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

Abstract

To provide a technique capable of improving the step coverage of a film formed on a substrate.SOLUTION: A substrate processing method includes a process which includes the steps of (a1) supplying a first reformed gas to a substrate, (a2) supplying a first process gas having a first element to the substrate, (b1) supplying a second reformed gas to the substrate, and (b2) supplying, to the substrate, a second process gas that has a second element and that is easier to adsorb to an opening side of the substrate than the first processing gas under the same conditions, in which the step (a1) and the step (a2) are performed a first number of times and the step (b1) and the step (b2) are performed a second number of times, thereby forming a film including the first element and the second element. The step (b1) is performed in conditions where the second reformed gas is easier to adsorb to a surface of the substrate than the first reformed gas under the same conditions.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

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

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-085236 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can improve the step coverage of a film formed on a substrate. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, (a1) supplying a first modifying gas to a substrate; (a2) supplying a first process gas having a first element to the substrate; (b1) supplying a second modifying gas to the substrate; (b2) supplying to the substrate a second process gas having a second element and more easily adsorbed to the surface of the substrate than the first process gas under the same conditions; a step of performing (a1) and (a2) a first number of times and (b1) and (b2) a second number of times to form a film containing the first element and the second element; (b1) provides a technique in which the second modifying gas is more easily adsorbed to the surface of the substrate than the first modifying gas under the same conditions. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to improve the step coverage of a film formed on a substrate. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of a vertical processing furnace of a substrate processing system suitably used in each aspect of the present disclosure, showing a vertical cross-sectional view of the processing furnace portion. [Figure 2] FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing system suitably used in each aspect of the present disclosure, and is a cross-sectional view of the processing furnace portion taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic configuration diagram of the controller 121 of the substrate processing system suitably used in each aspect of the present disclosure, and is a block diagram showing the control system of the controller 121. [Figure 4] FIG. 4 is a diagram showing an example of a substrate processing sequence according to one embodiment of the present disclosure. [Figure 5] FIG. 5 is a diagram showing an example of a substrate processing sequence according to one embodiment of the present disclosure. [Figure 6]FIG. 6(a) is a diagram showing adsorption locations of a first modifying gas in the recesses of a wafer. FIG. 6(b) is a diagram showing adsorption locations of a first process gas supplied to a wafer after the first modifying gas has adsorbed into the recesses of the wafer. FIG. 6(c) is a diagram showing a first film formed after a predetermined number of cycles including a step of applying the first modifying gas to the wafer and a step of supplying the first process gas. FIG. 6(d) is a diagram showing adsorption locations of a second modifying gas in the recesses of a wafer after the first film has been formed. FIG. 6(e) is a diagram showing adsorption locations of a second process gas supplied to a wafer after the second modifying gas has adsorbed into the first film. FIG. 6(f) is a diagram showing a second film formed after a predetermined number of cycles including a step of supplying the second modifying gas to the wafer and a step of supplying the second process gas. [Figure 7] FIG. 7 is a diagram showing an example of a first recess and a second recess provided in the surface of a wafer. DETAILED DESCRIPTION OF THE INVENTION

[0008] <One aspect of the present disclosure> Hereinafter, one embodiment of the present disclosure will be described mainly with reference to Figures 1 to 4, 6(a) to 6(f), and 7. Note that the drawings used in the following description are all schematic, and the dimensional relationships between elements, the ratios of elements, etc. shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, etc. do not necessarily match between multiple drawings.

[0009] (1) Configuration of the substrate processing equipment 1, the process furnace 202 has a heater 207 as a heating mechanism (temperature adjustment 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) gases with 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 has a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is disposed concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) and has a cylindrical shape with open upper and lower ends. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing member. The reaction tube 203 is installed vertically, similar to the heater 207. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to be able to accommodate wafers 200 as substrates. In the processing chamber 201, processing of the wafers 200 is performed.

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

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

[0013] 2, the nozzles 249a to 249c are provided in a circular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, along the inner wall of the reaction tube 203 from the bottom to the top, so as to rise upward in the arrangement direction of the wafers 200. That is, the nozzles 249a to 249c are provided in regions that horizontally surround the wafer arrangement region on the sides of the wafer arrangement region where the wafers 200 are arranged, so as to extend along the wafer arrangement region.

[0014] The nozzle 249a is disposed farther from the exhaust port 231a (described later) than the nozzles 249b and 249c. That is, the nozzles 249b and 249c are disposed closer to the exhaust port 231a than the nozzle 249a. In addition, the nozzles 249b and 249c are disposed symmetrically with respect to the center of the wafer 200 when the wafer 200 is loaded into the processing chamber 201, that is, a line passing through the center of the reaction tube 203 and the center of the exhaust port 231a, in a plan view. The nozzles 249a and 249b are disposed opposite each other on a straight line across the center of the reaction tube 203.

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

[0016] A second modifying gas is supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0017] A first reactive gas serving as a first processing gas is supplied from the gas supply pipe 232c into the processing chamber 201 via the MFC 241c, the valve 243c, and the nozzle 249c.

[0018] A first source gas serving as a first process gas is supplied from the gas supply pipe 232d into the processing chamber 201 via the MFC 241d, the valve 243d, the gas supply pipe 232b, and the nozzle 249b.

[0019] A second source gas serving as a second process gas is supplied from the gas supply pipe 232e into the processing chamber 201 via the MFC 241e, the valve 243e, the gas supply pipe 232b, and the nozzle 249b.

[0020] A second reactive gas serving as a second process gas is supplied from the gas supply pipe 232f into the process chamber 201 via the MFC 241f, the valve 243f, the gas supply pipe 232c, and the nozzle 249c.

[0021] Inert gases are supplied from the gas supply pipes 232g to 232i through the MFCs 241g to 241i, the valves 243g to 243i, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c into the processing chamber 201. The inert gases act as purge gases, carrier gases, dilution gases, etc.

[0022] The first modifying gas supply unit mainly includes the gas supply pipe 232a, the MFC 241a, and the valve 243a. The second modifying gas supply unit mainly includes the gas supply pipe 232b, the MFC 241b, and the valve 243b. The first process gas supply unit (first source gas supply unit, first reactant gas supply unit) mainly includes the gas supply pipes 232c and 232d, the MFCs 241c and 241d, and the valves 243c and 243d. The second process gas supply unit (second source gas supply unit, second reactant gas supply unit) mainly includes the gas supply pipes 232e and 232f, the MFCs 241e and 241f, and the valves 243e and 243f. The inert gas supply unit mainly includes the gas supply pipes 232g to 232i, the MFCs 241g to 241i, and the valves 243g to 243i.

[0023] Any or all of the various gas supply units described above may be configured as an integrated gas supply system 248 in which valves 243a-243i, MFCs 241a-241i, etc. are integrated. The integrated gas supply system 248 is connected to each of the gas supply pipes 232a-232i, and is configured so that the supply operation of various gases into the gas supply pipes 232a-232i, i.e., the opening and closing operation of the valves 243a-243i and the flow rate adjustment operation by the MFCs 241a-241i, etc., are controlled by a controller 121, which will be described later. The integrated gas supply system 248 is configured as an integrated or separate integrated unit, and can be attached and detached to and from the gas supply pipes 232a-232i, etc., so that maintenance, replacement, expansion, etc. of the integrated gas supply system 248 can be performed on an integrated unit basis.

[0024] An exhaust port 231a for exhausting the atmosphere inside the processing chamber 201 is provided at the bottom of the sidewall of the reaction tube 203. The exhaust port 231a may be provided along the sidewall of the reaction tube 203 from the bottom to the top, i.e., along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246 serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) that detects the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 can evacuate and stop the evacuation inside the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, the pressure inside the processing chamber 201 can be adjusted by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. An exhaust system is mainly 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.

[0025] Below the manifold 209, a seal cap 219 is provided as a furnace port cover capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is made of a metal material such as SUS and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a sealing member that abuts against the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 is provided to rotate the boat 217 (described later). A rotation shaft 255 of the rotation mechanism 267 penetrates the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the boat 217, thereby rotating the wafers 200. The seal cap 219 is configured to be vertically raised and lowered by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the wafers 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219.

[0026] A shutter 219s is provided below the manifold 209 as a furnace port cover that can airtightly close the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is removed from the processing chamber 201. The shutter 219s is made of a metal material such as SUS and has a disk shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a sealing member that abuts against the lower end of the manifold 209. The opening and closing operation (lifting and lowering operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0027] The boat 217, serving as a substrate support, is configured to support multiple wafers (e.g., 25 to 200 wafers) 200 in a horizontal position, aligned vertically with their centers aligned, and arranged in multiple stages, i.e., spaced apart. The boat 217 is made of a heat-resistant material such as quartz or SiC. A heat insulating plate 218, also made of a heat-resistant material such as quartz or SiC, is supported in multiple stages below the boat 217. Note that in this specification, a numerical range such as "25 to 200 wafers" means that the lower and upper limits are included in the range. Therefore, for example, "25 to 200 wafers" means "25 to 200 wafers." The same applies to other numerical ranges.

[0028] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 can be adjusted to a desired temperature distribution. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0029] 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 also be connected to the controller 121.

[0030] The storage device 121c is configured with, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. Control programs for controlling the operation of the substrate processing apparatus, process recipes describing procedures and conditions for substrate processing (described later), etc., are readably recorded and stored in the storage device 121c. The process recipe is a combination of procedures for substrate processing (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 recipes, control programs, etc. are collectively referred to simply as programs. The process recipes are also simply referred to as recipes. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (work area) for temporarily storing programs, data, etc. read by the CPU 121a.

[0031] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241i, valves 243a to 243i, 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.

[0032] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a recipe from the storage device 121c in response to an input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 241a to 241i, the opening and closing operations of the valves 243a to 243g, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the boat elevator 115, the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, and the like.

[0033] 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, a USB memory, a semiconductor memory such as an SSD, etc. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to simply as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0034] (2) Substrate processing process An example of a processing sequence for forming a film on a wafer 200, which is a substrate having recesses such as trenches formed in its surface, using the above-mentioned substrate processing apparatus as one step in the manufacturing process of a semiconductor device will be described mainly with reference to Figures 4 and 6(a) to 6(f). In the following description, the operation of each part constituting the substrate processing apparatus is controlled by a controller 121.

[0035] In the processing sequence of this embodiment, (a1) supplying a first modifying gas to the wafer 200; (a2) supplying a first process gas having a first element to the wafer 200; (b1) supplying a second modifying gas to the wafer 200; (b2) supplying a second process gas to the wafer 200, the second process gas having a second element and more easily adsorbed to the surface of the wafer 200 than the first process gas under the same conditions; a step of performing (a1) and (a2) a first number of times (n1 times, n1 is an integer of 1 or 2 or more) and performing (b1) and (b2) a second number of times (n2 times, n2 is an integer of 1 or 2 or more) to form a film containing a first element and a second element (film formation step); (b1) is performed under conditions in which the second modifying gas is more easily adsorbed onto the surface of the wafer 200 than the first modifying gas under the same conditions.

[0036] In the following example, the first process gas is a gas (film formation gas) containing a first source gas and a first reactive gas, and the second process gas is a gas (film formation gas) containing a second source gas and a second reactive gas. Here, the second source gas is a gas that is more easily adsorbed to the surface of the wafer 200 than the first source gas under the same conditions. In the following example, the first process gas containing the first element is supplied with a first source gas and a first reactive gas containing the first element, and the second process gas containing the second element is supplied with a second source gas and a second reactive gas containing the second element.

[0037] In the following example, the first modifying gas is a gas (film formation inhibiting gas) that inhibits the reaction between the first processing gas (first raw material gas and / or first reactive gas) and the surface of the wafer 200, and the second modifying gas is a gas (film formation inhibiting gas) that inhibits the reaction between the second processing gas (second raw material gas and / or second reactive gas) and the surface of the wafer 200.

[0038] In the following, as a typical example, in the film formation step, as shown in FIG. a cycle including step A1 of supplying a first modifying gas to the wafers 200, step A2 of supplying a first source gas as a first process gas to the wafers 200, and step A3 of supplying a first reactive gas as a first process gas to the wafers 200 is performed a first number of times (n1 times, n1 is an integer of 1 or 2 or more) to form a first film containing a first element; This embodiment describes a case where a cycle including step B1 of supplying a second modifying gas to the wafer 200 on which a first film is formed, step B2 of supplying a second source gas as a second process gas to the wafer 200 on which the first film is formed, and step B3 of supplying a second reactive gas as a second process gas to the wafer 200 on which the first film is formed is performed a second number of times (n2 times, where n2 is an integer of 1 or 2 or more) to form a second film containing a second element on the first film, thereby forming a laminated film composed of a first film containing the first element and a second film containing the second element. In this embodiment, this embodiment describes a case where a laminated film is formed by performing the first film formation and the second film formation once each. Here, the laminated film may be a film containing the first element and the second element. Alternatively, the laminated film formation may be the formation of a film containing the first element and the second element.

[0039] In this specification, for convenience, the processing sequence shown in Fig. 4 may be expressed as follows: Similar notations will be used in the following explanations of modified examples and other aspects.

[0040] (First reformed gas → First raw material gas → First reactant gas) × n1 → (Second reformed gas → Second raw material gas → Second reactant gas) × n2

[0041] The term "wafer" used in this specification may refer to the wafer itself or to 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 refer to the surface of the wafer itself or to the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0042] The term "layer" as used herein includes at least one of a continuous layer and a discontinuous layer. The layer formed in each step described below may include a continuous layer, a discontinuous layer, or both.

[0043] (Wafer charge and boat load) When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s, and the lower end opening of the manifold 209 is opened (shutter open). Thereafter, as shown in FIG. 1 , the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b. In this manner, the wafers 200 are prepared in the processing chamber 201.

[0044] (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 exhausted) by the vacuum pump 246 so that the interior 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 (pressure adjustment). Furthermore, the wafers 200 inside the processing chamber 201 are heated by the heater 207 so that the desired processing temperature is reached. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the interior of the processing chamber 201 has a desired temperature distribution (temperature adjustment). Furthermore, the rotation mechanism 267 starts to rotate the wafers 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0045] <Laminated film formation> (First film formation) In forming the first film, the following steps A1, A2, and A3 are performed.

[0046] [Step A1] In step A1, a first modifying gas is supplied to the wafer 200 in the processing chamber 201.

[0047] Specifically, the valve 243a is opened to allow a first modifying gas to flow into the gas supply pipe 232a. The flow rate of the first modifying gas is adjusted by the MFC 241a, and the first modifying gas is supplied into the processing chamber 201 through the nozzle 249a and exhausted from the exhaust port 231a. At this time, the first modifying gas is supplied to the wafer 200 (first modifying gas supply). At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201 through each of the nozzles 249a to 249c.

[0048] By supplying the first modifying gas to the wafer 200 under processing conditions described below, the first modifying gas can be adsorbed onto the surface of the wafer 200, thereby modifying at least a portion of the surface of the wafer 200. Furthermore, by supplying the first modifying gas to the wafer 200 under processing conditions described below, the first modifying gas can be made less likely to adsorb onto the surface of the wafer 200 than the second modifying gas under the same conditions. Furthermore, by supplying the first modifying gas to the wafer 200 under processing conditions described below, the amount of the first modifying gas adsorbed onto the deep side 302 of the recess 300 can be made smaller than the amount of the first modifying gas adsorbed onto the opening side 301 (see FIG. 6(a)). In steps A2 and A3 described below, the first modifying gas prevents the first source gas and / or the first reactive gas from adsorbing onto the surface of the wafer 200, thereby inhibiting (suppressing) the progress of the film formation reaction on the surface of the wafer 200. In this specification, the "deep side 302 of the recess 300" refers to a location, such as the bottom of the recess 300, where the gas supplied to the wafer 200 is less likely to reach compared to the opening side 301 of the recess 300, and the surrounding area.

[0049] The processing conditions for supplying the first modifying gas in step A1 are as follows: Treatment temperature: 300 to 850°C, preferably 600 to 750°C Processing pressure: 1 to 5000 Pa First reformed gas supply flow rate: 0.05 to 10.0 slm First reforming gas supply time: 5 to 300 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm is exemplified.

[0050] In this specification, the processing temperature 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. Furthermore, a gas supply flow rate of 0 slm means that the gas is not supplied. These also apply to the following explanations.

[0051] The first modifying gas may be, for example, a gas containing a halogen. The halogen includes at least one of chlorine (Cl), fluorine (F), bromine (Br), and iodine (I). The first modifying gas may be, for example, fluorine (F2) gas, chlorine (Cl2) gas, bromine (Br2) gas, iodine (I2) gas, nitrogen fluoride (NF3) gas, chlorine fluoride (ClF3) gas, hydrogen fluoride (HF) gas, hydrogen chloride (HCl) gas, hydrogen bromide (HBr) gas, or hydrogen iodide (HI) gas. One or more of these may be used as the first modifying gas.

[0052] The first modifying gas may be, for example, a halosilane gas containing silicon (Si) and a halogen. The halosilane gas may be, for example, a chlorosilane gas containing Si and Cl, such as dichlorosilane (SiH2Cl2) gas, trichlorosilane (SiHCl3) gas, tetrachlorosilane (SiCl4), pentachlorodisilane (Si2H1Cl5), or hexachlorodisilane (Si2Cl6) gas. One or more of these may be used as the first modifying gas.

[0053] Furthermore, a gas containing an organic compound can be used as the first modifying gas. The gas containing an organic compound can be a gas containing at least one selected from the group consisting of an ether compound, a ketone compound, an amine compound, and an organic hydrazine compound. The gas containing an ether compound can be a gas containing at least one of dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, isopropyl ether, furan, tetrahydrofuran, pyran, tetrahydropyran, etc. The gas containing a ketone compound can be a gas containing at least one of dimethyl ketone, diethyl ketone, methyl ethyl ketone, methyl propyl ketone, etc. The gas containing an amine compound can be a gas containing at least one of methylamine compounds such as monomethylamine, dimethylamine, and trimethylamine, ethylamine compounds such as monoethylamine, diethylamine, and triethylamine, and methylethylamine compounds such as dimethylethylamine and methyldiethylamine. The gas containing an organic hydrazine compound can be a gas containing at least one of methylhydrazine-based gases such as monomethylhydrazine, dimethylhydrazine, and trimethylhydrazine. As the first modifying gas, one or more of these can be used.

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

[0055] After the first modifying gas is adsorbed onto the surfaces of the wafers 200 (surfaces in the recesses 300), the valve 243a is closed to stop the supply of the first modifying gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gaseous substances remaining in the processing chamber 201. At this time, the valves 243g to 243i are opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c acts as a purge gas, thereby purging the space in which the wafers 200 exist, i.e., the processing chamber 201.

[0056] [Step A2] After step A1 is completed, the first source gas containing the first element is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 after the first modifying gas has been adsorbed on the surface of the recess 300.

[0057] Specifically, the valve 243d is opened to allow the first source gas to flow into the gas supply pipe 232d. The flow rate of the first source gas is adjusted by the MFC 241d, and the first source gas is supplied into the processing chamber 201 via the gas supply pipe 232a and the nozzle 249a, and is exhausted from the exhaust port 231a. At this time, the first source gas is supplied to the wafers 200 (first source gas supply). At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201 via each of the nozzles 249a to 249c.

[0058] By supplying the first source gas containing the first element to the wafer 200 under processing conditions to be described later, the first source gas can be adsorbed to portions of the surface of the wafer 200 (surfaces within the recessed portion 300) where the first modifying gas has not been adsorbed (see FIG. 6(b)). More specifically, the adsorption of the first source gas is inhibited at the portions of the surface within the recessed portion 300 where the first modifying gas has been adsorbed, and the first source gas (first element) is preferentially adsorbed to the portions where the first modifying gas has not been adsorbed, thereby forming a first-element-containing layer in those portions (regions).

[0059] The processing conditions for supplying the first source gas in step A2 are as follows: Processing pressure: 1 to 10,000 Pa First raw material gas supply flow rate: 0.05 to 3 slm, preferably 0.1 to 2 slm First raw material gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds Other processing conditions may be the same as the processing conditions when the first modifying gas is supplied in step A1.

[0060] After the first element-containing layer is formed on the surface of the wafer 200 (the surface inside the recess 300), the valve 243d is closed to stop the supply of the first source gas into the processing chamber 201. Then, gaseous substances remaining in the processing chamber 201 are removed (purged) from the processing chamber 201 using the same processing procedure and processing conditions as those for purging in step A1.

[0061] [Step A3] After step A2 is completed, a first reaction gas is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 after the first element-containing layer has been formed on the surface inside the recess 300.

[0062] Specifically, the valve 243c is opened to allow a first reactive gas to flow into the gas supply pipe 232c. The flow rate of the first reactive gas is adjusted by the MFC 241c, and the first reactive gas is supplied into the processing chamber 201 through the nozzle 249c and exhausted from the exhaust port 231a. At this time, the first reactive gas is supplied to the wafer 200 (first reactive gas supply). At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201 through each of the nozzles 249a to 249c.

[0063] By supplying a first reactive gas to the wafer 200 after the formation of the first element-containing layer under the processing conditions described below, it is possible to react at least a portion of the first element-containing layer with the first reactive gas, modify the first element-containing layer, and form a first modified layer.

[0064] The processing conditions for supplying the first reactive gas in step A3 are as follows: Processing pressure: 1 to 10,000 Pa First reactant gas supply flow rate: 1 to 30 slm, preferably 2 to 20 slm First reaction gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds Other processing conditions may be the same as the processing conditions when the first modifying gas is supplied in step A1.

[0065] The first reactive gas may be, for example, oxygen (O2) gas, ozone (O3) gas, hydrogen (H2) gas + oxygen (O2) gas, or oxygen radical (O2 * An oxygen (O)-containing gas such as H2 gas or O2 gas can be used. In this specification, the description of two gases together, such as "H2 gas + O2 gas," means a mixed gas of H2 gas and O2 gas. When a mixed gas is supplied, the two gases may be mixed (premixed) in a supply pipe and then supplied into the processing chamber 201, or the two gases may be supplied separately from different supply pipes into the processing chamber 201 and mixed (postmixed) in the processing chamber 201. One or more of these gases can be used as the first reactive gas.

[0066] After the first element-containing layer formed inside the recess 300 is changed into the first modified layer, the valve 243c is closed to stop the supply of the first reactive gas into the processing chamber 201. Then, gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201 (purging) using the same processing procedures and conditions as those for purging in step A1.

[0067] [Perform the specified number of times] By performing steps A1, A2, and A3 non-simultaneously, i.e., non-synchronized, in this order, a cycle of n1 times (n1 is an integer of 1 or greater) can form a first film on the surface of the wafer 200 (see FIG. 6(c)). For example, an Al-containing gas containing aluminum (Al) as a first element can be used as the first source gas, and an oxygen (O)-containing gas can be used as the first reactive gas. In this case, an aluminum oxide film (AlO film) is formed as the first film on the surface of the wafer 200. It is preferable to repeat the above cycle multiple times. That is, it is preferable to set the thickness of the first modified layer formed per cycle to be thinner than the desired film thickness, and to repeat the above cycle multiple times until the thickness of the first film formed by stacking the first modified layers reaches the desired film thickness.

[0068] (Second film formation) In forming the second film, the following steps B1, B2, and B3 are performed.

[0069] [Step B1] In step B1, a second modifying gas is supplied to the wafer 200 on which the first film is formed.

[0070] Specifically, the valve 243b is opened to allow the second modifying gas to flow into the gas supply pipe 232b. The flow rate of the second modifying gas is adjusted by the MFC 241b, and the second modifying gas is supplied into the processing chamber 201 through the nozzle 249b and exhausted from the exhaust port 231a. At this time, the second modifying gas is supplied to the wafer 200 (second modifying gas supply). At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0071] By supplying the second modifying gas to the wafer 200 under processing conditions described below, the second modifying gas can be adsorbed onto the surface of the first film, thereby modifying at least a portion of the surface of the first film. Furthermore, by supplying the first modifying gas to the wafer 200 under processing conditions described below, the second modifying gas can be more easily adsorbed onto the surface of the wafer 200 than the first modifying gas under the same conditions. By supplying the second modifying gas to the wafer 200 under processing conditions described below, the amount of the second modifying gas adsorbed on the deep side 302 of the recess 300 can be made smaller than the amount adsorbed on the opening side 301 (see FIG. 6(d)). The second modifying gas prevents the second source gas and the second reactive gas from adsorbing onto the surface of the first film in steps B2 and B3 described below, thereby inhibiting (suppressing) the progress of the film-forming reaction on the surface of the first film.

[0072] The processing conditions for supplying the second modifying gas in step B1 are as follows: Processing pressure: 1 to 1000 Pa Second reformed gas supply flow rate: 0.01 to 1 slm Second reforming gas supply time: 2 to 250 seconds is exemplified.

[0073] At this time, for reasons described below, it is preferable to set the conditions of step A1 and step B1 so that the second modifying gas is more easily adsorbed to the surface of the wafer 200 than the first modifying gas under the same conditions. For example, it is preferable to set the pressure (processing pressure) in the space where the wafer 200 exists in step B1 lower than the processing pressure in step A1. Also, for example, it is preferable to set the time during which the second modifying gas is supplied to the wafer 200 in step B1 shorter than the time during which the first modifying gas is supplied to the wafer 200 in step A1. Also, for example, it is preferable to set the partial pressure of the second modifying gas in the space where the wafer 200 exists (inside the processing chamber 201) in step B1 lower than the partial pressure of the first modifying gas in the processing chamber 201 in step A1.

[0074] As the second modifying gas, a predetermined gas can be arbitrarily selected from the first modifying gases exemplified in step A1. The second modifying gas used in step B1 and the first modifying gas used in step A1 may be the same gas (gas having the same molecular structure) or different gases (gas having different molecular structures). When the first modifying gas and the second modifying gas are the same gas, the configuration of the gas supply system can be simplified.

[0075] When a gas different from the first modifying gas is used as the second modifying gas, the gas species of the first and second modifying gases may be selected so that the second modifying gas has a higher adsorption property to the surface of the wafer 200 than the first modifying gas. This allows the second modifying gas to be more easily adsorbed to the surface of the wafer 200 than the first modifying gas under the same conditions, which is preferable for reasons described below. For example, it is preferable to use a second modifying gas having a molecular weight larger than that of the first modifying gas. It is also preferable to use a second modifying gas having a molecular radius larger than that of the first modifying gas. It is also preferable to use a second modifying gas having a higher reactivity to the surface of the wafer 200 than the first modifying gas under the same conditions. It is also preferable to use a gas that chemically reacts with the adsorption sites on the surface of the wafer 200 as the second source gas, and a gas that physically adsorbs to the adsorption sites on the surface of the wafer 200 as the first source gas. As a result, the amount of the second modifying gas adsorbed to the deep side 302 of the recess 300 can be made smaller than the amount of the first modifying gas adsorbed to the deep side 302 of the recess 300 in step A1. Here, the "adsorbability to the surface of the wafer 200" of the gas refers to the ease with which the gas is adsorbed to the opening side 301 of the wafer 200. Furthermore, for example, when an organic gas and an inorganic gas are used as the first source gas and the second source gas, an organic gas and an inorganic gas can be used as the first modifying gas and the second modifying gas accordingly.

[0076] After the second modifying gas is adsorbed, the valve 243b is closed to stop the supply of the second modifying gas into the processing chamber 201. Then, gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201 (purged) using the same processing procedures and conditions as those used in the purging in step A1.

[0077] [Step B2] After step B1 is completed, a second source gas containing a second element is supplied to the wafers 200 in the processing chamber 201, that is, to the wafers 200 after the second modifying gas has been adsorbed onto the surfaces of the recesses 300.

[0078] Specifically, the valve 243e is opened to allow the second source gas to flow into the gas supply pipe 232e. The flow rate of the second source gas is adjusted by the MFC 241e, and the second source gas is supplied into the processing chamber 201 via the gas supply pipe 232b and the nozzle 249b, and is exhausted from the exhaust port 231a. At this time, the second source gas is supplied to the wafers 200 (second source gas supply). At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201 via the nozzles 249a to 249c, respectively.

[0079] By supplying the second source gas containing the second element to the wafer 200 under processing conditions to be described later, the second source gas can be adsorbed to portions of the surface of the wafer 200 (the surface of the first film in the recess 300) where the second modifying gas has not been adsorbed (see FIG. 6(e)). More specifically, the adsorption of the second source gas is inhibited at the portions of the surface of the first film in the recess 300 where the second modifying gas has been adsorbed, and the second source gas (second element) is preferentially adsorbed to the portions where the second modifying gas has not been adsorbed, thereby forming a second-element-containing layer in those portions (regions).

[0080] The processing conditions for supplying the second source gas in step B2 are as follows: Processing pressure: 1 to 10,000 Pa Second raw material gas supply flow rate: 0.05 to 3 slm, preferably 0.1 to 2 slm Second raw material gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds Other processing conditions may be the same as the processing conditions when the first modifying gas is supplied in step A1.

[0081] The first element contained in the first source gas and the second element contained in the second source gas may be the same element or different elements.

[0082] After the second element-containing layer is formed on the first film, the valve 243e is closed to stop the supply of the second source gas into the processing chamber 201. Then, gaseous substances remaining in the processing chamber 201 are removed from the processing chamber 201 (purging) using the same processing procedure and processing conditions as those used in the purging in step A1.

[0083] [Step B3] After step B2 is completed, a second reaction gas is supplied to the wafer 200 in the processing chamber 201, that is, the wafer 200 after the second element-containing layer has been formed on the surface inside the recess 300.

[0084] Specifically, the valve 243f is opened to allow the second reactive gas to flow into the gas supply pipe 232f. The flow rate of the second reactive gas is adjusted by the MFC 241f, and the second reactive gas is supplied into the processing chamber 201 via the gas supply pipe 232c and the nozzle 249c, and is exhausted from the exhaust port 231a. At this time, the second reactive gas is supplied to the wafers 200 (second reactive gas supply). At this time, the valves 243g to 243i may be opened to supply an inert gas into the processing chamber 201 via each of the nozzles 249a to 249c.

[0085] By supplying a second reactive gas to the wafer 200 after the second element-containing layer has been formed under the processing conditions described below, at least a portion of the second element-containing layer can be reacted with the second reactive gas, and the second element-containing layer can be modified to form a second modified layer.

[0086] The processing conditions for supplying the second reaction gas in step B3 are as follows: Processing pressure: 1 to 10,000 Pa Second reactant gas supply flow rate: 1 to 30 slm, preferably 2 to 20 slm Second reactant gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds Other processing conditions may be the same as the processing conditions when the first modifying gas is supplied in step A1.

[0087] The second reactive gas can be any gas selected from the first reactive gases exemplified in step A2. The second reactive gas used in step B3 and the first reactive gas used in step A3 may have the same or different molecular structures.

[0088] [Perform the specified number of times] By performing steps B1, B2, and B3 asynchronously, i.e., in this order, n2 times (n2 is an integer of 1 or greater), it is possible to form a second film on the surface of the wafer 200 (see FIG. 6(f)). For example, a Hf-containing gas containing hafnium (Hf) as the second element can be used as the second source gas, and an O-containing gas can be used as the second reactive gas. In this case, a hafnium oxide film (HfO film) is formed as the second film on the surface of the wafer 200. It is preferable to repeat the above-described cycle multiple times. That is, it is preferable to set the thickness of the second modified layer formed per cycle thinner than the desired film thickness, and to repeat the above-described cycle multiple times until the thickness of the second film formed by stacking the second modified layer reaches the desired film thickness.

[0089] By performing a cycle of steps A1, A2, and A3 in this order n1 times (first number of times) to form a first film, and performing a cycle of steps B1, B2, and B3 in this order n2 times (second number of times) to form a second film, a laminated film can be formed on the surface of wafer 200, consisting of the first film and the second film stacked in this order.

[0090] (After purging and atmospheric pressure recovery) After the formation of the stacked film is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a to 249c into the processing chamber 201 and exhausted from the exhaust port 231a. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure return).

[0091] (Boat unloading and wafer discharge) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafers 200, supported by the boat 217, are unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After the boat unloading, the shutter 219s is moved, and the opening at the lower end of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). After being unloaded to the outside of the reaction tube 203, the processed wafers 200 are removed from the boat 217 (wafer discharge).

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

[0093] (a) In step B1, conditions are set such that the second modifying gas is more easily adsorbed to the surface of the wafer 200 than the first modifying gas under the same conditions. At this time, the amount of the second modifying gas adsorbed to the deep side 302 of the recess 300 is less than the amount of the first modifying gas adsorbed to the deep side 302 of the recess 300 in step A1. This makes it possible to improve the step coverage of the laminated film formed by laminating the first film and the second film. Furthermore, in step B2, by making it easier for the second source gas to be adsorbed to the deep side 302 of the recess 300, it is possible to improve the film formation rate. These are described below.

[0094] As described above, in step B2, the wafer 200 is supplied with the second source gas, which is more likely to be adsorbed to the opening side 301 than the first source gas under the same conditions. Furthermore, gas supplied to the wafer 200 having the recessed portion 300 tends to reach (be adsorbed to) the opening side 301 more easily and to reach (be adsorbed to) the deep side 302 less easily. Therefore, compared with the first source gas supplied under the same conditions, the second source gas tends to be more adsorbed to the opening side 301 and less adsorbed to the deep side 302. Therefore, for example, when the first modifying gas and the second modifying gas are adsorbed to the same extent on the deep side 302, the thickness of the second film on the deep side 302 tends to be smaller than that of the first film, and the step coverage of the second film tends to be lower than that of the first film. Therefore, it is preferable that the amount of the second modifying gas adsorbed to the deep side 302 be smaller than the amount of the first modifying gas adsorbed to the deep side 302. Furthermore, if the step coverage of the second film decreases, the step coverage of the stacked film formed by the first film and the second film also decreases.

[0095] In this embodiment, step B1 is performed under conditions that allow the second modifying gas to be more easily adsorbed onto the surface of the wafer 200 than the first modifying gas under the same conditions. This allows the amount of the second modifying gas adsorbed onto the deep side 302 in step B1 to be less than the amount of the first modifying gas adsorbed onto the deep side 302 in step A1. That is, the second modifying gas is preferentially adsorbed onto the opening side 301 (see FIGS. 6(a) and 6(d)). This makes it possible to easily inhibit the adsorption of the second source gas onto the opening side 301 and to make it less inhibited the adsorption of the second source gas onto the deep side 302. This reduces the difference in the amount of adsorption of the second source gas between the opening side 301 and the deep side 302 of the recess 300, thereby forming a second film with excellent step coverage (see FIG. 6(f)). Furthermore, the improved step coverage of the second film allows for improved step coverage of the stacked film.

[0096] Furthermore, since the process gas (source gas or reactive gas) is less likely to reach the deep side 302 of the recess 300 than the opening side 301, the amount of process gas adsorbed on the deep side 302 is smaller than that on the opening side 301. Therefore, if the second modifying gas is adsorbed on the deep side 302, it will lead to an overall delay in the formation of the second film. In this embodiment, as described above, the second modifying gas is preferentially adsorbed on the opening side 301. In other words, the amount of the second modifying gas adsorbed on the deep side 302 is reduced. Therefore, even if a gas that inhibits adsorption of the process gas is used, a decrease in the film formation rate of the second film on the deep side 302 can be suppressed. This also leads to a suppression of a decrease in the film formation rates of the second film and the stacked film. However, it is preferable that the supply conditions of the second modifying gas in step B1 be set so as to prevent excessive adsorption of the second modifying gas on the opening side 301 from adversely affecting the step coverage of the second film.

[0097] (b) By making the amount of the first modifying gas adsorbed on the deep side 302 of the recess 300 less than the amount of the first modifying gas adsorbed on the opening side 301 (see FIG. 6(a)), it is possible to easily inhibit the adsorption of the first source gas on the opening side 301 and to make it difficult to inhibit the adsorption of the first source gas on the deep side 302. This makes it possible to reduce the difference in the amount of adsorption of the first source gas on the opening side 301 and the deep side 302 of the recess 300, thereby making it possible to form a first film and a laminated film with excellent step coverage (see FIG. 6(c)).

[0098] (c) The pressure (processing pressure) in the space where the wafer 200 exists in step B1 may be set lower than the processing pressure in step A1. This allows the amount of the second modifying gas adsorbed to the deep side 302 of the recess 300 in step B1 to be smaller than the amount of the first modifying gas adsorbed to the deep side 302 of the recess 300 in step A1. This allows the step coverage and film formation rate of the second film and the stacked film to be improved.

[0099] (d) The time for supplying the second modifying gas to the wafers 200 in step B1 may be shorter than the time for supplying the first modifying gas to the wafers 200 in step A1. This makes it possible to make the amount of the second modifying gas adsorbed to the deep side 302 of the recess 300 in step B1 smaller than the amount of the first modifying gas adsorbed to the deep side 302 of the recess 300 in step A1. This makes it possible to improve the step coverage and film formation rate of the second film and the stacked film.

[0100] (e) In step B1, the partial pressure of the second modifying gas in the space (inside the processing chamber 201) where the wafer 200 exists may be set lower than the partial pressure of the first modifying gas in the processing chamber 201 in step A1. This makes it possible to make the amount of the second modifying gas adsorbed to the deep side 302 of the recess 300 in step B1 smaller than the amount of the first modifying gas adsorbed to the deep side 302 of the recess 300 in step A1. This makes it possible to improve the step coverage and film formation rate of the second film and the stacked film.

[0101] (f) By using the second modifying gas, which has a higher adsorptivity to the opening side 301 of the wafer 200 than the first modifying gas, the step coverage and film formation rate of the second film and the stacked film can be further improved.

[0102] (g) By using at least one of the first and second source gases as a gas containing no organic ligand, the amount of carbon (C) incorporated as an impurity into the laminated film can be reduced, thereby improving the etching resistance and electrical properties of the first and / or second film and the laminated film.

[0103] (h) The above-mentioned effects can be similarly obtained when a predetermined gas is arbitrarily selected from various modifying gases, various raw material gases, various reactive gases, and various inert gases.

[0104] <Other Aspects of the Present Disclosure> Although various aspects of the present disclosure have been specifically described above, the present disclosure is not limited to the above-described aspects and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0105] For example, in the above-described embodiment, a case has been described in which a first film is formed followed by a second film to form a laminated film. That is, a case has been described in which a cycle of performing steps A1, A2, and A3 in this order is performed n1 times, followed by a cycle of performing steps B1, B2, and B3 in this order n2 times to form a film containing a first element and a second element. However, the present disclosure is not limited to these embodiments. For example, a laminated film may be formed by forming a first film after a second film. That is, a cycle of performing steps B1, B2, and B3 in this order n2 times, followed by a cycle of performing steps A1, A2, and A3 in this order n1 times to form a film containing a first element and a second element. In these cases, the same effects as those of the above-described embodiment can be obtained.

[0106] For example, in the above-described embodiment, a laminated film composed of a first film containing a first element and a second film containing a second element is formed. However, the present disclosure is not limited to this embodiment. For example, a film containing the first element and the second element (a film mainly composed of the first element and the second element) may be formed by using a first gas containing a first element and a second gas containing a second element, whichever is less likely to adsorb to the surface of the wafer 200 as the first process gas and the other as the second process gas. For example, of titanium tetrachloride (TiCl4) gas containing titanium (Ti), which is a metal element, and ammonia (NH3) gas containing nitrogen (N), NH3 gas, which is less likely to adsorb to the surface of the wafer 200, may be used as the first process gas (reactive gas), and TiCl4 gas may be used as the second process gas (source gas). In this case, the first element is N, the second element is Ti, and a titanium nitride film (TiN film) is formed as a film containing the first element and the second element. That is, one of the first process gas and the second process gas may be a source gas and the other may be a reactive gas. In this case, the source gas may be a gas exemplified as a first source gas or a second source gas, as described later. Furthermore, the reactive gas may be a gas exemplified as a first reactive gas or a second reactive gas, as described later. In this case, the same effects as those of the above embodiment can be obtained.

[0107] For example, in the above-described embodiment, a laminate film is formed by forming the first film and the second film once each. However, the present disclosure is not limited to this embodiment. For example, the laminate film may be formed by alternately forming the first film and the second film multiple times. Even in this case, the same effect as in the above-described embodiment can be obtained. Here, the laminate film formed by laminating a first film containing a first element and a second film containing a second element may be a film containing the first element and the second element.

[0108] For example, in the above-described embodiment, both the first and second reactive gases are O-containing gases. However, the present disclosure is not limited to such an embodiment. For example, the first and second reactive gases may be not only O-containing gases but also nitrogen (N)-containing gases, carbon (C)-containing gases such as organic gases, hydrogen (H)-containing gases such as H2 gas, or mixtures thereof. Examples of N-containing gases include nitrogen-containing gases (N- and H-containing gases) containing N-H bonds, such as ammonia (NH3) gas, hydrazine (NH2) gas, diazene (NH2) gas, and N3H8 gas, as well as N2 gas. By supplying these gases to the wafer 200, for example, a metal film, a metal nitride film, a metal carbide film, a metal oxynitride film, a metal oxycarbide film, a metal carbonitride film, or a metal oxycarbonitride film may be formed as the first and / or second film or stacked film. Even in these cases, the same effects as those of the above-described embodiment can be obtained.

[0109] When the first element and the second element are, for example, Si, the first source gas and the second source gas can be, for example, a gas containing halogen and Si, i.e., a halosilane-based gas. Halogen includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. The halosilane-based gas can be, for example, the above-mentioned chlorosilane-based gas containing Cl and Si.

[0110] The first and / or second source gases may include, for example, a gas containing a metal element such as titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), aluminum (Al), molybdenum (Mo), tungsten (W), silicon (Si), or germanium (Ge) as the first and / or second element. The gas containing a metal element may include, for example, a gas containing a molecule having a metal element and a ligand bonded thereto, such as trimethylaluminum (Al(CH3)3) gas. The ligand may be, for example, an organic ligand, preferably a hydrocarbon group containing at least one selected from the group consisting of alkyl groups such as methyl, ethyl, propyl, and butyl, cyclopentadienyl, cyclohexadienyl, and cycloheptatrienyl.

[0111] Here, the first and / or second source gases containing Zr may be, for example, a gas containing at least one selected from the group consisting of tetrakisethylmethylaminozirconium (Zr[N(CH3)C2H5]4), tetrakisdiethylaminozirconium (Zr[N(C2H5)2]4), tetrakisdimethylaminozirconium (Zr[N(CH3)2]4), Zr(MMP)4, Zr(O-tBu)4, and trisdimethylaminocyclopentadienylzirconium ((C5H5)Zr[N(CH3)2]3). One or more of these may be used as the first and / or second source gases.

[0112] Furthermore, examples of gases containing Hf as the first element and / or second element include gases containing at least one selected from the group consisting of tetrakisethylmethylaminohafnium (Hf[N(CH3)C2H5]4), tetrakisdiethylaminohafnium (Hf[N(C2H5)2]4), tetrakisdimethylaminohafnium (Hf[N(CH3)2]4), Hf(O-tBu)4, Hf(MMP)4, and trisdimethylaminocyclopentadienylhafnium ((C5H5)Hf[N(CH3)2]3). One or more of these can be used as the first source gas and / or the second source gas.

[0113] Furthermore, examples of gases containing Ti as the first element and / or second element include gases containing at least one selected from the group consisting of tetrakisethylmethylaminotitanium (Ti[N(CH3)C2H5]4), tetrakisdiethylaminotitanium (Ti[N(C2H5)2]4), tetrakisdimethylaminotitanium (Ti[N(CH3)2]4), Ti(O-tBu)4, Ti(MMP)4, and trisdimethylaminocyclopentadienyltitanium ((C5H5)Ti[N(CH3)2]3). One or more of these can be used as the first source gas and / or the second source gas.

[0114] Furthermore, as the first source gas and / or the second source gas, for example, an inorganic metal source gas containing a metal element and a halogen element can also be used. For example, inorganic metal source gases containing metal elements and halogen elements such as titanium tetrachloride (TiCl4) gas, titanium tetrafluoride (TiF4) gas, zirconium tetrachloride (ZrCl4) gas, zirconium tetrafluoride (ZrF4) gas, hafnium tetrachloride (HfCl4) gas, hafnium tetrafluoride (HfF4) gas, tantalum pentachloride (TaCl5) gas, tantalum pentafluoride (TaF5) gas, niobium pentachloride (NbCl5) gas, niobium pentafluoride (NbF5) gas, aluminum trichloride (AlCl3) gas, aluminum trifluoride (AlF3) gas, molybdenum pentachloride (MoCl5) gas, molybdenum pentafluoride (MoF5) gas, tungsten hexachloride (WCl6) gas, and tungsten hexafluoride (WF6) gas can be used. One or more of these can be used as the first source gas and / or the second source gas.

[0115] Furthermore, as the gas containing Si as the first element and / or the second element, for example, a silane-based gas such as monosilane (SiH4) gas, disilane (Si2H6) gas, or trisilane (Si3H8) gas can be used. The above-mentioned halosilane gas can also be used. One or more of these can be used as the first source gas and / or the second source gas.

[0116] As described above, the second source gas (second process gas) is a gas that is more likely to be adsorbed to the surface of the wafer 200 than the first source gas (first process gas) under the same conditions. This relationship is more likely to hold when, for example, the second source gas is a gas that is more reactive with the surface of the wafer 200 than the first source gas under the same conditions. This relationship is also more likely to hold when, for example, the second source gas is a gas having a functional group that is more reactive with adsorption sites on the surface of the wafer 200 than the first source gas under the same conditions. This relationship is also more likely to hold when, for example, the first source gas is a gas that does not have a cyclic structure in its molecule and the second source gas is a gas that has a cyclic structure (e.g., a five-membered carbon ring structure) in its molecule. This relationship is also more likely to hold when, for example, the second source gas is a gas that has more ligands than the first source gas. A gas with a larger molecular weight may be more likely to be adsorbed to the surface of the wafer 200 due to van der Waals forces between the second source gas and the surface of the wafer 200. For this reason, even when a gas having a larger molecular weight than the first source gas is used as the second source gas, the second source gas may be more easily adsorbed onto the surface of the wafer 200 than the first source gas under the same conditions.

[0117] For example, in the above-described embodiment, the first process gas includes a first precursor gas containing a first element and a first reactive gas, and the second process gas includes a second precursor gas containing a second element and a second reactive gas. However, the present disclosure is not limited to this embodiment. For example, the first process gas may not include the first reactive gas, and the second process gas may not include the second reactive gas. In other words, the first film formation step (step A3) may not be performed, and the second film formation step (step B3) may not be performed. Even in these cases, the same effects as those of the above-described embodiment can be obtained.

[0118] For example, in the above-described embodiment, the first modifying gas is supplied once in step A1. However, the present disclosure is not limited to this embodiment. For example, in step A1, the first modifying gas may be supplied multiple times with purging or evacuation of the processing chamber 201 performed in between. In this case, the same effects as those of the above-described embodiment can be obtained. The same applies to the supply of the first source gas, first reactant gas, second modifying gas, second source gas, and second reactant gas in steps A2, A3, B1, B2, and B3, respectively.

[0119] For example, in the above-described embodiment, steps A1, A2, and A3 are performed in this order a predetermined number of times in forming the first film. However, the present disclosure is not limited to this embodiment. For example, steps A1, A2, and A3 may be performed a predetermined number of times, and then only steps A2 and A3 may be performed a predetermined number of times. In this case, the same effect as in the above-described embodiment can be obtained. The same applies to the formation of the second film (steps B1, B2, and B3).

[0120] For example, in step B1, the supply time of the second modifying gas may be longer than the supply time of the first modifying gas in step A1 while the partial pressure of the second modifying gas is set to be lower than the partial pressure of the first modifying gas in step A1. In this way, it is possible to increase the amount of the second modifying gas adsorbed to the opening side 301 while suppressing an increase in the amount of the second modifying gas adsorbed to the deep side 302. Therefore, it is possible to further enhance the effect of the above-mentioned aspect.

[0121] For example, it is preferable to set the supply flow rate of the second reforming gas in step B1 lower than the supply flow rate of the first reforming gas in step A1 (see FIG. 5). In this way, the partial pressure of the second reforming gas in step B1 can be set lower than the partial pressure of the first reforming gas in step A1, so that the amount of the second reforming gas adsorbed to the deep side 302 of the recessed portion 300 in step B1 can be set lower than the amount of the first reforming gas adsorbed to the deep side 302 of the recessed portion 300 in step A1. This can provide the same effect as the above-mentioned aspect.

[0122] For example, in the above-described embodiment, a recess 300 formed in the wafer 200 has an opening facing the space where the wafer 200 is processed, as shown in FIG. 6(a). However, the present disclosure is not limited to this embodiment. For example, the recess formed in the substrate may have a first recess having an opening facing the space where the substrate is processed, and a second recess having an opening within the first recess, as shown in FIG. 7. Furthermore, a plurality of pillars may be formed inside the substrate, for example, so as to cross the second recess in the same direction as the depth direction (e.g., vertical direction) of the first recess. A space is formed between each pillar in the second recess, through which the supplied gas can communicate. When a substrate having such a structure is processed according to the above-described embodiment, a film is formed on the surfaces of the first recess, the second recess, and the pillars. Even when such a substrate is used, the same effects as those of the above-described embodiment can be obtained.

[0123] For example, in the above-described embodiment, a film containing a first element and a second element is formed on the surface of the recess 300 provided in the wafer 200. However, the present disclosure is not limited to this embodiment. For example, the formation of a film containing the first element and the second element may be performed a predetermined number of times (one or more times) to fill the recess 300 with the film containing the first element and the second element (filled film formation, bottom-up film formation). In this case, the amount and size of voids (seams) present in the film can be reduced.

[0124] In the above-described embodiment, a film containing a first element and a second element is formed on the surface of the recess 300 formed in the wafer 200. However, the present disclosure is not limited to this embodiment. For example, when the wafer 200 has a first surface and a second surface different from the first surface, and the second process gas (second source gas and / or second reactive gas) is a gas that is more easily adsorbed to the first surface than the first process gas (first source gas and / or first reactive gas) under the same conditions, a process of supplying gases corresponding to the first modifying gas, the first process gas, the second modifying gas, and the second process gas may be performed to selectively form a film containing the first element and the second element on the second surface. In such a case, step B1 is performed under conditions under which the second modifying gas is more easily adsorbed to the first surface than the first modifying gas under the same conditions. This prevents the formation of a film on the first surface, i.e., suppresses selective breakdown.

[0125] It is preferable that the recipes used for each process are individually prepared according to the process content and recorded and stored in the storage device 121c via an electric communication line or the external storage device 123. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from the multiple recipes recorded and stored in the storage device 121c. This makes it possible to form films with various film types, composition ratios, film qualities, and film thicknesses with good reproducibility using a single substrate processing apparatus. It also reduces the burden on the operator, prevents operational errors, and enables each process to be started quickly.

[0126] The above-mentioned recipes do not necessarily have to be newly created, but may be prepared by modifying an existing recipe already installed in the substrate processing apparatus, for example. 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 modified recipe is recorded. Alternatively, an existing recipe already installed in the substrate processing apparatus may be directly modified by operating the input / output device 122 provided in the existing substrate processing apparatus.

[0127] In the above-described 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-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer-type substrate processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace. Furthermore, each process can be performed using the same process procedures and process conditions as in the above-described embodiment and modified examples, and the same effects as in the above-described embodiment and modified examples can be obtained.

[0128] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and processing conditions in such a case may be the same as those of the above-described embodiments and modifications, for example. [Explanation of symbols]

[0129] 200 wafers (substrates) 300 recess 301 Opening side 302 Deep Side

Claims

1. (a1) supplying a first modifying gas to a substrate; (a2) supplying a first source gas to the substrate, the first source gas having a first element and inhibited from reacting with the surface of the substrate by the first modifying gas; and (b1) supplying a second modifying gas to the substrate; (b2) supplying to the substrate a second source gas whose reaction with the surface of the substrate is inhibited by the second modifying gas, which has a second element, and which is more easily adsorbed to the surface of the substrate than the first source gas under the same conditions; and to form a film containing the first element and the second element, (b1) is performed under conditions in which the second modifying gas is more easily adsorbed onto the surface of the substrate than the first modifying gas supplied in (a1); Substrate processing method.

2. The substrate processing method of claim 1 , wherein the substrate has a recess.

3. the film is a stacked film including a first film containing the first element and a second film containing the second element; The substrate processing method according to claim 1 .

4. The molecular weight of the second source gas is larger than the molecular weight of the first source gas. The substrate processing method according to claim 1 .

5. the reactivity of the second source gas with respect to the surface of the substrate is higher than the reactivity of the first source gas with respect to the surface of the substrate under the same conditions; The substrate processing method according to claim 1 .

6. The first modified gas and the second modified gas are different gases. The substrate processing method according to any one of claims 1 to 5.

7. (b1) making the pressure in the space in which the substrate is present lower than the pressure in the space in (a1); The substrate processing method according to claim 6 .

8. (b1) supplying the second modifying gas to the substrate for a period shorter than (a1) supplying the first modifying gas to the substrate; The substrate processing method according to claim 6 .

9. (b1) making the partial pressure of the second modifying gas in the space where the substrate is present lower than the partial pressure of the first modifying gas in the space in (a1); The substrate processing method according to claim 6 .

10. (b1) supplying the second modifying gas to the substrate for a period longer than (a1) supplying the first modifying gas to the substrate; The substrate processing method according to claim 9 .

11. the adsorption of the second modifying gas to the surface of the substrate is higher than the adsorption of the first modifying gas to the surface of the substrate; The substrate processing method according to claim 6 .

12. The first modified gas and the second modified gas are the same gas, (b1) making the pressure in the space in which the substrate is present lower than the pressure in the space in (a1); (b1) supplying the second modifying gas to the substrate for a time period shorter than (a1) supplying the first modifying gas to the substrate; and (b1) making the partial pressure of the second modifying gas in the space where the substrate is present lower than the partial pressure of the first modifying gas in the space in (a1); (a1) and (b1) are performed so as to satisfy at least one of the following conditions: The substrate processing method according to any one of claims 1 to 5.

13. The recess includes a first recess having an opening facing a space for processing the substrate, and a second recess having an opening formed in a surface forming a side wall of the first recess. The substrate processing method according to claim 2 .

14. In the step of performing (a1) and (a2), (a3) supplying a first reactive gas to the substrate; Further, The substrate processing method according to any one of claims 1 to 5.

15. In the step of performing (b1) and (b2), (b3) supplying a second reactive gas to the substrate; Further, The substrate processing method according to claim 14.

16. (a1) supplying a first modifying gas to a substrate having a recess; (a2) supplying a first source gas to the substrate, the first source gas having a first element and inhibited from reacting with the surface of the substrate by the first modifying gas; and (b1) supplying a second modifying gas to the substrate; (b2) supplying to the substrate a second source gas whose reaction with the surface of the substrate is inhibited by the second modifying gas, which has a second element, and which is more easily adsorbed to the surface of the substrate than the first source gas under the same conditions; and to form a film containing the first element and the second element, (b1) is performed under conditions in which the second modifying gas is more easily adsorbed onto the surface of the substrate than the first modifying gas supplied in (a1); A method for manufacturing a semiconductor device.

17. a first modifying gas supply unit that supplies a first modifying gas to the substrate; a first source gas supply unit that supplies a first source gas having a first element to the substrate, the first source gas being inhibited from reacting with the surface of the substrate by the first modifying gas; a second modifying gas supply unit that supplies a second modifying gas to the substrate; a second source gas supply unit that supplies to the substrate a second source gas whose reaction with the surface of the substrate is inhibited by the second modifying gas, which contains a second element, and which is more easily adsorbed to the surface of the substrate than the first source gas under the same conditions; (a1) supplying the first modifying gas to the substrate; (a2) supplying the first source gas to the substrate; A process of performing (b1) supplying the second modifying gas to the substrate; (b2) supplying the second source gas to the substrate; A process of performing to form a film containing the first element and the second element, (b1) is a process performed under conditions in which the second modifying gas is more easily adsorbed to the surface of the substrate than the first modifying gas supplied in (a1); a control unit configured to be able to control the first modifying gas supply unit, the first raw material gas supply unit, the second modifying gas supply unit, and the second raw material gas supply unit; A substrate processing apparatus having:

18. (a1) supplying a first modifying gas to a substrate; (a2) supplying a first source gas to the substrate, the first source gas having a first element and inhibited from reacting with the surface of the substrate by the first modifying gas; and (b1) supplying a second modifying gas to the substrate; (b2) supplying to the substrate a second source gas whose reaction with the surface of the substrate is inhibited by the second modifying gas, which has a second element, and which is more easily adsorbed to the surface of the substrate than the first source gas under the same conditions; and to form a film containing the first element and the second element, (b1) is a step performed under conditions in which the second modifying gas is more easily adsorbed to the surface of the substrate than the first modifying gas supplied in (a1), A program executed by a computer in a substrate processing apparatus.

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