Processing method, method for manufacturing a semiconductor device, processing apparatus, and program

Abstract

To provide a processing method, a processing apparatus, a manufacturing method for a semiconductor device, and a program for improving the filling characteristics when a recess portion is filled with a film.SOLUTION: A processing sequence executes step E of supplying an etching agent to a wafer and removing a native oxide films on the surfaces of first and second materials before performing step C, step C of supplying an oxidizing agent as a reactant to the wafer and oxidizing the surface of the first material to form a hydroxyl-group termination on the surface of the first material, step D of heating the wafer and performing annealing (ANL) to sublimate an oxide formed on the surface of the second material and remove the hydroxyl-group termination formed on the surface of the second material, step A of supplying the precursor to the wafer to form a film-formation restraining layer on the surface of the first material (Si) in a recess portion on the wafer surface, and step B of supplying a film-formation substance to the wafer having the film-formation restraining layer formed on the surface of the first material and growing a film on the surface of the second material (SiGe) in the recess portion.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] This disclosure relates to processing methods, methods for manufacturing semiconductor devices, processing apparatuses, and programs. [Background technology]

[0002] As part of the manufacturing process for semiconductor devices, a film may be formed on the surface of a substrate. In this case, the film may be formed to fill in recesses provided on the surface of the substrate (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2014-183218 [Patent Document 1] Japanese Patent Publication No. 2017-069407 [Overview of the project] [Problems that the invention aims to solve]

[0004] The purpose of this disclosure is to provide a technology that improves the embedding characteristics when filling recesses with a film. [Means for solving the problem]

[0005] According to one aspect of this disclosure, (a) A step of supplying a precursor to a substrate having a recess on its surface, the top and sides of which are made of a first material containing a first element, and the bottom surface of which is made of a second material containing a second element different from the first element, thereby adsorbing at least a portion of the molecular structure of the molecules constituting the precursor onto the surface of the first material in the recess, thereby forming a film formation inhibiting layer on the surface of the first material, (b) A step of growing a film on the surface of the second material in the recess by supplying a film-forming material to the substrate on which the film-forming suppression layer is formed on the surface of the first material, Technology to perform this will be provided. [Effects of the Invention]

[0006] According to this disclosure, it is possible to improve the embedding characteristics when filling recesses with a film. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus preferably used in one embodiment of the present disclosure, and shows the processing furnace 202 portion in a vertical cross-sectional view. [Figure 2] Figure 2 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus preferably used in one embodiment of the present disclosure, and shows the processing furnace 202 portion as a cross-sectional view along line AA in Figure 1. [Figure 3] Figure 3 is a schematic configuration diagram of a controller 121 of a substrate processing apparatus preferably used in one embodiment of the present disclosure, and is a block diagram showing the control system of the controller 121. [Figure 4] Figure 4 shows a processing sequence in one aspect of the present disclosure. [Figure 5]Figure 5(a) is a magnified cross-sectional view of the surface of a substrate having a laminated structure on its surface in which a second material (SiGe) and a first material (Si) are alternately stacked, an insulating film is provided on top of this, and a portion of the sidewall of the laminated structure made up of the second material (SiGe) is removed, thereby providing a recess in the sidewall of the laminated structure whose depth direction is parallel to the surface of the substrate (lateral direction). Figure 5(b) is a magnified cross-sectional view of the surface of a substrate having the structure on its surface as shown in Figure 5(a), in the process of forming a silicon carbide film (SiOC) using the processing sequence of this embodiment. Figure 5(c) is a magnified cross-sectional view of the surface of a substrate having the structure on its surface as shown in Figure 5(a), after the processing of forming a silicon carbide film (SiOC) using the processing sequence of this embodiment has been performed. Figure 5(d) is a partially enlarged cross-sectional view of the surface of a substrate having the configuration shown in Figure 5(a) on its surface, after annealing following the formation of a silicon carbide film (SiOC) using the processing sequence in this embodiment. [Figure 6] Figure 6(a) is a magnified cross-sectional view of the surface of a substrate having a laminated structure on its surface in which a second material (SiGe) and a first material (Si) are alternately stacked, an insulating film is provided on top of this, and a portion of the sidewall of the laminated structure made up of the second material (SiGe) is removed, thereby creating a recess in the sidewall of the laminated structure whose depth direction is parallel to the surface of the substrate (lateral direction). Figure 6(b) is a magnified cross-sectional view of the surface of a substrate having the structure shown in Figure 6(a) after a silicon carbide film (SiOC) has been formed on the substrate using a conventional film deposition method. Figure 6(c) is a magnified cross-sectional view of the surface of a substrate having the structure shown in Figure 6(b) after an etching treatment has been performed to remove excess film formed on the upper surface of the recess, etc. [Figure 7] Figure 7 is a cross-sectional TEM image of evaluation sample 1 in the example. [Figure 8] Figure 8 shows a cross-sectional TEM image of evaluation sample 2 in the example. Mode for Carrying Out the Invention

[0008] <One Aspect of the Present Disclosure> Hereinafter, one aspect of the present disclosure will be described mainly with reference to FIGS. 1 to 4 and FIGS. 5(a) to 5(d). All the drawings used in the following description are schematic, and the dimensional relationship of each element, the ratio of each element, and the like shown in the drawings do not necessarily match the actual ones. Also, the dimensional relationship of each element, the ratio of each element, and the like do not necessarily match between a plurality of drawings.

[0009] (1) Configuration of Substrate Processing Apparatus As shown in FIG. 1, a processing furnace 202 has a heater 207 serving as a temperature regulator (heating unit). The heater 207 has a cylindrical shape and is vertically installed by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas with heat.

[0010] Inside the heater 207, a reaction tube 203 is disposed concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), for example, and is formed into a cylindrical shape with a closed upper end and an open lower end. Below the reaction tube 203, a manifold 209 is disposed concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS), for example, and is formed into a cylindrical shape with open upper and lower ends. The upper end of the manifold 209 is engaged with the lower end of the reaction tube 203, and is configured to support the reaction tube 203. An O-ring 220a serving as a seal member is provided between the manifold 209 and the reaction tube 203. The reaction tube 203 is vertically installed in the same manner as the heater 207. A processing container (reaction container) is mainly constituted by the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the cylindrical hollow portion of the processing container. The processing chamber 201 is configured to be capable of accommodating a wafer 200 as a substrate. Processing on the wafer 200 is performed inside the processing chamber 201.

[0011] In the processing chamber 201, nozzles 249a to 249c serving as first to third supply parts are respectively provided so as to penetrate through the side wall 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, for example. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c respectively. The nozzles 249a to 249c are different nozzles from each other, and each of the nozzles 249a and 249c is provided adjacent to the nozzle 249b.

[0012] Mass flow controllers (MFCs) 241a to 241c serving as flow rate controllers (flow rate control parts) and valves 243a to 243c serving as opening / closing valves are respectively provided in the gas supply pipes 232a to 232c in order from the upstream side of the gas flow. Gas supply pipes 232d and 232f are respectively connected to a downstream side of the valve 243a of the gas supply pipe 232a. Gas supply pipes 232e and 232g are respectively connected to a downstream side of the valve 243b of the gas supply pipe 232b. A gas supply pipe 232h is connected to a downstream side of the valve 243c of the gas supply pipe 232c. MFCs 241d to 241h and valves 243d to 243h are respectively provided in the gas supply pipes 232d to 232h in order from the upstream side of the gas flow. The gas supply pipes 232a to 232h are made of a metal material such as SUS, for example.

[0013] As shown in Figure 2, nozzles 249a to 249c are provided in an annular space in plan view between the inner wall of the reaction tube 203 and the wafer 200, extending upward from the lower part of the inner wall of the reaction tube 203 towards the direction of wafer 200 arrangement. That is, nozzles 249a to 249c are provided in a region horizontally surrounding the wafer arrangement region, on the side of the wafer arrangement region where the wafers 200 are arranged, and are provided along the wafer arrangement region. In plan view, nozzle 249b is positioned to be directly opposite the exhaust port 231a (described later) with the center of the wafer 200 being transported into the processing chamber 201 in between. Nozzles 249a and 249c are positioned to sandwich a straight line L passing through the center of nozzle 249b and the center of exhaust port 231a along the inner wall of the reaction tube 203 (outer periphery of the wafer 200) from both sides. Straight line L is also the straight line passing through nozzle 249b and the center of wafer 200. In other words, nozzle 249c is located on the opposite side of nozzle 249a, with respect to the straight line L. Nozzles 249a and 249c are arranged symmetrically with respect to the straight line L as the axis of symmetry. Gas supply holes 250a to 250c are provided on the sides of nozzles 249a to 249c, respectively. Each of the gas supply holes 250a to 250c opens so as to face (oppose) the exhaust port 231a in a plan view, making it possible to supply gas toward the wafer 200. Multiple gas supply holes 250a to 250c are provided extending from the bottom to the top of the reaction tube 203.

[0014] From the gas supply pipe 232a, a precursor (precursor gas) is supplied into the processing chamber 201 via the MFC 241a, valve 243a, and nozzle 249a.

[0015] From the gas supply pipe 232b, a raw material (raw material gas), which is one of the film-forming materials (film-forming gases), is supplied into the processing chamber 201 via FC241b, valve 243b, and nozzle 249b.

[0016] From the gas supply pipe 232c, a reactant (reaction gas), which is both a film-forming material (film-forming gas) and a reactant, is supplied into the processing chamber 201 via the MFC 241c, valve 243c, and nozzle 249c.

[0017] From the gas supply pipe 232d, a catalyst (catalytic gas), which is both a film-forming material (film-forming gas) and a reactant, is supplied into the processing chamber 201 via the MFC 241d, valve 243d, gas supply pipe 232a, and nozzle 249a.

[0018] From the gas supply pipe 232e, the etching agent (etching gas) is supplied into the processing chamber 201 via the MFC 241e, valve 243e, gas supply pipe 232b, and nozzle 249b.

[0019] Inert gas is supplied from gas supply pipes 232f to 232h into the processing chamber 201 via MFCs 241f to 241h, valves 243f to 243h, gas supply pipes 232a to 232c, and nozzles 249a to 249c, respectively. The inert gas acts as a purge gas, carrier gas, diluent gas, etc.

[0020] The precursor supply system is mainly composed of gas supply pipe 232a, MFC 241a, and valve 243a. The raw material supply system is mainly composed of gas supply pipe 232b, MFC 241b, and valve 243b. The reactant supply system is mainly composed of gas supply pipe 232c, MFC 241c, and valve 243c. The catalyst supply system is mainly composed of gas supply pipe 232d, MFC 241d, and valve 243d. The etching agent supply system is mainly composed of gas supply pipe 232e, MFC 241e, and valve 243e. The inert gas supply system is mainly composed of gas supply pipes 232f~232h, MFC 241f~241h, and valves 243f~243h. The raw material supply system, the reactant supply system, and each or all of them are also referred to as the film-forming material supply system. The raw material supply system, the reactant supply system, and the catalyst supply system, individually or all of them, are also referred to as the film-forming material supply system. The reactant supply system and the catalyst supply system, individually or all of them, are also referred to as the reactant supply system.

[0021] Of the various supply systems described above, one or all of them may be configured as an integrated supply system 248, which is comprised of valves 243a to 243h and MFCs 241a to 241h. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232h, and the supply operation of various substances (various gases) into the gas supply pipes 232a to 232h, i.e., the opening and closing operation of valves 243a to 243h and the flow rate adjustment operation of MFCs 241a to 241h, is controlled by a controller 121, which will be described later. The integrated supply system 248 is configured as an integrated or segmented integrated unit, and can be attached to and detached from the gas supply pipes 232a to 232h, etc., in units of the integrated unit, and is configured so that maintenance, replacement, and expansion of the integrated supply system 248 can be performed in units of the integrated unit.

[0022] An exhaust port 231a for exhausting the atmosphere inside the processing chamber 201 is provided at the lower part of the side wall of the reaction tube 203. As shown in Figure 2, the exhaust port 231a is located in a position opposite (facing) the nozzles 249a to 249c (gas supply holes 250a to 250c) with the wafer 200 in between, in a plan view. The exhaust port 231a may also be provided along the upper part of the side wall of the reaction tube 203, that is, along the wafer arrangement region. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246, which is a vacuum evacuation device, is connected to the exhaust pipe 231 via a pressure sensor 245, which is a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201, and an APC (Auto Pressure Controller) valve 244, which is a pressure regulator (pressure adjustment unit). The APC valve 244 can be opened and closed while the vacuum pump 246 is operating to evacuate and stop the vacuum evacuation in the processing chamber 201. Furthermore, while the vacuum pump 246 is operating, the valve opening can be adjusted based on the pressure information detected by the pressure sensor 245 to adjust the pressure in the processing chamber 201. The exhaust system mainly consists of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may also be considered as part of the exhaust system.

[0023] Below the manifold 209, a seal cap 219 is provided as a furnace opening 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 disc shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a sealing member that contacts the lower end of the manifold 209. Below the seal cap 219, a rotating mechanism 267 for rotating the boat 217, which will be described later, is installed. The rotating shaft 255 of the rotating mechanism 267 passes through the seal cap 219 and is connected to the boat 217. The rotating mechanism 267 is configured to rotate the wafer 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered vertically by a boat elevator 115, which is installed outside the reaction tube 203 as a lifting mechanism. The boat elevator 115 is configured as a transport device (transport mechanism) that moves the wafer 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219.

[0024] Below the manifold 209, a shutter 219s is provided as a furnace opening 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 is formed in a disc shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a sealing member that contacts the lower end of the manifold 209. The opening and closing operation of the shutter 219s (such as lifting and lowering or rotating) is controlled by the shutter opening and closing mechanism 115s.

[0025] The boat 217, which serves as a substrate support, is configured to support multiple wafers 200, for example 25 to 200 wafers 200, in a horizontal position and aligned vertically with their centers aligned, in multiple layers, that is, arranged with spacing between them. The boat 217 is made of a heat-resistant material such as quartz or SiC. Below the boat 217, multiple layers of heat-insulating plates 218, also made of a heat-resistant material such as quartz or SiC, are supported.

[0026] A temperature sensor 263 is installed inside the reaction tube 203 as a temperature detector. By adjusting the amount of power supplied to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 is adjusted to the desired temperature distribution. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0027] As shown in Figure 3, the controller 121, which is the control unit (control means), is configured as a computer equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, storage device 121c, and I / O port 121d. The RAM 121b, storage device 121c, and I / O port 121d are configured to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, configured as, for example, a touch panel, is connected to the controller 121. Furthermore, an external storage device 123 can be connected to the controller 121.

[0028] The storage device 121c is composed of, for example, flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. The storage device 121c contains, in a readable format, control programs that control the operation of the substrate processing device, and process recipes that describe the procedures and conditions for substrate processing, as described later. The process recipe functions as a program, combining the procedures in the substrate processing described later so that the controller 121 causes the substrate processing device to execute them and obtain a predetermined result. Hereinafter, process recipes and control programs will be collectively referred to simply as "programs." Similarly, process recipes will be referred to simply as "recipes." In this specification, the term "program" may include only recipes, only control programs, or both. The RAM 121b is configured as a memory area (work area) where programs and data read by the CPU 121a are temporarily held.

[0029] I / O port 121d is connected to the MFCs 241a to 241h, valves 243a to 243h, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotary mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, etc.

[0030] 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 operation commands from the input / output device 122. The CPU 121a is configured to control the flow rate adjustment operation of various substances (various gases) by the MFCs 241a to 241h, the opening and closing operation of valves 243a to 243h, the opening and closing operation of the APC valve 244 and the pressure adjustment operation of the APC valve 244 based on the pressure sensor 245, the starting and stopping 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 rotating mechanism 267, the raising and lowering operation of the boat 217 by the boat elevator 115, and the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, in accordance with the contents of the read recipe.

[0031] The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 onto a computer. The external storage device 123 includes, for example, magnetic disks such as HDDs, optical disks such as CDs, magneto-optical disks such as MOs, and semiconductor memory such as USB memory and SSDs. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to simply as recording media. In this specification, the term recording media may include only the storage device 121c, only the external storage device 123, or both. Note that the program may be provided to the computer using communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0032] (2) Substrate processing process Using the substrate processing apparatus described above, an example of a processing sequence in which a film is formed in recesses on the surface of a wafer 200 (which serves as a substrate) to fill the recesses, as one step in the manufacturing process of a semiconductor device, will be explained mainly with reference to Figures 4 and 5(a) to 5(d). In the following explanation, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

[0033] As shown in Figure 5(a), the surface of the wafer 200 has a recess whose depth direction is parallel to the surface of the wafer 200 (lateral direction), with the top and sides made of a first material containing a first element, and the bottom surface made of a second material containing a second element different from the first element. Figure 5(a) shows an example where the first element is silicon (Si), the second element is germanium (Ge), the first material is silicon (Si), and the second material is silicon germanium (SiGe). In other words, in this example, the second material contains the second element in addition to the first element. Furthermore, the wafer 200 is made of single-crystal Si. In other words, the wafer 200 contains the first element.

[0034] More specifically, the surface of the wafer 200 is provided with a laminated structure in which a second material (SiGe) and a first material (Si) are alternately stacked, and an insulating film (Insulator) is provided on top of this. That is, the surface of the wafer 200 is provided with a laminated structure in which silicon germanium (SiGe) films and silicon (Si) films are alternately stacked, and an insulating film (Insulator) is provided on top of this. By removing a portion of the side wall of the laminated structure of SiGe films and Si films that is composed of SiGe films, a recess is provided in the side wall of the laminated structure, in which the top and sides are composed of the first material (Si) and the bottom is composed of the second material (SiGe), and the depth direction is parallel to the surface of the wafer 200 (lateral direction). In this specification, as shown in Figure 5(a), the portion of the recess made of the second material (SiGe) is referred to as the bottom surface, and with respect to that, the portion of the recess made of the first material (Si), which is in contact with the bottom surface and is provided perpendicular to the bottom surface is referred to as the side surface, and the portion of the recess made of the first material (Si), which is not in contact with the bottom surface and is provided parallel to the bottom surface is referred to as the top surface.

[0035] The processing sequence shown in Figure 4 is: Step A involves supplying a precursor material to a wafer 200 having a recess on its surface, where the top and sides are made of a first material containing a first element, and the bottom surface is made of a second material containing a second element different from the first element, thereby adsorbing at least a portion of the molecular structure of the molecules constituting the precursor material onto the surface of the first material in the recess, thereby forming a film formation inhibiting layer on the surface of the first material. The process includes step B, which involves supplying a film-forming material to a wafer 200 on which a film-forming inhibition layer has been formed on the surface of a first material, thereby growing a film on the surface of a second material in a recess.

[0036] As shown in Figure 4, in step B, Step B1 involves supplying raw materials as film-forming materials to wafer 200, Step B2 involves supplying an oxidizing agent as a reactant and film-forming material to wafer 200, A predetermined number of cycles are performed in which the process is carried out non-simultaneously. This causes the film to grow starting from the bottom surface of the recess, and the film to grow from the bottom up within the recess, thereby filling the recess with the film.

[0037] In this case, in at least one of step B1 and step B2, a catalyst may be supplied to the wafer 200 as a film-forming material. Figure 4 shows an example in which a catalyst is supplied to the wafer 200 as a film-forming material in both step B1 and step B2.

[0038] Furthermore, the processing sequence shown in Figure 4 further includes step C, in which an oxidizing agent is supplied to the wafer 200 as a reactant before step A is performed, and the surface of the first material is oxidized to form hydroxyl group terminations on the surface of the first material. At this time, the surface of the second material is also oxidized and hydroxyl group terminations are formed on the surface of the second material as well.

[0039] Furthermore, the processing sequence shown in Figure 4 includes a step D, which involves heating the wafer 200 and performing annealing (hereinafter also referred to as ANL) after step C and before step A, to sublimate the oxide formed on the surface of the second material and remove the hydroxyl group terminations formed on the surface of the second material. At this time, the hydroxyl group terminations formed on the surface of the first material are left behind while the hydroxyl group terminations formed on the surface of the second material are removed. As a result, hydroxyl group terminations are formed on the surface of the first material before step A, and either no hydroxyl group terminations are formed on the surface of the second material before step A, or a much smaller amount of hydroxyl group terminations are formed than the amount on the surface of the first material. Hereinafter, hydroxyl group terminations will also be referred to as OH terminations.

[0040] Furthermore, the processing sequence shown in Figure 4 further includes step E, in which an etching agent is supplied to the wafer 200 to remove the native oxide film on the surfaces of the first and second materials, before step C is performed.

[0041] Furthermore, the processing sequence shown in Figure 4 includes step F, in which, after step B, the wafer 200 is heated and heat-treated to perform post-treatment, or post-treatment (hereinafter also referred to as PT), on the film formed to fill the recesses.

[0042] In this embodiment, the first element is Si, the second element is Ge, the first material is Si, the second material is SiGe, and in step B, an example is described in which a silicon carbide film (SiOC film), which is one of the films containing silicon (Si), oxygen (O), and carbon (C), or a silicon oxide film (SiO film), which is one of the films containing silicon (Si) and oxygen (O), is grown as the film.

[0043] In this specification, the processing sequence described above may also be shown as follows for convenience. The same notation will be used in the following descriptions of modifications and other embodiments.

[0044] Etching agent → Oxidizing agent → ANL → Precursor → (Raw material + Catalyst → Oxidizing agent + Catalyst) × n → PT

[0045] In this specification, the term "wafer" may refer to the wafer itself or to a laminate of a wafer and a predetermined layer or film formed on its surface. In this specification, the term "surface of a wafer" may refer to the surface of the wafer itself or to the surface of a predetermined layer formed on the wafer. In this specification, the phrase "form a predetermined layer on a wafer" may refer to directly forming a predetermined layer on the surface of the wafer itself or to forming a predetermined layer on top of a layer already formed on the wafer. In this specification, the term "substrate" has the same meaning as the term "wafer."

[0046] (Wafer charge and boat load) When multiple wafers 200 are loaded into the boat 217 (wafer charging), the shutter 219s is moved by the shutter opening / closing mechanism 115s, opening the lower end opening of the manifold 209 (shutter opening). Then, as shown in Figure 1, the boat 217 supporting the multiple wafers 200 is lifted by the boat elevator 115 and transported into the processing chamber 201 (boat loading). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0047] (Pressure adjustment and temperature adjustment) The processing chamber 201, i.e., the space where the wafer 200 is located, is evacuated (reduced pressure exhaust) by a vacuum pump 246 to achieve a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by a pressure sensor 245, and the APC valve 244 is feedback-controlled based on this measured pressure information. The wafer 200 inside the processing chamber 201 is also heated by a heater 207 to reach a desired processing temperature. At this time, the amount of power supplied to the heater 207 is feedback-controlled based on the temperature information detected by a temperature sensor 263 to ensure a desired temperature distribution inside the processing chamber 201. The rotation of the wafer 200 is also started by a rotation mechanism 267. The exhaust of the processing chamber 201, the heating of the wafer 200, and the rotation are all continued at least until the processing of the wafer 200 is completed.

[0048] (Step E: Removal of native oxide film) Subsequently, an etching agent is supplied to the wafer 200.

[0049] Specifically, valve 243e is opened, and etching agent (etching gas) is flowed into the gas supply pipe 232e. The flow rate of the etching agent is adjusted by MFC 241e and supplied into the processing chamber 201 via gas supply pipe 232b and nozzle 249b, and exhausted from exhaust port 231a. At this time, etching agent is supplied to the wafer 200 from the side of the wafer 200 (etching agent supply). At this time, valves 243f to 243h may be opened to supply inert gas into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0050] By supplying an etching agent to the wafer 200 under the processing conditions described later, the native oxide film formed on the surface of the wafer 200 can be removed. In other words, the native oxide film on the surfaces of the first material and the second material on the surface of the wafer 200 can be removed. Specifically, the native oxide film on the surface of a recess on the surface of the wafer 200, where the top and side surfaces are made of the first material (Si) and the bottom surface is made of the second material (SiGe), and the depth direction is parallel to the surface of the wafer 200 (lateral direction), can be removed.

[0051] After removing the native oxide film formed on the surface of the wafer 200, valve 243e is closed to stop the supply of etching agent into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove any remaining gaseous substances. At this time, valves 243f to 243h are opened, and inert gas is supplied into the processing chamber 201 via nozzles 249a to 249c. The inert gas supplied from nozzles 249a to 249c acts as a purge gas, thereby purging the processing chamber 201.

[0052] The processing conditions for supplying the etching agent are as follows: Processing temperature: Room temperature (25°C) to 200°C, preferably 50 to 150°C Processing pressure: 10-13332 Pa, 20-1333 Pa Etching agent supply flow rate: 0.5 to 5 slm, preferably 0.5 to 2 slm Etching agent supply time: 1 to 120 minutes, preferably 1 to 60 minutes Inert gas supply flow rate (per gas supply pipe): 0-20 slm Examples are given.

[0053] The processing conditions for purging are: Processing temperature: Room temperature (25℃) to 500℃ Processing pressure: 1-30 Pa Inert gas supply flow rate (per gas supply pipe): 0.5~20 slm Inert gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds Examples are given.

[0054] In this specification, numerical ranges such as "25~200°C" mean that the lower and upper limits are included within that range. For example, "25~200°C" means "25°C or more and 200°C or less." The same applies to other numerical ranges. In this specification, processing temperature refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and processing pressure refers to the pressure inside the processing chamber 201. Also, gas supply flow rate: 0 slm means the case in which the gas is not supplied. These also apply in the following explanations.

[0055] As an etching agent, for example, a fluorine (F)-containing gas can be used. As an F-containing gas, for example, hydrogen fluoride (HF) gas, fluorine (F2) gas, etc. can be used. In addition to these, as an etching agent, for example, an aqueous solution of HF can also be used. That is, the etching agent may be a gaseous substance or a liquid substance. Furthermore, the etching agent may be a liquid substance such as a mist. One or more of these can be used as the etching agent.

[0056] As the inert gas, nitrogen (N2) gas, argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, and other noble gases can be used. This also applies to each step described later. One or more of these can be used as the inert gas.

[0057] (Step C: Oxidation) Subsequently, an oxidizing agent (oxidizing gas) is supplied to the wafer 200 as a reactant.

[0058] Specifically, valve 243c is opened, and an oxidizing agent, one of the reactants, is flowed into the gas supply pipe 232c as a reactant. The flow rate of the oxidizing agent is regulated by MFC 241c and supplied into the processing chamber 201 via nozzle 249c, and exhausted from exhaust port 231a. At this time, the oxidizing agent is supplied to the wafer 200 from the side of the wafer 200 (oxidizing agent supply). At this time, valve 243d may be opened, and the catalyst may be flowed into the gas supply pipe 232d. In this case, the flow rate of the catalyst is regulated by MFC 241d and supplied into the processing chamber 201 via gas supply pipe 232a and nozzle 249a, where it is mixed with the oxidizing agent and exhausted from exhaust port 231a. At this time, a mixture of catalyst and oxidizing agent (mixed gas) is supplied to the wafer 200 from the side of the wafer 200. Alternatively, at this time, valves 243f to 243h may be opened to supply inert gas into the processing chamber 201 through nozzles 249a to 249c, respectively.

[0059] By supplying an oxidizing agent, or a mixture of an oxidizing agent and a catalyst, to the wafer 200 under the processing conditions described later, the surface of the first material (Si) on the surface of the wafer 200 after the native oxide film has been removed can be oxidized to form OH terminations on the surface of the first material (Si). An oxide film (oxide) such as a silicon oxide film (SiO film) will be formed on the surface of the first material (Si), and OH terminations will be formed on its surface. By supplying a mixture of an oxidizing agent and a catalyst to the wafer 200, the oxidation rate can be increased at low temperatures. However, if it is necessary to lower the oxidation rate, or if the oxidation rate is to be adjusted by temperature, the supply of the catalyst can be omitted.

[0060] At this time, the surface of the second material (SiGe) on the surface of the wafer 200 is also oxidized, and OH terminations are formed on the surface of the second material (SiGe) as well. Oxide films such as germanium oxide film (GeO film) and silicon germanium oxide film (SiGeO film) are formed on the surface of the second material (SiGe), and OH terminations are formed on its surface.

[0061] After forming OH terminations on the surface of the first material (Si) on the surface of the wafer 200, the valve 243d is closed to stop the supply of oxidizing agent into the processing chamber 201. At this time, if a catalyst was being supplied simultaneously, the valve 243d is also closed to stop the supply of catalyst into the processing chamber 201. Then, using the same processing procedure and conditions as in step E, any remaining gaseous substances in the processing chamber 201 are removed from the processing chamber 201 (purging).

[0062] The processing conditions for supplying the oxidizing agent are as follows: Processing temperature: Room temperature (25°C) to 500°C, preferably room temperature to 300°C Processing pressure: 1 to 101325 Pa, preferably 1 to 13332 Pa Oxidizing agent supply flow rate: 0.1 to 10 slm, preferably 0.5 to 5 slm Oxidizing agent supply time: 1 to 120 minutes, preferably 1 to 60 minutes Catalyst supply flow rate: 0~10000sccm Inert gas supply flow rate (per gas supply pipe): 0-20 slm Examples are given.

[0063] As an oxidizing agent, for example, an oxygen (O)-containing gas or an oxygen (O) and hydrogen (H)-containing gas can be used. As an O-containing gas, for example, oxygen (O2) gas, ozone (O3) gas, nitrous oxide (N2O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO2) gas, carbon monoxide (CO) gas, carbon dioxide (CO2) gas, etc. can be used. As an O and H-containing gas, for example, water vapor (H2O gas), hydrogen peroxide (H2O2), hydrogen (H2) gas + oxygen (O2) gas, H2 gas + ozone (O3) gas, etc. can also be used. Note that an O and H-containing gas is also an O-containing gas. In addition to these, a cleaning solution, for example, a cleaning solution containing ammonia water, hydrogen peroxide water, and pure water, may be used as an oxidizing agent. That is, oxidation may be performed by APM cleaning. In this case, oxidation can be performed by exposing the wafer 200 to the cleaning solution. As described above, the oxidizing agent may be a gaseous substance or a liquid substance. Furthermore, the oxidizing agent may be a liquid substance such as a mist. One or more of these can be used as the oxidizing agent.

[0064] As catalysts, for example, amine gases containing carbon (C), nitrogen (N), and hydrogen (H) can be used. Examples of amine gases include pyridine (C5H5N) gas, aminopyridine (C5H6N2) gas, picoline (C6H7N) gas, lutidine (C7H9N) gas, and piperazine (C4H 10 N2) gas, piperidine (C5H 11 Cyclic amine gases such as N) gas, or linear amine gases such as triethylamine ((C2H5)3N, abbreviated as TEA) gas and diethylamine ((C2H5)2NH, abbreviated as DEA) gas can be used. This also applies to step B described later.

[0065] (Step D: ANL) After forming OH terminations on the surface of the first material (Si), purging is performed in the processing chamber 201 as described above. In parallel with this purging, the wafer 200 is heated and annealed. As described above, heating of the wafer 200 is continued at least until the processing of the wafer 200 is completed, so annealing will start when the supply of the oxidizing agent or catalyst is stopped.

[0066] By annealing the wafer 200 under the processing conditions described later, oxides such as GeO formed on the surface of the second material (SiGe) can be sublimated, thereby removing the OH terminations formed on the surface of the second material (SiGe).

[0067] At this time, not only the second material (SiGe) but also the first material (Si) is heated in the same way. However, since the oxide film such as the SiO film formed on the surface of the first material (Si) has strong Si-O bonds, it will not sublimate under the processing conditions described later. In other words, even if annealing is performed, the OH terminators formed on the surface of the first material (Si) can be maintained without being removed.

[0068] Thus, the annealing process in step D allows for the removal of oxides such as GeO formed on the surface of the second material (SiGe) while retaining (maintaining) oxide films such as the SiO film formed on the surface of the first material (Si). In other words, the annealing process in step D allows for the removal of OH terminations formed on the surface of the second material (SiGe) while retaining (maintaining) the OH terminations formed on the surface of the first material (Si). However, it is possible that not all of the OH terminations formed on the surface of the second material (SiGe) are removed, and a small portion may remain.

[0069] As a result, the surface of the first material (Si) before step A will have OH terminations formed on its surface. Also, the surface of the second material (SiGe) before step A will either have no OH terminations formed on its surface, or it will have a much smaller amount of OH terminations formed on its surface than the amount on the surface of the first material (Si). In other words, the amount (density, concentration) of OH terminations on the surface of the first material (Si) before step A will be greater (higher) than the amount (density, concentration) of OH terminations on the surface of the second material (SiGe).

[0070] The processing conditions in annealing (ANL) are as follows: Processing temperature: 100-500°C, preferably 100-300°C Processing pressure: 1 to 13332 Pa, preferably 1 to 1333 Pa Inert gas supply flow rate (per gas supply pipe): 0-20 slm Annealing time: 1 to 120 minutes, preferably 1 to 60 minutes Examples are given.

[0071] (Step A: Formation of a film formation inhibiting layer) Subsequently, the precursor material is supplied to the wafer 200.

[0072] Specifically, valve 243a is opened, and the precursor material is introduced into the gas supply pipe 232a. The precursor material's flow rate is adjusted by MFC 241a, and it is supplied into the processing chamber 201 via nozzle 249a and exhausted through exhaust port 231a. At this time, the precursor material is supplied to the wafer 200 from the side of the wafer 200 (precursor material supply). At this time, valves 243f to 243h may be opened to supply inert gas into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0073] By supplying a precursor material to the wafer 200 under the processing conditions described later, at least a portion of the molecular structure of the molecules constituting the precursor material can be selectively (preferentially) adsorbed onto the surface of the first material (Si) among the first material (Si) and second material (SiGe) in the recesses on the surface of the wafer 200, thereby selectively (preferentially) forming a film formation suppression layer on the surface of the first material (Si). Specifically, while suppressing the adsorption of at least a portion of the molecular structure of the molecules constituting the precursor material onto the surface of the second material (SiGe), the OH groups terminating the surface of the first material (Si) react with the precursor material, making it possible to selectively adsorb at least a portion of the molecular structure of the molecules constituting the precursor material onto the surface of the first material (Si). This makes it possible to terminate the surface of the first material (Si) with at least a portion of the molecular structure of the molecules constituting the precursor material. Examples of trialkylsilyl groups such as trimethylsilyl (Si-Me3) and triethylsilyl (Si-Et3) can be cited as at least a part of the molecular structure of the molecules constituting the precursor. In these cases, the Si of the trimethylsilyl or triethylsilyl group is adsorbed onto the surface of the first material (Si), and the outermost surface of the first material (Si) is terminated by alkyl groups such as methyl or ethyl groups. At least a part of the molecular structure of the molecules constituting the precursor that terminates the surface of the first material (Si), such as alkyl groups (alkylsilyl groups) such as methyl (trimethylsilyl) or ethyl (triethylsilyl) groups, acts as a film formation inhibiting layer (film formation suppression layer), i.e., an inhibitor, in the film formation process (selective growth) described later, preventing the adsorption of raw materials onto the surface of the first material (Si) and inhibiting the progress of the film formation reaction on the surface of the first material (Si).

[0074] In this step, at least a portion of the molecular structure of the molecules constituting the precursor may be adsorbed onto a part of the surface of the second material (SiGe), but the amount of adsorption is small, and the amount of adsorption onto the surface of the first material (Si) is overwhelmingly larger. Such selective (preferential) adsorption is possible because the processing conditions in this step are set so that the precursor does not undergo gas phase decomposition in the processing chamber 201. In addition, the surface of the first material (Si) is OH-terminated over its entire surface, whereas many areas of the surface of the second material (SiGe) are not OH-terminated. In this step, since the precursor does not undergo gas phase decomposition in the processing chamber 201, at least a portion of the molecular structure of the molecules constituting the precursor does not accumulate on the surfaces of the first material (Si) and the second material (SiGe). Instead, at least a portion of the molecular structure of the molecules constituting the precursor is selectively adsorbed onto the surface of the first material (Si), thereby selectively terminating the surface of the first material (Si) with at least a portion of the molecular structure of the molecules constituting the precursor.

[0075] After selectively forming a film-forming inhibiting layer on the surface of the first material (Si), valve 243a is closed to stop the supply of precursor material into the processing chamber 201. Then, using the same processing procedure and conditions as in step E, any remaining gaseous substances in the processing chamber 201 are removed (purged).

[0076] The processing conditions in the supply of precursor materials are as follows: Processing temperature: Room temperature (25°C) to 500°C, preferably room temperature to 250°C Processing pressure: 5~1000Pa Precursor supply flow rate: 1 to 3000 sccm, preferably 1 to 500 sccm Precursor supply time: 1 second to 120 minutes, preferably 30 seconds to 60 minutes Inert gas supply flow rate (per gas supply pipe): 0-20 slm Examples are given.

[0077] As a precursor, for example, a substance containing one or more atoms to which a first functional group and a second functional group are directly bonded can be used. The first functional group in the precursor is preferably a functional group that enables chemical adsorption of the precursor to an adsorption site (e.g., an OH terminus) on the surface of the first material (Si). The first functional group preferably contains an amino group, and more preferably contains a substituted amino group. When the precursor contains an amino group (preferably a substituted amino group), the amount of chemical adsorption of the precursor to the surface of the first material (Si) can be increased. In particular, from the viewpoint of adsorption to the surface of the first material (Si), it is preferable that all of the first functional groups of the precursor are substituted amino groups.

[0078] The substituents on the substituted amino group are preferably alkyl groups, more preferably alkyl groups having 1 to 5 carbon atoms, and particularly preferably alkyl groups having 1 to 4 carbon atoms. The alkyl groups on the substituted amino group may be linear or branched. Specific examples of alkyl groups on the substituted amino group include methyl, ethyl, n-propyl, n-butyl, isopropyl, isobutyl, sec-butyl, and tert-butyl groups. The number of substituents on the substituted amino group is 1 or 2, but 2 is preferred. When the number of substituents on the substituted amino group is 2, the two substituents may be the same or different.

[0079] The number of first functional groups in the precursor is preferably two or less, and more preferably one. If the precursor has multiple first functional groups, they may be the same or different.

[0080] The second functional group in the precursor is preferably a functional group capable of modifying the outermost surface of the first material (Si) into a film-forming inhibiting region. The second functional group is preferably a chemically stable functional group, and more preferably a hydrocarbon group. The hydrocarbon group may be an aliphatic hydrocarbon group such as an alkyl group, alkenyl group, or alkynyl group, or an aromatic hydrocarbon group. Among these, alkyl groups are preferred as hydrocarbon groups. In particular, from the viewpoint of high chemical stability, it is preferable that all of the second functional groups in the precursor are alkyl groups.

[0081] The alkyl group as the second functional group is more preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably an alkyl group having 1 to 4 carbon atoms. The alkyl group of the substituted amino group may be linear or branched. Specific examples of alkyl groups of the substituted amino group include methyl, ethyl, n-propyl, n-butyl, isopropyl, isobutyl, sec-butyl, and tert-butyl groups.

[0082] The number of secondary functional groups in the precursor can be an integer of 1 or more. If the number of primary functional groups in the precursor is 1, it is preferable that the number of secondary functional groups in the precursor is 3. Also, if the number of primary functional groups in the precursor is 2, it is preferable that the number of secondary functional groups in the precursor is 2. The multiple secondary functional groups in the precursor may be the same or different.

[0083] Examples of atoms to which the first and second functional groups are directly bonded in the precursor include carbon (C) atoms, silicon (Si) atoms, germanium (Ge) atoms, and tetravalent metal atoms. Examples of tetravalent metal atoms include titanium (Ti) atoms, zirconium (Zr) atoms, hafnium (Hf) atoms, molybdenum (Mo) atoms, and tungsten (W) atoms. Note that the atoms to which the first and second functional groups are directly bonded may be metal atoms capable of bonding to four or more ligands, in addition to tetravalent metal atoms. In this case, the number of second functional groups can be increased, and a stronger inhibitory effect can be achieved.

[0084] Among these, C atoms, Si atoms, and Ge atoms are preferred as atoms to which the first and second functional groups are directly bonded. This is because when any of C atoms, Si atoms, or Ge atoms are used as atoms to which the first and second functional groups are directly bonded, at least one of the following properties can be obtained: high adsorption of the precursor to the surface of the first material (Si), and high chemical stability of the precursor, i.e., the residue derived from the precursor, after adsorption to the surface of the first material (Si). Among these, Si atoms are more preferred as atoms to which the first and second functional groups are directly bonded. This is because when Si atoms are used as atoms to which the first and second functional groups are directly bonded, a good balance can be obtained between high adsorption of the precursor to the surface of the first material (Si), and high chemical stability of the precursor, i.e., the residue derived from the precursor, after adsorption to the surface of the first material (Si). As described above, atoms to which the first and second functional groups are directly bonded have the first and second functional groups directly bonded; however, hydrogen (H) atoms or a third functional group may also be bonded to them.

[0085] The third functional group bonded to the atom to which the first and second functional groups are directly bonded can be any functional group other than those described above as the first and second functional groups. Examples of the third functional group include a functional group composed of two or more of the following: a carbon atom, a silicon atom, a tetravalent metal atom, a metal atom capable of bonding to four or more ligands, an oxygen atom, a nitrogen (N) atom, and a hydrogen atom, in appropriate combination.

[0086] The precursor contains one or more atoms to which the first and second functional groups are directly bonded, but may also contain two or more atoms to which the first and second functional groups are directly bonded. Hereafter, for convenience, atoms to which the first and second functional groups are directly bonded will also be referred to as atom X.

[0087] The precursor preferably has a structure containing a tetravalent atom to which the first and second functional groups are directly bonded. More preferably, the precursor has a structure containing a tetravalent atom to which only the first and second functional groups are directly bonded. Of these, it is particularly preferable that the precursor has a structure containing one Si to which only the first and second functional groups are directly bonded. In other words, it is particularly preferable that the precursor has a structure in which only the first and second functional groups are directly bonded to a Si atom as the central atom.

[0088] The precursor preferably has a structure containing one amino group per molecule. More preferably, the precursor has a structure containing one amino group and at least one alkyl group per molecule. Even more preferably, the precursor has a structure containing one amino group and three alkyl groups per molecule. Furthermore, the precursor preferably has a structure in which one amino group is bonded to a central Si atom. More preferably, the precursor has a structure in which one amino group and at least one alkyl group are bonded to a central Si atom. Even more preferably, the precursor has a structure in which one amino group and three alkyl groups are bonded to a central Si atom. As mentioned above, the amino group is preferably a substituted amino group. The substituents on the substituted amino group are as described above.

[0089] As the precursor, for example, it is preferable to use a compound represented by the following formula 1.

[0090] Formula 1: [R 1 n 1 -(X)-[R 2 m 1 In formula 1, R 1 represents a first functional group directly bonded to X, R 2 represents a second functional group directly bonded to X or a hydrogen atom, X represents a tetravalent atom selected from the group consisting of a carbon atom, a silicon atom, a germanium atom, and a tetravalent metal atom, n 1 represents 1 or 2, and m 1 represents 2 or 3.

[0091] R 1 the first functional group represented by has the same definition as the above-mentioned first functional group, and preferred examples are also the same. When n 1 is 2, the two R 1 groups may each be the same or different. R 2 the second functional group represented by has the same definition as the above-mentioned second functional group, and preferred examples are also the same. When m 1 is 2 or 3, among the two or three R 2 groups, one or two may be hydrogen atoms and the remainder may be second functional groups, or all may be second functional groups. When all of the two or three R 2 groups are second functional groups, all of the second functional groups may each be the same or different. As the tetravalent atom represented by X, a silicon atom is preferable. 1 is preferable as n 2 3 is preferable as m 2 .

[0092] Examples of precursors that can be used include (dimethylamino)trimethylsilane ((CH3)2NSi(CH3)3, abbreviation: DMATMS), (diethylamino)triethylsilane ((C2H5)2NSi(C2H5)3, abbreviation: DEATES), (dimethylamino)triethylsilane ((CH3)2NSi(C2H5)3, abbreviation: DMATES), (diethylamino)trimethylsilane ((C2H5)2NSi(CH3)3, abbreviation: DEATMS), (trimethylsilyl)amine ((CH3)3SiNH2, abbreviation: TMSA), (triethylsilyl)amine ((C2H5)3SiNH2, abbreviation: TESA), (dimethylamino)silane ((CH3)2NSiH3, abbreviation: DMAS), (diethylamino)silane ((C2H5)2NSiH3, abbreviation: DEAS), etc.

[0093] Furthermore, examples of precursors include bis(dimethylamino)dimethylsilane ([(CH3)2N]2Si(CH3)2, abbreviation: BDMADMS), bis(diethylamino)diethylsilane ([(C2H5)2N]2Si(C2H5)2, abbreviation: BDEADES), bis(dimethylamino)diethylsilane ([(CH3)2N]2Si(C2H5)2, abbreviation: BDMADES), bis(diethyl (Mino)dimethylsilane ([(C2H5)2N]2Si(CH3)2, abbreviation: BDEADMS), bis(dimethylamino)silane ([(CH3)2N]2SiH2, abbreviation: BDMAS), bis(dimethylaminodimethylsilyl)ethane ([(CH3)2N(CH3)2Si]2C2H6, abbreviation: BDMADMSE), bis(dipropylamino)silane ([(C3H7)2N]2SiH2, abbreviation: B DPAS), bis(dipropylamino)dimethylsilane ([(C3H7)2N]2Si(CH3)2, abbreviation: BDPADMS), bis(dipropylamino)diethylsilane ([(C3H7)2N]2Si(C2H5)2, abbreviation: BDPADES), (dimethylsilyl)diamine ((CH3)2Si(NH2)2, abbreviation: DMSDA), (diethylsilyl)diamine ((C2H5)2Si(NH2 )2, abbreviation: DESDA), (dipropylsilyl)diamine ((C3H7)2Si(NH2)2, abbreviation: DESDA), bis(dimethylaminodimethylsilyl)methane ([(CH3)2N(CH3)2Si]2CH2, abbreviation: BDMADMSM), bis(dimethylamino)tetramethyldisilane ([(CH3)2N]2(CH3)4Si2, abbreviation: BDMATMDS), etc. can also be used.

[0094] These are all organic compounds having a structure in which an amino group and an alkyl group are directly bonded to Si. These compounds can also be called aminoalkyl compounds or alkylamino compounds. The precursor may be a gaseous substance or a liquid substance. The precursor may also be a liquid substance such as a mist. One or more of these can be used as the precursor.

[0095] (Step B: Film deposition process (selective growth)) Subsequently, the next steps B1 and B2 are executed sequentially. In these steps, the output of the heater 207 is adjusted to maintain the temperature of the wafer 200 at or below the temperature of the wafer 200 in step A, preferably at a temperature lower than the temperature of the wafer 200 in step A.

[0096] [Step B1] In this step, raw materials (raw material gas) and catalysts (catalyst gas) are supplied as film-forming materials to the wafer 200 in the processing chamber 201, i.e., the wafer 200 after a film-forming suppression layer has been selectively formed on the surface of the first material (Si).

[0097] Specifically, valves 243b and 243d are opened, and the raw material is introduced into gas supply pipe 232b, and the catalyst into gas supply pipe 232d. The flow rates of the raw material and catalyst are adjusted by MFCs 241b and 241d, respectively, and supplied into the processing chamber 201 via nozzles 249b and 249a. In the processing chamber 201, they are mixed and exhausted from exhaust port 231a. At this time, the raw material and catalyst are supplied to the wafer 200 (raw material + catalyst supply). At this time, valves 243f to 243h may also be opened to supply inert gas into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0098] By supplying the raw material and catalyst to the wafer 200 under the processing conditions described later, it becomes possible to selectively (preferentially) chemically adsorb at least a portion of the molecular structure of the molecules constituting the raw material onto the surface of the second material (SiGe) while suppressing the chemical adsorption of at least a portion of the molecular structure of the molecules constituting the raw material onto the surface of the first material (Si). As a result, the first layer is selectively (preferentially) formed on the surface of the second material (SiGe). The first layer contains at least a portion of the molecular structure of the molecules constituting the raw material. That is, the first layer contains at least a portion of the atoms constituting the raw material.

[0099] In this step, by supplying the catalyst together with the raw materials, the above-described reaction can be carried out in a non-plasma atmosphere and under low temperature conditions as described later. In this way, by forming the first layer in a non-plasma atmosphere and under low temperature conditions as described later, it is possible to maintain the molecules and atoms constituting the film formation suppression layer formed on the surface of the first material (Si) without them disappearing (desorbing) from the surface of the first material (Si).

[0100] Furthermore, by forming the first layer in a non-plasma atmosphere and under low temperature conditions as described later, it is possible to prevent the raw materials from undergoing thermal decomposition (gas phase decomposition), i.e., self-decomposition, within the processing chamber 201. This suppresses the layer deposition of at least a portion of the molecular structure of the molecules constituting the raw materials on the surfaces of the first material (Si) and the second material (SiGe), making it possible to selectively adsorb the raw materials onto the surface of the second material (SiGe).

[0101] After selectively forming the first layer on the surface of the second material (SiGe), valves 243b and 243d are closed to stop the supply of raw materials and catalyst to the processing chamber 201, respectively. Then, residual gases and other substances in the processing chamber 201 are removed from the processing chamber 201 using the same processing procedure and conditions as in step E (purging). It is preferable that the processing temperature when purging in this step is the same as the processing temperature when supplying the raw materials and catalyst.

[0102] The processing conditions for raw material + catalyst supply are as follows: Processing temperature: Room temperature (25°C) to 120°C, preferably room temperature to 90°C. Processing pressure: 133~1333 Pa Raw material supply flow rate: 1~2000sccm Catalyst supply flow rate: 1~2000sccm Inert gas supply flow rate (per gas supply pipe): 0-20000 sccm Gas supply time for each gas: 1-60 seconds Examples are given.

[0103] In this step, when forming the first layer, at least a portion of the molecular structure of the molecules constituting the raw material may be adsorbed onto a part of the surface of the first material (Si). However, the amount of adsorption is very small, far less than the amount of at least a portion of the molecular structure of the molecules constituting the raw material adsorbed onto the surface of the second material (SiGe). Such selective (preferential) adsorption is possible because the processing conditions in this step are low temperature conditions as described above, and the raw material does not undergo gas phase decomposition in the processing chamber 201. Furthermore, a film formation inhibiting layer is formed over the entire surface of the first material (Si), whereas a film formation inhibiting layer is not formed over many areas of the surface of the second material (SiGe).

[0104] As raw materials, for example, Si and halogen-containing gases can be used. Halogens include chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. Si and halogen-containing gases preferably contain halogens in the form of chemical bonds between Si and halogens. Si and halogen-containing gases may further contain C, in which case it is preferable that C is contained in the form of Si-C bonds. As Si and halogen-containing gases, for example, silane-based gases containing Si, Cl and alkylene groups and having Si-C bonds, i.e., alkylene chlorosilane-based gases, can be used. Alkylene groups include methylene groups, ethylene groups, propylene groups, butylene groups, etc. It is preferable that alkylene chlorosilane-based gases contain Cl in the form of Si-Cl bonds and C in the form of Si-C bonds.

[0105] Examples of Si and halogen-containing gases include alkylene chlorosilane gases such as bis(trichlorosilyl)methane ((SiCl3)2CH2, abbreviated as BTCSM) gas and 1,2-bis(trichlorosilyl)ethane ((SiCl3)2C2H4, abbreviated as BTCSE) gas, alkylchlorosilane gases such as 1,1,2,2-tetrachloro-1,2-dimethyldisilane ((CH3)2Si2Cl4, abbreviated as TCDMDS) gas and 1,2-dichloro-1,1,2,2-tetramethyldisilane ((CH3)4Si2Cl2, abbreviated as DCTMDS) gas, and gases containing cyclic structures composed of Si and C and halogens, such as 1,1,3,3-tetrachloro-1,3-disilacyclobutane (C2H4Cl4Si2, abbreviated as TCDSCB) gas. Furthermore, as the Si and halogen-containing gas, inorganic chlorosilane gases such as tetrachlorosilane (SiCl4, abbreviated as STC) gas, hexachlorodisilane (Si2Cl6, abbreviated as HCDS) gas, and octachlorotrisilane (Si3Cl8, abbreviated as OCTS) gas can also be used. One or more of these can be used as raw materials. The raw materials may be gaseous or liquid substances. In addition, the raw materials may be liquid substances such as mist substances.

[0106] Furthermore, instead of Si and halogen-containing gases, aminosilane gases such as tetrakis(dimethylamino)silane (Si[N(CH3)2]4, abbreviated as 4DMAS) gas, tris(dimethylamino)silane (Si[N(CH3)2]3H, abbreviated as 3DMAS) gas, bis(diethylamino)silane (Si[N(C2H5)2]2H2, abbreviated as BDEAS) gas, bis(tert-butylamino)silane (SiH2[NH(C4H9)]2, abbreviated as BTBAS) gas, and (diisopropylamino)silane (SiH3[N(C3H7)2], abbreviated as DIPAS) gas can also be used as raw materials. One or more of these can be used as raw materials.

[0107] As a catalyst, for example, catalysts similar to those exemplified in step C above can be used.

[0108] [Step B2] After step B1 is completed, an oxidizing agent (oxidizing gas) and a catalyst (catalytic gas) are supplied as film-forming materials to the wafer 200 in the processing chamber 201, i.e., the wafer 200 after the first layer has been selectively formed on the surface of the second material (SiGe).

[0109] Specifically, valves 243c and 243d are opened, allowing the oxidizer to flow into gas supply pipe 232c and the catalyst into gas supply pipe 232d. The flow rates of the oxidizer and catalyst are adjusted by MFCs 241c and 241d, respectively, and supplied to the processing chamber 201 via nozzles 249c and 249a. They are mixed in the processing chamber 201 and exhausted from exhaust port 231a. At this time, the oxidizer and catalyst are supplied to the wafer 200 (oxidizer + catalyst supply). At this time, valves 243f to 243h may also be opened to supply inert gas to the processing chamber 201 via nozzles 249a to 249c, respectively.

[0110] By supplying the oxidizing agent and catalyst to the wafer 200 under the processing conditions described later, it becomes possible to oxidize at least a portion of the first layer formed on the surface of the second material (SiGe) in step B1. As a result, a second layer is formed on the surface of the second material (SiGe), which is the oxidized first layer.

[0111] In this step, by supplying the catalyst together with the oxidizing agent, the above reaction can be carried out in a non-plasma atmosphere and under low temperature conditions as described later. In this way, by forming the second layer in a non-plasma atmosphere and under low temperature conditions as described later, it is possible to maintain the molecules and atoms constituting the film formation suppression layer formed on the surface of the first material (Si) without them disappearing (desorbing) from the surface of the first material (Si).

[0112] After oxidizing the first layer formed on the surface of the second material (SiGe) to transform it into the second layer, valves 243c and 243d are closed to stop the supply of the oxidizer and catalyst to the processing chamber 201, respectively. Then, using the same processing procedure and conditions as in step E, any remaining gases, etc., in the processing chamber 201 are removed (purged). It is preferable that the processing temperature when purging in this step is the same as the processing temperature when supplying the oxidizer and catalyst.

[0113] The processing conditions for supplying the oxidizing agent and catalyst are as follows: Processing temperature: Room temperature (25°C) to 120°C, preferably room temperature to 100°C Processing pressure: 133~1333 Pa Oxidizer supply flow rate: 1-2000 sccm Catalyst supply flow rate: 1~2000sccm Inert gas supply flow rate (per gas supply pipe): 0-20000 sccm Gas supply time for each gas: 1-60 seconds Examples are given.

[0114] As the oxidizing agent, for example, an oxidizing agent similar to the various oxidizing agents exemplified in step C above can be used. As the catalyst, for example, a catalyst similar to the various catalysts exemplified in step C above can be used.

[0115] [Perform the prescribed number of times] By performing the above steps B1 and B2 non-simultaneously, i.e., without synchronization, a predetermined number of cycles (n times, where n is an integer of 1 or more), a film can be selectively (preferentially) grown on the surface of the second material (SiGe) among the first material (Si) and second material (SiGe) in the recesses on the surface of the wafer 200, as shown in Figure 5(b). For example, when using the above-mentioned raw materials, oxidizer, and catalyst, a SiOC film or an SiO film can be selectively grown as a film on the surface of the second material (SiGe). It is preferable to repeat the above cycle multiple times. That is, it is preferable to make the thickness of the second layer formed per cycle thinner than the desired film thickness, and to repeat the above cycle multiple times until the film thickness formed by stacking the second layers reaches the desired film thickness.

[0116] By repeating the above cycle multiple times, a film can be grown starting from the surface of the second material (SiGe) that constitutes the bottom surface of the recess on the surface of the wafer 200, toward the opening side of the recess. At this time, since a film formation inhibiting layer is formed on the surface of the first material (Si) that constitutes the top and side surfaces of the recess, film growth starting from the surface of the first material (Si) can be suppressed. In other words, by repeating the above cycle multiple times, film growth starting from the top and side surfaces of the recess can be suppressed while film growth starting from the bottom surface of the recess can be promoted, allowing the film to grow in the recess from the bottom up and filling the recess with film (SiOC) as shown in Figure 5(c).

[0117] Furthermore, when performing steps B1 and B2, as shown in Figures 5(b) and 5(c), the film formation inhibiting layer formed on the surface of the first material (Si) is maintained on the surface of the first material (Si) as described above, thereby suppressing film growth originating from the surface of the first material (Si). However, in cases where the formation of the film formation inhibiting layer on the surface of the first material (Si) is insufficient due to some factor, a very small amount of film growth originating from the surface of the first material (Si) may occur. However, even in this case, the thickness of the film formed originating from the surface of the first material (Si) will be much thinner than the thickness of the film formed originating from the surface of the second material (SiGe). Therefore, even in this case, the filling of the recesses by the bottom-up growth described above can be properly performed.

[0118] (Step F:PT) After the film deposition process is completed, the wafer 200 is heated and heat-treated to perform post-treatment (PT) on the film that has been formed to fill the recesses. At this time, the output of the heater 207 is adjusted so that the temperature inside the processing chamber 201, i.e., the temperature of the wafer 200 after the film has been formed to fill the recesses, is equal to or higher than the temperature of the wafer 200 in steps A and B, preferably higher than the temperature of the wafer 200 in steps A and B. By performing PT, impurities contained in the film that has been formed to fill the recesses can be removed and defects can be repaired. In addition, as shown in Figure 5(d), PT can remove residues and debris of the film deposition suppression layer from the surface of the first material (Si), i.e., the upper surface of the recesses and the interface between the side surfaces of the recesses and the film (SiOC). Note that this step may be performed with an inert gas supplied to the processing chamber 201, or with a reactive substance such as an oxidizing agent (oxidizing gas) supplied. When reactive substances such as oxidizing agents are supplied, it becomes possible to enhance the effect of removing residues and debris from the film formation inhibiting layer at the upper surface of the recess and at the interface between the side surface of the recess and the film. In this case, reactive substances such as inert gases and oxidizing agents (oxidizing gases) are also called assisting substances.

[0119] The treatment conditions for post-treatment (PT) are as follows: Processing temperature: 120-1000°C, preferably 400-700°C Processing pressure: 1~120000Pa Processing time: 1-18000 seconds Assist substance supply flow rate: 0-50 slm Examples are given.

[0120] (After-purge and return to atmospheric pressure) After the film deposition process is complete and the post-treatment (PT) is finished, inert gas is supplied as a purge gas into the processing chamber 201 from nozzles 249a to 249c and exhausted from exhaust port 231a. This purges the processing chamber 201, removing any remaining gases and reaction by-products (after-purging). Subsequently, the atmosphere inside the processing chamber 201 is replaced with inert gas (inert gas replacement), and the pressure inside the processing chamber 201 is returned to atmospheric pressure (atmospheric pressure return).

[0121] (Boat unloading and wafer discharge) Subsequently, the seal cap 219 is lowered by the boat elevator 115, opening the lower end of the manifold 209. Then, the processed wafer 200, supported by the boat 217, is unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After boat unloading, the shutters 219s are moved, and the lower end opening of the manifold 209 is sealed by the shutters 219s via the O-ring 220c (shutter closing). After the processed wafer 200 has been unloaded from the reaction tube 203, it is removed from the boat 217 (wafer discharge).

[0122] (3) Effects of this embodiment According to this embodiment, one or more of the following effects can be obtained.

[0123] (a) Step A involves supplying a precursor material to the wafer 200 to form a film formation inhibiting layer on the surface of the first material (Si) in the recesses on the surface of the wafer 200, and Step B involves supplying a film formation material to the wafer 200 on which the film formation inhibiting layer has been formed on the surface of the first material to grow a film on the surface of the second material (SiGe) in the recesses. By performing these steps, it is possible to suppress film growth starting from the top and side surfaces of the recesses while promoting film growth starting from the bottom surface of the recesses. This makes it possible to grow a film in the recesses from the bottom up, and to fill the recesses with a film without creating voids or seams in the film. In other words, it becomes possible to form a void-free and seamless film in the recesses, thereby improving the filling characteristics.

[0124] (b) By suppressing film growth originating from the top and sides of the recesses while promoting film growth originating from the bottom of the recesses, the inside of the recesses can be filled with a film without growing a film on the top surface of the recesses. As a result, as shown in Figure 5(c), a state can be created in which no film (SiOC) is formed on the top surface of the recesses when the film deposition process is completed. In other words, when the film deposition process is completed, the inside of the recesses in the sidewalls of the laminated structure on the surface of the wafer 200, in which the second material (SiGe) and the first material (Si) are alternately stacked, can be filled with a film (SiOC), and the sidewalls can be made flat. As a result, the conventional step of removing excess film formed on the top surface of the recesses, etc., by etching after the film deposition process can be omitted.

[0125] As mentioned above, even though a film formation inhibiting layer is formed on the surface of the first material, slight film growth may occur originating from the surface of the first material due to some factor. In this case, it may be necessary to etch the excess film formed on the upper surface of the recess, etc. However, even in that case, the excess film formed on the upper surface of the recess, etc. is very small, as mentioned above, and it is possible to significantly reduce the load in the etching process and significantly shorten the time required for etching.

[0126] On the other hand, when filling the recesses with a film such as an SiOC film using a conventional film deposition method that only performs step B, a film (SiOC) is formed on the entire side wall of the laminated structure on the surface of the wafer 200, where the second material (SiGe) and the first material (Si) are alternately stacked, as shown in Figure 6(b). In this case, as shown in Figure 6(b), voids or seams (hereinafter referred to as voids) may be formed in the formed film due to the shape of the recesses. In this case, in order to fill the recesses in the side wall of the laminated structure, where the second material and the first material are alternately stacked, with a film and to make the side wall flat, it is necessary to perform a process of etching the excess film formed on the upper surface of the recesses, etc. For example, if the process of etching the excess film formed on the upper surface of the recesses, etc. is performed on a substrate having the configuration shown in Figure 6(b) on its surface, it is possible to create a state in which no film is formed on the upper surface of the recesses, as shown in Figure 6(c). However, in this case, as shown in Figure 6(c), voids formed in the film during deposition are maintained, and in some cases, etching can deepen the voids, making it impossible to flatten the sidewalls of the laminated structure in which the second and first materials are alternately stacked. Furthermore, when using conventional film deposition methods, it becomes essential to perform an etching step to remove excess film, which prolongs the total processing time and reduces productivity.

[0127] In contrast, according to this embodiment, it is possible to form a void-free and seamless film within the recesses while suppressing film growth on the upper surface of the recesses. Furthermore, when the film deposition process is completed, the recesses in the side walls of the laminated structure, in which the second material (SiGe) and the first material (Si) are alternately stacked, can be filled with the film (SiOC), and the side walls can be made flat. This makes it possible to omit the step of removing excess film formed on the upper surface of the recesses by etching after the film deposition process, which was essential in conventional film deposition methods. Even if, despite the formation of a film deposition suppression layer on the surface of the first material, a very small amount of film growth occurs starting from the surface of the first material due to some factor, the excess film formed on the upper surface of the recesses will be very small, significantly reducing the load in the etching process and significantly shortening the time required for etching. In other words, according to this embodiment, void-free and seamless embedding becomes possible, improving the embedding characteristics. Furthermore, by eliminating the process of etching excess film, or by reducing the load of the process of etching excess film, the total processing time can be shortened, thereby improving productivity.

[0128] (c) By ensuring that OH terminations are formed on the surface of the first material in the recesses on the wafer 200 surface before step A is performed, the adsorption of at least a portion of the molecular structure of the molecules constituting the precursor onto the surface of the first material in the recesses can be promoted, and a film formation inhibiting layer can be properly formed on the surface of the first material. Furthermore, in this case, by ensuring that the amount (density, concentration) of OH terminations on the surface of the first material (Si) before step A is greater (higher) than the amount (density, concentration) of OH terminations on the surface of the second material (SiGe), at least a portion of the molecular structure of the molecules constituting the precursor can be selectively (preferentially) adsorbed onto the surface of the first material among the first material and second material in the recesses, and a film formation inhibiting layer can be selectively (preferentially) formed on the surface of the first material. Note that it is also possible to ensure that no OH terminations are formed on the surface of the second material before step A is performed, in which case it is possible to increase the selectivity in the selective adsorption of at least a portion of the molecular structure of the molecules constituting the precursor onto the surface of the first material and in the selective formation of the film formation inhibiting layer on the surface of the first material.

[0129] (d) Before performing step A, step C is performed to form OH terminations on the surface of the first material in the recesses on the surface of the wafer 200. This promotes the adsorption of at least a portion of the molecular structure of the molecules constituting the precursor onto the surface of the first material in the recesses, making it possible to properly form a film formation inhibiting layer on the surface of the first material. In step C, an oxidizing agent, for example, is supplied to the wafer 200 as a reactant, and the surface of the first material is oxidized, making it possible to efficiently and controllly form OH terminations on the surface of the first material. In this case, OH terminations are also formed on the surface of the second material in step C. However, after performing step C and before performing step A, step D is performed to remove the OH terminations formed on the surface of the second material, making it possible to create a state in which no OH terminations are formed on the surface of the second material. In step D, by heating and annealing the wafer 200, oxide films such as SiO formed on the surface of the first material (Si) can be retained (maintained), while oxides such as GeO formed on the surface of the second material (SiGe) can be selectively sublimated and removed. In other words, in step D, by simply heating the wafer 200, the OH terminations formed on the surface of the second material (SiGe) can be selectively removed while retaining (maintaining) the OH terminations formed on the surface of the first material (Si).

[0130] This makes it possible to make the amount (density, concentration) of OH terminations on the surface of the first material (Si) before step A greater (higher) than the amount (density, concentration) of OH terminations on the surface of the second material (SiGe), allowing at least a portion of the molecular structure of the molecules constituting the precursor to be selectively (preferentially) adsorbed onto the surface of the first material among the first and second materials in the recess, thereby selectively (preferentially) forming a film formation inhibiting layer on the surface of the first material. Furthermore, by performing sufficient annealing in step D, it is also possible to make it possible to have no OH terminations formed on the surface of the second material before step A, in which case it becomes possible to increase the selectivity in the selective adsorption of at least a portion of the molecular structure of the molecules constituting the precursor onto the surface of the first material and the selective formation of the film formation inhibiting layer on the surface of the first material.

[0131] (e) Before performing step C, step E is performed to remove the native oxide film on the surfaces of the first and second materials in the recesses on the surface of the wafer 200, thereby removing any oxide films that may be unevenly formed on the surfaces of the first and second materials, and thereby removing any OH terminations that may be unevenly formed on the surfaces of the first and second materials. Subsequently, by performing step C, the surface of the first material can be uniformly oxidized, and an oxide film can be uniformly formed on the surface of the first material. As a result, OH terminations can be uniformly formed on the surface of the first material. This makes it possible to more uniformly adsorb at least a portion of the molecular structure of the molecules constituting the precursor onto the surface of the first material in the recesses in step A, and to more uniformly form a film formation inhibiting layer on the surface of the first material.

[0132] (f) After step B is completed, the temperature of the wafer 200 is set to be higher than or equal to the temperature of the wafer 200 in step A and step B, preferably higher than the temperature of the wafer 200 in step A and step B, and post-treatment (PT) is performed on the film formed to fill the recesses, thereby removing impurities contained in the film formed to fill the recesses and repairing defects. Furthermore, residues and debris of the film formation inhibiting layer can be removed from the surface of the first material, i.e., the upper surface of the recesses and the interface between the side surfaces of the recesses and the film. This may be done with an inert gas supplied into the processing chamber 201, or with a reactive substance such as an oxidizing agent (oxidizing gas) supplied. When a reactive substance such as an oxidizing agent is supplied, the effect of removing residues and debris of the film formation inhibiting layer from the upper surface of the recesses and the interface between the side surfaces of the recesses and the film can be enhanced.

[0133] (g) Each reaction in each step can be carried out in a non-plasma atmosphere, which suppresses excessive reactions in each step and improves the controllability of the reactions. Furthermore, since each step is carried out in a non-plasma atmosphere, plasma damage to the wafer 200 can be avoided, making this method applicable to processes where plasma damage is a concern.

[0134] (4) Variations The substrate processing sequence in this embodiment can be modified as shown in the following examples. These modifications can be combined in any way. Unless otherwise specified, the processing procedures and conditions in each step of each modification can be the same as those in each step of the substrate processing sequence described above.

[0135] (Variation 1) Depending on the surface condition of the wafer 200, step E (removal of native oxide film) may be omitted, as shown in the processing sequence below. For example, after forming a laminated structure on the surface of the wafer 200 in which the second material (SiGe) and the first material (Si) are alternately stacked as shown in Figure 5(a), if the surface of the wafer 200 is not exposed to the atmosphere, or if the amount of atmosphere exposure is small, or if the atmosphere exposure time is short, the surface of the first material and the surface of the second material may be in an appropriate surface condition. In such cases, step E can be omitted, and the processing sequence can be started from step C (oxidation). The same effects as in the above-described embodiment can be obtained in this modified example as well. Furthermore, by omitting step E, the total processing time can be shortened, and productivity can be improved.

[0136] Oxidizing agent → ANL → Precursor → (Raw material + Catalyst → Oxidizing agent + Catalyst) × n → PT

[0137] (Modification 2) Depending on the surface condition of the wafer 200, steps E (removal of native oxide film) and C (oxidation) may be omitted, as shown in the processing sequence below. For example, if an oxide film is uniformly formed on the surface of the first material (Si) and the second material (SiGe) on the surface of the wafer 200, steps E and C can be omitted, and the processing sequence can be started from step D (ANL). The same effects as in the above-described embodiment can be obtained in this modified example as well. Furthermore, by omitting steps E and C, the total processing time can be shortened, and productivity can be improved.

[0138] ANL → Precursor → (Raw material + Catalyst → Oxidizing agent + Catalyst) × n → PT

[0139] (Variation 3) Depending on the surface condition of the wafer 200, steps E (removal of native oxide film), C (oxidation), and D (ANL) may be omitted, as shown in the processing sequence below. For example, if an oxide film is uniformly formed on the surface of the first material and the second material on the surface of the wafer 200, and in step A (formation of film formation suppression layer), the wafer 200 is heated to a temperature of, for example, 100°C or higher, then in step A, the oxide film such as the SiO film formed on the surface of the first material can be retained while the oxide such as GeO formed on the surface of the second material can be sublimated and removed. That is, in step A, the OH terminations formed on the surface of the first material can be retained while the OH terminations formed on the surface of the second material can be removed. In this case, steps E, C, and D can be omitted, and the processing sequence can be started from step A. The same effects as in the above-described embodiment can be obtained in this modified example as well. Furthermore, by omitting steps E, C, and D, the total processing time can be shortened, and productivity can be improved.

[0140] Precursor → (Raw material + Catalyst → Oxidizing agent + Catalyst) × n → PT

[0141] (Modification 4) As shown in the processing sequence below, in step B1, the raw material may be supplied to the wafer 200 alone without supplying the catalyst. Also, in step B2, the oxidizing agent may be supplied to the wafer 200 alone without supplying the catalyst. By supplying the raw material and catalyst to the wafer 200, the chemical adsorption of at least a portion of the molecular structure of the molecules constituting the raw material onto the surface of the second material can be promoted at low temperatures. Furthermore, by supplying the oxidizing agent and catalyst to the wafer 200, the oxidation rate can be increased at low temperatures. However, in cases where the chemical adsorption of at least a portion of the molecular structure of the molecules constituting the raw material onto the surface of the second material, or the oxidation rate, is to be adjusted by temperature, the supply of the catalyst can be omitted. The same effects as in the above-described embodiment can be obtained in this modified example as well.

[0142] Etching agent → Oxidizing agent → ANL → Precursor → (Raw material → Oxidizing agent + Catalyst) × n → PT Etching agent → Oxidizing agent → ANL → Precursor → (Raw material + Catalyst → Oxidizing agent) × n → PT Etching agent → Oxidizing agent → ANL → Precursor → (Raw material → Oxidizing agent) × n → PT

[0143] (Variation 5) Step F(PT) may be omitted, as shown in the processing sequence below. For example, if the amount of impurities, etc., contained in the film formed to fill the recess is within an acceptable range, step F can be omitted. Step F can also be omitted if the residue of the film formation inhibiting layer, etc., on the upper surface of the recess or at the interface between the side surface of the recess and the film is acceptable, or if the amount of residues or remnants of the film formation inhibiting layer at the upper surface of the recess or at the interface between the side surface of the recess and the film is within an acceptable range. Furthermore, if the film formation inhibiting layer, etc., on the upper surface of the recess or at the interface between the side surface of the recess and the film is removed by the reactions in each step of the film formation process, step F can be omitted. The same effects as in the above-described embodiment can be obtained in this modified example as well. In addition, by omitting step F, the total processing time can be shortened, and productivity can be improved.

[0144] Etching agent → Oxidizing agent → ANL → Precursor → (Raw material + Catalyst → Oxidizing agent + Catalyst) × n

[0145] <Other aspects of this disclosure> The aspects of this disclosure have been specifically described above. However, this disclosure is not limited to the aspects described above and can be modified in various ways without departing from its essence.

[0146] For example, in step E, an etching agent may be supplied to the wafer 200 by plasma excitation. This can increase the etching rate when etching the native oxide film. In step C, a reactive substance such as an oxidizing agent may be supplied to the wafer 200 by plasma excitation. This can increase the oxidation rate. In step D, an inert gas may be supplied by plasma excitation. This makes it possible to remove oxides such as GeO formed on the surface of the second material by sublimation, and at the same time treat the surface of the second material after the oxides have been removed. In step D, an assisting substance may be supplied by plasma excitation. This makes it possible to further enhance the effect of desorbing residues and debris of the film formation inhibiting layer at the upper surface of the recess and at the interface between the side surface of the recess and the film.

[0147] Furthermore, in step B, in addition to SiOC and SiO films, silicon-based oxide films such as silicon oxynitride films (SiOCN films), silicon oxynitride films (SiON films), silicon boronitride films (SiBON films), and silicon boronitride films (SiBOCN films) may be formed. Also in step B, metallic oxide films such as aluminum oxide films (AlO films), titanium oxide films (TiO films), hafnium oxide films (HfO films), and zirconium oxide films (ZrO films) may be formed.

[0148] It is preferable that the recipes used for each process be prepared individually according to the processing content and stored in the storage device 121c via a telecommunications line or external storage device 123. When starting each process, it is preferable that the CPU 121a appropriately selects the appropriate recipe from among the multiple recipes stored in the storage device 121c according to the processing content. This makes it possible to form films of various film types, composition ratios, film quality, and film thickness with good reproducibility using a single substrate processing device. Furthermore, it reduces the burden on the operator and allows each process to be started quickly while avoiding operational errors.

[0149] The above-mentioned recipes are not limited to newly created ones; they may also be prepared, for example, by modifying existing recipes already installed in the board processing device. When modifying a recipe, the modified recipe may be installed in the board processing device via a telecommunications line or a recording medium containing the recipe. Alternatively, existing recipes already installed in the board processing device may be directly modified by operating the input / output device 122 provided in the existing board processing device.

[0150] The above-described embodiments illustrate an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at once. This disclosure is not limited to the above-described embodiments and can be suitably applied, for example, to forming a film using a single-wafer substrate processing apparatus that processes one or several substrates at once. Furthermore, the above-described embodiments illustrate an example of forming a film using a substrate processing apparatus having a hot-wall type processing furnace. This disclosure is not limited to the above-described embodiments and can be suitably applied to forming a film using a substrate processing apparatus having a cold-wall type processing furnace.

[0151] Even when using these substrate processing devices, each process can be carried out using the same processing procedures and conditions as described above, and the same effects as described above can be obtained.

[0152] The above embodiments can be used in combination as appropriate. The processing procedure and processing conditions in this case can be the same as, for example, the processing procedure and processing conditions of the above embodiments. [Examples]

[0153] Using the substrate processing apparatus described above, an evaluation sample 1 was fabricated by performing the processing sequence described above on a wafer having a laminated structure on its surface in which SiGe films and Si films are alternately stacked, as shown in Figure 5(a), with the top and sides made of Si films and the bottom surface made of SiGe films, and recesses whose depth direction is parallel to the wafer surface (lateral direction). This process filled the recesses with an SiOC film. Subsequently, a cross-sectional TEM image of evaluation sample 1 was taken. Figure 7 shows the cross-sectional TEM image of evaluation sample 1.

[0154] Using the substrate processing apparatus described above, evaluation sample 2 was fabricated by performing the processing sequence of the modified example 3 described above on a wafer with a similar configuration to the wafer used to fabricate evaluation sample 1, thereby forming an OSOC film that fills the recesses. Subsequently, a cross-sectional TEM image of evaluation sample 2 was taken. Figure 8 shows the cross-sectional TEM image of evaluation sample 2.

[0155] As shown in Figure 7, in evaluation sample 1, the SiOC film is selectively formed only within the recesses, and not on the upper surface of the recesses. Furthermore, it can be seen that no voids or seams are present in the SiOC film formed within the recesses. It can be seen that by controlling (increasing) the number of cycles in step B when preparing evaluation sample 1, it is possible to suppress the growth of the SiOC film on the upper surface of the recesses while further selectively growing the SiOC film within the recesses, thereby filling the recesses in the sidewalls of a laminated structure in which SiGe films and Si films are alternately stacked with SiOC film, and making the sidewalls flat.

[0156] As shown in Figure 8, in evaluation sample 2, a void-free and seamless SiOC film is formed to fill the recess. In evaluation sample 2, although a small amount of SiOC film is also formed on the upper surface of the recess, the SiOC film has a flat profile on the sidewalls of the laminated structure, which consists of alternating layers of SiGe and Si films. In this case, by etching the SiOC film formed on the sidewalls of the laminated structure, which consists of alternating layers of SiGe and Si films, by the thickness of the SiOC film formed on the upper surface of the recess, it is possible to expose the Si film on the sidewalls, i.e., the upper surface (Si) of the recess, while maintaining the flatness of the sidewalls of the laminated structure. Furthermore, when preparing evaluation sample 2, by controlling (reducing) the number of cycles in step B and stopping the film formation when the recess is filled with SiOC film, it is possible to flatten the sidewalls of the laminated structure, which consists of alternating layers of SiGe and Si films, without forming an SiOC film on the upper surface of the recess. [Explanation of Symbols]

[0157] 200 wafers (substrates)

Claims

1. (a) (c) A step of oxidizing the surfaces of a first material containing silicon and a second material containing germanium that are located in recesses on the surface of the substrate to form hydroxyl group terminators on each surface, and (d) A step of heating the substrate to remove oxides formed on the surface of the second material to remove hydroxyl group terminators formed on the surface of the second material, wherein a precursor is supplied to the substrate, thereby adsorbing at least a portion of the molecular structure of the molecules constituting the precursor onto the surface of the first material in the recesses to form an inhibitor on the surface of the first material. (b) A step of growing a film on the surface of the second material in the recess by supplying a film-forming material to the substrate on which the inhibitor has been formed on the surface of the first material, A processing method having the following characteristics.

2. The processing method according to claim 1, wherein before (e) and (c) are performed, a step is taken to remove the native oxide film on the surfaces of the first material and the second material.

3. The processing method according to claim 1 or 2, wherein in (a), the amount of hydroxyl groups on the surface of the first material before supplying the precursor is greater than the amount of hydroxyl groups on the surface of the second material before supplying the precursor.

4. The processing method according to claim 1 or 2, wherein, in (a), hydroxyl group terminators are not formed on the surface of the second material before the supply of the precursor.

5. (c) The processing method according to any one of claims 1 to 4, wherein a reactant is supplied to the substrate, and the surface of the first material and the surface of the second material are oxidized to form hydroxyl group terminations on the surface of the first material and the surface of the second material.

6. (d) The processing method according to any one of claims 1 to 5, wherein the substrate is heated and the oxide formed on the surface of the second material sublimes, thereby removing the hydroxyl group terminators formed on the surface of the second material.

7. (d) The processing method according to any one of claims 1 to 6, wherein the hydroxyl group terminators formed on the surface of the first material remain and the hydroxyl group terminators formed on the surface of the second material are removed.

8. The processing method according to any one of claims 1 to 7, wherein the recess has a bottom surface made of the second material.

9. The processing method according to any one of claims 1 to 8, wherein the recess includes a side surface made of the first material.

10. The processing method according to any one of claims 1 to 9, wherein the recess includes an upper surface made of the first material.

11. (b) The processing method according to any one of claims 1 to 10, wherein a film is grown on the surface of the second material in the recess, thereby growing the film in the recess from the bottom up and filling the recess with the film.

12. (b) In this case, (b1) A step of supplying raw materials as the film-forming material to the substrate, (b2) A step of supplying the reactant as the film-forming material to the substrate, A processing method according to any one of claims 1 to 11, which involves performing a cycle including the above a predetermined number of times.

13. The processing method according to claim 12, wherein in at least one of (b1) and (b2), a catalyst is further supplied to the substrate as the film-forming material.

14. The processing method according to any one of claims 1 to 13, wherein the second material further comprises silicon.

15. The processing method according to any one of claims 1 to 14, wherein the first material is silicon and the second material is silicon germanium.

16. (b) The processing method according to any one of claims 1 to 15, wherein the film is a film containing silicon, oxygen, and carbon.

17. The processing method according to any one of claims 1 to 16, wherein at least one of (a), (b), (c), and (d) is performed in a non-plasma atmosphere.

18. (a) (c) A step of oxidizing the surfaces of a first material containing silicon and a second material containing germanium that are located in recesses on the surface of the substrate to form hydroxyl group terminators on each surface, and (d) A step of heating the substrate to remove oxides formed on the surface of the second material to remove hydroxyl group terminators formed on the surface of the second material, wherein a precursor is supplied to the substrate, thereby adsorbing at least a portion of the molecular structure of molecules constituting the precursor onto the surface of the first material in the recesses to form an inhibitor on the surface of the first material. (b) A step of growing a film on the surface of the second material in the recess by supplying a film-forming material to the substrate on which the inhibitor has been formed on the surface of the first material, A method for manufacturing a semiconductor device having [a certain feature].

19. A precursor supply system that supplies a precursor to the substrate, A film deposition material supply system that supplies film deposition material to the substrate, (a) (c) A step of oxidizing the surfaces of a first material containing silicon and a second material containing germanium that are located in recesses on the surface of the substrate to form hydroxyl group terminators on each surface, and (d) A step of heating the substrate to remove oxides formed on the surface of the second material to remove hydroxyl group terminators formed on the surface of the second material, wherein the precursor is supplied to the substrate, thereby adsorbing at least a portion of the molecular structure of molecules constituting the precursor onto the surface of the first material in the recesses to form an inhibitor on the surface of the first material, (b) A process of growing a film on the surface of the second material in the recess by supplying the film-forming material to the substrate on which the inhibitor has been formed on the surface of the first material, A control unit is configured to control the precursor supply system and the film-forming material supply system so as to perform the following actions: A processing device.

20. (a) (c) The procedure of oxidizing the surfaces of a first material containing silicon and a second material containing germanium that are located in recesses on the surface of the substrate to form hydroxyl group terminators on each surface, and (d) The procedure of heating the substrate to remove oxides formed on the surface of the second material to remove hydroxyl group terminators formed on the surface of the second material, wherein a precursor is supplied to the substrate, thereby adsorbing at least a portion of the molecular structure of molecules constituting the precursor onto the surface of the first material in the recesses, thereby forming an inhibitor on the surface of the first material. (b) A procedure for growing a film on the surface of the second material in the recess by supplying a film-forming material to the substrate on which the inhibitor is formed on the surface of the first material, A program that causes a computer to execute a command on a processing unit.

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