Substrate processing method, method for manufacturing semiconductor device, program and substrate processing apparatus

Abstract

To provide a technology that can improve the surface flatness of a film formed on a substrate and improve the surface roughness of the film.SOLUTION: A substrate processing method has (a) a step for supplying a first gas and a second gas to a substrate to form a film, and (b) a step for improving the surface flatness of the film.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] 2. Description of the Related Art As one step in the manufacturing process of a semiconductor device, a process of forming a film on a substrate is sometimes performed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-118462 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique capable of improving the flatness of the surface of a film formed on a substrate and reducing the surface roughness of the film. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, (a) supplying a first gas and a second gas to a substrate to form a film; (b) improving the flatness of the surface of the film; The present invention provides a technique having the following features: Effect of the Invention

[0006] According to the present disclosure, it is possible to improve the flatness of the surface of a film formed on a substrate and reduce the surface roughness of the film. [Brief description of the drawings]

[0007] [Figure 1]FIG. 1 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus used in one embodiment, showing a processing furnace 202 in vertical cross section. [Diagram 2] FIG. 2 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus used in one embodiment, showing a processing furnace 202 portion in a cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. 3 is a schematic configuration diagram of the controller 121 of the substrate processing apparatus used in one embodiment, and is a block diagram showing a control system of the controller 121. [Figure 4] FIG. 4 is a diagram showing a processing sequence according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0009] (1) Configuration of the substrate processing device 1, the process furnace 202 has a heater 207 as a temperature control unit (heating unit). The heater 207 is cylindrical and is installed vertically by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas by heat.

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

[0011] In the processing chamber 201, nozzles 249a and 249b as a first supply unit and a second supply unit are provided so as to penetrate a sidewall of the manifold 209, respectively. The nozzles 249a and 249b are also referred to as a first nozzle and a second nozzle, respectively. The nozzles 249a and 249b are made of a heat-resistant material such as quartz or SiC. Gas supply pipes 232a and 232b are connected to the nozzles 249a and 249b, respectively. The nozzles 249a and 249b are provided adjacent to each other.

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

[0013] As shown in FIG. 2, the nozzles 249a and 249b are provided in a space between the inner wall of the reaction tube 203 and the wafers 200, which is annular in plan view, from the lower part to the upper part of the inner wall of the reaction tube 203, so as to rise upward in the arrangement direction of the wafers 200. That is, the nozzles 249a and 249b are provided in a region horizontally surrounding the wafer arrangement region on the side of the wafer arrangement region in which the wafers 200 are arranged, so as to extend along the wafer arrangement region. Gas supply holes 250a and 250b for supplying gas are provided on the side of the nozzles 249a and 249b, respectively. The gas supply holes 250a and 250b are each open toward the center of the wafer 200 in plan view, so that gas can be supplied toward the wafer 200. A plurality of gas supply holes 250a and 250b are provided from the lower part to the upper part of the reaction tube 203.

[0014] A first gas is supplied from the gas supply pipe 232a through the MFC 241a, the valve 243a, and the nozzle 249a into the processing chamber 201. The first gas acts as a source gas, which is one of film forming gases.

[0015] A second gas is supplied from the gas supply pipe 232b through the MFC 241b, the valve 243b, and the nozzle 249b into the processing chamber 201. The second gas acts as a dopant gas, which is one of the film forming gases.

[0016] From the gas supply pipes 232c and 232d, an inert gas is supplied into the processing chamber 201 via the MFCs 241c and 241d, the valves 243c and 243d, the gas supply pipes 232a and 232b, and the nozzles 249a and 249b. The inert gas acts as a purge gas, a carrier gas, a dilution gas, etc.

[0017] A first gas supply system is mainly composed of the gas supply pipe 232a, the MFC 241a, and the valve 243a. A second gas supply system is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. An inert gas supply system is mainly composed of the gas supply pipes 232c and 232d, the MFCs 241c and 241d, and the valves 243c and 243d. Nozzles connected to the gas supply pipes constituting the various supply systems described above may be included in each of the supply systems.

[0018] Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which the valves 243a to 243d and the MFCs 241a to 241d are integrated. The integrated supply system 248 is connected to the gas supply pipes 232a to 232d, and is configured such that the supply operation of various substances (various gases) into the gas supply pipes 232a to 232h, that is, the opening and closing operation of the valves 243a to 243d and the flow rate adjustment operation by the MFCs 241a to 241d, are controlled by a controller 121 described later. The integrated supply system 248 is configured as an integrated or separate type integrated unit, and can be attached and detached to and from the gas supply pipes 232a to 232d, etc., in units of integrated units, and is configured such that maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed in units of integrated units.

[0019] An exhaust port 231a for exhausting the atmosphere in the processing chamber 201 is provided at the lower side of the side wall of the reaction tube 203. The exhaust port 231a may be provided along the side wall of the reaction tube 203 from the lower part to the upper part, that is, along the wafer arrangement region. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is made of a metal material such as SUS. A vacuum pump 246 as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure adjustment unit). The APC valve 244 can evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operated, and further, can adjust the pressure in the processing chamber 201 by adjusting the valve opening based on the pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operated. An exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. A vacuum pump 246 may be included in the exhaust system.

[0020] Below the manifold 209, a seal cap 219 is provided as a furnace port cover body capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is made of a metal material such as SUS, and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a seal member that abuts against the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 is provided for rotating the boat 217, which will be described later. A rotation shaft 255 of the rotation mechanism 267 is made of a metal material such as SUS, and is connected to the boat 217 through the seal cap 219. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The seal cap 219 is configured to be vertically raised and lowered by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer system (transfer mechanism) that transfers (transports) the wafers 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219.

[0021] A shutter 219s is provided below the manifold 209 as a furnace port cover that can airtightly close the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is carried out of the processing chamber 201. The shutter 219s is made of a metal material such as SUS and is formed in a disk shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a seal member that comes into contact with the lower end of the manifold 209. The opening and closing operation (lifting and lowering operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0022] The boat 217 as a substrate support is configured to support a plurality of wafers 200, for example 25 to 200, in multiple stages in a horizontal position and aligned vertically with their centers aligned, i.e., arranged at intervals. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, heat insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported in multiple stages.

[0023] A temperature sensor 263 serving as a temperature detector is installed in the reaction tube 203. By adjusting the power supply to the heater 207 based on temperature information detected by the temperature sensor 263, the temperature distribution in the process chamber 201 becomes a desired one. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0024] As shown in FIG. 3, the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122 configured as, for example, a touch panel is connected to the controller 121. An external storage device 123 can be connected to the controller 121. The substrate processing apparatus may be configured to include one control unit or multiple control units. That is, the control for performing the processing sequence described later may be performed using one control unit or multiple control units. The multiple control units may be configured as a control system connected to each other by a wired or wireless communication network, and the control for performing the processing sequence described later may be performed by the entire control system. In this specification, when the term "control section" is used, it may include one control section, or may include multiple control sections, or may include a control system made up of multiple control sections.

[0025] The storage device 121c is composed of, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), etc. In the storage device 121c, a control program for controlling the operation of the substrate processing apparatus, a process recipe in which procedures and conditions of the substrate processing described later are described, etc. are recorded and stored in a readable manner. The process recipe is a combination of procedures in the substrate processing described later that are executed by the controller 121 in the substrate processing apparatus to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. In addition, the process recipe is also simply referred to as a recipe. In this specification, when the word program is used, it may include only a recipe, only a control program, or both. The RAM 121b is configured as a memory area in which the programs and data read by the CPU 121a are temporarily stored.

[0026] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241d, valves 243a to 243d, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, and the like.

[0027] The CPU 121a is configured to be able 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 an input of an operation command from the input / output device 122, etc. The CPU 121a is configured to be able to control the flow rate adjustment operation of various substances (various gases) by the MFCs 241a to 241e, the opening and closing operations of the valves 243a to 243d, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the boat elevator 115, the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, etc., in accordance with the contents of the read recipe.

[0028] The controller 121 can be configured by installing the above-mentioned program recorded and stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory or an SSD. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both of them. The program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0029] (2) Substrate processing A method of processing a substrate as one step in a manufacturing process of a semiconductor device using the above-mentioned substrate processing apparatus, i.e., an example of a processing sequence for forming a film on a wafer 200 as a substrate, will be described mainly with reference to Fig. 4. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by a controller 121.

[0030] The processing sequence in this embodiment is as follows: (a) Step A of supplying a first gas and a second gas to a wafer 200 to form a film; (b) Step B of improving the flatness of the surface of the film; has.

[0031] In the following, an example will be described in which a cycle of non-simultaneous execution of step A and step B is performed a predetermined number of times (m times, m is an integer of 1 or 2 or more).

[0032] In addition, below, an example will be described in which a cycle including step B1 of removing gas from the space in which the wafer 200 exists and step B2 of supplying an inert gas thereafter is performed a predetermined number of times (n times, n is an integer of 1 or 2 or more).

[0033] In the following, an example in which a predetermined seed film is formed in advance on the surface of the wafer 200 will be described.

[0034] In FIG. 4, a indicates step A, b indicates step B, b1 indicates step B1, and b2 indicates step B2.

[0035] In this specification, the above-mentioned processing sequence may be expressed as follows for convenience. Similar notations will be used in the following explanations of modified examples and other aspects.

[0036] {(1st gas + 2nd gas) → (gas removal → inert gas) × n} × m

[0037] The term "wafer" used in this specification may mean the wafer itself or a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may mean the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. When it is stated in this specification that "a predetermined layer is formed on a wafer", it may mean that a predetermined layer is formed directly on the surface of the wafer itself or that a predetermined layer is formed on a layer or the like formed on the wafer. When the term "substrate" is used in this specification, it is synonymous with the term "wafer".

[0038] As used herein, the term "layer" includes continuous and / or discontinuous layers.

[0039] (Wafer charge and boat load) When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209. Thereafter, as shown in FIG. 1, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat loading). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b. In this manner, the wafers 200 are prepared (provided) in the processing chamber 201.

[0040] (Pressure and temperature regulation) After the boat loading is completed, the inside of the processing chamber 201, i.e., the space in which the wafers 200 are present, is evacuated (reduced pressure exhaust) by the vacuum pump 246 so that the inside of the processing chamber 201 is at a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Also, the wafers 200 in the processing chamber 201 are heated by the heater 207 so that the wafers 200 are at a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the inside of the processing chamber 201 has a desired temperature distribution. Also, the rotation mechanism 267 starts rotating the wafers 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0041] (Deposition process: Step A) In this step, a first gas and a second gas are supplied to the wafer 200 in the processing chamber 201 .

[0042] Specifically, the valves 243a and 243b are opened to allow the first gas and the second gas to flow into the gas supply pipes 232a and 232b, respectively. The first gas and the second gas are adjusted in flow rate by the MFCs 241a and 241b, respectively, and are supplied into the processing chamber 201 through the nozzles 249a and 249b, mixed in the processing chamber 201, and exhausted from the exhaust port 231a. At this time, the first gas and the second gas are supplied to the wafer 200 from the side of the wafer 200 (first gas + second gas supply). At this time, the valves 243c and 243d may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a and 249b, respectively.

[0043] In this step, the process conditions for supplying the first gas and the second gas are as follows: Treatment temperature: 300 to 500°C, preferably 350 to 450°C Treatment pressure: 100 to 1000 Pa, preferably 200 to 700 Pa First gas supply flow rate: 0.5 to 3 slm, preferably 0.8 to 2 slm Second gas supply flow rate: 0.001 to 0.02 slm, preferably 0.005 to 0.01 slm Inert gas supply flow rate (per gas supply pipe): 0 to 20 slm Gas supply time: 1 to 300 minutes The process conditions shown here are conditions under which the first gas and the second gas undergo gas-phase decomposition (thermal decomposition) when each of the first gas and the second gas exists alone in the process chamber 201, that is, conditions under which a CVD reaction occurs. That is, the process conditions shown here are conditions under which the adsorption (deposition) of the first gas and the second gas onto the surface of the wafer 200 is not self-limited, that is, conditions under which the adsorption of the first gas and the second gas onto the wafer 200 is non-self-limited.

[0044] In this specification, the expression of a numerical range such as "300 to 500°C" means that the lower limit and the upper limit are included in the range. Therefore, for example, "300 to 500°C" means "300°C or more and 500°C or less". The same applies to other numerical ranges. In this specification, the processing temperature means the temperature of the wafer 200 or the temperature in the processing chamber 201, and the processing pressure means the pressure in the processing chamber 201, in other words, the pressure in the space in which the wafer 200 exists. In addition, the processing time means the time for which the processing continues. In addition, when the supply flow rate includes 0 slm, 0 slm means a case in which the substance (gas) is not supplied. These are the same in the following explanations.

[0045] By supplying the first gas and the second gas to the wafer 200 under the above-mentioned processing conditions, each of the first gas and the second gas is decomposed in the gas phase, and at least a portion of the molecular structure of the molecules constituting the first gas and at least a portion of the molecular structure of the molecules constituting the second gas are adsorbed (deposited) onto the surface of the wafer 200, i.e., onto the seed film formed on the wafer 200, thereby forming a film.

[0046] The first gas may be a gas containing a compound represented by the formula M1Rx, where M1 is a first element, R is a group (also called a residue, a substituent, or a ligand), and x is an integer of 1 or more. The first gas may be a gas containing the first element and one or more Rs bonded to the first element in one molecule. Here, R is selected from a hydrogen element, an alkyl group, a halogen element, and the like.

[0047] The first gas may be, for example, monosilane (SiH4) gas, disilane (Si2H6) gas, trisilane (Si3H8) gas, or tetrasilane (Si4H 10 ) gas, pentasilane (SiH 12 ) gas, hexasilane (Si6H 14 As the first gas, one or more of these gases can be used.

[0048] As the first gas, for example, a halosilane gas containing Si as the first element and halogen as R can be used. Halogen includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. As the first gas, for example, a chlorosilane gas such as monochlorosilane (SiH3Cl) gas, dichlorosilane (SiH2Cl2) gas, trichlorosilane (SiHCl3) gas, tetrachlorosilane (SiCl4) gas, hexachlorodisilane gas (Si2Cl6) gas, octachlorotrisilane (Si3Cl8) gas, etc. can be used as the first gas. One or more of these can be used as the first gas.

[0049] As the first gas, in addition to chlorosilane gas, for example, fluorosilane gas such as tetrafluorosilane (SiF4) gas or difluorosilane (SiH2F2) gas, bromosilane gas such as tetrabromosilane (SiBr4) gas or dibromosilane (SiH2Br2) gas, or iodosilane gas such as tetraiodosilane (SiI4) gas or diiodosilane (SiH2I2) gas can be used. One or more of these can be used as the first gas.

[0050] In addition to these, the first gas may be, for example, a gas containing Si as the first element and an alkyl group as R, that is, an alkylsilane-based gas. The alkyl group is an alkane (general formula C n H 2n+2 It is a general term for the remaining atomic group obtained by removing one H atom from a chain saturated hydrocarbon represented by the general formula C n H 2n+1 The alkyl group includes a methyl group, an ethyl group, a propyl group, a butyl group, and the like. As the first gas, for example, an alkylsilane gas such as monomethylsilane (SiH3CH3) gas, dimethylsilane (SiH2(CH3)2) gas, trimethylsilane (SiH(CH3)3) gas, hexamethyldisilane ((CH3)3Si2(CH3)3) gas, monoethylsilane (SiH3C2H5) gas, triethylsilane (SiH(C2H5)3) gas, diethylsilane (SiH2(C2H5)2) gas, and the like can be used. As the first gas, one or more of these can be used.

[0051] The second gas may be a gas containing a compound represented by the formula M2Ry, where M2 is a second element, R is a group (also called a residue, a substituent, or a ligand), and y is an integer of 1 or more. The second gas may be a gas containing the second element and one or more Rs bonded to the second element in one molecule. Here, R is selected from a hydrogen element, an alkyl group, a halogen element, and the like.

[0052] As the second gas, for example, a phosphine-based gas such as phosphine (PH3) gas or diphosphine (P2H6) gas containing phosphorus (P), which is a Group 15 element, as the second element and H as R can be used. One or more of these can be used as the second gas.

[0053] As the second gas, for example, a halogenated phosphorus gas such as phosphorus trichloride (PCl3) gas containing P, which is a Group 15 element, as the second element and halogen as R can be used.

[0054] As the inert gas, for example, nitrogen (N2) gas, argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, or other rare gases can be used. As the inert gas, one or more of these can be used. This also applies to each step described later.

[0055] By supplying a first gas containing a first element and a second gas containing a second element to the wafer 200 under the above-mentioned conditions, a film containing the first element and the second element, specifically, a first-element-containing film doped with the second element, can be formed on the surface of the wafer 200.

[0056] After a film is formed on the surface of the wafer 200, the valves 243a to 243d are closed to stop the supply of the first gas, the second gas, and the inert gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gas remaining in the processing chamber 201 (purging). At this time, the valves 243c and 243d are opened to supply an inert gas into the processing chamber 201. The inert gas acts as a purge gas.

[0057] (Planarization process: Step B) Thereafter, the following steps B1 and B2 are executed in sequence.

[0058] [Step B1] In this step, while the wafer 200 having a film formed on its surface is accommodated in the processing chamber 201, the processing chamber 201 is evacuated so as to reduce the pressure therein to a predetermined level.

[0059] Specifically, with the APC valve 244 at its maximum valve opening (fully open), the vacuum pump 246 draws a vacuum (evacuates the processing chamber 201). At this time, the valves 243c and 243d are kept closed, and no inert gas is supplied to the processing chamber 201. Note that "fully open" does not necessarily mean that the valve opening is 100%, and an error of -10% may be acceptable. The error is preferably -5%. Note that a valve opening including such an error is also called "approximately fully open" or "substantially fully open."

[0060] The processing conditions in this step are as follows: Treatment temperature: 300 to 500°C, preferably 350 to 450°C Treatment pressure: 0.1 to 10 Pa, preferably 0.1 to 5 Pa Vacuuming time: 1 to 100 minutes The processing pressure in this step is lower than the processing pressure in step A.

[0061] By evacuating the processing chamber 201, the first gas, the second gas, reaction products, inert gas, etc. remaining in the processing chamber 201 are removed from the processing chamber 201, and the processing chamber 201, and at least the surface of the wafer 200, are cleaned.

[0062] After the evacuation of the processing chamber 201 is completed, the valve opening of the APC valve 244 is adjusted (reduced) to control so that the inside of the processing chamber 201 is pressurized to a predetermined pressure. When the inside of the processing chamber 201 reaches the predetermined pressure, the next step B2 is executed.

[0063] [Step B2] In this step, an inert gas is supplied to the wafer 200 in the processing chamber 201 .

[0064] Specifically, the valves 243c and 243d are opened to allow the inert gas to flow into the gas supply pipes 232c and 232d. The inert gas is supplied into the process chamber 201 via the nozzles 249a and 249b, and exhausted from the exhaust port 231a, with the flow rate adjusted by the MFCs 241c and 241d. At this time, the inert gas is supplied to the wafer 200 from the side of the wafer 200 (inert gas supply).

[0065] The processing conditions for supplying the inert gas in this step are as follows: Treatment temperature: 300 to 500°C, preferably 350 to 450°C Treatment pressure: 1 to 100 Pa, preferably 10 to 30 Pa Inert gas supply flow rate (per gas supply pipe): 2 to 10 slm, preferably 3 to 5 slm Inert gas supply time: 1 to 100 minutes The treatment pressure in this step is preferably lower than the treatment pressure in step A.

[0066] By supplying an inert gas to the wafer 200 under the above-mentioned processing conditions, the processing chamber 201 is purged, the first gas, the second gas, reaction by-products, etc. remaining in the processing chamber 201 are removed from the processing chamber 201, and the atmosphere within 201 is replaced with the inert gas.

[0067] After purging of the processing chamber 201 is completed, the valves 243c and 243d are closed, and the supply of the inert gas into the processing chamber 201 is stopped.

[0068] [Perform the specified number of times] By performing the above-mentioned steps A and B asynchronously, that is, in this order, m times (m is an integer of 1 or 2 or more), a cycle can be formed on the surface of the wafer 200 with a desired thickness. The above-mentioned cycle is preferably repeated a plurality of times. That is, it is preferable to make the thickness of the film formed per cycle thinner than the desired film thickness, and to repeat the above-mentioned cycle a plurality of times until the film formed by stacking the films formed in each cycle has a desired film thickness. In addition, in step B performed after performing step A, a cycle (hereinafter sometimes referred to as a planarization cycle) in which steps B1 and B2 are performed asynchronously, that is, in this order, n times (n is an integer of 1 or 2 or more) is performed. This can improve the flatness of the surface of the film formed on the wafer 200. The flatness of the surface of the film will be described in detail later.

[0069] (Purge and return to atmospheric pressure) After the film formation process is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a and 249b into the processing chamber 201, and exhausted from the exhaust port 231a. This causes the processing chamber 201 to be purged, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (purging). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (return to atmospheric pressure).

[0070] (Boat unloading and wafer discharging) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafers 200 are supported by the boat 217 and transferred from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After the boat unloading, the shutter 219s is moved, and the lower end opening of the manifold 209 is sealed by the shutter 219s via the O-ring 220c. After being transferred to the outside of the reaction tube 203, the processed wafers 200 are taken out of the boat 217 (wafer discharging).

[0071] (3) Effects of this embodiment According to this embodiment, one or more of the following effects can be obtained.

[0072] (a) In step B, by improving the flatness of the surface of the film formed on the wafer 200, it becomes possible to improve the surface roughness (roughness) of the film. This will be described below. Here, the surface roughness (roughness) means the height difference of the film in the wafer plane (synonymous with surface roughness), and the smaller the value, the smoother the surface. That is, improving the surface roughness means reducing the height difference of the film and improving the smoothness of the surface.

[0073] In the present disclosure, a state where the number of R is less than that in M1Rx is also referred to as M1Ra. a is an integer of 1 or more, and is in the relationship of a < x. Also, a state where the number of R is less than that in M2Ry is also referred to as M2Rb. b is an integer of 1 or more, and is in the relationship of b < y. In the following example, the case of using a material where M1 is Si and R is H, and a material where M2 is P and R is H will be described. In this case, M1Rx is SiH4, and M1Ra includes at least one of SiH3, SiH2, SiH, etc. M2Ry is PH3, and M2Rb includes at least one of PH2, PH, etc.

[0074] As described above, step A is performed under conditions in which the first gas and the second gas are thermally decomposed. As a result, in step A, at least a part of the molecular structure of the molecules constituting the first gas and at least a part of the molecular structure of the molecules constituting the second gas are adsorbed (deposited) on the wafer 200, forming a film. Specifically, for example, when M1Rx gas is used as the first gas and M2Ry gas is used as the second gas, the molecules constituting the first gas (M1Rx) and the molecules constituting the second gas (M2Ry) are physically adsorbed on the wafer 200, or a part of the molecular structure of the molecules constituting the first gas (M1Ra) and a part of the molecular structure of the molecules constituting the second gas (M2Rb) are physically adsorbed or chemically adsorbed, and these are deposited, forming a film containing the first element and the second element. Since M1Ra, M2Rb, etc. are physically adsorbed or chemically adsorbed on the outermost surface of the film formed in this manner, the flatness of the surface of the film is likely to deteriorate, and the surface roughness may increase.

[0075] (b) In this embodiment, in step B, at least a part of the molecules (M1Rx, M1Ra, M2Ry, M2Rb) adsorbed on the top surface of the film formed on the wafer 200 is removed. Specifically, in step B2, an inert gas is supplied to the wafer 200, so that the molecules of the inert gas collide with the molecules (M1Rx, M1Ra, M2Ry, M2Rb) adsorbed on the surface of the film, and these are desorbed from the surface of the film. This improves the flatness of the surface of the film and improves the surface roughness of the film. Note that removing at least a part of the molecules (M1Rx, M1Ra, M2Ry, M2Rb) adsorbed on the top surface of the film in step B results in a reduction in the number of atoms (first element, second element) constituting the film and a reduction in the number of molecules adsorbed on the surface of the film. In this specification, the molecules adsorbed on the outermost surface of the film or the molecules adsorbed on the surface of the film include molecules constituting the first gas (M1Rx), molecules constituting the second gas (M2Ry), a part of the molecular structure of the molecules constituting the first gas (M1Ra), and a part of the molecular structure of the molecules constituting the second gas (M2Rb).

[0076] (c) In addition, in this embodiment, at least the physically adsorbed molecules among the molecules physically adsorbed and chemically adsorbed on the surface of the film are removed in step B. Specifically, in step B2, an inert gas is supplied to the wafer 200, and the molecules of the inert gas are collided with the molecules physically adsorbed on the surface of the film (M1Rx, M1Ra, M2Ry, M2Rb) and the molecules chemically adsorbed on the surface of the film, and at least the physically adsorbed molecules are desorbed from the surface of the film. In this way, by desorbing the physically adsorbed molecules, which account for the overwhelming majority of the molecules physically adsorbed and chemically adsorbed on the surface of the film, from the surface of the film, the flatness of the surface of the film can be effectively improved and the surface roughness of the film can be effectively improved. In addition, by desorbing the physically adsorbed molecules, which have a weaker adsorption force (bonding force) to the surface of the wafer 200 among the molecules physically adsorbed and chemically adsorbed on the surface of the film, from the surface of the film, the flatness of the surface of the film can be effectively improved and the surface roughness of the film can be effectively improved. In this specification, the term "physical adsorbed molecules" refers to molecules constituting the first gas (M1Rx), molecules constituting the second gas (M2Ry), a part of the molecular structure of the molecules constituting the first gas (M1Ra), and a part of the molecular structure of the molecules constituting the second gas (M2Rb). In addition, in this specification, the term "chemically adsorbed molecules" refers to a part of the molecular structure of the molecules constituting the first gas (M1Ra) and a part of the molecular structure of the molecules constituting the second gas (M2Rb).

[0077] (d) In this embodiment, in step B, some of the molecules chemically adsorbed on the surface of the film are removed. Specifically, in step B2, an inert gas is supplied to the wafer 200, and the molecules of the inert gas collide with the molecules (M1Rx, M1Ra, M2Ry, M2Rb) adsorbed on the surface of the film, and some of the molecules (M1Ra, M2Rb) chemically adsorbed on the surface of the film are desorbed from the surface of the film. The molecules chemically adsorbed on the surface of the film here include not only molecules completely chemically adsorbed on the surface of the film, but also molecules that are in the process of being chemically adsorbed. The molecules that are completely chemically adsorbed on the surface of the film, that is, molecules that are not firmly adsorbed on the surface of the film, but molecules that are in the process of being chemically adsorbed (molecules that are not completely chemically adsorbed), that is, molecules that have a weak adsorption (bonding) force to the surface of the film. In this manner, by desorbing from the surface of the film the molecules that are in the process of being chemically adsorbed and are capable of being desorbed from the surface of the film, the flatness of the surface of the film can be effectively improved, and the surface roughness of the film can be effectively improved.

[0078] (e) Step B includes step B1 of removing gas from the processing chamber 201, and step B2 of supplying an inert gas thereafter. As described above, in step B2, an inert gas is supplied to the wafer 200 in the processing chamber 201, whereby the molecules of the inert gas collide with the molecules (M1Ra, M2Rb, etc.) adsorbed on the surface of the film, and these are desorbed from the surface of the film. In step B in this embodiment, step B1 is performed before the start of step B2, and the first gas, the second gas, etc. remaining in the processing chamber 201 are removed from the processing chamber 201, thereby cleaning the inside of the processing chamber 201 and at least the surface of the wafer 200 before the start of step B2. Here, cleaning the inside of the processing chamber 201 and at least the surface of the wafer 200 means reducing the number of molecules (M1Ra, M2Rb, etc.) present in the processing chamber 201 and at least the surface of the wafer 200. This can improve the probability that the molecules of the inert gas collide with the molecules (M1Ra, M2Rb, etc.) adsorbed on the surface of the film in step B2. As a result, the molecules (M1Ra, M2Rb, etc.) adsorbed on the surface of the film can be easily desorbed from the surface of the film. Furthermore, by improving the cleanliness inside the processing chamber 201 in step B1, it becomes possible to suppress the molecules (M1Ra, M2Rb, etc.) desorbed from the surface of the film from being re-adsorbed onto the surface of the wafer 200 in step B2. As a result, the flatness of the surface of the film can be effectively improved, and the surface roughness of the film can be effectively improved.

[0079] (f) The process pressure in each of steps B1 and B2 in step B is lower than the process pressure in step A. As a result, in step B1, the inside of the process chamber 201 can be effectively cleaned, and in step B2, the molecules (M1Ra, M2Rb, etc.) desorbed from the surface of the film can be effectively prevented from being re-adsorbed onto the surface of the wafer 200.

[0080] (g) In step B1, the APC valve 244 is fully opened to effectively remove gas remaining in the process chamber 201 and clean the process chamber 201. This improves the probability that the molecules of the inert gas supplied in step B2 collide with the molecules (M1Ra, M2Rb, etc.) adsorbed on the surface of the film, and facilitates desorption of these molecules (M1Ra, M2Rb, etc.). In addition, it is possible to prevent M1Ra, M2Rb, etc. desorbed from the surface of the film in step B2 from being re-adsorbed on the surface of the wafer 200.

[0081] (h) In step B, the valve opening of the APC valve 244 during step B2 is set smaller than the valve opening of the APC valve 244 before step B2 is performed. This can improve the probability that the molecules of the inert gas supplied in step B2 collide with the molecules (M1Ra, M2Rb, etc.) adsorbed on the surface of the film.

[0082] (i) In step B, by performing a planarization cycle including steps B1 and B2 n times (n is an integer of 1 or 2 or more), particularly multiple times, the flatness of the film surface can be effectively improved and the surface roughness of the film can be effectively improved.

[0083] (j) In this embodiment, in step A, two different types of gases, the first gas and the second gas, are simultaneously supplied to the wafer 200, which can easily cause excessive gas reaction and deteriorate the flatness of the film surface. However, according to this embodiment, the deterioration of the flatness of the film surface can be suppressed.

[0084] <Other Aspects of the Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0085] For example, in the above-mentioned embodiment, the first element contained in the first gas is Si. However, the present disclosure is not limited to such an embodiment. For example, the first element may be Ge (germanium). In this case, the first gas may be, for example, germane (GeH4) gas, digermane (Ge2H6) gas, trigermane (Ge3H8) gas, tetragermane (Ge4H 10 ) Gas, Pentagermane (Ge5H 12 ) gas, hexagermane (Ge6H 14 In this embodiment, the same effects as those in the above embodiment can be obtained.

[0086] For example, in the above-mentioned embodiment, the second element contained in the second gas is P, which is a group 15 element, as an example. However, the present disclosure is not limited to such an embodiment. For example, the second element may be arsenic (As), which is a group 15 element, or boron (B), Al (aluminum), gallium (Ga), or In (indium), which are group 13 elements. In this case, the second gas may be, for example, arsine (AsH3) gas, monoborane (BH3) gas, diborane (B2H6) gas, triborane (B3H8) gas, tetraborane (B4H 10 ) gas, boron trichloride (BCl3) gas, diboron tetrachloride (B2Cl4), aluminum chloride (AlCl3), gallium chloride (GaCl3), and indium chloride (InCl3) can be used as the second gas. In this embodiment, the same effects as those in the above embodiment can be obtained.

[0087] Although not specifically described in the above embodiment, a wafer 200 having a three-dimensional structure such as a trench, groove, or hole formed on the surface may be used. In this embodiment, the same effects as those in the above embodiment can be obtained. A film formed on the surface inside a recess tends to easily cause voids and seams during filling, but in this embodiment, it is possible to prevent the occurrence of voids and seams during filling.

[0088] In the above-mentioned embodiment, the case where the supply period of the first gas and the supply period of the second gas overlap in whole in step A, that is, the case where the first gas and the second gas are supplied simultaneously, has been described as an example. However, the present disclosure is not limited to such an embodiment. For example, in step A, the first gas and the second gas may be supplied so that at least a part of the supply period of the first gas and the supply period of the second gas overlap. In this embodiment, the same effect as the above-mentioned embodiment can be obtained. Note that the supply period of the first gas and the supply period of the second gas overlap at least a part of the period, and there are the following supply patterns. The following supply patterns are performed in step A. Here, "+" means that there is a period in which the gases described before and after "+" are supplied simultaneously, and "→" means that the gases are supplied in order and not simultaneously. When the same gas is described before and after "→", it means that the gas is continuously supplied. (1) First gas + second gas (2) First gas + second gas → first gas (3) First gas → First gas + Second gas (4) First gas → First gas + Second gas → First gas (5) First gas → First gas + Second gas → Second gas

[0089] In the above embodiment, in step B, step B1 of removing gas from the processing chamber 201 is performed, and then step B2 of supplying an inert gas is performed. However, the present disclosure is not limited to such an embodiment. For example, in step B, step B2 of supplying an inert gas may be performed first, and then step B1 of removing gas from the processing chamber 201 may be performed. In this embodiment, the same effects as those in the above embodiment can be obtained.

[0090] Although not specifically described in the above embodiment, when a cycle of steps A and B is performed a predetermined number of times, it is preferable to set the thickness of the film formed per cycle to a thickness of one atomic layer (1 to 2 Å), a thickness of two atomic layers, preferably a thickness of five atomic layers, and more preferably a thickness exceeding several atomic layers, and to repeat the above cycle 10 to 150 times until the final thickness reaches 100 to 150 Å. In this embodiment, the same effects as those in the above embodiment can be obtained. Furthermore, in this embodiment, in step B2, the molecules (SiH2, PH2, etc.) adsorbed on the surface of the film can be more efficiently desorbed from the surface of the film.

[0091] Although not specifically described in the above embodiment, when a cycle of non-simultaneous execution of step A and step B is performed m times (m is an integer of 1 or 2 or more), it is preferable to change the processing conditions in step B according to the thickness of the film formed per cycle. This is because, when the thickness of the film formed per cycle is large (thick), the flatness of the film surface tends to deteriorate, and when the thickness of the film formed per cycle is small (thin), the flatness of the film surface tends not to deteriorate. For this reason, when the thickness T1 of the film formed per cycle is thinner than the thickness T2 of the film formed per cycle, it is preferable to shorten the execution time of step B per cycle, reduce the processing pressure in step B, or reduce the supply flow rate of the inert gas supplied in step B1, compared to when the thickness of the film is T2. In this embodiment, the same effect as in the above embodiment can be obtained. In addition, in this embodiment, the flatness of the film surface can be further improved more effectively.

[0092] Although not described in detail in the above embodiment, regarding the implementation time of step A and the implementation time of step B, the implementation time of step A may be longer than the implementation time of step B, or the implementation time of step A may be shorter than the implementation time of step B. In either case, the same effect as in the above embodiment can be obtained.

[0093] In the above-mentioned embodiment, the case where the wafer 200 having a predetermined seed film formed on its surface is used has been described. However, the present disclosure is not limited to such an embodiment. For example, the wafer 200 having no predetermined seed film formed on its surface may be used. In this case, it is preferable to perform a step of forming a predetermined seed film on the surface of the wafer 200 before starting step A. In this embodiment, the same effect as the above-mentioned embodiment can be obtained.

[0094] In the above embodiment, the first gas and the second gas are supplied in step A. However, the present disclosure is not limited to this embodiment. For example, the second gas may not be supplied in step A. In this embodiment, the same effects as those in the above embodiment can be obtained.

[0095] It is preferable that the recipes used for each process are prepared individually according to the process contents, and are recorded and stored in the storage device 121c via an electric communication line or an external storage device 123. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process contents from among the multiple recipes recorded and stored in the storage device 121c. This makes it possible to form films of various film types, composition ratios, film qualities, and film thicknesses with good reproducibility using a single substrate processing device. It is also possible to reduce the burden on the operator, and to quickly start each process while avoiding operational errors.

[0096] The above-mentioned recipes may not only be newly created, but may also be prepared by modifying an existing recipe that has already been installed in the substrate processing apparatus. When modifying a recipe, the modified recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the recipe has been recorded. Also, an existing recipe that has already been installed in the substrate processing apparatus may be directly modified by operating the input / output device 122 provided in the existing substrate processing apparatus.

[0097] In the above-mentioned embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-mentioned embodiment, and can be suitably applied to, for example, a case where a film is formed using a single-wafer type substrate processing apparatus that processes one or several substrates at a time. In addition, in the above-mentioned embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall type processing furnace has been described. The present disclosure is not limited to the above-mentioned embodiment, and can be suitably applied to, for example, a case where a film is formed using a substrate processing apparatus having a cold-wall type processing furnace.

[0098] In the above embodiment, the above processing sequence is performed in the same processing chamber of the same processing apparatus (in-situ). The present disclosure is not limited to the above embodiment, and for example, one step and another step of the above processing sequence may be performed in different processing chambers of different processing apparatuses (ex-situ), or may be performed in different processing chambers of the same processing apparatus.

[0099] When using these substrate processing apparatuses, each process can be performed according to the same process procedures and under the same process conditions as in the above-described aspects and modifications, and the same effects as in the above-described aspects and modifications can be obtained.

[0100] The above-mentioned aspects and modifications may be used in appropriate combination. The processing procedures and processing conditions in such a case may be the same as those of the above-mentioned aspects and modifications. [Explanation of symbols]

[0101] 200 wafers (substrates)

Claims

1. (a) supplying a first gas and a second gas to a substrate to form a film; (b) improving the flatness of the surface of the film; A substrate processing method comprising the steps of:

2. (a) is carried out under conditions in which the first gas and the second gas are thermally decomposed; The method for processing a substrate according to claim 1 .

3. In (a), the first gas and the second gas are supplied such that a supply period of the first gas and a supply period of the second gas overlap each other at least partially. The method for processing a substrate according to claim 1 .

4. In the step (a), at least a part of a molecular structure of a molecule constituting the first gas and at least a part of a molecular structure of a molecule constituting the second gas are adsorbed onto a surface of the film; The substrate processing method according to claim 2 .

5. In step (b), at least the physically adsorbed molecules are removed from among the molecules physically adsorbed and the molecules chemically adsorbed on the surface of the film. The substrate processing method according to claim 4 .

6. In step (b), a part of the molecules chemically adsorbed on the surface of the film is removed. The substrate processing method according to claim 4 .

7. A recess is formed in the substrate, The film is formed on a surface within the recess. The method for processing a substrate according to claim 1 .

8. (b) supplying an inert gas to the membrane; The method for processing a substrate according to claim 1 .

9. (b) includes: (b1) a step of removing gas from a space in which the substrate is present; and (b2) a step of supplying the inert gas thereafter. The substrate processing method according to claim 8 .

10. In (b), a cycle including (b1) and (b2) is performed a predetermined number of times. The substrate processing method according to claim 9 .

11. In (b), when (b1) is performed, the valve for exhausting the space is set to a fully open state. The substrate processing method according to claim 9 .

12. In (b), the opening degree of the valve when (b2) is being executed is made smaller than the opening degree before (b2) is executed. The method of claim 11.

13. (b) reducing the number of atoms constituting the film; The method for processing a substrate according to claim 1 .

14. (b) reducing the number of at least one of molecules and atoms adsorbed on the surface of the film; The substrate processing method according to claim 4 .

15. (b) removing at least a portion of the molecules adsorbed on the outermost surface of the film; The substrate processing method according to claim 4 .

16. (a) and (b) are non-simultaneously performed a predetermined number of times, and the processing conditions in (b) are changed according to the thickness of the film formed per cycle. The method of claim 1 .

17. When the thickness T1 of the film formed per cycle is thinner than the thickness T2 of the film formed per cycle, the implementation time of (b) per cycle is made shorter than when the thickness of the film is T2. The method of claim 16.

18. (a) supplying a first gas and a second gas to a substrate to form a film; (b) improving the flatness of the surface of the film; A method for manufacturing a semiconductor device having the above structure.

19. (a) supplying a first gas and a second gas to a substrate to form a film; (b) improving the planarity of the surface of the film; A program for causing a computer to execute the above for substrate processing.

20. a first gas supply system that supplies a first gas to the substrate; a second gas supply system that supplies a second gas to the substrate; a control unit configured to be able to control the first gas supply system and the second gas supply system so as to perform (a) a process of supplying the first gas and the second gas to the substrate to form a film, and (b) a process of improving a flatness of a surface of the film; A substrate processing apparatus comprising:

Images