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

Abstract

The present disclosure provides a technique whereby it is possible to improve step coverage during film formation. According to one embodiment, provided is a technique involving: (a1) a step for modifying at least a part of a substrate by supplying a first modifying gas to the substrate; (a2) a step for supplying a first process gas containing a first element to the substrate, and preferentially adsorbing the first element in a region not modified by the first modifying gas; (b1) a step for modifying at least a part of the substrate by supplying, to the substrate, a second modifying gas having a decomposition temperature different from that of the first modifying gas; and (b2) a step for supplying a second process gas containing a second element to the substrate, and preferentially adsorbing the second element in a region not modified by the second modifying gas.

Description

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

[0001] The present disclosure is a technique that is effective when applied to a substrate processing method, a semiconductor device manufacturing method, a substrate processing apparatus, and a program.

[0002] 2. Description of the Related Art As device shapes have become finer and more complex in recent LSI manufacturing processes, there has been a demand for finer processing techniques (see, for example, Patent Documents 1 and 2).

[0003] JP 2017-69407 A JP 2013-197307 A

[0004] The present disclosure provides a technique for improving step coverage and filling characteristics in film formation.

[0005] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0006] A representative embodiment of the present disclosure provides a technique comprising: (a1) supplying a first modifying gas to a substrate to modify at least a portion of the substrate; (a2) supplying a first processing gas containing a first element to the substrate to preferentially adsorb the first element to an area not modified by the first modifying gas; (b1) supplying a second modifying gas having a decomposition temperature different from that of the first modifying gas to the substrate to modify at least a portion of the substrate; and (b2) supplying a second processing gas containing a second element to the substrate to preferentially adsorb the second element to an area not modified by the second modifying gas.

[0007] The present disclosure can improve step coverage and filling characteristics during film formation.

[0008] FIG. 1 is a vertical cross-sectional view of a substrate processing apparatus according to an embodiment. FIG. 2 is a block diagram showing the configuration of a controller provided in the substrate processing apparatus of FIG. 1. FIG. 3 is a diagram showing a first substrate processing method according to an embodiment. FIG. 4 is a diagram showing a second substrate processing method according to an embodiment. FIG. 5 is a diagram showing the configuration of a gas supply pipe system used in the second substrate processing method. FIG. 6 is a diagram explaining film formation when a first modifying gas is used. FIG. 7(a) is a diagram showing adsorption locations of the first modifying gas. FIG. 7(b) is a diagram showing adsorption locations of the second modifying gas. FIG. 8(a) is a diagram showing adsorption locations of the first modifying gas in a first film formation step. FIG. 8(b) is a diagram showing a film formed in the first film formation step. FIG. 8(c) is a diagram showing adsorption locations of the second modifying gas in a second film formation step. FIG. 8(d) is a diagram showing a film formed in the second film formation step.

[0009] Hereinafter, embodiments will be described with reference to the drawings. However, in the following description, the same components are denoted by the same reference numerals, and repeated description may be omitted. Note that the drawings may be depicted more schematically than the actual embodiment to clarify the description, but these are merely examples and do not limit the interpretation of the present disclosure. Furthermore, all drawings used in the following description are schematic, and the dimensional relationships, ratios, etc. of the elements shown in the drawings may not necessarily match those of the actual embodiment. Furthermore, the dimensional relationships, ratios, etc. of the elements may not necessarily match between multiple drawings.

[0010] (1) Configuration of the Substrate Processing Apparatus Fig. 1 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus according to the present disclosure, showing a vertical cross-sectional view of the processing furnace portion. As shown in Fig. 1, the processing 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.

[0011] A reaction tube 203 is disposed inside the heater 207 concentrically with the heater 207. The reaction tube 203 is made of, for example, quartz (SiO ２The reaction tube 203 is made of a heat-resistant material such as silicon carbide (SiC) or silicon carbide (SiC) and has a cylindrical shape with a closed top and an open bottom. 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 top and bottom ends. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 to support the reaction tube 203. An O-ring 220a serving as a sealing member is provided between the manifold 209 and the reaction tube 203. 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 accommodate wafers 200 as substrates. In this processing chamber 201, processing of the wafer 200 is performed.

[0012] Nozzles 249a to 249e serving as first to fifth supply units are provided within the processing chamber 201, penetrating the sidewall of the manifold 209, respectively. In FIG. 1, three nozzles, 249a to 249c, are depicted, while two nozzles, 249d to 249e, are omitted from the drawing to avoid complicating the illustration. The nozzles 249a to 249e are also referred to as the first to fifth nozzles. The nozzles 249a to 249e are made of a heat-resistant material such as quartz or SiC. Gas supply pipes 232a to 232e are connected to the nozzles 249a to 249e, respectively. The nozzles 249a to 249e are different nozzles.

[0013] The gas supply pipes 232a to 232e are respectively provided with mass flow controllers (MFCs) 241a to 241e, which are flow rate control devices (flow rate control parts), and valves 243a to 243e, which are on-off valves, in order from the upstream side of the gas flow. Gas supply pipes 232f to 232j are connected to the gas supply pipes 232a to 232e downstream of the valves 243a to 243e. Gas supply pipes The gas supply pipes 232f to 232j are respectively provided with MFCs 241f to 241j and valves 243f to 243j in order from the upstream side of the gas flow. The gas supply pipes 232a to 232j are made of a metal material, such as SUS.

[0014] The nozzles 249a to 249e are respectively provided in an annular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, extending from the bottom to the top of the inner wall of the reaction tube 203 and rising upward in the arrangement direction of the wafers 200. That is, the nozzles 249a to 249e are respectively provided in regions horizontally surrounding the wafer arrangement region on the sides of the wafer arrangement region in which the wafers 200 are arranged, and extending along the wafer arrangement region. For example, in a plan view, the nozzle 249c is disposed so as to face an exhaust port 231a (described later) on a straight line across the center of the wafer 200 being loaded into the processing chamber 201. The nozzles 249a and 249b and the nozzles 249d and 249e are disposed so as to sandwich a straight line passing through the nozzle 249c and the center of the exhaust port 231a along the inner wall of the reaction tube 203 (the outer periphery of the wafers 200) from both sides. The straight line is also a line passing through the nozzle 249c and the center of the wafer 200. In other words, the nozzle 249c can be said to be provided on the opposite side of the nozzle 249a with the straight line in between. The nozzles 249a and 249b and the nozzles 249d and 249e are arranged symmetrically with the straight line as the axis of symmetry. Gas supply holes 250a to 250d for supplying gas are provided on the side surfaces of the nozzles 249a to 249e, respectively. Each of the gas supply holes 250a to 250d opens to face (face) the exhaust port 231a in a plan view, enabling gas to be supplied toward the wafer 200. A plurality of the gas supply holes 250a to 250d are provided from the bottom to the top of the reaction tube 203.

[0015] A first process gas (first source gas) containing a first element, such as a silicon-containing gas containing silicon (Si) as the first element, is supplied from the gas supply pipe 232a into the process chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a. The Si-containing gas may be, for example, a silane gas containing Si as the main element.

[0016] From the gas supply pipe 232b, a first modifying gas (first film formation inhibiting gas, first inhibitor), for example, a gas containing Si as a first element and a halogen element, i.e., a halosilane gas, is supplied into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0017] From the gas supply pipe 232c, a second processing gas (second raw material gas) containing a second element, for example, silane gas containing Si as the second element, is supplied into the processing chamber 201 via an MFC 241c, a valve 243c, and a nozzle 249c.

[0018] From the gas supply pipe 232d, a second modifying gas (second film formation inhibiting gas, second inhibitor), for example, a gas containing Si as a second element and a halogen element, i.e., a halosilane gas, is supplied into the processing chamber 201 via the MFC 241d, the valve 243d, and the nozzle 249d.

[0019] A reaction gas is supplied from the gas supply pipe 232e into the processing chamber 201 via an MFC 241e, a valve 243e, and a nozzle 249e.

[0020] From the gas supply pipes 232f to 232j, an inert gas such as nitrogen (N ２ ) gases are supplied into the processing chamber 201 via the MFCs 241f to 241j, the valves 243f to 243j, and the nozzles 249a to 249e, respectively. The inert gas acts as a purge gas, a carrier gas, a dilution gas, and the like.

[0021] A first process gas (first source gas) supply system is mainly constituted by the gas supply pipe 232a, the MFC 241a, and the valve 243a. A first modifying gas supply system is mainly constituted by the gas supply pipe 232b, the MFC 241b, and the valve 243b. A second process gas (second source gas) supply system is mainly constituted by the gas supply pipe 232c, the MFC 241c, and the valve 243c. A second modifying gas supply system is mainly constituted by the gas supply pipe 232d, the MFC 241d, and the valve 243d. A reactive gas supply system is mainly constituted by the gas supply pipe 232e, the MFC 241e, and the valve 243e. An inert gas supply system is mainly constituted by the gas supply pipes 232f to 232j, the MFCs 241f to 241j, and the valves 243f to 243j.

[0022] 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 243j, the MFCs 241a to 241j, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232j, and is configured so that the supply operation of various gases into the gas supply pipes 232a to 232j, i.e., the opening and closing operation of the valves 243a to 243j and the flow rate adjustment operation by the MFCs 241a to 241j, etc., are controlled by a controller 121, which will be described later. The integrated supply system 248 is configured as an integrated or separate integrated unit, and can be attached and detached to and from the gas supply pipes 232a to 232j, etc., so that maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed on an integrated unit basis.

[0023] 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 is provided at a position facing (opposite) the nozzles 249a to 249e (gas supply holes 250a to 250e) across the wafer 200. The exhaust port 231a may be provided along the sidewall of the reaction tube 203 from the bottom to the top, i.e., along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246 serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 is configured to be able to evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating, and further, to be able to adjust the pressure inside the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be considered to be included in the exhaust system.

[0024] A seal cap 219 serving as a furnace port cover capable of airtightly closing the lower end opening of the manifold 209 is provided below 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 serving as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the seal cap 219. A rotation mechanism 267 for rotating the boat 217 (described later) is provided below the seal cap 219. A rotation shaft 255 of the rotation mechanism 267 passes through 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 serving as an elevating mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers (transfers) wafers 200 into and out of the process chamber 201 by raising and lowering the seal cap 219. 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 unloaded from the process 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 rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0025] The boat 217 serving as a substrate support is configured to support a plurality of wafers 200, for example, 25 to 200 wafers 200, in multiple stages, in a horizontal position, with their centers aligned and aligned vertically, 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, also made of a heat-resistant material such as quartz or SiC, are supported in multiple stages.

[0026] In this specification, when a numerical range such as "25 to 200 sheets" is expressed, it means that the lower limit and upper limit are included in the range. Therefore, for example, "25 to 200 sheets" means "25 sheets or more and 200 sheets or less." The same applies to other numerical ranges.

[0027] 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 temperature information detected by the temperature sensor 263, the temperature distribution inside the processing chamber 201 becomes a desired one. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0028] 2, 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, which is configured as, for example, a touch panel, is connected to the controller 121.

[0029] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk 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 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 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.

[0030] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241j, valves 243a to 243j, 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, etc.

[0031] The CPU 121a is configured to read and execute a control program from the storage device 121c, and also to read a recipe from the storage device 121c in response to input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 241a to 241j, the opening and closing operations of the valves 243a to 243j, 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.

[0032] The controller 121 can be configured by installing the above-mentioned program 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. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0033] (2) Substrate Processing Steps (2-1) First Substrate Processing Method FIG. 3 is a diagram illustrating a first substrate processing method according to an embodiment. An example of a substrate processing method for forming, for example, a film containing a first element (first film, first layer) and a film containing a second element (second film, second layer) on a wafer 200 as one step in a method for manufacturing a semiconductor device will be described with reference to FIG. 3 . In this example, the process involves forming a film containing a first element and a film containing a second element inside a recess formed on the surface of the wafer 200, and is performed using the processing furnace 202 of the substrate processing apparatus 10 described above. In the following description, the operation of each component constituting the substrate processing apparatus 10 is controlled by a controller 121.

[0034] The substrate processing process (semiconductor device manufacturing process) according to this embodiment includes, for example, the steps of: (a1) supplying a first modifying gas (first film-formation inhibiting gas, first inhibitor) to a substrate (wafer 200) to modify at least a portion of the substrate; (a2) supplying a first processing gas (first source gas) containing a first element to the substrate to preferentially adsorb the first element to an area not modified by the first modifying gas; (b1) supplying a second modifying gas (second film-formation inhibiting gas, second inhibitor) having a decomposition temperature different from that of the first modifying gas to the substrate to modify at least a portion of the substrate; and (b2) supplying a second processing gas (second source gas) containing a second element to the substrate to preferentially adsorb the second element to an area not modified by the second modifying gas.

[0035] In this specification, the term "wafer" may mean "the wafer itself" or "a laminate of a wafer and a predetermined layer, film, etc. formed on its surface." In this specification, the term "surface of a wafer" may mean "the surface of the wafer itself" or "the surface of a predetermined layer, film, etc. formed on the wafer." In this specification, the phrase "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, etc. formed on the wafer. In this specification, the term "substrate" is synonymous with the term "wafer."

[0036] 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, the processing time refers to the time the processing continues. These terms also apply to the following explanations.

[0037] (Substrate Loading Process) In the substrate loading process, (wafer charging and boat loading) and (pressure adjustment and temperature adjustment) are performed.

[0038] (Wafer Charging and Boat Loading) When a plurality of wafers 200 are loaded into the boat 217 (wafer charging), the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209 (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 loading). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0039] (Pressure Adjustment and Temperature Adjustment) 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 as to reach 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 this measured pressure information. Furthermore, the wafers 200 inside the processing chamber 201 are heated by the heater 207 so as to reach a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so as to achieve a desired temperature distribution inside the processing chamber 201. 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.

[0040] (First Film Forming Step: S1) Next, the first film forming step S1 is performed. In the first film forming step S1, the following steps (processes) are executed.

[0041] (Step a1) In this step, a first modifying gas is supplied to the wafer 200 in the processing chamber 201 to modify at least a part of the wafer 200 .

[0042] Specifically, the valve 243b is opened to allow the first modifying gas to flow into the gas supply pipe 232b. The flow rate of the first modifying gas is adjusted by the MFC 241b, and the first modifying gas is supplied into the processing chamber 201 via the nozzle 249b and exhausted from the exhaust port 231a. At this time, the first modifying gas is supplied to the wafer 200 (first modifying gas supply step). At this time, the valves 243f, 243h, 243i, and 243j are opened to supply N gas into the processing chamber 201 via the nozzles 249a, 249c, 249d, and 249e, respectively.

[0043] (Purge step sp1) After that, the valve 243b 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 gases remaining in the processing chamber 201. At this time, the valves 243f to 243j are opened to introduce N 2 into the processing chamber 201 through the nozzles 249a to 249e. ２ Gas is supplied from nozzles 249a to 249e. ２ The gas acts as a purge gas, thereby purging the inside of the processing chamber 201 .

[0044] (Step a2) After step a1 is completed, a first process gas (first source gas) is supplied to the surface of the wafer 200 in the process chamber 201. Adsorption of the first process gas is inhibited at locations on the surface of the wafer 200 where the first modifying gas was adsorbed in step a1. That is, in this step, the first process gas containing the first element is supplied to the wafer 200, and the first element is preferentially adsorbed to areas of the wafer 200 that have not been modified by the first modifying gas.

[0045] Specifically, the valve 243a is opened to allow a first process gas to flow into the gas supply pipe 232a. The flow rate of the first process gas is adjusted by the MFC 241a, and the first process gas is supplied into the process chamber 201 through the nozzle 249a and exhausted from the exhaust port 231a. At this time, the first process gas is supplied to the wafer 200 (first process gas supply step). Also, at this time, the valves 243g to 243i are opened to allow N 2 O 3 to flow into the process chamber 201 through the nozzles 249b to 249d, respectively. ２ Supply gas.

[0046] (Purge step sp2) After the nuclei are formed on the surface of the wafer 200, the valve 243a is closed to stop the supply of the first process gas into the process chamber 201. Then, by the same process procedure as in the purge step sp1, gases remaining in the process chamber 201 are removed from the process chamber 201.

[0047] [Predetermined Number of Times Performing Process sc1] By performing the above-mentioned steps a1 and a2 alternately, i.e., asynchronously and without synchronization, a cycle a predetermined number of times (n1 times, n1 is an integer greater than or equal to 1), a film containing the first element can be formed on the wafer 200.

[0048] In the first film formation step, by controlling at least one of the processing temperature and processing time (first modifying gas, first processing gas supply time) shown below, it is possible to control the thickness of the film containing the first element formed on the wafer 200. Furthermore, in the first film formation step, it is also possible to control the thickness of the film containing the first element formed on the wafer 200 by controlling the number of times the above-mentioned cycle is performed (number of cycles).

[0049] The processing conditions in step a1 are: first modifying gas supply flow rate: 10 to 1000 sccm; first modifying gas supply time: 0.5 to 10 minutes; ２ Gas supply flow rate (per gas supply pipe): 10 to 10,000 sccm, Processing temperature (first temperature): 350 to 420° C., and Processing pressure: 100 to 1,000 Pa, for example.

[0050] The processing conditions in step a2 are, for example, first processing gas supply flow rate: 10 to 1000 sccm, and first processing gas supply time: 0.5 to 10 minutes. The other processing conditions are the same as those in step a1.

[0051] (Heating step st1: Temperature adjustment step) After a film containing the first element is formed on the wafer 200, the output of the heater 207 is adjusted so that the temperature inside the processing chamber 201, i.e., the temperature of the wafer 200, is changed to a second temperature higher than the first temperature. When performing this step, the valves 243f to 243j are opened, and N is introduced into the processing chamber 201 through the nozzles 249a to 249e. ２Gas is supplied and exhausted through the exhaust port 231a to purge the inside of the processing chamber 201. After the temperature of the wafer 200 reaches the second temperature and stabilizes, a second film formation step, which will be described later, is started.

[0052] (Second Film Forming Step: S2) Next, the second film forming step S2 is performed. In the second film forming step S2, the following steps (processes) are executed.

[0053] (Step b1) In this step, a second modifying gas having a decomposition temperature different from that of the first modifying gas is supplied to the wafer 200 in the processing chamber 201, i.e., to the surface of the film containing the first element formed on the wafer 200, thereby modifying at least a portion of the substrate. Here, an example will be described in which the decomposition temperature of the first modifying gas is lower than that of the second modifying gas.

[0054] Specifically, the valve 243d is opened to allow the second modifying gas to flow into the gas supply pipe 232d. The flow rate of the second modifying gas is adjusted by the MFC 241d, and the second modifying gas is supplied into the processing chamber 201 via the nozzle 249d and exhausted from the exhaust port 231a. At this time, the second modifying gas is supplied to the wafers 200 (second modifying gas supply step). At this time, the valves 243f, 243g, 243h, and 243j are opened to allow N 2 O 3 to flow into the processing chamber 201 via the nozzles 249a, 249b, 249c, and 249e, respectively. ２ Supply gas.

[0055] (Purge step sp3) After that, the valve 243b is closed to stop the supply of the second modifying gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gases remaining in the processing chamber 201. At this time, the valves 243f to 243j are opened to introduce N 2 into the processing chamber 201 through the nozzles 249a to 249e. ２ Gas is supplied from nozzles 249a to 249c. ２ The gas acts as a purge gas, thereby purging the inside of the processing chamber 201 .

[0056] (Step b2) After step b1 is completed, a second process gas (second source gas) is supplied to the surface of the wafer 200 in the process chamber 201. Adsorption of the second process gas is inhibited at locations on the surface of the wafer 200 where the second modifying gas was adsorbed in step a1. That is, in this step, a second process gas containing a second element is supplied to the wafer 200, and the second element is preferentially adsorbed to areas of the wafer 200 that have not been modified by the second modifying gas.

[0057] Specifically, the valve 243c is opened to allow the second process gas to flow into the gas supply pipe 232c. The flow rate of the second process gas is adjusted by the MFC 241c, and the second process gas is supplied into the process chamber 201 through the nozzle 249c and exhausted from the exhaust port 231a. At this time, the second process gas is supplied to the wafer 200 (second process gas supply step). At this time, the valves 243g to 243i are opened to allow N 2 O 3 to flow into the process chamber 201 through the nozzles 249b to 249d, respectively. ２ Supply gas.

[0058] (Purge step sp4) After a film containing the second element is formed on the surface of the wafer 200, the valve 243c is closed to stop the supply of the second processing gas into the processing chamber 201. Then, by the same processing procedure as in the purge step sp3, gases remaining in the processing chamber 201 are removed from the processing chamber 201.

[0059] [Predetermined Number of Times Performing Process sc2] By alternately performing the above-mentioned steps b1 and b2, i.e., by performing the cycle of performing the steps asynchronously without synchronization, a predetermined number of times (n2 times, n2 is an integer greater than or equal to 1), a film containing a second element of a desired thickness can be formed on the wafer 200 on a film containing a first element.

[0060] The processing conditions in the second film forming step S2 are: second modifying gas supply flow rate: 10 to 5000 sccm second modifying gas supply time: 1 to 300 minutes second processing gas supply flow rate: 10 to 5000 sccm second processing gas supply time: 1 to 300 minutes N ２ Gas supply flow rate (per gas supply pipe): 10 to 20,000 sccm, Processing temperature (second temperature): 450 to 550° C., and Processing pressure: 30 to 400 Pa, for example.

[0061] (Substrate Unloading Process) In the substrate unloading process, the following steps are executed.

[0062] (After-Purge and Return to Atmospheric Pressure) After the formation of the film containing the second element on the wafer 200 is completed, N 2 is supplied as a purge gas from each of the nozzles 249a to 249e. ２ The gas is supplied into the processing chamber 201 and exhausted from the exhaust port 231a. This purges the processing chamber 201, and gas 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 an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure return).

[0063] (Boat Unloading and Wafer Discharge) 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 lower end opening 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 discharging).

[0064] One technique for obtaining a film with good step coverage will be described with reference to FIGS. 6( a) to 6(c). FIG. 6 shows an example in which a trench (groove) 300, which is a recess, is formed in the surface of a substrate 200, and a first processing gas (first element) is adsorbed inside the trench 300. When a first modifying gas is supplied to the substrate surface as shown in FIG. 6(a), the upper part of the trench (near the entrance of the recess) 301 collides with the gas more frequently than the lower part of the trench 302 (deeper part of the recess) 302. This allows the first modifying gas to be preferentially adsorbed (or reacted) with the upper part of the trench 301. When the first modifying gas is supplied to the surface of the substrate 200 after the first processing gas, the first modifying gas is already adsorbed in the upper part of the trench 301, preventing adsorption of the first processing gas (first element), but adsorption occurs in the lower part of the trench 302 (FIG. 6(b)). That is, in the first film formation step, a first process gas containing a first element is supplied to the wafer 200, and the first element is preferentially adsorbed to the lower trench portion 302, which has not been modified by the first modifying gas. As a result, the amount of the first element adsorbed to the upper trench portion 301 is small, so an increase in the film thickness of the film formed is suppressed, while the first element is sufficiently adsorbed to the lower trench portion 302, which promotes an increase in the film thickness (FIG. 6(c)). Therefore, a film 303 containing the first element with better step coverage can be obtained.

[0065] In the example shown in the first substrate processing method, the decomposition temperature of the first modifying gas is different from that of the second modifying gas, and the first modifying gas has a lower decomposition temperature than the second modifying gas. This can be rephrased as meaning that the first modifying gas is more easily decomposed or more reactive than the second modifying gas. In such a case, the adsorption points of the first modifying gas in the trench 300 are shown in FIG. 7A and the adsorption points of the second modifying gas in the trench 300 are shown in FIG. 7B. For the gas to be adsorbed in the trench lower portion 302, it must penetrate into the trench 300 from the trench upper portion 301 and reach the trench lower portion 302 without decomposing. In contrast, because the gas is more easily accessible to the trench upper portion 301 than the trench lower portion 302, the ease of gas adsorption in the trench upper portion 301 due to the decomposition temperature does not change as significantly as in the trench lower portion 302.

[0066] Therefore, it can be said that the first modifying gas is less likely to modify the trench lower portion 302 than the second modifying gas, or that the first modifying gas preferentially adsorbs to (or reacts with) the trench upper portion 301. It can also be said that the second modifying gas modifies the trench lower portion 302 side more than the region inside the trench 300 modified by the first modifying gas. It can also be said that the second modifying gas can modify the trench lower portion 302 side more than the region inside the trench 300 modified by the first modifying gas.

[0067] For example, when the first and second film formation steps are performed as described above, the first modifying gas preferentially modifies the upper trench portion 301 ( FIG. 8( a)). This inhibits adsorption of the first element in the upper trench portion 301, while forming a film 303a containing the first element in the lower trench portion 302 without inhibiting adsorption of the first element ( FIG. 8( b)). The second modifying gas then modifies a wider region toward the lower trench portion 302 than the first modifying gas ( FIG. 8( c)). This allows a film 303b containing the second element to be formed throughout the trench 300 with a more uniform thickness than the film 303a, while suppressing an increase in film thickness in the upper trench portion 301 ( FIG. 8( d)). This allows for uniform film formation with good step coverage throughout the entire trench 300. Furthermore, as described above, by varying the temperature between the first and second film formation steps, the ease of decomposition of the first and second modifying gases changes. This allows the regions in the trench 300 modified by the first and second modifying gases to be varied, respectively, thereby controlling the adsorption sites of the first and second elements. Furthermore, by varying the temperature between the first and second film formation steps, the ease of decomposition of the first or second process gas can be controlled. For example, by setting the temperature in the second film formation step higher than the temperature in the first film formation step, the second process gas can be more easily decomposed, thereby increasing the thickness of the film containing the second element formed in the trench upper portion 301.

[0068] Alternatively, the first process gas (first source gas) may have a lower decomposition temperature than the second process gas (second source gas). In this case, the first process gas decomposes more easily than the second process gas, allowing a film to be formed at a high rate even in the trench lower portion 302, which is difficult for the gas to reach. Furthermore, the second process gas decomposes less easily than the first process gas, reducing the difference in decomposition rate between the trench upper portion 301 and the trench lower portion 302, making it easier to form a film with a uniform thickness. Therefore, a film can be formed uniformly with good step coverage throughout the trench 300.

[0069] The upper trench portion 301 can be rephrased as a portion easily reached by the gas, and the lower trench portion 302 can be rephrased as a portion difficult to reach by the gas. In this case, the first modifying gas is less likely to adsorb to portions difficult to reach by the gas, and therefore primarily modifies the portions easily reached by the gas. Therefore, in step a2, the first processing gas can adsorb the first element to portions difficult to reach by the gas, while inhibiting adsorption of the first element to portions easily reached by the gas. Thereafter, by using a second modifying gas that is easily adsorbed to portions difficult to reach by the gas, a film containing the second element can be formed in step b2 with good step coverage.

[0070] In the first substrate processing method, an example has been described in which a film containing a second element is formed on a film containing a first element by performing a second film formation step after a first film formation step. The method of the present disclosure is not limited to this, and can also be suitably used in a case in which, for example, a cycle including the first film formation step and the second film formation step is performed a predetermined number of times to form a film in which a film containing a first element and a film containing a second element are stacked.

[0071] (2-2) Second Substrate Processing Method Fig. 4 is a diagram showing a second substrate processing method according to an embodiment, and Fig. 5 is a diagram showing the configuration of a gas supply pipe system used in the second substrate processing method.

[0072] The second substrate processing method shown in Fig. 4 is composed of a first film formation step, a second film formation step, and a third film formation step. The third film formation step in Fig. 4 corresponds to the second film formation step in Fig. 3. The first film formation step in Fig. 3 can also be considered to be divided into the first film formation step and the second film formation step in Fig. 4.

[0073] In FIG. 4, the first and second film formation steps are performed at the same first processing temperature, and the third film formation step is performed at a second processing temperature higher than the first processing temperature.

[0074] As shown in FIG. 5, compared to the gas supply pipe system of FIG. 1, the gas supply pipe system includes a gas supply pipe 232m, an MFC 241m, a valve 243m, a gas supply pipe 232n, an MFC 241n, a valve 243n, a nozzle 249f, and a gas supply hole 250f.

[0075] The second substrate processing method will be described below with reference to FIG. 4, but the description of the same parts as those in FIG. 3 will be omitted.

[0076] (First Film Forming Step: S1) In the first film forming step S1, the following steps (processes) are performed.

[0077] (Step a1) In this step, a first modifying gas is supplied to the wafer 200 in the processing chamber 201 to modify at least a part of the wafer 200 .

[0078] Specifically, the valve 243b is opened to allow the first modifying gas to flow into the gas supply pipe 232b. The flow rate of the first modifying gas is adjusted by the MFC 241b, and the first modifying gas is supplied into the processing chamber 201 through the nozzle 249b and exhausted from the exhaust port 231a. At this time, the first modifying gas is supplied to the wafer 200 (first modifying gas supply step). At this time, the valves 243f, 243h, 243i, 243j, and 243n are opened to allow N 2 O 3 to flow into the processing chamber 201 through the nozzles 249a, 249c, 249d, 249e, and 249f, respectively. ２ Supply gas.

[0079] (Purge step sp1) After that, the valve 243b 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 gases remaining in the processing chamber 201. At this time, the valves 243f to 243n are opened to introduce N 2 into the processing chamber 201 through the nozzles 249a to 249f. ２ Gas is supplied from nozzles 249a to 249f. ２ The gas acts as a purge gas, thereby purging the inside of the processing chamber 201 .

[0080] (Step a2) After step a1 is completed, a first process gas is supplied to the surface of the wafer 200 in the process chamber 201. Adsorption of the first process gas is inhibited at locations on the surface of the wafer 200 where the first modifying gas was adsorbed in step a1. That is, in this step, the first process gas containing the first element is supplied to the wafer 200, and the first element is preferentially adsorbed to areas of the wafer 200 that have not been modified by the first modifying gas.

[0081] Specifically, the valve 243a is opened to allow a first process gas to flow into the gas supply pipe 232a. The flow rate of the first process gas is adjusted by the MFC 241a, and the first process gas is supplied into the process chamber 201 via the nozzle 249a and exhausted from the exhaust port 231a. At this time, the first process gas is supplied to the wafers 200 (first process gas supply step). At this time, the valves 243g to 243i and 243n are opened to supply N2 gas into the process chamber 201 via the nozzles 249b to 249d and 249f, respectively.

[0082] (Purge step sp2) After the nuclei are formed in the lower portion 302 of the recess 300, the valve 243a is closed to stop the supply of the first process gas into the process chamber 201. Then, by the same process procedure as in the purge step sp1, gases remaining in the process chamber 201 are removed from the process chamber 201.

[0083] [Predetermined Number of Times Performing Step sc1] A film containing the first element can be formed by alternately performing the above-mentioned steps a1 and a2, i.e., by performing the cycle of performing the steps a1 and a2 asynchronously and without synchronization, a predetermined number of times (n1 times, n1 is an integer greater than or equal to 1).

[0084] In the first film formation step, by controlling at least one of the processing temperature and processing time (first modifying gas supply time, first processing gas supply time) shown below, it is possible to control the thickness of the film containing the first element formed on the wafer 200. Furthermore, in the first film formation step, it is also possible to control the thickness of the film containing the first element formed on the wafer 200 by controlling the number of times the above-mentioned cycle is performed (number of cycles).

[0085] The processing conditions in step a1 are: first modifying gas supply flow rate: 10 to 1000 sccm; first modifying gas supply time: 0.5 to 10 minutes; ２ Gas supply flow rate (per gas supply pipe): 10 to 10,000 sccm, Processing temperature (first temperature): 350 to 420° C., and Processing pressure: 100 to 1,000 Pa, for example.

[0086] The processing conditions in step a2 are, for example, first processing gas supply flow rate: 10 to 1000 sccm, and first processing gas supply time: 0.5 to 10 minutes. The other processing conditions are the same as those in step a1.

[0087] (Second Film Forming Step: S2) After the first film forming step S1, the second film forming step S2 is performed. In the second film forming step S2, the following steps (processes) are performed.

[0088] (Step b1) In this step, a second modifying gas is supplied to the wafer 200 in the processing chamber 201 to modify at least a portion of the wafer 200.

[0089] Specifically, the valve 243d is opened to allow the second modifying gas to flow into the gas supply pipe 232d. The flow rate of the second modifying gas is adjusted by the MFC 241d, and the second modifying gas is supplied into the processing chamber 201 through the nozzle 249d and exhausted from the exhaust port 231a. At this time, the second modifying gas is supplied to the wafer 200 (second modifying gas supply step). At this time, the valves 243f, 243g, 243h, 243j, and 243n are opened to allow N 2 O 3 to flow into the processing chamber 201 through the nozzles 249a, 249b, 249c, 249e, and 249f, respectively. ２Supply gas.

[0090] (Purge step sp3) After that, the valve 243d is closed to stop the supply of the second modifying gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gases remaining in the processing chamber 201. At this time, the valves 243f to 243n are opened to introduce N 2 into the processing chamber 201 through the nozzles 249a to 249f. ２ Gas is supplied from nozzles 249a to 249f. ２ The gas acts as a purge gas, thereby purging the inside of the processing chamber 201 .

[0091] (Step b2) After step b1 is completed, a second process gas (second source gas) is supplied to the surface of the wafer 200 in the process chamber 201. Adsorption of the second process gas is inhibited at the locations on the surface of the wafer 200 where the second modifying gas was adsorbed in step b1. That is, in this step, the second process gas containing the second element is supplied to the wafer 200, and the second element is preferentially adsorbed to the areas of the wafer 200 that have not been modified by the second modifying gas.

[0092] Specifically, the valve 243a is opened to allow the second process gas to flow into the gas supply pipe 232a. The flow rate of the second process gas is adjusted by the MFC 241a, and the second process gas is supplied into the process chamber 201 through the nozzle 249a and exhausted from the exhaust port 231a. At this time, the first process gas is supplied to the wafer 200 (second process gas supply step). At this time, the valves 243g to 243i and 243n are opened to allow N 2 gas to flow into the process chamber 201 through the nozzles 249b to 249d and 249f, respectively. ２ Supply gas.

[0093] (Purge step sp4) After a film containing the second element is formed on the surface of the wafer 200, the valve 243a is closed to stop the supply of the second process gas into the process chamber 201. Then, by the same process procedure as in the purge step sp3, gases remaining in the process chamber 201 are removed from the process chamber 201.

[0094] [Step sc2 of performing steps a predetermined number of times] By performing the above-mentioned steps b1 and b2 alternately, i.e., asynchronously and without synchronization, a cycle is performed a predetermined number of times (n2 times, n2 is an integer greater than or equal to 1), so that a film containing a second element can be formed on a film containing a first element.

[0095] In the second film formation step, by controlling at least one of the processing temperature and processing time (second modifying gas supply time, second processing gas supply time) shown below, it is possible to control the thickness of the film containing the second element formed on the wafer 200. In addition, in the second film formation step, it is also possible to control the thickness of the film containing the second element formed on the wafer 200 by controlling the number of times the above-mentioned cycle is performed (number of cycles).

[0096] The processing conditions in step b1 are: second modifying gas supply flow rate: 10 to 1000 sccm second modifying gas supply time: 0.5 to 10 minutes N ２ Gas supply flow rate (per gas supply pipe): 10 to 10,000 sccm, Processing temperature (first temperature): 350 to 420° C., and Processing pressure: 100 to 1,000 Pa, for example.

[0097] The processing conditions in step b2 are, for example, second processing gas supply flow rate: 10 to 1000 sccm, and second processing gas supply time: 0.5 to 10 minutes. The other processing conditions are the same as those in step b1.

[0098] (Heating step st1: Temperature adjustment step) After a film containing the second element is formed on the wafer 200, the output of the heater 207 is adjusted so that the temperature inside the processing chamber 201, i.e., the temperature of the wafer 200, is changed to a second temperature higher than the first temperature (350 to 420° C.). When performing this step, the valves 243f to 243j and 243n are opened, and N is introduced into the processing chamber 201 through the nozzles 249a to 249f. ２ Gas is supplied and exhausted through the exhaust port 231a to purge the inside of the processing chamber 201. After the temperature of the wafer 200 reaches and stabilizes at the second temperature, the steps described below are started. Here, the second temperature is, for example, in the temperature range of 450 to 550°C.

[0099] (Third Film Forming Step: S3) Next, the third film forming step S3 is performed. In the third film forming step S3, the following steps (processes) are executed.

[0100] (Step c1) In this step, a third modifying gas having a different decomposition temperature from the first modifying gas and the second modifying gas is supplied to the wafer 200 in the processing chamber 201, i.e., the surface of the film containing the second element formed on the wafer 200, to modify at least a portion of the substrate.

[0101] Specifically, the valve 243c is opened to allow the third modifying gas to flow into the gas supply pipe 232c. The flow rate of the third modifying gas is adjusted by the MFC 241c, and the third modifying gas is supplied into the processing chamber 201 through the nozzle 249c and exhausted from the exhaust port 231a. At this time, the third modifying gas is supplied to the wafer 200 (second modifying gas supply step). At this time, the valves 243f, 243g, 243i, 243j, and 243n are opened to allow N 2 O 3 to flow into the processing chamber 201 through the nozzles 249a, 249b, 249d, 249e, and 249f, respectively. ２ Supply gas.

[0102] (Purge step sp5) After that, the valve 243c is closed to stop the supply of STS gas into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gases remaining in the processing chamber 201. At this time, the valves 243f to 243j and 243n are opened to introduce N 2 into the processing chamber 201 through the nozzles 249a to 249f. ２ The N2 gas supplied from the nozzles 249a to 249f acts as a purge gas, thereby purging the inside of the processing chamber 201.

[0103] (Step c2) After step c1 is completed, a third process gas (third source gas) is supplied to the surface of the wafer 200 in the process chamber 201. Here, adsorption of the third process gas is inhibited at the locations on the surface of the wafer 200 where the third modifying gas was adsorbed in step c1. That is, in this step, the third process gas containing the third element is supplied to the wafer 200, and the third element is preferentially adsorbed to the areas of the wafer 200 that have not been modified by the third modifying gas.

[0104] Specifically, the valve 243m is opened to allow the third process gas to flow into the gas supply pipe 232m. The flow rate of the third process gas is adjusted by the MFC 241m, and the third process gas is supplied into the process chamber 201 through the nozzle 249f and exhausted from the exhaust port 231a. At this time, the third process gas is supplied to the wafer 200 (third process gas supply step). At this time, the valves 243g to 243i are opened to allow N 2 O 3 to flow into the process chamber 201 through the nozzles 249b to 249d, respectively. ２ Supply gas.

[0105] (Purge step sp6) After a film containing the third element (third film, third layer) is formed on the surface of the wafer 200, the valve 243m is closed to stop the supply of the third process gas into the process chamber 201. Then, by the same processing procedure as in the purge step sp5, gases remaining in the process chamber 201 are removed from the process chamber 201.

[0106] [Step sc3 of performing a predetermined number of times] By performing the cycle of the above-mentioned steps c1 and c2 alternately, i.e., asynchronously and without synchronization, a predetermined number of times (n3 times, n3 is an integer greater than or equal to 1), a film containing a third element with a desired film thickness can be formed on a film containing a second element.

[0107] The processing conditions in the third film-forming step S3 are as follows: Third modifying gas supply flow rate: 10 to 5000 sccm Third modifying gas supply time: 1 to 300 minutes Third processing gas supply flow rate: 10 to 5000 sccm Third processing gas supply time: 1 to 300 minutes N ２ Gas supply flow rate (per gas supply pipe): 10 to 20,000 sccm, Processing temperature (second temperature): 450 to 550° C., and Processing pressure: 30 to 400 Pa, for example.

[0108] The second substrate processing method has the following advantages in addition to the advantages of the first substrate processing method.

[0109] The first and second film formation steps are performed at the same temperature. The decomposition temperature of the first modifying gas is lower than the decomposition temperature of the second modifying gas. Therefore, the regions modified by the first and second modifying gases, i.e., the regions preferentially adsorbing the first element and the regions preferentially adsorbing the second element, can be differentiated without changing the temperature inside the processing chamber 201 between the first and second film formation steps.

[0110] In the third film formation step, a film containing the third element is formed on the film formed with good step coverage by the first film formation step and the second film formation step at a temperature higher than those in the first film formation step and the second film formation step. Therefore, in the third film formation step, a film containing the third element with good step coverage can be formed at a film formation rate higher than those in the first film formation step and the second film formation step.

[0111] In the first and second film formation steps, the decomposition temperature of the first process gas may be the same as that of the second process gas. Alternatively, the first and second process gases may be the same gas. From the above, in film formation using process gases with the same decomposition temperature, it is possible to control the location where the first element (second element) is primarily adsorbed without changing the temperature conditions. This can be used to improve the uniformity of the film thickness from the deep portion 302 of the recess 300 to the vicinity 301 of the inlet of the recess 300 in the film formed in the first and second film formation steps.

[0112] In the second substrate processing method, an example has been described in which a Si film is formed by performing a first film formation step, a second film formation step, and then a third film formation step. The method of the present disclosure is not limited to this, and for example, the third film formation step may be performed after a cycle including the first film formation step and the second film formation step is performed a predetermined number of times.

[0113] It goes without saying that the present disclosure is not limited to the above-described embodiment, and various modifications are possible.

[0114] In the above-described embodiment, the first modifying gas, the second modifying gas, and the third modifying gas may be, for example, a gas containing a first halogen element, a second halogen element, and a third halogen element, which are halogen elements. Examples of halogen elements include chlorine (Cl), fluorine (F), bromine (Br), and iodine (I). Alternatively, the first modifying gas, the second modifying gas, and the third modifying gas may be a gas containing a first halogen element, a second halogen element, and a third halogen element, respectively. Here, halogen elements have the effect of inhibiting gas adsorption and are unlikely to remain as impurities in the film, so they are unlikely to deteriorate the electrical properties of the film.

[0115] As the halogen-containing gas, for example, a halosilane gas containing Si and a halogen element can be used. As the halosilane gas, for example, a chlorosilane gas containing Si and Cl can be used, for example, dichlorosilane (SiH ２ Cl ２ , abbreviated as DCS) gas, trichlorosilane (SiHCl ３ ) gas, tetrachlorosilane (SiCl ４ , abbreviated as TCS), pentachlorodisilane (Si ２ H １ Cl ５ , abbreviated as PCDS), hexachlorodisilane (Si ２ Cl ６ , abbreviated as HCDS) gas, etc. Furthermore, as the halogen-element-containing gas, for example, a hydrogen halide gas can be used, and examples thereof include hydrogen fluoride (HF) gas, hydrogen chloride (HCl) gas, hydrogen bromide (HBr) gas, and hydrogen iodide (HI) gas. That is, the first modifying gas, the second modifying gas, and the third modifying gas may be appropriately selected from these gases so that the magnitude relationship of the decomposition temperatures satisfies the relationship described in the above embodiment.

[0116] In the above-described embodiment, when the first element, the second element, and the third element are Si, the first processing gas, the second processing gas, and the third processing gas can be Si-containing gases. For example, silane gas containing Si as a main element can be used as the Si-containing gas. For example, monosilane (SiH ４ , abbreviation: MS) gas, disilane gas (Si ２ H ６ , abbreviated as DS), trisilane (Si ３ H ８ , abbreviated as TS) gas, etc. Furthermore, halosilane gas may also be used as the silane gas.

[0117] In the first substrate processing method, a film containing a second element may be formed using a film containing a first element as a seed layer (seed film). This allows high-density crystalline nuclei to be formed in the film containing the first element, and these nuclei can be used as growth nuclei to grow a film containing the second element in an amorphous, epitaxial, or poly state. Similarly, in the second substrate processing method, a film containing a second element may be formed using a film containing a first element as a seed layer. Furthermore, a film containing a third element may be formed using a film containing a second element as a seed layer. Furthermore, a film containing a third element may be formed using a film composed of the first element and the second element as a seed layer.

[0118] In the above-described embodiment, the first element may be, for example, Si or germanium (Ge), which are Group 14 elements, or aluminum (Al), gallium (Ga), or indium (In), which are Group 13 elements. Alternatively, the first element may be, for example, a transition metal element. Examples of the transition metal element include titanium (Ti), zirconium (Zr), and hafnium (Hf), which are Group 4 elements; niobium (Nb) and tantalum (Ta), which are Group 5 elements; molybdenum (Mo) and tungsten (W), which are Group 6 elements; manganese (Mn), which is Group 7 element; ruthenium (Ru), which is Group 8 element; cobalt (Co), which is Group 9 element; and nickel (Ni), which is Group 10 element. Similarly to the first element, these elements may also be used as the second or third element.

[0119] In the first substrate processing method, the first element and the second element may be different elements. In the second substrate processing method, one or more of the first element, the second element, and the third element may be different elements.

[0120] A higher-order halosilane gas has a lower decomposition temperature than a lower-order halosilane gas. For example, among halosilane gases, HCDS gas has a lower decomposition temperature than TCS gas. That is, when the first modifying gas and the second modifying gas are halosilane gases, the decomposition temperature of the first modifying gas can be made lower than that of the second modifying gas by making the first modifying gas a halosilane gas with a higher order than that of the second modifying gas. Note that the same relationship also holds when the first modifying gas and the second modifying gas are gases containing an element other than Si as a main element. That is, when the first modifying gas and the second modifying gas are gases containing the same element as a main element, the decomposition temperature of the first modifying gas can be made lower than that of the second modifying gas by making the first modifying gas a gas with a higher order than that of the second modifying gas.

[0121] A similar relationship also holds for silane gas. For example, DS gas has a lower decomposition temperature than MS gas, and TS gas has a lower decomposition temperature than DS gas. That is, when the first process gas and the second process gas are silane gases, the decomposition temperature of the first process gas can be lower than that of the second process gas by making the first process gas a silane gas of a higher order than the second process gas. The same relationship also holds when the first process gas and the second process gas are gases containing an element other than Si as a main element. That is, when the first process gas and the second process gas are gases containing the same element as a main element, the decomposition temperature of the first process gas can be lower than that of the second process gas by making the first process gas a gas of a higher order than the second process gas.

[0122] For two halosilane gases with the same order, the lower the molecular symmetry, the lower the decomposition temperature may be. For example, PCDS gas has a lower decomposition temperature than HCDS gas, and TCS gas has a lower decomposition temperature than DCS gas. That is, when the first modifying gas and the second modifying gas are halosilane gases with the same order, the decomposition temperature of the first modifying gas may be lower than that of the second modifying gas by using a halosilane gas with lower molecular symmetry than the second modifying gas as the first modifying gas. Note that a similar relationship may also hold when the first modifying gas and the second modifying gas are gases with the same order but containing an element other than Si as the main element. That is, when the first modifying gas and the second modifying gas are gases with the same order but containing the same element as the main element, the decomposition temperature of the first modifying gas may be lower than that of the second modifying gas by using a gas with lower molecular symmetry than the second modifying gas.

[0123] A similar relationship may also hold true for the first process gas (first source gas) and the second process gas (second source gas). For example, DCS gas has a lower decomposition temperature than MS gas. That is, when the first process gas and the second process gas are silane gases of the same order, the decomposition temperature of the first process gas may be lower than that of the second process gas by making the first process gas lower in molecular symmetry than that of the second process gas. A similar relationship may also hold true when the first process gas and the second process gas are gases containing an element other than Si as a main element. That is, when the first process gas and the second process gas are gases of the same order but containing the same element as a main element, the decomposition temperature of the first process gas may be lower than that of the second process gas by making the first process gas lower in molecular symmetry than that of the second process gas.

[0124] The relationship between the molecular structure and the decomposition temperature of the first modifying gas and the second modifying gas described above is similar when the first modifying gas is replaced with the third modifying gas and when the second modifying gas is replaced with the third modifying gas. The relationship between the molecular structure and the decomposition temperature of the first processing gas (first source gas) and the second processing gas (first source gas) is similar when the first processing gas (first source gas) is replaced with the third processing gas (third source gas) and when the second processing gas (second source gas) is replaced with the third processing gas (third source gas).

[0125] In the above-described embodiment (the first substrate processing method or the second substrate processing method), an example has been described in which the first film formation step alternately performs a predetermined number of cycles of steps a1 and a2. The method of the present disclosure is not limited to this example. For example, in the above-described embodiment, after a certain number of cycles, the supply conditions of the first modifying gas in step a1 or the first process gas (first source gas) in step a2 may be changed, or a cycle in which step a1 is not performed may be provided. Similarly, in the above-described embodiment, for example, after a certain number of cycles, the supply conditions of the second modifying gas in step b1 or the second process gas (second source gas) in step b2 may be changed, or a cycle in which step b1 is not performed may be provided. Similarly, in the above-described embodiment, in the third film formation step, for example, after a certain number of cycles, the supply conditions of the third modifying gas in step c1 or the third process gas (third source gas) in step c2 may be changed, or a cycle in which step c1 is not performed may be provided.

[0126] In the above-described embodiment, an example has been described in which N gas is used as the inert gas, but this is not limiting, and rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas may also be used.

[0127] In the above embodiment, an example has been described in which a first source gas is supplied to the processing chamber 201 (wafer 200) as a first processing gas in (a2) of the first film formation step, but the technology of the present disclosure is not limited to this. As the first processing gas, for example, silane gas may be supplied as the first source gas to the processing chamber 201, and an oxygen-containing gas or a nitrogen-containing gas may be supplied as the first reactive gas to the processing chamber 201. Specifically, after silane gas is supplied to the processing chamber 201, the valve 243e may be opened to supply an oxygen-containing gas or a nitrogen-containing gas as a first reactive gas into the gas supply pipe 232e to the processing chamber 201 (first reactive gas supply step). In this case, in the first film formation step, silicon oxide (SiO ２ In this case, the first source gas and the first reactive gas may be supplied into the processing chamber 201 in sequence a predetermined number of times.

[0128] Similarly, the second process gas may be a combination of a second source gas and a second reactive gas, or the second process gas may be a combination of the second source gas and the second reactive gas, which are sequentially supplied a predetermined number of times to the process chamber 201. Similarly, the third process gas may be a combination of a third source gas and a third reactive gas, or the third process gas may be a combination of the third source gas and the third reactive gas, which are sequentially supplied a predetermined number of times to the process chamber 201. The second process gas or the third process gas may be, for example, an oxygen-containing gas or a nitrogen-containing gas.

[0129] The oxygen-containing gas may be, for example, oxygen (O ２ ) gas, nitrous oxide (N ２ O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO ２ ) gas, ozone (O ３ ) gas, water vapor (H ２ O gas), carbon monoxide (CO) gas, carbon dioxide (CO ２ ) gas, etc., ２ Gas + Hydrogen (H ２ ) Gas, O ３ Gas + H ２ Gas, H ２ O gas + H ２ In this specification, "O ３ Gas + H２ In the case of a description of two gases, such as "O gas", ３ Gas and H ２ The nitrogen-containing gas is, for example, ammonia (NH ３ ) gas, hydrazine (N ２ H ４ ) gas, diazene (N ２ H ２ ) gas, N ３ H ８ nitrogen-containing gases (N and H-containing gases) containing N-H bonds, such as N ２ A gas can be used.

[0130] 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 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.

[0131] When using these substrate processing apparatuses, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0132] 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.

[0133] 10: Substrate processing apparatus 248: Integrated supply system 121: Control unit (controller)

Claims

1. (a1) supplying a first modifying gas to a substrate to modify at least a portion of the substrate; (a2) supplying a first process gas containing a first element to the substrate so that the first element is preferentially adsorbed to an area of ​​the substrate that has not been modified by the first modifying gas; (b1) supplying a second modifying gas having a decomposition temperature different from that of the first modifying gas to the substrate to modify at least a portion of the substrate; (b2) supplying a second process gas containing a second element to the substrate so that the second element is preferentially adsorbed to an area of ​​the substrate that has not been modified by the second modifying gas; A substrate processing method comprising the steps of:

2. 2. The substrate processing method according to claim 1, wherein in (a2), a first source gas containing the first element and a first reactive gas are supplied as the first process gas.

3. 2. The substrate processing method according to claim 1, wherein in (b2), a second source gas containing the second element as the second process gas and a second reactive gas are supplied.

4. 2. The method of claim 1, wherein the first process gas has a decomposition temperature that is the same as that of the second process gas.

5. 2. The method of claim 1, wherein (a1) and (a2) are performed at the same temperature as (b1) and (b2).

6. After performing (a1), (a2), (b1), and (b2) a predetermined number of times, (c) supplying a third process gas to the substrate, the third process gas including a third element and having a decomposition temperature higher than those of the first process gas and the second process gas, to the substrate to adsorb the third element, 2. The method of claim 1, wherein (c) is performed at a temperature higher than (a1), (a2), (b1), and (b2).

7. (b1) and (b2) are performed a predetermined number of times after (a1) and (a2) are performed a predetermined number of times; The first reformed gas has a lower decomposition temperature than the second reformed gas. The method of claim 1 .

8. 8. The method of claim 7, wherein (a1) and (a2) are performed at a lower temperature than (b1) and (b2).

9. The substrate processing method of claim 1 , wherein the first processing gas has a lower decomposition temperature than the second processing gas.

10. The substrate has a recess, (b1) and (b2) are performed a predetermined number of times after (a1) and (a2) are performed a predetermined number of times; The first reformed gas has a lower decomposition temperature than the second reformed gas, 2 . The substrate processing method according to claim 1 , wherein the second modifying gas modifies a deeper portion of the recess than a region inside the recess is modified by the first modifying gas.

11. 11. The method of claim 10, wherein (a1) and (a2) are performed at a lower temperature than (b1) and (b2).

12. The substrate processing method of claim 10 , wherein the first process gas has a lower decomposition temperature than the second process gas.

13. 13. The substrate processing method according to claim 1, wherein the first modifying gas contains a first halogen element, and the second modifying gas contains a second halogen element.

14. 13. The substrate processing method according to claim 1, wherein the first modifying gas contains the first element, and the second modifying gas contains the second element.

15. the first modifying gas and the second modifying gas are gases containing the same element as a main element, The first reformed gas is a gas of a higher order than the second reformed gas. The substrate processing method according to any one of claims 9 to 12.

16. The first reforming gas and the second reforming gas are gases having the same element as a main element and having the same order, The first reforming gas has a lower molecular symmetry than the second reforming gas. The substrate processing method according to any one of claims 9 to 12.

17. 13. The substrate processing method according to claim 1, wherein in (b2), a second layer containing the second element is formed using a first layer containing the first element adsorbed on the substrate in (a2) as a seed layer.

18. (a1) supplying a first modifying gas to a substrate to modify at least a portion of the substrate; (a2) supplying a first process gas containing a first element to the substrate so that the first element is preferentially adsorbed to an area of ​​the substrate that has not been modified by the first modifying gas; (b1) supplying a second modifying gas having a decomposition temperature different from that of the first modifying gas to the substrate to modify at least a portion of the substrate; (b2) supplying a second process gas containing a second element to the substrate so that the second element is preferentially adsorbed to an area of ​​the substrate that has not been modified by the second modifying gas; A method for manufacturing a semiconductor device having the above structure.

19. A first modifying gas supply system that supplies a first modifying gas to the substrate; a first process gas supply system that supplies a first process gas containing a first element to the substrate; a second modifying gas supply system that supplies a second modifying gas having a decomposition temperature different from that of the first modifying gas to the substrate; a second process gas supply system that supplies a second process gas containing a second element to the substrate; (a1) supplying the first modifying gas to the substrate to modify at least a portion of the substrate; (a2) supplying the first process gas to the substrate to cause the first element to be preferentially adsorbed to an area not modified by the first modifying gas; (b1) supplying the second modifying gas having a decomposition temperature different from that of the first modifying gas to the substrate to modify at least a portion of the substrate; (b2) supplying the second process gas to the substrate to preferentially adsorb the second element to an area of ​​the substrate that has not been modified by the second modifying gas; a control unit configured to be able to control the first modifying gas supply system, the first processing gas supply system, the second modifying gas supply system, and the second processing gas supply system so as to execute the above-mentioned steps; A substrate processing apparatus comprising:

20. (a1) supplying a first modifying gas to a substrate to modify at least a portion of a surface of the substrate; (a2) supplying a first process gas containing a first element to the substrate, so that the first element is preferentially adsorbed to an area of ​​the substrate that has not been modified by the first modifying gas; (b1) supplying a second modifying gas having a decomposition temperature different from that of the first modifying gas to the substrate to modify at least a portion of a surface of the substrate; (b2) supplying a second process gas containing a second element to the substrate so that the second element is preferentially adsorbed to an area of ​​the substrate that has not been modified by the second modifying gas; A program for causing a computer to execute the procedure having the steps.