layer large enough that reactant molecules cannot pass through.

[0052] In this disclosure, for example, the expression "selectively forming a layer on the surface of the first material out of the first and third materials" refers to the relative relationship between the degree of layer formation on each surface. In other words, this expression means that a layer is formed so that the degree of layer formation on the surface of the first material is higher than the degree of layer formation on the surface of the third material. In other words, the expression "selectively" in this disclosure means that processing one material is performed preferentially over processing another material. This also applies to the description of the processing in step B described below.

[0053] That is, in step A, the above-mentioned inhibitor can be adsorbed not only on the surface of the first material but also on the surface of the third material, forming a second inhibitor layer on the surface of the third material. Figure 4(b) shows the formation of a second inhibitor layer on the surface of the third material. In this case, the density of the inhibitor adsorbed on the surface of the third material is lower than the density of the inhibitor adsorbed on the surface of the first material. That is, the density of the second inhibitor layer is lower than the density of the first inhibitor layer. Furthermore, the thickness of the second inhibitor layer can be thinner than the thickness of the first inhibitor layer. The second inhibitor layer is an aggregate of inhibitors and includes a low-density layer, i.e., a discontinuous layer, that discontinuously (sparsely) covers the surface of the third material. The gaps in the discontinuous portions of the discontinuous layer that constitutes the second inhibitor layer are large enough for molecules of the reactant to pass through, partially exposing the surface of the third material, allowing the reactant to come into contact with the surface of the third material in step B, which will be described later.The reaction between the third material and the reactant then proceeds from the contact point.In other words, the second inhibitor layer has a low inhibitor effect and does not substantially function as a protective layer to protect the third material in step B, which will be described later.

[0054] After forming the first inhibitor layer on the surface of the first material and the second inhibitor layer on the surface of the third material, respectively, the valve 243a is closed to stop the supply of the modifying agent into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gaseous substances remaining in the processing chamber 201. At this time, the valves 243d to 243f are opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c acts as a purge gas, thereby purging the processing chamber 201 (purging). Note that the processing temperature during purging in this step is preferably the same as the processing temperature during supply of the modifying agent.

[0055] The processing conditions for supplying the modifier in step A are as follows: Treatment temperature: room temperature (25°C) to 500°C, preferably room temperature to 250°C Treatment pressure: 1 to 2000 Pa, preferably 10 to 1000 Pa Treatment time: 1 to 3600 seconds, preferably 5 to 300 seconds Modifier supply flow rate: 0.001 to 10 slm, preferably 0.1 to 0.5 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm is exemplified.

[0056] In this specification, when a numerical range such as "25 to 500°C" is expressed, it means that the lower limit and the upper limit are included in the 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. In this specification, the processing temperature means the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure means the pressure inside the processing chamber 201. The processing time means the time the processing continues. In addition, when the supply flow rate includes 0 slm, 0 slm means that the substance (gas, etc.) is not supplied. These also apply to the following explanations.

[0057] As the modifying agent, for example, a substance containing at least one of a hydrocarbon group such as an alkyl group and an amino group can be used.

[0058] For example, modifiers include 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(CH 3)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), (dipropylamino)trimethylsilane ((C3H7)2NSi(CH3)3), (dibutylamino)trimethylsilane ((C4H9)2NSi(CH3)3), (dimethylamino)trimethylsilane ((CH3)2NSi(CH3)3), (diethylamino)triethylsilane ((C2H5)2NSi(C2H 5)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 these can be used. In addition to these organic substances, inorganic substances can also be used as the modifier.

[0059] As the inert gas, nitrogen (N2) gas or a rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, or xenon (Xe) gas can be used. One or more of these can be used as the inert gas. This also applies to each step described below.

[0060] (Step B) After step A is completed, the following steps B1 and B2 are performed to alternately expose the wafer 200 to the first reactant and the second reactant. In this embodiment, steps B1 and B2 are performed consecutively without purging the processing chamber 201 between them.

[0061] (Step B1) In step B1, the wafer 200 is exposed to a first reactant.

[0062] Specifically, valve 243b is opened to allow a first reactant to flow into gas supply pipe 232b. The flow rate of the first reactant is adjusted by MFC 241b, and the first reactant is supplied into processing chamber 201 via nozzle 249b and exhausted from exhaust port 231a. At this time, the first reactant is supplied onto wafer 200 from the side of wafer 200, and wafer 200 is exposed to the first reactant (first reactant supply, exposure). At this time, valves 243d to 243f may be opened to supply an inert gas into processing chamber 201 via nozzles 249a to 249c, respectively.

[0063] By exposing the wafer 200 to the first reactant under processing conditions described below, the first reactant can be adsorbed onto the surface of the third material, i.e., the surface of the third material that is not covered with the second inhibitor, and the inside of the processing chamber 201 can be filled with an atmosphere of the first reactant.

[0064] After the first reactant is adsorbed onto the surface of the third material and the inside of the processing chamber 201 is filled with the first reactant, the valve 243b is closed and the supply of the first reactant into the processing chamber 201 is stopped.

[0065] (Step B2) In step B2, the wafer 200 is exposed to a second reactant.

[0066] Specifically, valve 243c is opened to allow the second reactant to flow into gas supply pipe 232c. The flow rate of the second reactant is adjusted by MFC 241c, and the second reactant is supplied into processing chamber 201 via nozzle 249c and exhausted from exhaust port 231a. At this time, the second reactant is supplied onto wafer 200 from the side of wafer 200, and wafer 200 is exposed to the second reactant (second reactant supply, exposure). At this time, valves 243d to 243f may be opened to supply an inert gas into processing chamber 201 via nozzles 249a to 249c, respectively.

[0067] By exposing the wafer 200 to the second reactant under processing conditions described below, the surface of the third material can be reacted with the first reactant adsorbed on the surface of the third material and the second reactant. The surface of the third material can also be reacted with the first reactant and the second reactant floating in the processing chamber 201. These reactions alter the surface of the third material, and as shown in FIG. 4(c), a solid reaction product such as ammonium silicofluoride, i.e., ammonium hexafluorosilicate ((NH4)2SiF6), can be generated on the surface of the third material.

[0068] After the surface of the third material is altered to generate a reaction product, the valve 243c is closed to stop the supply of the second reactant into the processing chamber 201.

[0069] (Performed a specified number of times) By performing the cycle including steps B1 and B2 a predetermined number of times (m times, where m is an integer of 1 or greater), at least a portion of the third material can be altered and converted into a layer containing the reaction product. It is preferable to repeat the cycle multiple times. That is, it is preferable to set the thickness of the third material to be altered per cycle thinner than the desired altered thickness (predetermined thickness, predetermined depth) of the third material, and repeat the cycle multiple times until the altered thickness of the third material reaches the desired altered thickness (predetermined thickness, predetermined depth). By performing the cycle a predetermined number of times, it is possible to alter the entire third material and convert the entire third material into a layer containing the reaction product, as shown in FIG. 4(d).

[0070] In this step, it is possible to selectively alter at least a portion of the third material while suppressing the alteration of the first material. The selective alteration of the third material is possible in this step because, as described above, the high-density first inhibitor layer functions as a protective layer for the first material, while the low-density second inhibitor layer does not substantially function as a protective layer for the third material. The alteration of the third material, for example, begins at the gaps between the inhibitors contained in the second inhibitor layer and progresses to the entire surface of the third material. To promote this selective alteration, it is preferable to perform step B under conditions that suppress at least one of the removal and deactivation of the first inhibitor layer. The low-density second inhibitor layer may be removed or deactivated from the surface of the third material during the alteration of the underlying third material. Figure 4(d) shows the case where the second inhibitor layer is removed from the surface of the third material during the alteration of the third material. In this step, the second inhibitor layer may be left on the surface of the third material without being removed.

[0071] The processing conditions for supplying the first reactant in step B1 are as follows: Treatment temperature: room temperature to 90°C, preferably 45 to 80°C, more preferably 50 to 70°C Treatment pressure: 10 to 2000 Pa, preferably 50 to 1000 Pa Processing time: 60 to 180 seconds, preferably 60 to 120 seconds First reactant supply flow rate: 0.5 to 3 slm, preferably 1 to 2 slm Inert gas supply flow rate (per gas supply pipe): 0.5 to 10 slm, preferably 1 to 5 slm is exemplified.

[0072] The processing conditions for supplying the second reactant in step B2 are as follows: Treatment temperature: room temperature to 90°C, preferably 45 to 80°C, more preferably 50 to 70°C Treatment pressure: 10 to 2000 Pa, preferably 50 to 1000 Pa Processing time: 60 to 180 seconds, preferably 60 to 120 seconds Second reactant supply flow rate: 0.1 to 3 slm, preferably 0.2 to 2 slm Inert gas supply flow rate (per gas supply pipe): 0.5 to 10 slm, preferably 1 to 5 slm is exemplified.

[0073] The first reactant may be a fluorine (F)-containing substance, which is a halogen-containing substance. Examples of the F-containing substance include chlorine (Cl) and F-containing substances such as chlorine trifluoride (ClF), chlorine fluoride (ClF), nitrogen trifluoride (NF), hydrogen fluoride (HF), and fluorine (F), N and F-containing substances, and hydrogen (H) and F-containing substances. Specifically, examples of the first reactant include interhalogen compounds, nitrogen halides, hydrogen halides, and simple halogens. Furthermore, the first reactant is not limited to gaseous substances, and may be an aqueous solution containing an F-containing substance, such as an HF aqueous solution. One or more of these may be used as the first reactant.

[0074] A reducing agent can be used as the second reactant. Examples of reducing agents include hydrogen (H), ammonia (NH), diazene (NH), hydrazine (NH), N, monomethylamine ((CH)NH), dimethylamine ((CH)NH), trimethylamine ((CH)N), monoethylamine ((CH)NH), diethylamine ((CH)NH), triethylamine ((CH)N), monomethylhydrazine ((CH)HN), dimethylhydrazine ((CH)NH), and trimethylhydrazine ((CH)N(CH)H), as well as N- and H-containing substances and C-, N-, and H-containing substances. Examples of the second reactant include hydrogen, hydrogen nitride, amines, and organic hydrazines. One or more of these can be used as the second reactant.

[0075] (Step C) After step B is completed, energy is applied to the wafer 200 in a predetermined procedure to simultaneously remove the reaction products generated on the surface of the wafer 200 and at least one of removing and neutralizing the inhibitors remaining on the surface of the wafer 200 (parallel removal). These procedures can be combined as desired.

[0076] For example, in this step, parallel removal may be performed by exposing the wafer 200 to a remover that reacts with at least one of the inhibitor and the reaction product, and applying energy to the wafer 200. The remover can be supplied to the wafer 200 from a remover supply system using the same procedure as in step B2. The remover is supplied from the gas supply pipe 232c through the nozzle 249c into the processing chamber 201 and exhausted from the exhaust port 231a. At this time, the remover is supplied to the wafer 200 from the side of the wafer 200, and the wafer 200 is exposed to the remover (removal agent supply, exposure). Note that by exposing the wafer 200 to a remover that reacts with at least one of the inhibitor and the reaction product, and applying energy to the wafer 200, parallel removal can be performed while at least one of a chemical reaction between the remover and the inhibitor and a chemical reaction between the remover and the reaction product occurs. As a result, parallel removal can be performed more efficiently and effectively.

[0077] Also, for example, in this step, parallel removal may be performed by applying thermal energy to the wafer 200. In this case, in this step, the wafer 200 may be heated by the heater 207 to a temperature equal to or higher than the temperature of the wafer 200 in step B or to a temperature higher than the temperature of the wafer 200 in step B (thermal energy supply). Also, in this step, the wafer 200 may be heated to the above-mentioned temperature by exposing the wafer 200 to a removing agent heated by the heater 207. In this case, the supply of the removing agent to the wafer 200 may be performed in the same manner as the above-mentioned removing agent supply and exposure.

[0078] Also, for example, in this step, parallel removal may be performed by applying plasma energy to the wafer 200. For example, in this step, the above-mentioned removing agent may be excited (activated) into a plasma state and supplied to the wafer 200 (plasma energy supply). In this case, in this step, the temperature of the wafer 200 may be set to a temperature equal to or lower than room temperature. Note that, as described above, the removing agent supply system can also supply a removing agent excited into a plasma state, and in this case, the supply of the removing agent to the wafer 200 can be performed in the same manner as the above-mentioned removing agent supply and exposure.

[0079] By applying energy to the wafer 200 under processing conditions described below, it becomes possible to simultaneously remove (sublimate) the reaction product generated in step B and remove or neutralize at least one of the inhibitors that were adsorbed onto the surface of the first material by performing step A and remained on the surface of the first material after performing step B (parallel removal), as shown in Fig. 4(e). Note that Fig. 4(e) shows a case in which the inhibitors that were adsorbed onto the surface of the first material are removed in parallel removal.

[0080] By removing the reaction products and inhibitors, the surfaces of the first material and the second material are exposed. By removing the inhibitors from the surface of the first material, it becomes possible to improve the in-plane thickness uniformity of the film, the interfacial characteristics between the film and the first material, and the surface roughness of the film when it is subsequently formed on the surface of the first material. By removing the reaction products from the surface of the second material, it becomes possible to improve the in-plane thickness uniformity of the film, the interfacial characteristics between the film and the second material, and the surface roughness of the film when it is subsequently formed on the surface of the second material. Surface roughness refers to the difference in height of the film surface within the wafer surface or any target surface, and a smaller value indicates a smoother surface. In this specification, improving (improving) surface roughness means that the difference in height of the film surface is reduced, and the smoothness is improved (improved). In parallel removal, if a remover that reacts with at least one of the inhibitor and the reaction product is used, the above-mentioned chemical action can be utilized, making it possible to more appropriately condition the surfaces of each material, thereby further enhancing the above-mentioned effects.

[0081] Note that, although FIG. 4(e) shows a case where the inhibitor adsorbed on the surface of the first material is removed during parallel removal, this embodiment is not limited to this case. For example, when performing parallel removal, the inhibitor adsorbed on the surface of the first material may be neutralized without being removed. Furthermore, when performing parallel removal, some of the inhibitors adsorbed on the surface of the first material may be removed and the remaining inhibitors may be neutralized. Even in these cases, the above-described effect of improving surface roughness can be similarly obtained for the film formed on the surface of the first material.

[0082] The processing conditions for applying energy to the wafer 200 in step C are as follows: Treatment temperature: 100 to 1000°C, preferably 400 to 700°C Treatment pressure: 1 to 120,000 Pa, preferably 1 to 4,000 Pa Treatment time: 1 to 18,000 seconds, preferably 1 to 9,000 seconds Remover supply flow rate: 0 to 50 slm, preferably 1 to 20 slm RF power: 0 to 10,000 W, preferably 0 to 5,000 W Examples include: RF power, which is the power applied to generate plasma when performing plasma treatment using a remover; 0 W RF power means that no plasma energy is generated; that is, the parallel removal described above can be performed by supplying a remover under non-plasma conditions; and a remover supply flow rate of 0 slm means that no remover is supplied; that is, the parallel removal described above can be performed without supplying a remover, for example, by using thermal energy generated by heating.

[0083] As the remover, for example, a reducing agent or an oxidizing agent can be used.

[0084] As the reducing agent, for example, N- and H-containing substances such as NH3, N2H2, N2H4, N3H8, H2, deuterium (D2), H-containing substances, deuterium (D)-containing substances, etc. can be used.

[0085] Examples of oxidizing agents that can be used include oxygen (O), ozone (O), water vapor (H), hydrogen peroxide (H), nitrous oxide (N), nitric oxide (NO), nitrogen dioxide (NO), carbon dioxide (CO), and other oxygen (O)-containing substances, H and O-containing substances, N and O-containing substances, and C and O-containing substances.

[0086] The remover may be a mixture of a reducing agent and an oxidizing agent, such as H2+O2, H2+O3, D2+O2, or D2+O3. In this disclosure, the combined description of two substances, such as "H2+O2," refers to a mixture of H2 and O2. When supplying a mixture, the two substances may be mixed (premixed) in a supply pipe and then supplied into the processing chamber 201. Alternatively, the two substances may be supplied separately from different supply pipes into the processing chamber 201 and mixed (postmixed) in the processing chamber 201.

[0087] Alternatively, the remover may be an inert gas such as He gas, Ne gas, Ar gas, Xe gas, or N2 gas. It is preferable to use a substance that reacts with at least one of the inhibitor and the reaction product as the remover. However, a substance that does not react with either of them may also be used.

[0088] One or more of these can be used as the remover. As described above, these substances may be excited into a plasma state and supplied as the remover, or may be excited by heat and supplied. Note that when an O-containing substance is used as the remover in step C, the surface of the wafer 200 (the surface of the second material) exposed by the removal of the third material may be oxidized. In this case, the oxide film newly formed on the surface of the wafer 200 will be an oxide film with higher uniformity, density, and quality than the third material (native oxide film).

[0089] (After purging and atmospheric pressure recovery) After step C is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a to 249c into the processing chamber 201 and exhausted from the exhaust port 231a. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure return).

[0090] (Boat unloading and wafer discharge) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafers 200, supported by the boat 217, are unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After the boat unloading, the shutter 219s is moved, and the opening at the lower end of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). After being unloaded to the outside of the reaction tube 203, the processed wafers 200 are removed from the boat 217 (wafer discharge).

[0091] It is preferable to perform steps A to C in the same processing chamber (in-situ). If a series of processes is performed in-situ, the wafer 200 is not exposed to the atmosphere during the process, and the wafer 200 can be processed consistently while being kept under vacuum, enabling stable processing.

[0092] (3) Effects of this mode According to this aspect, one or more of the following effects can be obtained.

[0093] (a) When an inhibitor is adsorbed on the surface of a first material on a substrate and a third material on a second material is selectively etched using a reactant, the third material may react with the reactant to produce a solid reaction product (e.g., ammonium silicofluoride). In this case, the reaction product must be removed after the supply of the reactant is stopped. Furthermore, if a film is subsequently formed on the surface of the first material, the inhibitor present on the surface of the first material must be removed and / or neutralized, which may reduce productivity.

[0094] To address these issues, this embodiment performs a cycle including the above-described steps A to C. This allows the inhibitor to be adsorbed onto the surface of the first material, and then at least a portion of the third material is reacted with the reactant to generate a reaction product. The reaction product and the inhibitor can then be simultaneously removed and / or neutralized. As a result, the third material can be selectively removed from among the first, second, and third materials, while maintaining high selectivity and significantly shortening the processing time and significantly improving productivity. Furthermore, the surfaces of the first and second materials are cleaned and exposed, allowing subsequent processing of the first and second materials to begin appropriately and quickly.

[0095] Note that if the removal of reaction products and the removal and / or neutralization of inhibitors are performed non-simultaneously, for example, sequentially, one additional step is required compared to the present embodiment, resulting in a corresponding decrease in productivity. Furthermore, if the removal of reaction products and the removal and / or neutralization of inhibitors are performed under different processing conditions, for example, at different processing temperatures, it becomes necessary to change the processing temperature (e.g., increase or decrease the temperature), further decreasing productivity. According to the present embodiment, two different processes can be performed simultaneously and in parallel under the same processing conditions, for example, at the same processing temperature, eliminating the need for an increase in the number of steps or for changing the processing temperature (e.g., increase or decrease the temperature). This elimination of these processes significantly increases productivity.

[0096] (b) The reactants include a first reactant and a second reactant that reacts with the first reactant, and in step B, a cycle including steps B1 and B2 is performed a predetermined number of times, thereby enabling efficient and effective generation of a reaction product. Furthermore, step B includes a period in which the substrate is alternately exposed to the first reactant and the second reactant, thereby enabling the reaction product to be generated with a uniform thickness with good controllability. As a result, the third material can be removed uniformly with good controllability.

[0097] Furthermore, in step B, when the first reactant and the second reactant are alternately supplied, purging of the processing chamber is not performed, thereby allowing the first reactant and the second reactant to mix in the processing chamber, and a reaction product can be generated at a high rate. As a result, the third material can be removed at a high rate. In addition, it is also possible to supply the first reactant and the second reactant to the substrate in a partially overlapping manner, and a reaction product can be generated at a higher rate. As a result, the third material can be removed at a higher rate.

[0098] (c) When the first reactant contains a halogen-containing substance and the second reactant contains a reducing agent, the reaction product can be efficiently and effectively generated in step B, and the above-mentioned effects can be effectively achieved. Furthermore, when the first reactant contains an F-containing substance and the second reactant contains hydrogen nitride, the above-mentioned effects can be more effectively achieved. Furthermore, when the first reactant contains F and H and the second reactant contains N and H, the above-mentioned effects can be even more effectively achieved.

[0099] (d) In step C, by applying at least one of thermal energy and plasma energy to the substrate, it becomes possible to more efficiently and effectively perform, simultaneously and in parallel, the removal of reaction products and the removal and / or inactivation of inhibitors, and to more effectively cause the above-described effects. In this case, in step C, by heating the substrate at a temperature equal to or higher than the temperature of the substrate in step B, it becomes possible to more effectively cause the above-described effects. Further, in this case, in step C, by exposing the substrate to a removing agent that reacts with at least one of the inhibitor and the reaction products, it is possible to cause at least one of a chemical reaction between the removing agent and the inhibitor and a chemical reaction between the removing agent and the reaction products. That is, in step C, it becomes possible to utilize (use in combination) the energy applied to the substrate and the chemical action, and to more efficiently and effectively perform, simultaneously and in parallel, the removal of reaction products and the removal and / or inactivation of inhibitors, and to more effectively cause the above-described effects.

[0100] (e) Since the third material contains the same elements as the elements constituting the first material, it becomes possible to selectively remove a part of the other while maintaining a part of the material containing the same constituent elements on the surface of the substrate without removing it. For example, when a thermal oxide film (SiO2), which is an oxide film containing Si and O, and a native oxide film and / or a chemical oxide film (SiO x , 0 < x < 2) are exposed on the surface of the substrate, it becomes possible to selectively remove the native oxide film and / or the chemical oxide film while maintaining the thermal oxide film. Thereby, it becomes possible to selectively remove a target portion to be removed, which is a part of the material containing the same constituent elements, with high accuracy, and it becomes possible to greatly improve the processing accuracy of the film.

[0101] (f) The first material and the third material both contain the same elements, the first material having a first composition, and the third material having a second composition different from the first composition, which makes it easier for the inhibitor to be adsorbed onto the surface of the first material and makes it easier for the third material to react with the reactant than the first material, thereby effectively causing selective adsorption of the inhibitor onto the surface of the first material and selective reaction of the third material with the reactant.

[0102] In this case, by including a stoichiometric composition in the first composition and a non-stoichiometric composition in the second composition, the inhibitor can be more easily adsorbed onto the surface of the first material, and the third material can be more easily reacted with the reactant than the first material. This makes it possible to more effectively achieve selective adsorption of the inhibitor onto the surface of the first material and selective reaction between the third material and the reactant. Furthermore, when the density of the third material is lower than the density of the first material, the above-mentioned effects can be similarly achieved.

[0103] (g) Both the first material and the third material contain a first element and a second element, and the atomic concentration of the second element contained in the third material is lower than the atomic concentration of the second element contained in the first material, which makes it easier for the inhibitor to be adsorbed onto the surface of the first material and makes the third material more likely to react with the reactant than the first material. This makes it possible to more effectively cause the inhibitor to be selectively adsorbed onto the surface of the first material and the third material to selectively react with the reactant.

[0104] The above-mentioned effect can also be obtained when the density of adsorption sites on the surface of the third material is lower than the density of adsorption sites on the surface of the first material, i.e., when the density of OH group terminations on the surface of the third material is lower than the density of OH group terminations on the surface of the first material.

[0105] (h) When the first material includes a thermal oxide film or a deposited oxide film, and the third material includes at least one of a native oxide film and a chemical oxide film, the above-mentioned effects can be more effectively produced.

[0106] (i) In step A, by adsorbing the inhibitor contained in the modifier not only to the surface of the first material but also to the surface of the third material, when the inhibitor is adsorbed to the surface of the first material, it is possible to allow the inhibitor to be adsorbed to the surface of the third material, and it is possible to increase the density of the inhibitor adsorbed to the surface of the first material. As a result, the inhibitor effect of the inhibitor adsorbed to the surface of the first material can be enhanced, and a selective reaction between the third material and the reactant can be effectively caused, making it possible to effectively selectively remove the third material.

[0107] (j) In step A, by making the density of the inhibitor adsorbed on the surface of the third material lower than the density of the inhibitor adsorbed on the surface of the first material, the inhibitor effect of the inhibitor adsorbed on the surface of the third material can be reduced, and the third material can be selectively removed more effectively.

[0108] (k) The above-mentioned effects can be similarly obtained even when a predetermined substance is arbitrarily selected from the various modifiers, various reactants (first reactant, second reactant), various removers, and various inert gases described above.

[0109] (4) Variations The processing sequence in this embodiment can be modified as shown in the following modified examples. These modified examples can be combined as desired. Unless otherwise specified, the processing procedures and processing conditions in each step of each modified example can be the same as the processing procedures and processing conditions in each step of the above-described processing sequence.

[0110] (Variation 1) A cycle including steps A to C may be performed multiple times. Figures 5(a) to 5(h) show a case where the cycle including steps A to C is performed multiple times, for example, twice, to selectively remove the third material from the first material, the second material, and the third material.

[0111] In the first cycle (first cycle), step A is performed on a substrate having the surface structure shown in FIG. 5(a), thereby selectively adsorbing an inhibitor onto the surface of the first material, as shown in FIG. 5(b). Next, step B is performed, converting a portion of the third material into a reaction product, as shown in FIG. 5(c). Next, step C is performed, simultaneously removing the reaction product and removing and / or neutralizing the inhibitor, as shown in FIG. 5(d). FIG. 5(d) illustrates the case where the inhibitor is removed from the surface of the first material. Thus, in the first cycle of this modified example, only a portion of the third material on the surface side is removed.

[0112] In the second cycle (second cycle), step A is performed on the substrate, which has the surface structure shown in FIG. 5(e) after the first cycle, to selectively adsorb the inhibitor onto the surface of the first material, as shown in FIG. 5(f). Next, step B is performed to convert the entire remaining portion of the third material into a reaction product, as shown in FIG. 5(g). Next, step C is performed to simultaneously remove the reaction product and remove and / or neutralize the inhibitor, as shown in FIG. 5(h). FIG. 5(h) illustrates the removal of the inhibitor from the surface of the first material. In this manner, in the second cycle of this modified example, all remaining portions of the third material are removed. As a result, the surfaces of the first material and the second material are exposed.

[0113] As described above, by performing the cycle including steps A to C multiple times, the third material can be selectively removed from the first, second, and third materials, and the same effects as those of the above-mentioned embodiment can be obtained in this modified example. Note that the cycle including steps A to C may be performed three or more times.

[0114] Note that performing step B may remove or disable part of the first inhibitor layer, exposing part of the first material. Even in this case, according to this modification, step A in the next cycle re-forms the first inhibitor layer so as to cover the surface of the first material. As a result, the re-formed first inhibitor layer protects the surface of the first material in step B, which is performed thereafter, and makes it possible to suppress etching of the first material. In other words, in each step from the second cycle onwards, the same reaction as in the first cycle can occur and proceed.

[0115] (Variation 2) As in the processing sequence shown below, in step B, purging of the processing chamber may be performed when the first reactant and the second reactant are alternately supplied.

[0116] Variation 2a: [modifier → P → (first reactant → second reactant → P) × m → parallel removal] × n Variation 2b: [modifier → P → (first reactant → P → second reactant) × m → parallel removal] × n Variation 2c: [modifier → P → (first reactant → P → second reactant → P) × m → parallel removal] × n

[0117] These modifications also achieve the same effects as the above-described embodiment. Furthermore, in these modifications, when alternately supplying the first and second reactants in step B, purging the processing chamber at a predetermined timing enables more precise control of the altered thickness of the third material in step B. In modifications 2a and 2b, similar to the above-described embodiment, the first and second reactants can be mixed in the processing chamber, allowing a reaction product to be generated at a high rate. As a result, the third material can be removed at a high rate. Furthermore, it is also possible to supply the first and second reactants to the substrate with a partial overlap, allowing a reaction product to be generated at a relatively high rate. As a result, the third material can be removed at a relatively high rate. Furthermore, in modification 2c, purging the processing chamber after each of steps B1 and B2 is performed, and the first and second reactants are not supplied to the substrate with an overlap, allowing more precise control of the altered thickness of the third material in step B.

[0118] (Variation 3) In the case where the reactants include a first reactant and a second reactant that reacts with the first reactant, step B may include a period during which the substrate is exposed to the first reactant and the second reactant simultaneously, as in the processing sequence shown below.

[0119] Variation 3a: [modifier → P → (first reactant + second reactant) × m → parallel removal] × n Variation 3b: [modifier → P → (first reactant + second reactant → P) × m → parallel removal] × n

[0120] These modifications also provide the same effects as those of the above-described embodiment. Furthermore, in these modifications, step B includes a period during which the substrate is simultaneously exposed to the first and second reactants, allowing the first and second reactants to be directly mixed in the processing chamber, thereby enabling the reaction product to be generated at a high rate. As a result, the third material can be removed at a high rate.

[0121] In these modified examples, the simultaneous supply of the first and second reactants is intermittently performed, thereby enabling enhanced control of the altered thickness of the third material (thickness of the reaction product to be generated). In addition, in modified example 3b, purging the processing chamber when the simultaneous supply of the first and second reactants is intermittently performed enables more precise control of the altered thickness of the third material in step B.

[0122] <Other Aspects of the Present Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0123] For example, the first material may include a deposited oxide film, and the third material may include a chemical oxide film. x1 The third material is a non-stoichiometric SiO x2 Here, x1 and x2 are real numbers that satisfy the relation 2>x1>x2>0. For example, when the first material is SiO 1.9 the third material being SiO 1.5 The first material may comprise a film of SiO 1.5 the third material being SiO 1.1 For example, the first material may include a stoichiometric SiO2 film (high density), and the third material may include a stoichiometric SiO2 film (low density). For example, the first material may include a non-stoichiometric SiO2 film. x The third material is non-stoichiometric SiO x The film may include a low density film, where x is a real number less than 2. In these embodiments, the same effects as those in the above-mentioned embodiments can be obtained.

[0124] For example, at least one of the first material and the third material may include a silicon oxycarbide film (SiOC film), a silicon oxynitride film (SiON film), a silicon oxycarbonitride film (SiOCN film), or the like, in addition to an SiO film. For example, the first material may include a SiOC film (high density), and the third material may include a SiOC film (low density). For example, the first material may include a SiOC film (high O concentration), and the third material may include a SiOC film (low O concentration). For example, the first material may include a SiOC film (O rich), and the third material may include a SiOC film (O poor). For example, the first material may include a SiOC film (O rich), and the third material may include a native oxide film. For example, the first material may include a SiON film (O rich), and the third material may include a native oxide film. For example, the first material may include a SiOCN film (O rich), and the third material may include a native oxide film. Here, "O-rich" refers to a composition in which the atomic concentration of oxygen (O) is excessive relative to the stoichiometric composition, and "O-poor" refers to a composition in which the atomic concentration of oxygen (O) is insufficient relative to the stoichiometric composition. In either case, the density of adsorption sites (OH terminations) on the surface of the third material is lower than the density of adsorption sites (OH terminations) on the surface of the first material. As long as this relationship is satisfied, the first material and the third material may be the same substance or different substances. These embodiments also provide the same effects as those described above.

[0125] Furthermore, for example, the second material may include a silicon carbonitride film (SiCN film), a silicon boron carbonitride film (SiBCN film), a silicon boron nitride film (SiBN film), a silicon film (Si film), or the like, in addition to a SiN film. The Si film referred to here may be any of an amorphous Si film, a poly-Si film, and an epitaxial Si film. The second material may also include single-crystal Si (Si wafer). The first material may also include a SiN film, a SiCN film, a SiBCN film, a SiBN film, a Si film, single-crystal Si, or the like. For example, the first material may include a SiN film, a SiCN film, a SiBCN film, or the like, the second material may include a Si film, single-crystal Si, or the like, and the third material may include a native oxide film, a chemical oxide film, or the like. In these embodiments, the same effects as those of the above-mentioned embodiment can be obtained.

[0126] Furthermore, for example, the processing procedure, processing conditions, type of remover used, etc. in step C can be selected appropriately depending on the types of various materials, inhibitors, reaction products, etc. present on the surface of the wafer 200.

[0127] For example, if a carbon (C)-containing film such as a SiCN film exists on the surface of the wafer 200, it is preferable to perform step C under conditions that can suppress desorption of C from the film. In this respect, in step C, heat treatment is preferable to plasma treatment, and treatment using an inert gas or a reducing agent is preferable to treatment using an oxidizing agent. When treatment using an oxidizing agent is performed, it is preferable to use an oxidizing agent with low oxidizing power.

[0128] Furthermore, for example, the third material (SiO x If the second material (e.g., SiN) underlying the second material (e.g., SiN) is easily oxidized and oxidation of the second material is desired, it is preferable to use an inert gas or a reducing agent as a remover rather than an oxidizing agent as a remover in step C to suppress oxidation of the second material. When using an oxidizing agent as a remover in step C, it is preferable to use an oxidizing agent with low oxidizing power. Alternatively, when the surface of the second material is covered with reaction products, the remover may be used as an oxidizing agent, and then the remover may be switched to an inert gas or a reducing agent. That is, in step C, parallel removal may be performed in two steps by switching the substance used as the remover midway. In this case, using an oxidizing agent as a remover in the first step allows for parallel removal at a high rate, and using an inert gas or a reducing agent as a remover in the second step allows for parallel removal while suppressing oxidation of the second material.

[0129] It is preferable that the recipes used for each process are individually prepared according to the process content and recorded and stored in the storage device 121c via an electric communication line or the external storage device 123. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from among the multiple recipes recorded and stored in the storage device 121c. This makes it possible to perform various processes with good reproducibility on materials of various types, composition ratios, densities, thicknesses, and states. It also reduces the burden on the operator, and allows each process to be started quickly while avoiding operational errors.

[0130] The above-mentioned recipes do not necessarily have to be newly created, but may be prepared by modifying an existing recipe that has already been installed in the processing device. When modifying a recipe, the modified recipe may be installed in the processing device via an electric communication line or a recording medium on which the recipe has been recorded. Alternatively, an existing recipe that has already been installed in the processing device may be directly modified by operating the input / output device 122 provided in the existing processing device.

[0131] In the above-described embodiments and modifications, examples have been described in which etching is performed using a batch-type processing apparatus that processes multiple substrates at a time. The present disclosure is not limited to the above-described embodiments and can be applied, for example, to etching using a single-wafer processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiments, examples have been described in which etching is performed using a processing apparatus having a hot-wall processing furnace. The present disclosure is not limited to the above-described embodiments and can be applied to etching using a processing apparatus having a cold-wall processing furnace.

[0132] In the above-described embodiment, the processing sequence is performed in the same processing chamber of the same processing apparatus (in-situ). The present disclosure is not limited to the above-described embodiment, and for example, one step and another step of the processing sequence may be performed in different processing chambers of different processing apparatuses (ex-situ), or may be performed in different processing chambers of the same processing apparatus.

[0133] When using these processing devices, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0134] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and processing conditions in such a case may be the same as those of the above-described embodiments and modifications, for example. [Explanation of symbols]

[0135] 200 wafers (substrates)

Claims

1. (a) exposing a substrate having a surface made of a first material and a third material formed on a second material to a modifier, thereby causing an inhibitor contained in the modifier to be adsorbed onto the surface of the first material; and (b) exposing the substrate to a reactant, thereby causing at least a portion of the third material to react with the reactant to generate a reaction product. (c) applying energy to the substrate to simultaneously remove the reaction product and remove and / or neutralize the inhibitor; a step of removing the third material by performing a predetermined number of cycles including the steps of:

2. the reactants include a first reactant and a second reactant that reacts with the first reactant; 2. The processing method of claim 1, wherein (b) includes at least one of a period in which the substrate is alternately exposed to the first reactant and the second reactant and a period in which the substrate is simultaneously exposed to the first reactant and the second reactant.

3. 3. The method of claim 2, wherein the first reactant comprises a halogen-containing material and the second reactant comprises a reducing agent.

4. 3. The method of claim 2, wherein the first reactant comprises a fluorine-containing material and the second reactant comprises hydrogen nitride.

5. 3. The method of claim 2, wherein the first reactant comprises fluorine and hydrogen, and the second reactant comprises nitrogen and hydrogen.

6. 2. The processing method according to claim 1, wherein in step (c), thermal energy is applied to the substrate.

7. 2. The processing method of claim 1, wherein in step (c), plasma energy is applied to the substrate.

8. 2. The processing method according to claim 1, wherein in (c), the substrate is heated to a temperature equal to or higher than the temperature of the substrate in (b), or to a temperature higher than the temperature of the substrate in (b).

9. 2. The method of claim 1, wherein in (c), the substrate is exposed to a remover that reacts with the inhibitor and / or the reaction product.

10. 10. The processing method according to claim 1, wherein the third material contains the same element as the element that constitutes the first material.

11. 10. The processing method according to claim 1, wherein the first material and the third material both contain the same plurality of elements, the first material has a first composition, and the third material has a second composition different from the first composition.

12. 12. The method of claim 11, wherein the first composition comprises a stoichiometric composition and the second composition comprises a non-stoichiometric composition.

13. The method according to any one of claims 1 to 9, wherein the density of the third material is lower than the density of the first material.

14. The processing method according to any one of claims 1 to 9, wherein the first material and the third material both contain a first element and a second element, and the atomic concentration of the second element contained in the third material is lower than the atomic concentration of the second element contained in the first material.

15. 10. The method according to claim 1, wherein the density of adsorption sites on the surface of the third material is lower than the density of adsorption sites on the surface of the first material.

16. 10. The processing method according to claim 1, wherein the density of hydroxyl group terminations on the surface of the third material is lower than the density of hydroxyl group terminations on the surface of the first material.

17. 10. The processing method according to claim 1, wherein the first material includes a thermal oxide film or a deposited oxide film, and the third material includes at least one of a native oxide film and a chemical oxide film.

18. 10. The processing method according to claim 1, wherein in (a), the inhibitor contained in the modifier is also adsorbed onto the surface of the third material.

19. 20. The method of claim 18, wherein the density of the inhibitor adsorbed on the surface of the third material is lower than the density of the inhibitor adsorbed on the surface of the first material.

20. (a) exposing a substrate having a surface made of a first material and a third material formed on a second material to a modifier, thereby causing an inhibitor contained in the modifier to be adsorbed onto the surface of the first material; and (b) exposing the substrate to a reactant, thereby causing at least a portion of the third material to react with the reactant to generate a reaction product. (c) applying energy to the substrate to simultaneously remove the reaction product and remove and / or neutralize the inhibitor; a step of removing the third material by performing a cycle including the steps of:

21. a device for preparing a substrate; an energy applying device that applies energy to the substrate; a control unit configured to be able to control the apparatus and the energy applying device to perform a process of removing the third material by performing a predetermined number of cycles including: (a) a process of preparing a substrate having a surface made of a first material and a third material formed on a second material, by exposing the substrate to a modifying agent, thereby causing an inhibitor contained in the modifying agent to be adsorbed onto a surface of the first material; (b) a process of exposing the substrate to a reacting agent, thereby causing at least a portion of the third material to react with the reacting agent, thereby generating a reaction product; and (c) a process of applying energy to the substrate, thereby removing the reaction product and at least one of removing and neutralizing the inhibitor in parallel; A processing device having:

22. (a) exposing a substrate having a surface made of a first material and a third material formed on a second material to a modifier, thereby causing an inhibitor contained in the modifier to be adsorbed onto the surface of the first material; and (b) exposing the substrate to a reactant, thereby causing at least a portion of the third material to react with the reactant to generate a reaction product; (c) applying energy to the substrate to simultaneously remove the reaction products and remove and / or neutralize the inhibitor; a program that causes a processing device to execute, by a computer, a procedure for removing the third material by performing a cycle including the steps of:

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