Processing method, method of manufacturing semiconductor device, processing apparatus, and program product

Abstract

The invention relates to a processing method, a method of manufacturing a semiconductor device, a processing apparatus, and a program product. The present invention addresses the problem of providing a technique capable of efficiently etching a substrate surface and improving productivity. [Solution] The method comprises: (a) a step for forming a state in which a product substrate and a nitrogen-containing substance are disposed in a processing container; and (b) a step in which a fluorine-containing substance is supplied into the processing container in a state in which the product substrate and the nitrogen-containing substance are disposed, thereby etching the surface of the product substrate with a substance X generated by a chemical reaction between the nitrogen-containing substance and the fluorine-containing substance.

Description

TECHNICAL FIELD

[0001] The present application relates to a processing method, a manufacturing method of a semiconductor device, a processing apparatus, and a program product. BACKGROUND

[0002] As one of the processes of the manufacturing process of a semiconductor device, a process of performing a treatment of etching a surface of a substrate is sometimes performed (see, for example, Patent Literature 1).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2023-137735 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The present application provides a technology capable of efficiently performing etching of a surface of a substrate and improving productivity.

[0008] MEANS FOR SOLVING THE PROBLEMS

[0009] According to one embodiment of the present application, there is provided a technology including:

[0010] (a) a process of forming a state in which a product substrate and a nitrogen-containing substance are arranged in a processing vessel; and

[0011] (b) a process of etching a surface of the product substrate with a substance X generated by causing the nitrogen-containing substance to chemically react with a fluorine-containing substance by supplying the fluorine-containing substance into the processing vessel in which the product substrate and the nitrogen-containing substance are arranged.

[0012] EFFECTS OF THE INVENTION

[0013] According to the present application, it is possible to efficiently perform etching of a surface of a substrate and improve productivity. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Fig. 1 is a schematic configuration view of a vertical processing furnace of a processing apparatus, which is preferably used in the first embodiment of the present application, and is a view showing a part of a processing furnace 202 in a longitudinal sectional view.

[0015] Figure 2 Fig. 2 is a schematic configuration view of a vertical processing furnace of a processing apparatus, which is preferably used in the first embodiment of the present application, and is a view showing a part of a processing furnace 202 in a Figure 1 A-A line sectional view.

[0016] Figure 3This is a schematic configuration diagram of the controller 121 of the processing device preferred in the first aspect of the present invention, and a diagram showing the control system of the controller 121 in block form.

[0017] Figure 4 This is a diagram illustrating the process flow in the first embodiment of the present invention.

[0018] Figure 5 This is a diagram illustrating the process flow in the second aspect of the present invention.

[0019] Figure 6 (a) is a schematic diagram showing the state inside the processing container after step A has been performed in the first aspect of the present invention; Figure 6 (b) is a schematic diagram showing the state inside the processing container after step A has been performed in the second aspect of the present invention.

[0020] Figure 7 This is a schematic cross-sectional view of the surface portion of a substrate after a film has been formed by repeating the cycles including steps A to D multiple times.

[0021] Figure 8 This is a graph showing the results of the etching amount of the natural oxide film on the substrate surface.

[0022] Explanation of reference numerals in the attached figures

[0023] 200 wafers (product substrates) Detailed Implementation

[0024] <First aspect of the present invention>

[0025] The following is mainly based on Figures 1-3 , Figure 4 , Figure 6 Section (a) describes the first aspect of the present invention. Furthermore, the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings may not necessarily correspond to reality. Additionally, the dimensional relationships and ratios of the elements may not be consistent between the various drawings.

[0026] (1) Composition of the processing device

[0027] like Figure 1 As shown, the processing furnace 202 of the processing apparatus has a heater 207 that serves as a temperature regulator (heating unit). The heater 207 is cylindrical and is vertically mounted by being supported by a retaining plate. The heater 207 also functions as an activation mechanism (activation unit) for activating (exciting) gases by heat.

[0028] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) 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 arranged concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) and is formed into a cylindrical shape with open upper and lower ends. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing component. The reaction tube 203 is installed vertically, just like the heater 207. The processing container (reaction container) is mainly composed of the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the hollow part of the processing container. The processing chamber 201 is configured to accommodate a wafer 200, which serves as a substrate for a product. The wafer 200 is processed within the processing chamber 201.

[0029] Inside the processing chamber 201, nozzles 249a to 249c, serving as the first to third supply units, are respectively installed through the side wall of the manifold 209. These nozzles are also referred to as the first to the third nozzles. The nozzles 249a to 249c are made of heat-resistant materials such as quartz or SiC. Gas supply pipes 232a to 232c are connected to each of the nozzles 249a to 249c. Each of the nozzles 249a to 249c is a different nozzle, and each of the nozzles 249a and 249c is arranged adjacent to the nozzle 249b.

[0030] On gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c, serving as flow controllers (flow control units), and valves 243a to 243c, serving as on / off valves, are sequentially installed from the upstream side of the airflow. Gas supply pipes 232d and 232f are connected to gas supply pipe 232a downstream of valve 243a. Gas supply pipes 232e and 232g are connected to gas supply pipe 232b downstream of valve 243b. Gas supply pipe 232h is connected to gas supply pipe 232c downstream of valve 243c. On gas supply pipes 232d to 232h, MFCs 241d to 241h and valves 243d to 243h are sequentially installed from the upstream side of the airflow. Gas supply pipes 232a to 232h are made of, for example, a metal material such as SUS.

[0031] like Figure 2As shown, nozzles 249a to 249c are respectively arranged in a ring-shaped space (viewed from above) between the inner wall of the reaction tube 203 and the wafer 200, rising upwards from the lower part of the inner wall of the reaction tube 203 towards the arrangement direction of the wafer 200. That is, nozzles 249a to 249c are respectively arranged in a region horizontally surrounding the wafer arrangement area, on the side of the wafer arrangement area for arranging the wafer 200. In top view, nozzle 249b is arranged so as to clamp the center of the wafer 200 within the processing chamber 201 and is aligned with the exhaust port 231a (described later) in a straight line. Nozzles 249a and 249c are arranged to clamp a straight line L passing through the center of nozzle 249b and exhaust port 231a from both sides along the inner wall of the reaction tube 203 (outer periphery of the wafer 200). Straight line L also passes through the center of nozzle 249b and wafer 200. That is, nozzle 249c can also be positioned on the opposite side of nozzle 249a, sandwiching a straight line L. Nozzles 249a and 249c are arranged linearly symmetrically about the straight line L. Gas supply holes 250a and 250c are respectively provided on the side of nozzles 249a and 249c. Gas supply holes 250a and 250c open in a manner opposite (facing) the exhaust port 231a when viewed from above, and can supply gas to the wafer 200. Multiple gas supply holes 250a and 250c are provided from the bottom to the top of the reaction tube 203.

[0032] Fluorine (F)-containing substances are supplied into the processing chamber 201 from the gas supply pipe 232a via MFC 241a, valve 243a, and nozzle 249a.

[0033] Raw materials are supplied into the processing chamber 201 from the gas supply pipe 232b via MFC 241b, valve 243b, and nozzle 249b. The raw materials are used as one of the film-forming agents.

[0034] The dopant is supplied into the processing chamber 201 from the gas supply pipe 232c via MFC 241c, valve 243c, and nozzle 249c. The dopant is used as one of the film-forming agents.

[0035] The reducing agent is supplied to the processing chamber 201 through the gas supply pipe 232d via MFC 241d, valve 243d, gas supply pipe 232a, and nozzle 249a.

[0036] The reactant is supplied into the processing chamber 201 through gas supply pipe 232e, MFC 241e, valve 243e, gas supply pipe 232b, and nozzle 249b. The reactant is used as one of the film-forming agents.

[0037] Inactive gases are supplied to the treatment chamber 201 from gas supply pipes 232f to 232h via MFCs 241f to 241h, valves 243f to 243h, gas supply pipes 232a to 232c, and nozzles 249a to 249c. These inactive gases function as purge gas, carrier gas, and dilution gas.

[0038] The system primarily consists of a fluorine-containing substance supply system (gas supply pipe 232a, MFC 241a, valve 243a), a raw material supply system (gas supply pipe 232b, MFC 241b, valve 243b), a dopant supply system (gas supply pipe 232c, MFC 241c, valve 243c), a reducing agent supply system (gas supply pipe 232d, MFC 241d, valve 243d), a reactant supply system (gas supply pipe 232e, MFC 241e, valve 243e), and an inactive gas supply system (gas supply pipes 232f-232h, MFC 241f-241h, valves 243f-243h). Each, part of, or all of the raw material supply system, dopant supply system, and reactant supply system are also referred to as a film-forming agent supply system. Each or all of the raw material supply system and reactant supply system are also referred to as a coating agent (pre-coating agent) supply system.

[0039] Any or all of the aforementioned supply systems can also be configured as an integrated supply system 248, comprising valves 243a-243h, MFCs 241a-241h, etc. The integrated supply system 248 is connected to gas supply pipes 232a-232h, and its supply operations—namely, the opening and closing of valves 243a-243h and the flow regulation of MFCs 241a-241h—are controlled by the controller 121 described later. The integrated supply system 248 can be configured as a single or separate integrated unit, allowing for assembly and disassembly of the gas supply pipes 232a-232h, etc., and enabling maintenance, replacement, and addition of the integrated supply system 248 on a unit-by-unit basis.

[0040] An exhaust port 231a is provided below the side wall of the reaction tube 203 to exhaust the atmosphere inside the processing chamber 201. For example... Figure 2As shown, the exhaust port 231a is positioned opposite (facing) the nozzles 249a-249c (gas supply holes 250a-250c) when viewed from above, with the wafer 200 clamped in place. The exhaust port 231a can also be positioned from the lower part of the side wall of the reaction tube 203 along the upper part, that is, along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246, which serves as a vacuum exhaust device, is connected to the exhaust pipe 231 via a pressure sensor 245, which acts as a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201, and an APC (Auto Pressure Controller) valve 244, which acts as a pressure regulator (pressure regulating unit). The APC valve 244 is configured to allow for vacuum exhaust and cessation of vacuum exhaust within the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, while the vacuum pump 246 is operating, the pressure within the processing chamber 201 can be adjusted by regulating the valve opening based on pressure information detected by the pressure sensor 245. The exhaust system mainly consists of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. Alternatively, the vacuum pump 246 may be included in the exhaust system.

[0041] A sealing cover 219, serving as a furnace opening cover, is provided below the manifold 209 to airtightly seal the lower opening of the manifold 209. The sealing cover 219 is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220b, serving as a sealing member, is provided on the upper surface of the sealing cover 219 and abuts against the lower end of the manifold 209. A rotation mechanism 267, which rotates the crystal boat 217 (described later), is provided below the sealing cover 219. The rotation shaft 255 of the rotation mechanism 267 passes through the sealing cover 219 and is connected to the crystal boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the crystal boat 217. The sealing cover 219 is configured to move vertically via a crystal boat lift 115, which is a lifting mechanism located outside the reaction tube 203. The crystal boat lift 115 is configured as a conveying device (transfer mechanism) that moves the wafer 200 into and out of the processing chamber 201 by raising and lowering the sealing cover 219, and functions as a preparation device for placing the product substrate and nitrogen-containing material in the processing container. It should be noted that, as in the second embodiment described later, when the nitrogen-containing material is placed in the processing container by forming a nitride film (pre-coating film), the various parts of the processing apparatus used in the process of forming the nitride film (pre-coating agent supply system, etc.) and the crystal boat lift 115 that places the product substrate in the processing container function as preparation devices.

[0042] A gate 219s, serving as a furnace opening cover, is provided below the manifold 209. When the sealing cover 219 is lowered to remove the crystal boat 217 from the processing chamber 201, the gate 219s can airtightly seal the lower opening of the manifold 209. The gate 219s is made of a metal material such as SUS and is formed in a disc shape. An O-ring 220c, serving as a sealing component, is provided on the upper surface of the gate 219s and abuts against the lower end of the manifold 209. The opening and closing actions (lifting, rotating, etc.) of the gate 219s are controlled by a gate opening and closing mechanism 115s.

[0043] The crystal boat 217, serving as a substrate support, is configured to support multiple wafers 200, for example, 25 to 200 wafers 200, arranged horizontally and aligned centrally in a vertical direction in multiple layers, even if they are spaced apart. Furthermore, the crystal boat 217 can support dummy wafers (non-product substrates) containing nitrogen, i.e., non-product substrates with a nitride film formed on their surface, and wafers 200 serving as product substrates, in the same number (one or more) in multiple layers. It should be noted that the crystal boat 217 is configured to support and fill dummy wafers on the sides in addition to these. The crystal boat 217 is made of heat-resistant materials such as quartz or SiC. A heat-insulating plate 218, made of heat-resistant materials such as quartz or SiC, is supported in multiple layers at the bottom of the crystal boat 217.

[0044] A temperature sensor 263, serving as a temperature detector, is installed inside the reaction tube 203. By adjusting the energization of the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature within the processing chamber 201 is adjusted to achieve the desired temperature distribution. The temperature sensor 263 is disposed along the inner wall of the reaction tube 203.

[0045] like Figure 3As shown, the controller 121, serving as the control unit (control unit), 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, such as a touch panel, is connected to the controller 121. Furthermore, an external storage device 123 can be connected to the controller 121. It should be noted that the processing device can be configured to have one control unit or multiple control units. That is, one control unit can be used to control the processing sequence described later, or multiple control units can be used to control the processing sequence described later. Furthermore, multiple control units can be configured as a control system interconnected via a wired or wireless communication network, or the entire control system can control the processing sequence described later. When the term "control unit" is used in this specification, in addition to the case of having one control unit, there are also cases of having multiple control units, and cases of having a control system composed of multiple control units.

[0046] The storage device 121c is configured such as flash memory, HDD (Hard Disk Drive), or SSD (Solid State Drive). The storage device 121c contains, in a readable manner, a control program that controls the operation of the processing device, and a process flow that describes the steps and conditions of the substrate processing described later. The process flow is formed by the controller 121 causing the processing device to execute each step of the substrate processing described later, and combining them in a way that yields a predetermined result; it functions as a program. Hereinafter, the process flow, control program, etc., will be collectively referred to as a program (program workpiece). Additionally, the process flow will be referred to simply as a process. When the term "program" is used in this specification, it may include only the process flow, only the control program, or both. RAM 121b is configured as a memory area (working area) that temporarily holds the program, data, etc., read by the CPU 121a.

[0047] I / O port 121d is connected to the aforementioned MFC241a~241h, valves 243a~243h, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotating mechanism 267, crystal boat elevator 115, gate opening and closing mechanism 115s, etc.

[0048] CPU 121a is configured to read and execute control programs from storage device 121c, and to read processes from storage device 121c based on input of operation commands from input / output device 122. CPU 121a is configured to control, in accordance with the contents of the read processes, the following: flow regulation of various substances (various gases) using MFC 241a to 241h, opening and closing of valves 243a to 243h, opening and closing of APC valve 244, pressure regulation based on pressure sensor 245 and using APC valve 244, starting and stopping of vacuum pump 246, temperature regulation of heater 207 based on temperature sensor 263, rotation speed regulation of crystal boat 217 based on rotation mechanism 267, lifting and lowering of crystal boat 217 based on crystal boat elevator 115, opening and closing of gate 219s based on gate opening and closing mechanism 115s, etc.

[0049] The controller 121 can be configured by installing the aforementioned program, which is recorded and stored in the external storage device 123, into a computer. The external storage device 123 includes, for example, a hard disk such as an HDD, an optical disk such as a CD, a USB flash drive, or a semiconductor storage device such as an SSD. The storage device 121c and the external storage device 123 constitute a computer-readable recording medium. Hereinafter, they will be collectively referred to simply as a recording medium. When the term "recording medium" is used in this specification, it may include only the storage device 121c, only the external storage device 123, or both. It should be noted that providing the program to the computer may also be done without using the external storage device 123, but rather using communication means such as the Internet or dedicated lines.

[0050] (2) Processing procedures

[0051] As a step in the manufacturing process (manufacturing method) of semiconductor devices, it mainly uses Figure 4 An example of a method for processing a substrate using the aforementioned processing apparatus (processing method), namely, a processing sequence in which the processing sequence for etching the surface of the wafer 200, which serves as a substrate for a product, and the processing sequence for growing a film on the etched wafer 200 are performed consecutively a predetermined number of times, will be described. In the following description, the operation of each part constituting the processing apparatus is controlled by the controller 121. It should be noted that, depending on the processing content, the processing apparatus will also be referred to as a substrate processing apparatus, etching processing apparatus, etching apparatus, film forming processing apparatus, or film forming apparatus. Furthermore, depending on the processing content, the processing method will also be referred to as a substrate processing method, etching processing method, etching method, film forming processing method, or film forming method.

[0052] In the processing sequence of this method, the following steps are performed:

[0053] (a) Step A, which forms a state in which a wafer 200 serving as a substrate for a product and a nitrogen-containing (N) compound are disposed within a processing container; and

[0054] (b) Step B involves supplying an F-containing substance into a processing container in which the wafer 200 is disposed and the N-containing substance is present, thereby using the substance X generated by the chemical reaction between the N-containing substance and the F-containing substance to etch the surface of the wafer 200.

[0055] It should be noted that in the following examples, the case in which the nitrogen-containing material disposed in the processing container includes a dummy wafer as a non-product substrate with a nitride film formed on its surface is described.

[0056] Furthermore, the following example illustrates that, after step B, the following steps are performed:

[0057] (c) Step C, which involves supplying a film-forming agent into a processing container in which a wafer 200 with an etched surface is disposed, thereby forming a film on the wafer 200.

[0058] Furthermore, in the following example, steps A to C will be explained as follows: the wafer 200 is supported by a wafer boat 217 serving as a support member.

[0059] Further, (d) outside the processing container, step D, which eliminates the adhesion of the wafer 200 to the crystal boat 217 caused by the film formed in step C, is performed by peeling the wafer 200 from the crystal boat 217.

[0060] Repeat the loop containing steps A through D multiple times.

[0061] The term "wafer" as used in this specification can refer to the wafer itself, or to a laminate of the wafer and a specified layer or film formed on its surface. The term "surface of the wafer" as used in this specification can refer to the surface of the wafer itself, or to the surface of a specified film, etc., formed on the wafer. In this specification, when described as "forming a specified film on the surface of the wafer," it can mean forming the specified film directly on the surface of the wafer itself, or forming the specified film on top of a film, etc., formed on the wafer. In this specification, the term "substrate" is also synonymous with the term "wafer."

[0062] The terms "agent" and "substance" as used in this specification include at least one of gaseous and liquid substances. Liquid substances include mist substances. That is, substances containing F, reducing agents, and film-forming agents (raw materials, dopants, reactants, etc.) may each contain gaseous substances, liquid substances such as mist substances, or both.

[0063] (Step A)

[0064] First, multiple wafers 200 and dummy wafers with nitride films formed on their surfaces are loaded (wafer filling) into the crystal boat 217.

[0065] On the surface of wafer 200, there are cases where oxides are formed. These oxides sometimes contain a non-stoichiometric silicon oxide film (SiO2). x The oxide film (where x is a real number less than 2) and at least one of a silicon oxide film (SiO2 film) with a stoichiometric composition. Additionally, the oxide sometimes includes at least one of native oxide films and chemically oxidized oxide films. It should be noted that SiO2 will also be referred to as such below. x The membrane or SiO2 membrane is collectively referred to as SiO membrane.

[0066] As a dummy wafer with a nitride film formed on its surface, a substrate with a nitride film containing silicon nitride (Si3N4, hereinafter also referred to as SiN), i.e., a silicon nitride film (SiN film), can be used. The dummy wafer is preferably formed in a predetermined number of layers, with each wafer 200 (i.e., a product substrate) or every other multiple product substrates. Hereinafter, for convenience, the dummy wafer with a SiN film formed on its surface will also be referred to as a SiN wafer.

[0067] After the wafer filling is completed, the gate 219s is moved by the gate opening and closing mechanism 115s, opening the lower end of the manifold 209 (gate opening). Then, as... Figure 1 As shown, the crystal boat 217, which supports the wafer 200 and the SiN wafer, is lifted by the crystal boat elevator 115 and moved into the (crystal boat loading) processing chamber 201. In this state, the sealing cover 219 is in a state where the lower end of the manifold 209 is sealed via the O-ring 220b.

[0068] The loading of the crystal boat is completed, such as Figure 6 As shown in (a), the wafer 200 serving as a product substrate and the non-product substrate (SiN wafer) containing nitrogen with a nitride film formed on its surface are disposed in the processing chamber 201. The SiN wafer serving as the non-product substrate is disposed at a position away from the wafer 200 serving as the product substrate and adjacent to the wafer 200.

[0069] (Pressure and temperature regulation)

[0070] After the crystal boat loading is completed, vacuum exhaust (pressure reduction exhaust) is performed by vacuum pump 246 to bring the pressure (vacuum level) inside processing chamber 201, i.e., the space where wafer 200 exists, to the desired pressure. At this time, the pressure inside processing chamber 201 is measured by pressure sensor 245, and feedback control is applied to APC valve 244 based on this measured pressure information. Additionally, heating is performed using heater 207 to bring wafer 200 inside processing chamber 201 to the desired processing temperature. At this time, feedback control is applied to the energizing status of heater 207 based on temperature information detected by temperature sensor 263 to achieve the desired temperature distribution inside processing chamber 201. Furthermore, the rotation of wafer 200 by rotation mechanism 267 begins. Exhausting from processing chamber 201, heating wafer 200, and rotation all continue at least until the processing of wafer 200 is completed.

[0071] (Step B)

[0072] Then, an F-containing material is supplied to the processing chamber 201, which is configured as a wafer 200 serving as a substrate and as a SiN wafer containing N.

[0073] Specifically, valve 243a is opened to allow the F-containing substance to flow into the gas supply pipe 232a. The F-containing substance is regulated by MFC 241a and supplied into the processing chamber 201 via nozzle 249a, and exhausted from the exhaust port 231a. At this time, the F-containing substance is supplied to the wafer 200 and the N-containing substance from the side, exposing the wafer 200 and the N-containing substance to the F-containing substance (F-containing substance supply and exposure). At this time, valves 243f to 243h can also be opened to supply inactive gases into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0074] By supplying an F-containing substance to a processing chamber 201 containing a wafer 200 and an N-containing substance under the processing conditions described later, a chemical reaction can occur between the N-containing substance and the F-containing substance to generate substance X. Substance X includes substances generated during the etching process of the N-containing substance disposed in the processing chamber 201 by the F-containing substance, such as substances generated by the decomposition of reaction products generated during the etching process of the N-containing substance by the F-containing substance. Substance X includes substances containing nitrogen (N) and hydrogen (H). By generating substance X in the processing chamber 201 supplied with the F-containing substance, substance X can be used to etch the surface of the wafer 200, i.e., the oxides on the surface of the wafer 200.

[0075] For example, if the oxide on the surface of the wafer 200 disposed in the processing chamber 201 includes silicon oxide (SiO2), the N-containing substance disposed in the processing chamber 201 includes silicon nitride (Si3N4), and the F-containing substance supplied to the processing chamber 201 includes hydrogen fluoride (HF), the reaction shown in the following formula can be carried out under the conditions described later.

[0076] Si3N4 + 16HF → 3(NH4)2SiF6 + 2H2

[0077] (NH4)2SiF6→SiF4+2HF+2NH3

[0078] SiO2+4HF+4NH3→SiF4+2H2O+4NH3

[0079] That is, within the processing chamber 201, a nitrogen-containing substance (Si3N4) and an fluorine-containing substance (HF) can undergo a chemical reaction to produce solid reaction products such as ammonium fluoride, i.e., ammonium hexafluorosilicate ((NH4)2SiF6). Furthermore, within the processing chamber 201, this solid reaction product can be decomposed (thermally decomposed, etc.) to produce hydrogen nitride such as ammonia (NH3) as substance X. By generating nitrogen- and hydrogen-containing substances X such as NH3 in the presence of the fluorine-containing substance (HF), the etching reaction of oxides (SiO2) present on the surface of the wafer 200 can be promoted within the processing chamber 201, removing oxides from the surface of the wafer 200. It should be noted that during the process of removing oxides using the fluorine-containing substance and substance X, the solid reaction product (NH4)2SiF6 may be regenerated. However, in this reaction system, the solid reaction product is immediately decomposed upon generation, and the above reactions occur in a chain reaction. That is, in this reaction system, the reaction, the generation of solid reaction products, the decomposition of solid reaction products, and the etching occur repeatedly in a chain, which can suppress the solid reaction products from remaining as solid residues on the outermost surface of the oxide that is the object of etching.

[0080] According to the present invention, as described above, the etching reaction can be initiated without using the reaction of the F-containing substance (HF) with water (H2O) as a trigger. That is, according to the present invention, at the beginning of step B, the etching reaction can be initiated in the absence of H2O in the processing chamber 201 to etch the oxides on the surface of the wafer 200.

[0081] After etching the surface of wafer 200, valve 243a is closed to stop the supply of F-containing material to processing chamber 201. Then, vacuum exhaust is performed in processing chamber 201 to remove any remaining gaseous substances. At this time, valves 243f to 243h are opened, and inactive gas is supplied to processing chamber 201 through nozzles 249a to 249c. The inactive gas supplied from nozzles 249a to 249c acts as a purging gas, thereby purging processing chamber 201. It should be noted that the processing temperature during purging in this step is preferably the same as the processing temperature when supplying the F-containing material.

[0082] At this time, valve 243d can also be opened to supply a reducing agent into the processing chamber 201, either in place of the inactive gas or together with the inactive gas. Alternatively, cyclic purging can be performed using the inactive gas and / or the reducing agent. During cyclic purging, the purging of the processing chamber 201 by supplying at least one of the inactive gas and the reducing agent, and the venting (vacuum venting) of the processing chamber 201 can be alternated a predetermined number of times, preferably multiple times. Furthermore, in this case, while venting the processing chamber 201, the supply of the reducing agent and the supply of the inactive gas can be alternated a predetermined number of times, preferably multiple times. Additionally, in this case, while continuously supplying one of the inactive gas and the reducing agent into the processing chamber 201, the supply of the other of the inactive gas and the reducing agent into the processing chamber 201 and the venting of the processing chamber 201 can be alternated a predetermined number of times, preferably multiple times. Therefore, substances remaining in the treatment chamber 201 can be efficiently and effectively discharged and removed. It should be noted that when using an inert gas as the purging gas, the treatment chamber 201 is purged primarily through physical action. On the other hand, when using a reducing agent as the purging gas, not only physical action but also chemical action can occur, further improving the purging effect. It should also be noted that during cyclic purging, the opening and closing of valves 243f-243h and 243d should be appropriately controlled in conjunction with the timing of the supply of the inert gas and reducing agent.

[0083] Examples of processing conditions for supplying substance F in step B include:

[0084] Processing temperature: room temperature (25°C) to 200°C, preferably 50°C to 175°C, more preferably 100°C to 150°C, and even more preferably 120°C to 150°C.

[0085] Processing pressure: 10–3000 Pa, preferably 10–2000 Pa

[0086] Processing time: 1–120 minutes, preferably 1–100 minutes

[0087] Supply flow rate of F-containing substances: 0.5–3 slm, preferably 1–2 slm

[0088] Inactive gas supply flow rate (per gas supply tube): 0-10 slm, preferably 1-5 slm.

[0089] It should be noted that the numerical range "25~200℃" in this specification means that the lower and upper limits are included within the range. Therefore, for example, "25~200℃" means "above 25℃ and below 200℃". The same applies to other numerical ranges. Furthermore, the processing temperature in this specification refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure refers to the pressure inside the processing chamber 201. Additionally, the processing time refers to the duration of the processing. Also, when the supply flow rate includes 0slm, 0slm means that no substance (gas) is supplied. These same principles apply in the following descriptions.

[0090] Here, if the processing temperature when supplying the F-containing substance in step B is set below room temperature (25°C), although the etching rate can be increased, if other processes such as film formation are performed before or after the etching process, the time for changing the processing temperature (heating time and / or cooling time) between the etching process and other processes becomes too long, and sometimes the productivity decreases.

[0091] By maintaining the processing temperature at room temperature (25°C) or higher, a high etching rate can be maintained, and the temperature change time between processing and other processes can be shortened, thus suppressing productivity decline. By maintaining the processing temperature at 50°C or higher, while maintaining a high etching rate, the temperature change time between processing and other processes can be further shortened, further suppressing productivity decline. By maintaining the processing temperature at 100°C or higher, while maintaining a high etching rate, the temperature change time between processing and other processes can be significantly shortened, thus significantly improving productivity. By maintaining the processing temperature at 120°C or higher, while maintaining a high etching rate, the temperature change time between processing and other processes can be further significantly shortened, thus further improving productivity.

[0092] In addition, if the above processing temperature is set to a temperature higher than 200°C, although the time for changing the processing temperature between other processes can be greatly shortened, the etching rate becomes too low, and sometimes the productivity is reduced.

[0093] By keeping the processing temperature below 200°C, the reduction in etching rate can be suppressed while maintaining a significant reduction in the processing temperature change time between other processes, thus suppressing the reduction in productivity. By keeping the processing temperature below 175°C, the reduction in etching rate can be further suppressed while maintaining a significant reduction in the processing temperature change time between other processes, thus further suppressing the reduction in productivity. By keeping the processing temperature below 150°C, the reduction in etching rate can be significantly suppressed while maintaining a significant reduction in the processing temperature change time between other processes, thus significantly suppressing the reduction in productivity.

[0094] Therefore, the above-mentioned processing temperature is between room temperature (25°C) and 200°C, preferably between 50°C and 175°C, more preferably between 100°C and 150°C, and even more preferably between 120°C and 150°C.

[0095] As a substance containing fluorine (F), hydrogen (H)-containing substances such as hydrogen fluoride (HF) can be used. Other examples of substances containing fluorine (F₂), nitrogen trifluoride (NF₃), chlorine trifluoride (ClF₃), and chlorine fluoride (ClF) can be used. One or more of these substances can be used as a substance containing fluorine (F).

[0096] As inert gases, rare gases such as nitrogen (N2), argon (Ar), helium (He), neon (Ne), and xenon (Xe) can be used. One or more of these can be used as inert gases. This also applies to the steps described later.

[0097] As a reducing agent, substances containing hydrogen (H2) or deuterium (D2), or substances containing deuterium (D) can be used. One or more of them can be used as a reducing agent.

[0098] After step B, baking is performed under a reducing agent atmosphere as needed. Specifically, the output of heater 207 is adjusted to maintain the temperature of wafer 200 at the baking processing temperature. Then, valve 243d is opened to allow the reducing agent to flow into gas supply pipe 232d. The reducing agent, with flow rate regulated by MFC 241d, is supplied into processing chamber 201 via gas supply pipe 232a and nozzle 249a, and exhausts from exhaust port 231a. At this time, the reducing agent is supplied to wafer 200 from the side, exposing wafer 200 to the reducing agent.

[0099] Examples of processing conditions in baking include:

[0100] Processing temperature: 700–1000℃, preferably 800–900℃

[0101] Processing pressure: 30–2000 Pa, preferably 30–1000 Pa

[0102] Processing time: 30–120 minutes, preferably 30–90 minutes

[0103] Reducing agent supply flow rate: 1-10 slm, preferably 1-5 slm

[0104] Inactive gas supply flow rate (per gas supply tube): 0–20 slm, preferably 1–10 slm.

[0105] By supplying a reducing agent to the wafer 200 under the aforementioned processing conditions, substances including organic matter, moisture, and other byproducts remaining on the surface of the wafer 200 and in the processing chamber 201 can be removed by reacting with the reducing agent. At this time, if substances that were not completely removed by the purging in step B remain on the surface of the wafer 200 and in the processing chamber 201, these substances can also be removed by reacting with the reducing agent. That is, through this step, the surface of the wafer 200 and the processing chamber 201 can be made clean, and this clean state can be maintained until step C is performed. It should be noted that, during the period from step B to step C, if the surface of the wafer 200 and the processing chamber 201 can be kept clean, the baking process can be omitted. Figure 4 An example is shown where the baking process is omitted.

[0106] (Step C)

[0107] After step B is completed, or after the baking process is completed, the output of heater 207 is adjusted to maintain the temperature of wafer 200 at the specified processing temperature described later. Additionally, raw materials and reducing agents, serving as film-forming agents, are supplied to wafer 200.

[0108] Specifically, valves 243b and 243d are opened to allow the raw materials and reducing agent to flow into gas supply pipes 232b and 232d, respectively. The flow rates of the raw materials and reducing agent are regulated by MFCs 241b and 241d, and supplied to the processing chamber 201 via nozzles 249b and 249a, and exhausted from the exhaust port 231a. At this time, the raw materials and reducing agent are supplied to the wafer 200 from the side, exposing the wafer 200 to the raw materials and reducing agent (raw material + reducing agent supply, exposure). Alternatively, valves 243f to 243h can be opened to supply inactive gases into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0109] Under the processing conditions described later, by exposing the wafer 200 to the raw materials and reducing agent, a predetermined film can be formed on the surface of the wafer 200 after the oxide has been removed. The surface of the wafer 200 is composed of single-crystal Si. Furthermore, by using the substances described later as raw materials and reducing agents respectively, an epitaxial Si film can be grown and formed on the surface of the wafer 200 as a film. At this time, by the action of the reducing agent, the surface of the wafer 200 and the processing chamber 201 can be kept in a clean state, and by performing epitaxial growth appropriately, a high-purity epitaxial Si film can be formed.

[0110] After a predetermined film is formed on the surface of wafer 200, valves 243b and 243d are closed to stop the supply of raw materials and reducing agent to the processing chamber 201. Then, gaseous substances remaining in the processing chamber 201 are removed (purged) through the same processing steps and conditions as in step B. It should be noted that the processing temperature during purging in this step is preferably the same as the processing temperature during the supply of raw materials and reducing agent.

[0111] Examples of processing conditions for supplying raw materials and reducing agents in step C include:

[0112] Processing temperature: 500–650℃, preferably 550–600℃

[0113] Processing pressure: 4–200 Pa, preferably 1–120 Pa

[0114] Processing time: 10–120 minutes, preferably 20–60 minutes

[0115] Raw material supply flow rate: 0.1–5 slm, preferably 0.2–3 slm

[0116] Reducing agent supply flow rate: 1-20 slm, preferably 1-10 slm

[0117] Inactive gas supply flow rate (per gas supply tube): 0–20 slm, preferably 0.1–10 slm.

[0118] As raw materials, for example, silane (SiH4), silane (Si2H6), trisilane (Si3H8), and tetrasilane (Si4H) can be used. 10 Hydrogenated silicon, etc.

[0119] As a reducing agent, substances containing H, such as H2 and D2, or substances containing D can be used. One or more of these can be used as a reducing agent.

[0120] (Post-purging and atmospheric pressure recovery)

[0121] After step C is completed, inert gases are supplied as purge gases into the processing chamber 201 through nozzles 249a to 249c, and exhaust gases are discharged through exhaust port 231a. This purges the processing chamber 201, removing residual gases and reaction byproducts (post-purge). Then, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure inside the processing chamber 201 is restored to atmospheric pressure (atmospheric pressure restoration).

[0122] (Jingzhou Unloading)

[0123] Next, the sealing cover 219 is lowered by the crystal boat lift 115, opening the lower end of the manifold 209. Then, the processed wafer 200, supported by the crystal boat 217, is moved from the lower end of the manifold 209 to the outside of the reaction tube 203 (crystal boat unloading). After the crystal boat is unloaded, the gate 219s is moved, and the lower end opening of the manifold 209 is sealed by the gate 219s via the O-ring 220c (gate closing).

[0124] (Step D)

[0125] After the wafer boat is unloaded, outside the processing chamber 201, a process is performed to eliminate the adhesion of the wafer 200 to the wafer boat 217 caused by the film formed in step C. This process can be performed, for example, by temporarily peeling (picking up) the wafer 200 from the wafer boat 217. For example, this process can be performed by performing the opposite action to loading the wafer 200 into the wafer boat 217 during wafer filling. At this time, if the SiN wafer is attached to the wafer boat 217, the same process is performed on the SiN wafer. For example, by temporarily peeling the SiN wafer from the wafer boat 217 together with the wafer 200, the adhesion of the SiN wafer to the wafer boat 217 can be eliminated.

[0126] [Number of times stipulated for implementation]

[0127] By performing the cycle comprising steps A through D a predetermined number of times (n times, where n is an integer of 1 or 2 or more), a film of desired thickness can be formed on wafer 200. It is preferable to perform this cycle multiple times. That is, as... Figure 7 As illustrated, it is preferable that the thickness of the film formed by performing one cycle including steps A to D (the respective thicknesses of the first film and the second film) is thinner than the desired film thickness, and the above cycle is repeated multiple times until the thickness of the film stacked on the wafer 200 becomes the specified thickness. Figure 7 An example is shown where the loop is performed twice. Additionally, Figure 7The first film in the diagram shows the film formed in the first cycle, and the second film shows the film formed in the second cycle. The dashed lines indicate the areas where the oxide has been removed by etching in step B of each cycle. It should be noted that the dashed line between the wafer and the first film indicates the areas where the oxide formed on the wafer surface has been removed by etching in step B of the first cycle. Furthermore, the dashed line between the first and second films indicates the areas where the oxide formed on the surface of the first film has been removed by etching in step D of the first cycle when the wafer 200 was removed from the processing chamber 201.

[0128] It should be noted that when multiple cycles are performed, in the wafer filling after the second cycle, the wafer 200 and SiN wafer temporarily removed from the wafer boat 217 in step D are reloaded into the wafer boat 217. Furthermore, when multiple cycles are performed, if the surface of the non-product substrate (SiN wafer) containing nitrogen, loaded into the wafer boat 217 after a certain cycle is covered by a film, it is preferable to start the next cycle after replacing the non-product substrate with a new non-product substrate (SiN wafer) with the nitride film exposed on its surface. It should be noted that when multiple cycles are performed, the non-product substrate can continue to be used as a nitrogen-containing substrate while at least a portion of the nitride film is exposed on its surface.

[0129] (Chip removal)

[0130] After forming a film of the desired thickness on the wafer 200, the processed wafer 200 and the unprocessed substrate (SiN wafer) are removed from the boat 217 (wafer removal).

[0131] Through the above operations, the processing steps in one aspect of the present invention are completed.

[0132] It should be noted that steps B and C above are preferably performed in the same processing chamber (in-situ). If a series of processes are performed in-situ, the wafer 200 will not be exposed to the atmosphere during the process, and stable processing can be carried out consistently while the wafer 200 is placed under vacuum.

[0133] (3) The effect of this method

[0134] According to this method, one or more of the following effects can be obtained.

[0135] (a) In step A, a state is formed in which a product substrate and a nitrogen-containing substance are disposed in a processing container. In step B, a nitrogen-containing substance is supplied to the processing container. Thus, the surface of the product substrate can be etched using substance X, which is generated by chemically reacting the nitrogen-containing substance with the nitrogen-containing substance. Through the action of substance X, the etching reaction can be promoted and etching can be performed efficiently.

[0136] Furthermore, in step A, a state is formed in which a substrate containing a product and a nitrogen-containing substance are disposed within the processing container, and in step B, a nitrogen-containing substance is supplied into the processing container. This allows for a higher processing temperature during etching, and even if other processes such as film formation are performed before or after etching, the etching temperature can be made close to the processing temperature of those other processes. This shortens the time required to change the processing temperature between etching and other processes, i.e., reduces at least one of the heating and cooling times, thereby increasing productivity.

[0137] Furthermore, by increasing the processing temperature during etching, the solid reaction products generated during the reaction can be decomposed and removed while an fluorine-containing substance is being supplied. This prevents the solid reaction products generated during the reaction from remaining on the outermost surface of the oxide being etched, thus preventing further reaction. Additionally, after the fluorine-containing substance is stopped, there is no need for a separate process to raise the processing temperature and sublimate the solid reaction products, thereby increasing productivity.

[0138] (b) In steps A and B, by placing the N-containing substance at a position that is away from and adjacent to the product substrate, the generation site of substance X can be appropriately optimized so that it is a site that is neither too close to nor too far from the product substrate and can effectively generate an etching reaction, thereby effectively achieving the above-mentioned effect.

[0139] (c) The above-mentioned effects can be effectively obtained by including Si in the N-containing material and H in the F-containing material. In addition, the above-mentioned effects can be obtained more effectively by including SiN in the N-containing material and HF in the F-containing material.

[0140] (d) The above-mentioned effects can be effectively obtained by including N and H in substance X. Furthermore, the above-mentioned effects can be obtained even more effectively by making substance X a substance produced during the etching process of a N-containing material by a F-containing material. Additionally, the above-mentioned effects can be obtained even more effectively by making substance X a substance produced by the decomposition of reaction products generated during the etching process of a N-containing material by a F-containing material.

[0141] (e) In step B, the aforementioned effect can be effectively obtained by etching the oxide on the surface of the substrate. Furthermore, the aforementioned effect can be obtained more effectively by making the oxide comprise a silicon oxide film with a non-stoichiometric composition. Additionally, the aforementioned effect can be obtained more effectively by making the oxide comprise at least one of a native oxide film and a chemically oxidized oxide film.

[0142] (f) By setting the processing temperature in step B to 100°C or higher, it is possible to significantly shorten the time between processing temperatures and other processes while maintaining a high etching rate, thereby greatly improving productivity. In addition, by setting the processing temperature in step B to 100°C or higher, it is possible to effectively suppress the situation where solid reaction products generated during the etching reaction remain on the outermost surface of the oxide to be etched, thus preventing the reaction from proceeding.

[0143] By setting the processing temperature in step B to 120°C or higher, it is possible to maintain a high etching rate while significantly reducing the time required to change processing temperatures between other processes, thereby further improving productivity. Furthermore, by setting the processing temperature in step B to 120°C or higher, it is possible to more effectively suppress the situation where solid reaction products generated during the etching process remain on the outermost surface of the oxide being etched, thus preventing further reaction.

[0144] (g) In step B, it becomes unnecessary to use the reaction between the F-containing substance and H2O as a trigger for etching, and it is not necessary to adjust the process so that a trace amount of H2O is present in the processing container at least at the beginning of step B. Furthermore, since it is not necessary to have a trace amount of H2O in the processing container at the beginning of step B, the processing temperature during etching can be increased to a higher temperature, and the processing container can be kept in a clean state.

[0145] (h) By including the nitrogen-containing material in a non-product substrate with a nitride film formed on its surface, and in steps A and B forming a state where non-product substrates are arranged every other product substrate within the processing container, the aforementioned effects can be effectively achieved. Furthermore, the nitrogen-containing material (the non-product substrate with a nitride film formed on its surface) can be supported by the same support member as the product substrate. Therefore, it is not necessary to provide a separate component for arranging the nitrogen-containing material within the processing container. Additionally, the nitrogen-containing material (the non-product substrate with a nitride film formed on its surface) can be transported to the support member using the same transport device as the product substrate, eliminating the need for a separate transport device for transporting the nitrogen-containing material.

[0146] (i) In step C, by supplying a film-forming agent into a processing container in which a product substrate with an etched surface is disposed, a film is formed on the product substrate, thereby reducing the impurity concentration (oxygen concentration, etc.) at the interface between the product substrate and the film.

[0147] (j) By performing the cycle including steps A to D multiple times, the impurity concentration (oxygen concentration, etc.) at the interface between the substrate and the film can be reduced. In addition, the impurity concentration (oxygen concentration, etc.) at the interface between the film formed in the first cycle and the film formed in the second cycle can be reduced.

[0148] (k) In step B, since substance X is produced by a chemical reaction between the N-containing substance and the F-containing substance within the processing container, there is no need to install a separate supply line for supplying substance X to the processing container, thereby reducing equipment costs. Furthermore, by omitting the supply line for substance X, the supply system can be simplified, and the manpower and costs associated with maintaining the supply system can be reduced.

[0149] (l) The above-mentioned effect can also be obtained by arbitrarily selecting a specified substance from the above-mentioned various F-containing substances, various film-forming agents, various reducing agents and various inactive gases.

[0150] <Second aspect of the present invention>

[0151] Next, the main use Figure 5 , Figure 6 Section (b) describes the second aspect of the present invention.

[0152] In this method, the nitrogen-containing substance disposed within the processing container through steps A and B includes a nitride film formed within the processing container. This method differs from the first method described above. The processing sequence of this method, including steps A (A1, A2, A3) and step B, will be explained below.

[0153] First, with no wafer 200 housed in the processing chamber 201, similar to the first method described above, after adjusting the pressure and temperature within the processing chamber 201, a pre-coating process (step A1) is performed to form a nitride film as a pre-coating film within the processing chamber 201. In step A1, the steps of supplying raw materials to the processing chamber 201 as a pre-coating agent (raw material supply) and supplying a reactant to the processing chamber 201 as a pre-coating agent (reactant supply) are performed sequentially a predetermined number of times.

[0154] During raw material supply, valve 243b is opened, allowing the raw material to flow into the gas supply pipe 232b. The raw material is regulated by MFC 241b and supplied into the processing chamber 201 via nozzle 249b, and exhausted from exhaust port 231a. At this time, the surfaces of the components inside the processing chamber 201 are exposed to the raw material (raw material supply, exposure). Alternatively, valves 243f to 243h can be opened to supply inactive gases into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0155] After supplying raw materials into the processing chamber 201 for a specified time, valve 243b is closed to stop supplying raw materials into the processing chamber 201. Then, gaseous substances and the like remaining in the processing chamber 201 are removed from the processing chamber 201 (purging) by the same processing steps and conditions as in step B of the first method described above.

[0156] During reactant supply, valve 243e is opened, allowing the reactant to flow into gas supply pipe 232e. The reactant flow rate is regulated by MFC 241e and supplied to processing chamber 201 via nozzle 249b, and exhaust is achieved through exhaust port 231a. At this time, the surfaces of components within processing chamber 201 are exposed to the reactant (reactant supply, exposure). Alternatively, valves 243f to 243h can be opened to supply inactive gases into processing chamber 201 via nozzles 249a to 249c, respectively.

[0157] After supplying the reactant into the processing chamber 201 for a predetermined time, valve 243e is closed to stop supplying the reactant into the processing chamber 201. Then, by using the same processing steps and conditions as in step B of the first method described above, the gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201 (purging).

[0158] Then, by performing the cycle including the supply of raw materials and the supply of reactants a predetermined number of times (n times, where n is an integer of 1 or 2 or more), a nitride film (pre-coated film) of desired thickness is formed on the surface of components within the processing chamber 201, such as the inner wall of the reaction tube 203. It should be noted that pre-coating can also be performed with an empty crystal boat 217 contained within the processing chamber 201. In this case, a nitride film (pre-coated film) of desired thickness is formed on the surface of components within the processing chamber 201, such as the inner wall of the reaction tube 203 and the surface of the crystal boat 217. When the substances described later are used as raw materials and reactants, a silicon nitride film (SiN film) is formed on the surface of the components within the processing chamber 201 as the nitride film.

[0159] Examples of processing conditions for supplying raw materials in step A1 include:

[0160] Processing temperature: 300–800℃, preferably 400–650℃

[0161] Processing pressure: 1–2000 Pa, preferably 1–1333 Pa

[0162] Processing time: 1–180 seconds, preferably 10–120 seconds

[0163] Raw material supply flow rate: 0.001~2slm, preferably 0.01~1slm

[0164] Inactive gas supply flow rate (per gas supply tube): 0–20 slm, preferably 0.1–10 slm.

[0165] Examples of processing conditions for supplying the reactants in step A1 include:

[0166] Processing temperature: 300–800℃, preferably 400–650℃

[0167] Processing pressure: 1–4000 Pa, preferably 1–1333 Pa

[0168] Processing time: 1–180 seconds, preferably 10–120 seconds

[0169] Reactant supply flow rate: 0.01–20 slm, preferably 0.01–10 slm

[0170] Inactive gas supply flow rate (per gas supply tube): 0–20 slm, preferably 0.1–10 slm.

[0171] As raw materials, for example, monochlorosilane (SiH3Cl), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), tetrachlorosilane (SiCl4), hexachlorodisilane (Si2Cl6), and other chlorosilanes, as well as hydride, which is exemplified as a raw material in step C of the first method described above, can be used. One or more of them can be used as raw materials.

[0172] Hydrogen nitrides such as ammonia (NH3), diazoxide (N2H2), hydrazine (N2H4), and N3H8 can be used as reactants. One or more of these can be used as reactants.

[0173] After a nitride film of the desired thickness is formed on the surface of the component inside the processing chamber 201, post-purging and atmospheric pressure recovery are performed through the same processing steps as in the first method described above.

[0174] Subsequently, through the same processing steps as in the first method described above, multiple wafers 200 serving as product substrates are loaded (wafer filling) into the crystal boat 217 (step A2). It should be noted that, unlike the first method, in this method, non-product substrates (SiN wafers) with a nitride film formed on their surface are not loaded into the crystal boat 217. Therefore, in this method, the number of product substrates processed in one operation can be increased accordingly, thereby improving productivity.

[0175] After wafer filling is completed, following the same processing steps as in the first method described above, the wafer boat 217 supporting the wafer 200 is moved into the processing chamber 201 (crystal boat loading), and the wafer 200 is placed in the processing chamber 201 where a nitride film has been formed (step A3). Through the completion of crystal boat loading, as... Figure 6 As shown in (b), the processing chamber 201 is configured with a wafer 200 serving as a substrate and a nitrogen-containing material (a nitride film formed on the surface of the component within the processing chamber 201). Similar to the first embodiment described above, the nitrogen-containing material is positioned away from and adjacent to the wafer 200.

[0176] The processing steps and conditions in subsequent steps can be set to be the same as those in the first method described above. It should be noted that in step B, the surface of the substrate can be etched using substance X, which is generated by chemically reacting a nitride film formed on the surface of the component within the processing chamber 201 (i.e., the inner wall of the reaction tube 203) with an F-containing substance. Through the action of substance X, the etching reaction is promoted, and etching can be performed efficiently, just as in the first method described above.

[0177] In this method, by performing the cycle including steps A to D a predetermined number of times (n times, where n is an integer of 1 or 2 or more), a film of the desired thickness can be formed on the wafer 200. It should be noted that after one cycle is completed, if the nitride film formed on the surface of the component in the processing chamber 201 in step A1 is covered by the film, a nitride film needs to be formed (pre-coated) on the surface of the component in the processing chamber 201 again before proceeding to the next cycle. Therefore, the cycle including steps A (A1, A2, A3) to D needs to be performed a predetermined number of times. Figure 6 An example of pre-coating performed in one cycle is shown. However, if, after one cycle, the nitride film formed on the surface of the component inside the processing chamber 201 is not completely covered by the film, or at least a portion of it is exposed, pre-coating is not required again, and the cycles including steps A (A2, A3) to D can be performed a predetermined number of times. When the cycles are performed multiple times, the nitride film formed on the surface of the component inside the processing chamber 201 can continue to be used as a nitrogen-containing material during the period when at least a portion of the nitride film is exposed.

[0178] In this method, the same effect as in the first method described above can be achieved. Furthermore, according to this method, nitrogen-containing materials can be formed on the surface of components within the processing container, eliminating the need for separately providing components for placing nitrogen-containing materials within the processing container. Additionally, according to this method, since it is not necessary to use a non-product substrate with a nitride film formed on its surface, product substrates can be fully loaded onto the support, increasing the number of product substrates processed at one time and improving productivity. Furthermore, according to this method, nitrogen-containing materials can be conformally and uniformly formed on the surface of components within the processing container, for example, on the inner wall of the reaction tube 203, enabling uniform generation of material X throughout the entire area within the processing container and improving the uniformity of the etching process.

[0179] <Other aspects of the invention>

[0180] The present invention has been specifically described above. However, the present invention is not limited to the above-described manner, and various modifications can be made without departing from its spirit.

[0181] For example, in step B of the first and second methods described above, F-containing gas can be supplied to the processing container intermittently, i.e., in a pulsed manner. For example, the supply of F-containing gas to the processing container and the purging and / or vacuum exhaust of the processing container can be alternated a predetermined number of times (m times, where m is an integer of 1 or 2 or more). In this case, the same effect as the first and second methods described above can be obtained. Furthermore, according to this method, by temporarily removing the reaction products and residual gas from the processing container during etching, the reaction can be reset, thus suppressing the generation of excessive etching reaction and improving the controllability of the etching amount.

[0182] Furthermore, for example, in step C of the first and second methods described above, in addition to the raw materials and reducing agent, a dopant can be supplied to the substrate as a film-forming agent. The dopant can be supplied from the dopant supply system described above. As a dopant, a substance containing any element from Group 15 such as phosphorus (P) and arsenic (As) and Group 13 such as boron (B) can be used. Examples of dopants include phosphine (PH3), arsine (AsH3), diborane (B2H6), and trichloroborane (BCl3). One or more of these can be used as dopants. In this method, the same effect as in the first and second methods described above can also be obtained. In addition, according to this method, it is possible to form a film doped with a dopant (P, As, B, etc.) on the substrate.

[0183] Alternatively, for example, in step C of the first and second methods described above, a film containing semiconductor elements can be formed on the substrate using a substance containing semiconductor elements other than Si. For example, a substance containing germanium (Ge) such as monogerane (GeH4) can be used as a raw material to form a Ge-containing film on the substrate. Alternatively, for example, a film containing Si and a Ge-containing substance can be formed on the substrate using both as raw materials. Alternatively, for example, a film containing metal elements such as tungsten (W), molybdenum (Mo), aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and tantalum (Ta) can be used as a raw material to form a film containing metal elements on the substrate. In these cases, the same effects as in the first and second methods described above can be obtained.

[0184] Alternatively, for example, in step C of the first and second methods described above, in addition to the epitaxial film, an amorphous film, a polycrystalline film, or a mixed-crystal film thereof can also be formed on the substrate. In these cases, the same effect as in the first and second methods described above can also be obtained.

[0185] Alternatively, for example, in the pre-coating step (step A1) of the second method described above, the raw materials and reactants can be supplied to the processing container simultaneously. In this method, the same effects as in the first and second methods described above can also be obtained.

[0186] The processing steps for each process are preferably prepared separately according to the processing content, and are pre-recorded and stored in the storage device 121c via an electrical communication line and an external storage device 123. Furthermore, when starting each process, the CPU 121a preferably selects an appropriate process from the multiple processes recorded and stored in the storage device 121c according to the processing content. This allows for various processes with good reproducibility to be performed on membranes of different types, compositions, qualities, and thicknesses using the processing apparatus. In addition, it reduces the operator's workload, allowing for the rapid initiation of each process while avoiding operational errors.

[0187] The aforementioned process is not limited to the case of new fabrication; for example, it can also be prepared by modifying an existing process already installed in the processing device. In the case of process modification, the modified process can also be installed in the processing device via an electrical communication line and a recording medium containing the process. Alternatively, an existing process already installed in the processing device can be directly modified by operating the input / output device 122 of an existing processing device.

[0188] In the above-described method, an example of processing using a batch processing apparatus that processes multiple substrates at a time has been described. The present invention is not limited to the above-described method; for example, it can also be applied to cases where processing is performed using a monolithic processing apparatus that processes one or more substrates at a time. Furthermore, in the above-described method, an example of processing using a processing apparatus with a hot-wall type furnace has been described. The present invention is not limited to the above-described method; it can also be applied to cases where processing is performed using a processing apparatus with a cold-wall type furnace.

[0189] Furthermore, the above-described method illustrates an example of performing the above-described processing sequence within the same processing chamber (in-situ) of the same processing device. The present invention is not limited to the above-described method; for example, any step of the above-described processing sequence and any other step may be performed separately in different processing chambers (ex-situ) of different processing devices, or separately in different processing chambers of the same processing device.

[0190] When using these processing devices, each process can be performed with the same processing steps and processing conditions as described above and in the modified examples, and the same effects as described above and in the modified examples can be obtained.

[0191] The above methods and variations can be used in appropriate combinations. The processing steps and conditions can be set to be the same as those in the above methods and variations.

[0192] Example

[0193] As an example, in a processing container without an internal nitride film, a Si wafer with a natural oxide film on its surface and a Si wafer with a SiN film on its surface (hereinafter referred to as a SiN wafer) are placed inside. HF gas is supplied to the processing container to etch the surface of the Si wafer. The etching amount is measured when the processing temperature during HF gas supply is set to 30°C, 50°C, 100°C, 150°C, and 200°C. Other processing conditions during HF gas supply are set to the specified conditions within the range of the processing conditions in step B of the above method.

[0194] As a comparative example, in a processing container without an internal nitride film, no SiN wafer was placed; only a Si wafer with a natural oxide film formed on its surface was placed. HF gas was supplied to the processing container to etch the surface of the Si wafer. The etching amount was measured when the processing temperature for HF gas supply was set to 30°C, 55°C, 75°C, and 100°C. Other processing conditions for HF gas supply were the same as those in the examples.

[0195] Figure 8 The results show the determination of the etching amount of the natural oxide film on the surface of the Si wafer. Figure 8 The horizontal axis represents the processing temperature [°C] during HF gas supply, and the vertical axis represents the etching amount of the natural oxide film [any unit (au)]. Additionally, Figure 8 The solid lines represent the measured etching amount of the native oxide film in the examples, and the dashed lines represent the measured etching amount of the native oxide film in the comparative examples. Figure 8 As shown, the etching amount of the native oxide film in the embodiment does not decrease at all until the processing temperature reaches 100°C, and the decrease is slight even in the range of 100°C to 150°C. A sufficiently usable etching amount can be obtained in the range of 150°C to 175°C. In contrast, the etching amount of the native oxide film in the comparative example decreases significantly in the temperature range exceeding 55°C. Therefore, it can be seen that, according to the embodiment, the etching of the native oxide film on the Si wafer surface can be performed efficiently at relatively high temperatures, significantly improving productivity.

Claims

1. The processing method, which has the following characteristics: (a) A process that forms a state in which a substrate of articles and a nitrogen-containing substance are disposed within a processing container; and (b) A process of etching the surface of the product substrate by supplying a fluorine-containing substance into the processing container in which the product substrate and the nitrogen-containing substance are disposed, thereby using a substance X generated by chemically reacting the nitrogen-containing substance with the fluorine-containing substance.

2. The processing method according to claim 1, wherein, The nitrogen-containing material is disposed at a position away from the product substrate and adjacent to the product substrate.

3. The processing method according to claim 1, wherein, The nitrogen-containing substance contains silicon, and the fluorine-containing substance contains hydrogen.

4. The processing method according to claim 1, wherein, The nitrogen-containing substance comprises silicon nitride, and the fluorine-containing substance comprises hydrogen fluoride.

5. The processing method according to claim 4, wherein, The substance X contains nitrogen and hydrogen.

6. The processing method according to claim 1, wherein, The substance X is produced during the etching process of the nitrogen-containing substance by the fluorine-containing substance.

7. The processing method according to claim 1, wherein, The substance X is produced by the decomposition of reaction products generated during the etching process of the nitrogen-containing substance by the fluorine-containing substance.

8. The processing method according to claim 1, wherein, In (b), the oxide on the surface of the substrate of the article is etched.

9. The method according to claim 8, wherein, The oxide comprises a silicon oxide film having a non-stoichiometric composition.

10. The processing method according to claim 8, wherein, The oxide comprises at least one of natural oxide films and chemical oxide films.

11. The processing method according to claim 1, wherein, Set the processing temperature in (b) to above 100°C.

12. The processing method according to claim 1, wherein, Set the processing temperature in (b) to above 120°C.

13. The processing method according to claim 1, wherein, The etching is carried out under conditions where the reaction of the fluorinated substance with H2O is not used as a trigger to initiate the etching (b).

14. The processing method according to any one of claims 1 to 13, wherein, The nitrogen-containing material is contained in a non-product substrate on which a nitride film has been formed.

15. The processing method according to claim 14, wherein, In (a) and (b), the non-product substrates are arranged every other product substrate within the processing container.

16. The processing method according to any one of claims 1 to 13, wherein, The nitrogen-containing material includes a nitride film formed within the processing container.

17. The processing method according to claim 16, wherein, (a) includes: (a1) The step of forming the nitride film within the processing container; and (a2) The process of placing the article substrate in the processing container on which the nitride film is formed.

18. The processing method according to any one of claims 1 to 13, wherein, Also includes: (c) A process of forming a film on the article substrate by supplying a film-forming agent into the processing container in which the article substrate with its surface etched is disposed.

19. The processing method according to claim 18, wherein, (a), (b), and (c) are performed with the substrate of the article supported by a support member. The processing method further includes (d) a step of removing the adhesion of the product substrate to the support caused by the film outside the processing container by peeling the product substrate from the support. Repeat the loop containing (a), (b), (c) and (d) multiple times.

20. A method for manufacturing a semiconductor device, comprising: (a) A process that forms a state in which a substrate of articles and a nitrogen-containing substance are disposed within a processing container; and (b) A process of etching the surface of the product substrate by supplying a fluorine-containing substance into the processing container in which the product substrate and the nitrogen-containing substance are disposed, thereby using a substance X generated by chemically reacting the nitrogen-containing substance with the fluorine-containing substance.

21. A processing apparatus, comprising: Handling containers; An apparatus for forming a state in which an article substrate and a nitrogen-containing substance are disposed within the processing container; A fluorinated substance supply system for supplying fluorinated substances into the processing container; and The control unit is configured to control the device and the fluorine-containing material supply system to perform the following processes: (a) a process in which the product substrate and the nitrogen-containing material are disposed in the processing container; and (b) a process in which the surface of the product substrate is etched by supplying the fluorine-containing material into the processing container in which the product substrate and the nitrogen-containing material are disposed, thereby utilizing a substance X generated by chemically reacting the nitrogen-containing material with the fluorine-containing material.

22. A program article that causes a processing device to perform the following steps via a computer: (a) the step of forming a state in which a substrate of articles and a nitrogen-containing substance are disposed within a processing container; and (b) The step of etching the surface of the article substrate by supplying a fluorine-containing substance into the processing container in which the article substrate and the nitrogen-containing substance are disposed, thereby using a substance X generated by chemically reacting the nitrogen-containing substance with the fluorine-containing substance.

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