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

Abstract

According to the present invention, a cycle which includes (a) a step for supplying a modifier to a substrate that has a recessed structure and (b) a step for supplying a starting material that contains a specific element to the substrate is performed a specific number of times so as to form a film that contains the specific element on the substrate. The modifier is a compound which has a rational formula R-O-R' wherein R is a branched alkyl group, and R' is a linear hydrocarbon chain. Consequently, the step coverage of a film that is formed on a substrate can be controlled.

Description

SUBSTRATE PROCESSING METHOD, SEMICONDUCTOR DEVICE MANUFACTURING APPARATUS, PROGRAM, AND SUBSTRATE PROCESSING APPARATUS

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

[0002] 2. Description of the Related Art As one step in the manufacturing process of a semiconductor device, a process of forming a film on a substrate may be performed.

[0003] JP 2008-124184 A

[0004] An object of the present disclosure is to provide a technique that makes it possible to control the step coverage of a film formed on a substrate.

[0005] According to one aspect of the present disclosure, there is provided a technology comprising: a step of forming a film containing a predetermined element on a substrate by repeating a cycle including: (a) a step of supplying a modifier to a substrate having a recessed structure; and (b) a step of supplying a raw material containing the predetermined element to the substrate a predetermined number of times, wherein the modifier is a compound having a rational formula R-O-R', where R is a branched alkyl group and R' is a linear hydrocarbon chain.

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

[0007] 1 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus preferably used in one aspect of the present disclosure, showing a processing furnace 202 portion in a vertical cross-sectional view. FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus preferably used in one aspect of the present disclosure, showing a processing furnace 202 portion in a cross-sectional view along line A-A in FIG. 1. FIG. 3 is a schematic configuration diagram of a controller 121 of a substrate processing apparatus preferably used in one aspect of the present disclosure, showing a control system of the controller 121 in a block diagram. FIG. 4 is a diagram showing a gas supply sequence in one aspect of the present disclosure. FIG. 5 is a diagram showing a gas supply sequence in another aspect of the present disclosure. FIG. 6 is a diagram showing a gas supply sequence in another aspect of the present disclosure. (a) is a diagram showing the molecular structural formula of a modifier suitable for use in one embodiment of the present disclosure, (b) is a diagram showing the molecular structural formula of a modifier suitable for use in another embodiment of the present disclosure, (c) is a diagram showing the molecular structural formula of a modifier suitable for use in another embodiment of the present disclosure, (d) is a diagram showing the molecular structural formula of a modifier suitable for use in another embodiment of the present disclosure, (e) is a diagram showing the molecular structural formula of a modifier suitable for use in another embodiment of the present disclosure, and (f) is a diagram showing the molecular structural formula of a modifier suitable for use in another embodiment of the present disclosure. (a) is a diagram showing the molecular structural formula of a modifier suitable for use in another embodiment of the present disclosure, (b) is a diagram showing the molecular structural formula of a modifier suitable for use in another embodiment of the present disclosure, and (c) is a diagram showing the molecular structural formula of a modifier suitable for use in another embodiment of the present disclosure.

[0008] First Embodiment (One Aspect of the Present Disclosure) One aspect of the present disclosure will be described below, mainly with reference to Figures 1 to 8. Note that all drawings used in the following description are schematic, and the dimensional relationships between elements, the ratios of elements, and the like shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, and the like do not necessarily match between multiple drawings.

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

[0010] 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 ２ The reaction tube 203 is made of a heat-resistant material such as silicon carbide (SiC) or silicon carbide (SiC), and is formed in a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is disposed concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is formed in a cylindrical shape with open upper and lower ends. An O-ring 220a serving as a sealing member is provided between the manifold 209 and the reaction tube 203. 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. The wafers 200 are processed in this processing chamber 201.

[0011] Nozzles 249a to 249c serving as first to third supply units are provided within the processing chamber 201, penetrating the sidewall of the manifold 209, respectively. 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 to 232c are respectively provided with mass flow controllers (MFCs) 241a to 241c, which are flow rate controllers (flow rate control units), and valves 243a to 243c, which are on-off valves, in order from the upstream side of the gas flow. Gas supply pipes 232d to 232f are connected to gas supply pipes 232a to 232c downstream of valves 243a to 243c. Gas supply pipes 232d to 232f are respectively provided with MFCs 241d to 241f and valves 243d to 243f in order from the upstream side of the gas flow.

[0013] As shown in FIG. 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, 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 249c are provided in a region horizontally surrounding the wafer arrangement region on the side of the wafer arrangement region where the wafers 200 are arranged, extending along the wafer arrangement region. Gas supply holes 250a to 250c for supplying gas are provided on the side surfaces of the nozzles 249a to 249c, respectively. Each of the gas supply holes 250a to 250c opens to face (face) the exhaust port 231a in a plan view, enabling gas to be supplied toward the wafers 200. A plurality of gas supply holes 250a to 250c are provided from the bottom to the top of the reaction tube 203.

[0014] A modifying agent (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.

[0015] A raw material (raw material gas) is supplied from the gas supply pipe 232b through the MFC 241b, the valve 243b, and the nozzle 249b into the processing chamber 201. The raw material is used as one of the film forming agents.

[0016] A reactant (reaction gas) is supplied from the gas supply pipe 232c through the MFC 241c, the valve 243c, and the nozzle 249c into the processing chamber 201. The reactant is used as one of the film forming agents.

[0017] Inert gas is supplied from the gas supply pipes 232d to 232f through the MFCs 241d to 241f, the valves 243d to 243f, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c into the processing chamber 201. The inert gas acts as a purge gas, a carrier gas, a dilution gas, etc.

[0018] A modifying agent supply system (modified gas supply system) is mainly constituted by the gas supply pipe 232a, the MFC 241a, and the valve 243a. A raw material supply system (raw material gas supply system) is mainly constituted by the gas supply pipe 232b, the MFC 241b, and the valve 243b. A reactant supply system (reactant gas supply system) is mainly constituted by the gas supply pipe 232c, the MFC 241c, and the valve 243c. An inert gas supply system is mainly constituted by the gas supply pipes 232d to 232f, the MFCs 241d to 241f, and the valves 243d to 243f.

[0019] Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which valves 243a to 243f, MFCs 241a to 241f, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232f, and is configured so that the supply operation of various substances (various gases) into the gas supply pipes 232a to 232f, i.e., the opening and closing operation of the valves 243a to 243f and the flow rate adjustment operation by the MFCs 241a to 241f, 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 232f, etc., so that maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed on an integrated unit basis.

[0020] An exhaust port 231a for exhausting the atmosphere inside the process chamber 201 is provided at the bottom of the sidewall of the reaction tube 203. As shown in FIG. 2, the exhaust port 231a is provided at a position facing the nozzles 249a to 249c (gas supply holes 250a to 250c) across the wafer 200 in a plan view. 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 process 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.

[0021] 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. 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 a 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 wafers 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered vertically 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 raises and lowers the seal cap 219 to load and unload (transfer) wafers 200 into and out of the process chamber 201.

[0022] A rotation mechanism 267 that rotates the boat 217 (described later) is installed 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 wafers 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered in the vertical direction by a boat elevator 115 that serves as an elevating mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that raises and lowers the seal cap 219 to load and unload (transfer) the wafers 200 into and out of the processing chamber 201.

[0023] A shutter 219s serving as a furnace port cover is provided below the manifold 209, and is capable of airtightly closing the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is carried out of the processing chamber 201. An O-ring 220c serving as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the shutter 219s. 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.

[0024] 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.

[0025] 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.

[0026] As shown in Fig. 3, the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122 configured as, for example, a touch panel is connected to the controller 121. An external storage device 123 can also be connected to the controller 121.

[0027] The storage device 121c is composed of, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), 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 in the substrate processing apparatus to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program (program product). The process recipe is also simply referred to as a recipe. 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) in which programs, data, etc. read by the CPU 121a are temporarily stored.

[0028] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241f, valves 243a to 243f, 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.

[0029] 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 substances (various gases) by the MFCs 241a to 241f, the opening and closing operation of the valves 243a to 243f, 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.

[0030] 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, or a semiconductor memory such as a USB memory or an SSD. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these 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.

[0031] (2) Substrate Processing Step An example of a processing sequence for forming a film on a wafer 200 as a substrate, as one step in the manufacturing process of a semiconductor device, using the substrate processing apparatus described above will be described mainly with reference to Fig. 4. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by a controller 121.

[0032] 4 , a film containing the first element is formed inside the recessed structure by performing a cycle including the following a predetermined number of times (n times, where n is an integer of 1 or 2 or more): Step A: supplying a modifying agent to a wafer 200 having a recessed structure to form an adsorption layer on the wafer 200, the adsorption layer containing the modifying agent adsorbed on the surface of the wafer 200; Step B: supplying a raw material containing a first element that is a first predetermined element to the wafer 200 to react the raw material with the surface of the wafer 200 and form a first layer containing the first element on the wafer 200; and Step C: supplying a reactant to the wafer 200 to react the reactant with the first layer and modify the first layer into a second layer containing the first element. In this embodiment, in the above-mentioned cycle, Step A starts before Step B, and Steps A and B are performed asynchronously.

[0033] The modifier used in this embodiment is a gas containing a compound having the rational formula R-O-R', where R is a branched alkyl group (i.e., a substituent formed from a branched alkane), and R' is a linear hydrocarbon chain.

[0034] In this specification, the above-described processing sequence may be expressed as follows for convenience: Similar notations will be used in the following explanations of modified examples and other aspects.

[0035] (modifier → raw material → reactant) × n

[0036] 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".

[0037] The term "recess" as used herein is not limited to a shape having a bottom surface, and may include, for example, a structure that does not include a bottom surface, such as a gap or a through-hole. In the case of a structure that does not include a bottom surface, the "bottom side" may refer to the direction (side) from each of two or more openings toward the back of the structure.

[0038] The term "agent" used in this specification includes at least one of a gaseous substance and a liquid substance. A liquid substance includes a mist substance. That is, each of the modifying agent and the film-forming agent (raw material, reactant) may contain a gaseous substance, a liquid substance such as a mist substance, or both.

[0039] (Wafer Charging and Boat Loading) When multiple wafers 200 are loaded into the boat 217 (wafer charging), the shutter 219s is moved by the shutter opening / closing mechanism 115s, opening the lower end of the manifold 209 (shutter opening). Then, as shown in FIG. 1 , the boat 217 supporting the multiple wafers 200 is lifted by the boat elevator 115 and loaded 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. Note that a recessed structure such as a trench or hole is formed on the surface of the wafer 200. The recessed structure is sometimes referred to as a three-dimensional structure. The aspect ratio of the recessed structure, i.e., the ratio calculated by (depth of the internal space of the recessed structure) / (width of the internal space of the recessed structure), is, for example, 10 or more.

[0040] (Pressure Adjustment and Temperature Adjustment) 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 this measured pressure information. 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. 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.

[0041] (Film Formation) Thereafter, the following steps A to C are carried out in order.

[0042] [Step A] In this step, a modifying agent is supplied to the wafer 200 in the processing chamber 201 .

[0043] Specifically, the valve 243a is opened to allow the modifying agent to flow into the gas supply pipe 232a. The flow rate of the modifying agent is adjusted by the MFC 241a, and the modifying agent is supplied into the processing chamber 201 through the nozzle 249a and exhausted from the exhaust port 231a. At this time, the modifying agent is supplied to the wafer 200 (modifying agent supply). The modifying agent may be supplied in a state diluted with a dilution gas such as an inert gas. At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through each of the nozzles 249a to 249c.

[0044] By supplying the modifying agent to the wafer 200 under the conditions described below, the modifying agent is adsorbed onto the surface of the wafer 200, and an adsorption layer containing the modifier adsorbed onto the surface of the wafer 200 can be formed on the wafer 200. As a result of the formation of the adsorption layer, at least some of the adsorption sites present on the surface of the wafer 200 are covered by the adsorption layer, while the remaining adsorption sites are not covered by the adsorption layer and are exposed. Here, the adsorption sites present on the surface of the wafer 200 mainly include terminations where at least some of the molecules constituting the raw material are capable of chemical adsorption. Examples of adsorption sites include terminations of hydroxyl groups (OH groups) (OH terminations) and terminations of NH groups (NH terminations) that terminate the surface of the wafer 200.

[0045] In this step, it is preferable to supply the modifier to the wafer 200 under conditions (e.g., temperature and pressure) that do not substantially cause the modifier to be thermally decomposed. By supplying the modifier under such conditions, the modifier in a non-thermally decomposed state can be physically adsorbed onto the surface of the wafer 200. Note that in this specification, physical adsorption primarily includes adsorption due to at least one intermolecular force, such as van der Waals forces and polar attractive forces (particularly hydrogen bonds). However, this does not exclude other forms of adsorption that are called physical adsorption.

[0046] The thickness of the adsorption layer is preferably less than one molecular layer. That is, the adsorption layer preferably contains the modifier adsorbed so as to discontinuously cover the surface of the wafer 200. As a result, it is possible to reliably expose some of the adsorption sites present on the surface of the wafer 200. However, at this stage, the modifier may be physically adsorbed onto the surface of the wafer 200 so as to form an adsorption layer with a thickness of at least one molecular layer (i.e., the surface of the wafer 200 is covered with a continuous layer), and then in step A2 described below, some of the modifier contained in the adsorption layer may be removed from the surface of the wafer 200 to form an adsorption layer with a thickness of less than one molecular layer.

[0047] In this step, an adsorption layer is formed on at least the surface near the opening (particularly the sidewall near the opening) of the inner surface of the recessed structure formed on the surface of the wafer 200. As will be described later, in this step, it is more preferable to also form an adsorption layer on the bottom surface and sidewall of the inner surface of the recessed structure.

[0048] After the adsorption layer is formed on the wafer 200, the valve 243a is closed to stop the supply of the modifying agent into the processing chamber 201.

[0049] After the supply of the modifying agent to the wafer 200 is completed (i.e., after the supply is stopped), as shown in FIG. 4 , it is preferable to perform step A2, in which the supply of the modifying agent to the processing chamber 201 is stopped and the processing chamber 201 is evacuated to remove gases and the like remaining in the processing chamber 201 from the processing chamber 201. By continuously performing step A2, a portion of the modifying agent contained in the adsorption layer can be removed (i.e., desorbed) from the surface of the wafer 200, and the density (which can also be expressed as "thickness") of the adsorption layer formed on the wafer 200 can be adjusted to a desired density. That is, in step A2, the evacuation of the processing chamber 201 can be continued until the density of the adsorption layer reaches the desired density. As a result, the thickness of the first layer formed per cycle can be optimized, and the film formation rate on the wafer 200 can be adjusted to a relatively large desired value. In step A2, it is preferable to set the evacuation conditions in the processing chamber 201, i.e., the evacuation time, the evacuation speed, etc., so that the film formation rate on the wafer 200 is the desired value.

[0050] 4, in step A2, it is preferable to open valves 243d to 243f and supply an inert gas into the processing chamber 201 through nozzles 249a to 249c. That is, in step A2, it is preferable to evacuate the processing chamber 201 while supplying the inert gas to the wafer 200. Also preferably, in step A2, as shown in FIG. 5A, a step of evacuating the processing chamber 201 while supplying the inert gas to the wafer 200 (inert gas purge step) and a step of evacuating the processing chamber 201 while stopping the supply of the inert gas (vacuum purge step) may be performed. Also preferably, in step A2, a purge cycle including a step of evacuating the processing chamber 201 while supplying the inert gas to the wafer 200 and a step of evacuating the processing chamber 201 while stopping the supply of the inert gas may be performed multiple times non-simultaneously.

[0051] By performing step A2 in any of these ways, a portion of the modifier physically adsorbed to the surface of the wafer 200 can be more efficiently removed from the surface of the wafer 200, and the density (thickness) of the adsorption layer formed on the wafer 200 can be more reliably adjusted to a desired density (thickness). As a result, for example, it becomes easier to adjust the thickness of the first layer formed per cycle to a desired size.

[0052] Examples of processing conditions for supplying the modifier in step A include: modifier supply flow rate (excluding dilution gas): 0.01 to 10 g / min, more preferably 0.1 to 5 g / min; dilution gas supply flow rate: 100 to 100,000 sccm, more preferably 1,000 to 50,000 sccm; modifier supply time: 1 to 600 seconds, more preferably 10 to 300 seconds; inert gas supply flow rate (per gas supply pipe): 0 to 50,000 sccm, more preferably 5,000 to 15,000 sccm; processing temperature: 70 to 500°C, more preferably 150 to 500°C; processing pressure: 10 to 5,000 Pa, more preferably 50 to 1,500 Pa.

[0053] By setting the processing temperature to 70°C or higher, it is possible to suppress re-liquefaction or re-solidification of the gas, particularly when a gas obtained by vaporizing a liquid or solid is used as the raw material. Furthermore, by setting the processing temperature to 150°C or higher, it is possible to more reliably suppress re-liquefaction or re-solidification of the gas. Furthermore, by setting the processing temperature to 500°C or lower, it is possible to suppress thermal decomposition of the modifier and also to suppress desorption of the modifier physically adsorbed on the surface of the wafer 200 from the surface. Therefore, it is easy to improve and maintain the effect of suppressing adsorption of the raw material by the adsorption layer described below.

[0054] In this specification, when a numerical range such as "100 to 100,000 sccm" is expressed, it means that the lower limit and the upper limit are included in the range. Therefore, for example, "100 to 100,000 sccm" means "100 sccm or more and 100,000 sccm or less." The same applies to other numerical ranges. In addition, a flow rate of 0 sccm means that the supply of the substance is not performed.

[0055] Examples of processing conditions in step A2 include: exhaust time: 1 to 600 seconds, more preferably 10 to 300 seconds; inert gas supply flow rate (per gas supply pipe): 0 to 100,000 sccm, more preferably 0 to 50,000 sccm.

[0056] The modifier can be a compound having the rational formula R-O-R', where R is a branched alkyl group (i.e., a substituent formed from a branched alkane) and R' is a linear hydrocarbon chain. That is, the modifier can be an ether compound having the above-mentioned ligand. Gases containing these compounds can be used as the modifier.

[0057] In addition, the modifier may be any one selected from the group consisting of an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group as the branched alkyl group (R), or a compound containing a substituent thereof.

[0058] As the modifier, it is particularly preferable to use, as the branched alkyl group (R), any one selected from the group consisting of an isobutyl group, a sec-butyl group, and a tert-butyl group, or a compound containing a substituent thereof.

[0059] As the modifier, a compound containing a tert-butyl group or a substituent thereof as the branched alkyl group (R) can be particularly preferably used. By using a compound having a branched alkyl group with the largest number of branches as R as the modifier, the effect of inhibiting the adsorption of raw materials can be significantly improved compared to branched alkyl groups with two or fewer branches.

[0060] The modifier may be a compound containing a linear alkyl group (or acyclic alkyl group) as the linear hydrocarbon chain (R'). In other words, the modifier may be a compound containing a linear hydrocarbon chain that does not contain an unsaturated bond as the linear hydrocarbon chain (R').

[0061] Furthermore, the modifier may be a compound containing a C1-C10 linear alkyl group such as a methyl group (C1), an ethyl group (C2), a propyl group (C3), an n-butyl group (C4), or an n-pentyl group (C5) as the linear alkyl group (or acyclic alkyl group) described above.

[0062] The modifier may be a compound containing a linear hydrocarbon chain containing an unsaturated bond as the linear hydrocarbon chain (R'). Examples of the linear hydrocarbon chain containing an unsaturated bond include a linear hydrocarbon chain containing at least one of a double bond and a triple bond, such as a vinyl group, and a linear hydrocarbon chain containing at least one of an alkene and an alkyne.

[0063] The modifier can be a compound represented by the rational formula R-O-R', which is a combination of any of the branched alkyl groups (R) and linear hydrocarbon chains (R') listed above. The modifier can be, for example, an ether compound having the structural formula shown in each of Figures 7(a) to 7(f), such as isopropyl methyl ether, sec-butyl methyl ether, tert-butyl methyl ether, isopropyl ethyl ether, or tert-butyl ethyl ether. One or more of these compounds can be used as the modifier.

[0064] As the modifier, it is preferable to use, among the above-mentioned modifiers, a compound having a molecular weight in the range of 40 to 130. Furthermore, it is more preferable to use, among the above-mentioned modifiers, a compound having a molecular weight in the range of 70 to 110.

[0065] If the molecular weight is less than 70, the modifier is less likely to physically adsorb to the surface of the wafer 200. In particular, if the molecular weight is less than 40, it may be difficult to physically adsorb the modifier to the surface of the wafer 200. Furthermore, if the molecular weight is greater than 110, the diffusion of the modifier molecules in the processing space is slow, making it difficult for the modifier to reach the depths of the recessed structures, and it may be difficult to exert the effect of suppressing raw material adsorption deep into the recessed structures. In particular, if the molecular weight is greater than 130, it may be difficult for the modifier to reach the depths of the recessed structures even when the processing conditions are adjusted. Using a modifier with a molecular weight of 40 or more makes it possible to physically adsorb the modifier to the surface of the wafer 200. Using a modifier with a molecular weight of 70 or more makes it easier for the modifier to physically adsorb to the surface of the wafer 200. Furthermore, by using a modifier having a molecular weight of 130 or less, it is possible to ensure the diffusion rate of the modifier molecules in the processing space and to extend the effect of the modifier in suppressing the adsorption of raw materials to the deep side of the recessed structure.By using a modifier having a molecular weight of 110 or less, it is possible to easily extend the effect of the modifier in suppressing the adsorption of raw materials to the deep side of the recessed structure.

[0066] When the above-mentioned ether compound is used as the modifying agent, it is preferable that the surface of the wafer 200 to which the modifying agent is supplied is OH-terminated. When the modifying agent is supplied to the OH-terminated surface of the wafer 200, the ease of physical adsorption of the modifying agent may be improved.

[0067] The inert gas is nitrogen (N ２ Inert gases that can be used include rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas. One or more of these gases can be used as the inert gas. This also applies to the steps described below.

[0068] [Step B] After step A is completed, a raw material is supplied to the wafer 200 in the processing chamber 201, that is, to the wafer 200 on whose surface an adsorption layer is formed.

[0069] Specifically, the valve 243b is opened to allow the raw material to flow into the gas supply pipe 232b. The raw material has its flow rate adjusted by the MFC 241b, is supplied into the processing chamber 201 via the nozzle 249b, and is exhausted from the exhaust port 231a. At this time, the raw material is supplied to the wafer 200 (raw material supply). The raw material may be supplied in a state diluted with a dilution gas such as an inert gas. At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 via the nozzles 249a to 249c, respectively.

[0070] By supplying a raw material to the wafer 200 under conditions described below, it is possible to react the raw material with the surface of the wafer 200. As described below, the raw material can be a compound containing a molecule (hereinafter also referred to as a raw material molecule) having a first element and a ligand bonded to an atom of the first element. When the raw material reaches the surface of the wafer 200, it reacts with the exposed surface of the wafer 200 that is not covered by an adsorption layer, i.e., with the adsorption sites exposed on the surface of the wafer 200. During this reaction, the ligand is desorbed from the first element contained in the raw material, and the first element, which has dangling bonds due to the desorption of the ligand, is chemically adsorbed (bonded) to the surface of the wafer 200. As this reaction progresses, a first layer containing the first element is formed on the wafer 200, i.e., on the exposed surface (exposed portion) of the wafer 200 that is not covered by an adsorption layer, and is composed of at least a portion of the molecules of the adsorbed raw material (e.g., a component portion of the molecule that does not contain the ligand desorbed from the first element and that adsorbs to the exposed surface of the wafer 200 together with the first element).

[0071] Here, when the raw material supplied into the processing chamber 201 is supplied from the opening side to the bottom side of the recessed structure on the wafer 200, it is first adsorbed to the inner surface (inner wall) near the opening, and the amount of raw material reaching the inner surface near the bottom may be relatively insufficient compared to the amount of raw material reaching the inner surface near the opening. Furthermore, the raw material supplied into the processing chamber 201 may be thermally decomposed, resulting in multiple adsorption to the inner surface near the opening before reaching the bottom. Therefore, due to the insufficient supply of raw material near the bottom and the tendency for multiple adsorption to occur near the opening, the thickness of the first layer formed in this step may be nonuniform across the wafer 200 and within the inner surface of the recessed structure on the wafer 200. As a result, the film thickness uniformity across the wafer surface of the film formed on the wafer 200 and the step coverage of the film formed within the inner surface of the recessed structure may be deteriorated.

[0072] To address this issue, according to this embodiment, the adsorption (sticking) of the raw material supplied in this step to the surface of the wafer 200 is suppressed by the adsorption layer formed in advance in step A. This suppresses the adsorption (consumption) of the raw material near the opening and promotes the supply of the raw material near the bottom. It also suppresses the occurrence of multiple adsorption to the inner surface near the opening. This makes it possible to control the thickness distribution of the film formed within the recessed structure on the wafer 200 (e.g., the inner surface of the recessed structure), particularly the step coverage. More specifically, it becomes possible to improve the step coverage of the film formed within the recessed structure, for example.

[0073] The unadsorbed raw materials and by-products generated by reactions such as adsorption and thermal decomposition are removed by exhaust from the processing chamber 201. Furthermore, a portion of the adsorption layer (i.e., the adsorbed modifier) ​​that has been desorbed from the surface of the wafer 200 during this step is removed from the processing chamber 201 by exhaust in this step and exhaust in subsequent steps.

[0074] After the formation of the first layer on the wafer 200 is completed, the valve 243b is closed to stop the supply of the raw material into the processing chamber 201.

[0075] After the supply of raw materials to wafer 200 is completed (i.e., after the supply is stopped), as shown in FIG. 4, it is preferable to perform step B2 in which the processing chamber 201 is evacuated while the supply of raw materials to the processing chamber 201 is stopped, and any gases remaining in the processing chamber 201 are removed from the processing chamber 201.

[0076] By performing step B2, the atmosphere containing raw materials and by-products remaining in the processing chamber 201 that have not reacted or that have contributed to the formation of the first layer can be removed from the processing chamber 201.

[0077] Furthermore, by performing step B2, it is possible to desorb the modifier contained in the adsorption layer, i.e., the modifier physically adsorbed on the surface of the wafer 200, from the surface of the wafer 200. As a result, it is possible to suppress the modifier from remaining in the film formed on the wafer 200, and to make this film a film with a low concentration of impurities caused by the modifier.

[0078] 4, in step B2, it is preferable to open the valves 243d to 243f and supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c. That is, in step B2, it is preferable to evacuate the processing chamber 201 while supplying the inert gas to the wafers 200.

[0079] Examples of processing conditions for supplying raw materials in step B include: Raw material supply flow rate (excluding dilution gas): 0.1 to 10 g / min, more preferably 0.5 to 5 g / min Dilution gas supply flow rate: 100 to 100,000 sccm, more preferably 1,000 to 50,000 sccm Raw material supply time: 10 to 600 seconds, more preferably 30 to 300 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 50,000 sccm, more preferably 5,000 to 15,000 sccm Other conditions can be the same as the processing conditions for supplying the modifier in step A.

[0080] The processing conditions in step B2 can be the same as those in step A2.

[0081] The raw material can be a gas containing molecules having a first element and a ligand bonded to an atom of the first element. The first element can be a metal element, preferably a transition metal element, more preferably a Group 4 element such as zirconium (Zr), hafnium (Hf), or titanium (Ti). In addition to the above-mentioned Group 4 elements, examples of the metal element include tantalum (Ta), niobium (Nb), aluminum (Al), molybdenum (Mo), and tungsten (W).

[0082] The first element is a metalloid element, preferably silicon (Si). In this specification, the metalloid element refers to Si as well as boron (B), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te).

[0083] The ligand bonded to the atom of the first element may be an organic ligand. The ligand bonded to the atom of the first element may be at least one of a hydrocarbon group and an amino group. The hydrocarbon group bonded to the atom of the first element may be any one selected from the group consisting of alkyl groups such as methyl, ethyl, propyl, and butyl, cyclopentadienyl, cyclohexadienyl, and cycloheptatrienyl, or a substituent thereof.

[0084] The raw material containing Zr as the first element is, for example, tetrakisethylmethylaminozirconium (Zr[N(CH ３ ) C ２ H ５ ] ４ ), tetrakis(diethylamino)zirconium (Zr[N(C ２ H ５ ) ２ ] ４ ), tetrakisdimethylaminozirconium (Zr[N(CH ３ ) ２ ] ４ ), Zr(MMP) ４ , Zr(O-tBu) ４ , tris(dimethylamino)cyclopentadienyl zirconium ((C ５ H ５ )Zr[N(CH ３ ) ２ ] ３ ) etc. As the raw material, one or more of these gases can be used.

[0085] Furthermore, examples of raw materials containing Hf as the first element include tetrakisethylmethylaminohafnium (Hf[N(CH ３ ) C ２ H ５ ] ４ ), tetrakisdiethylaminohafnium (Hf[N(C ２ H ５ ) ２ ] ４ ), tetrakisdimethylaminohafnium (Hf[N(CH ３ ) ２ ] ４ ), Hf(O-tBu) ４, Hf(MMP) ４ , tris(dimethylamino)cyclopentadienyl hafnium ((C ５ H ５ )Hf[N(CH ３ ) ２ ] ３ ) etc. As the raw material, one or more of these gases can be used.

[0086] Furthermore, as a raw material containing Ti as the first element, for example, tetrakisethylmethylaminotitanium (Ti[N(CH ３ ) C ２ H ５ ] ４ ), tetrakis(diethylamino)titanium (Ti[N(C ２ H5) ２ ] ４ ), tetrakisdimethylaminotitanium (Ti[N(CH ３ ) ２ ] ４ ), Ti(O-tBu) ４ , Ti(MMP) ４ , tris(dimethylamino)cyclopentadienyltitanium ((C ５ H ５ )Ti[N(CH ３ ) ２ ] ３ ) etc. As the raw material, one or more of these gases can be used.

[0087] Furthermore, as a raw material containing Si as the first element, for example, an aminosilane-based gas, that is, a gas containing Si and an amino group, can also be used. As the aminosilane-based gas, for example, (dimethylamino)trimethylsilane ((CH ３ ) ２ NSi(CH ３ ) ３ ), diethylaminotrimethylsilane ((C ２ H ５ ) ２ NSi(CH ３ ) ３ ), diethylaminotriethylsilane ((C ２ H ５ ) ２ NSi(C ２ H５ ) ３ ), dimethylaminotriethylsilane ((CH ３ ) ２ NSi(C ２ H ５ ) ３ (dialkylamino)trialkylsilanes such as (diisobutylamino)silane ((C ４ H ９ ) ２ NSiH ３ ), (diisopropylamino)silane ((C ３ H ７ ) ２ NSiH ３ ) and mono(dialkylamino)silanes such as (ethylmethylamino)silane (SiH ３ (N(CH ３ ) (C ２ H ５ )), (dimethylamino)silane (SiH ３ (N(CH ３ ) ２ ) and trimethoxydimethylaminosilane ((CH ３ ) ２ NSi(OCH ３ ) ３ ), trimethoxydialkylaminosilanes such as bis(dimethylamino)dimethylsilane ([(CH ３ ) ２ N] ２ Si(CH ３ ) ２ ), and tris(dimethylamino)methylsilane ([(CH ３ ) ２ N] ３ SiCH ３ ) and other tris(dialkylamino)alkylsilanes, and bis(diethylamino)silane ([(C ２ H ５ ) ２ N] ２ SiH ２ ) and bis(dialkylamino)silanes such as bis(tertiary butylamino)silane ([(C ４ H ９ ) NH] ２ SiH ２) and tris(dimethylamino)silane ([(CH ３ ) ２ N] ３ SiH), tris(dialkylamino)silanes such as tetrakis(dimethylamino)silane ([(CH ３ ) ２ As the raw material, one or more of these can be used.

[0088] [Step C] After step B is completed, a reactant is supplied to the wafer 200 in the processing chamber 201, that is, to the wafer 200 on whose surface the first layer containing the first element is formed.

[0089] Specifically, the valve 243c is opened to allow the reactant to flow into the gas supply pipe 232c. The reactant has its flow rate adjusted by the MFC 241c, is supplied into the processing chamber 201 via the nozzle 249c, and is exhausted from the exhaust port 231a. At this time, the reactant is supplied to the wafer 200 (reactant supply). The reactant may be supplied in a state diluted with a dilution gas such as an inert gas. At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 via the nozzles 249a to 249c, respectively.

[0090] By supplying a reactant to the wafer 200 under conditions described below, the reactant reacts with the first layer (i.e., a layer containing the first element and composed of at least a portion of the molecules of the raw material adsorbed on the surface of the wafer 200 in step B), thereby modifying the first layer into a second layer containing the first element. Here, when an oxidizing agent such as an oxygen-containing gas is used as the reactant, this step makes it possible to modify the first layer into a second layer containing the first element and oxygen (O). Similarly, when a nitriding agent such as a nitrogen-containing gas is used as the reactant, this step makes it possible to modify the first layer into a second layer containing the first element and nitrogen (N).

[0091] Here, by using an oxidizing agent as a reactant, OH terminations can be formed as adsorption sites in step B. Also, by using a nitriding agent, particularly a hydrogen nitride gas, as a reactant, NH terminations can be formed as adsorption sites in step B.

[0092] The reactants that have not reacted with the first layer and by-products generated by the reaction between the first layer and the reactants are removed from the process chamber 201 by evacuation.

[0093] After the formation of the second layer on the wafer 200 is completed, the valve 243 c is closed to stop the supply of reactants into the process chamber 201 .

[0094] After the supply of reactants to wafer 200 is completed (stopped), as shown in FIG. 4, it is preferable to perform step C2 in which the processing chamber 201 is evacuated while the supply of reactants to the processing chamber 201 is stopped, and any gases remaining in the processing chamber 201 are removed from the processing chamber 201.

[0095] By performing step C2, it is possible to remove from the processing chamber 201 an atmosphere containing unreacted reactants remaining in the processing chamber 201 or reactants that have contributed to the formation of the second layer, and by-products whose adsorption is suppressed by the adsorption layer.

[0096] 4, in step C2, it is preferable to open the valves 243d to 243f and supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c. That is, in step C2, it is preferable to evacuate the processing chamber 201 while supplying the inert gas to the wafers 200.

[0097] Examples of processing conditions for supplying reactants in step C include: reactant supply flow rate: 100 to 100,000 sccm, more preferably 1,000 to 10,000 sccm reactant supply time: 10 to 600 seconds, more preferably 30 to 300 seconds inert gas supply flow rate (per gas supply pipe): 0 to 50,000 sccm, more preferably 5,000 to 15,000 sccm Other conditions can be the same as the processing conditions for supplying the modifier in step A.

[0098] The processing conditions in step C2 can be the same as those in step A2.

[0099] As the reactant, for example, an oxygen (O)-containing gas, which is an oxidizing agent, can be used. As the O-containing gas, oxygen (O ２ ) gas, ozone (O ３ ) gas, nitrous oxide (N ２ O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO ２ ) gas, carbon monoxide (CO) gas, carbon dioxide (CO ２ ) gas, water vapor (H ２ O gas), hydrogen peroxide (H ２ O ２ ) gas, hydrogen (H ２ ) gas and oxygen (O ２ ) gas mixture, etc. Also, as the O-containing gas, for example, O activated by plasma excitation or the like can be used. ２ Gas (O ２ ＊ Gas) and H ２ O gas (H ２ O ＊ As the oxidizing agent, one or more of these can be used.

[0100] As a reactant, for example, a nitrogen (N)-containing gas, which is a nitriding agent, can be used. As the N-containing gas, for example, ammonia (NH ３ ) gas, diazene (N ２ H ２ ) gas, hydrazine (N ２ H ４ ) gas, N ３ H ８ The nitrogen-containing gas may be, for example, nitrogen activated by plasma excitation or the like. ２ Gas (N ２ ＊ gas) or the above-mentioned hydrogen nitride gas (e.g., NH ３ ＊ As the nitriding agent, one or more of these can be used.

[0101] As a reactant, for example, a hydrogen (H)-containing gas or a deuterium (D)-containing gas can be used as a reducing agent. ２ As the D-containing gas, for example, deuterium (D ２ ) gas can be used.

[0102] [Performance Predetermined Number of Times] By performing a cycle of the above-described steps A to C asynchronously, i.e., without synchronization, a predetermined number of times (n times, where n is an integer of 1 or 2 or greater), it is possible to form a film containing a first element on the wafer 200, i.e., on the surface of the wafer 200, including the inner surfaces of the recessed structures formed on the surface of the wafer 200. Here, particularly when an oxidizing agent is used as a reactant, it is possible to form a film containing the first element and O (i.e., an oxide film containing the first element). Examples of films containing the first element and O include metal oxide films such as zirconium oxide (ZrO) film, hafnium oxide (HfO) film, titanium oxide (TiO) film, tantalum oxide (TaO) film, niobium oxide (NbO) film, aluminum oxide (AlO) film, molybdenum oxide (MoO) film, and tungsten oxide (WO) film, and semimetal oxide films such as silicon oxide (SiO) film. Similarly, particularly when a nitriding agent is used as a reactant, it is possible to form a film containing the first element and N (i.e., a nitride film containing the first element). Examples of the film containing the first element and N include metal nitride films such as zirconium nitride (ZrN) film, hafnium nitride (HfN) film, titanium nitride (TiN) film, tantalum nitride (TaN) film, niobium nitride (NbN) film, aluminum nitride (AlN) film, molybdenum nitride (MoN) film, and tungsten nitride (WN) film, and semimetal nitride films such as silicon nitride (SiN) film.

[0103] The above-described cycle is preferably repeated multiple times, i.e., the thickness of the second layer formed per cycle is made thinner than the desired thickness, and the above-described cycle is preferably repeated multiple times until the thickness of the oxide film formed by stacking the second layer reaches the desired thickness.

[0104] (After-Purge and Atmospheric Pressure Return) After the formation of the film on the wafer 200 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).

[0105] (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).

[0106] (3) Effects of this Aspect According to this aspect, one or more of the following effects can be obtained.

[0107] (a) By using a compound having the rational formula R-O-R', where R is a branched alkyl group and R' is a linear hydrocarbon chain, as the modifier, the effect of suppressing the adsorption of raw materials by the adsorption layer formed on the wafer 200 can be enhanced. More specifically, in the molecular structure of the modifier physically adsorbed on the wafer 200, the branched alkyl group constituting R has a strong steric hindrance effect in the direction perpendicular to the adsorption surface (vertical direction). On the other hand, in the molecular structure of the modifier physically adsorbed on the wafer 200, the linear hydrocarbon chain constituting R' has a strong steric hindrance effect in the direction parallel to the adsorption surface (horizontal direction). Therefore, it is believed that the modifier having such a molecular structure can exert a strong steric hindrance effect in both the vertical and horizontal directions relative to the adsorption surface, thereby achieving a high adsorption suppression effect on raw materials.

[0108] (b) Furthermore, by using a modifier in which the branched alkyl group (R) is, in particular, any one of an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group, or a compound containing a substituent thereof, it is possible to obtain the above-mentioned strong steric hindrance effect in the longitudinal direction.

[0109] (c) Furthermore, by using as a modifier a compound containing a branched alkyl group having 4 or more C atoms, such as an isobutyl group, a sec-butyl group, or a tert-butyl group, or a substituent thereof, as the branched alkyl group (R), the steric hindrance effect can be made stronger than that of a compound containing a branched alkyl group having 3 or less C atoms, and the effect of suppressing adsorption of the raw material can be improved.

[0110] (d) Furthermore, by using as a modifier a compound containing a branched alkyl group with the largest number of branches, such as a tert-butyl group or a substituent thereof, as the branched alkyl group (R), the steric hindrance effect in the vertical direction described above can be significantly strengthened compared to a compound containing a branched alkyl group with two or fewer branches.

[0111] (e) Furthermore, by using a compound containing a C1-C10 linear alkyl group, such as a methyl group (C1), an ethyl group (C2), a propyl group (C3), an n-butyl group (C4), or an n-pentyl group (C5), as the linear hydrocarbon chain (R'), it is possible to relatively strengthen the lateral steric hindrance effect while suppressing an increase in molecular weight. In particular, by using a compound containing a C2-C10 linear alkyl group as the linear hydrocarbon chain (R'), it is possible to strengthen the lateral steric hindrance effect compared to a compound containing a C1 linear alkyl group (i.e., methyl) as R'. In particular, by using a compound containing a C1-C3 linear alkyl group as the linear hydrocarbon chain (R'), it is possible to ensure the lateral steric hindrance effect while keeping the molecular weight of the modifier within an appropriate range compared to a compound containing a C4-C10 linear alkyl group as R'.

[0112] (f) Furthermore, by using a modifier that is an ether compound, particularly for a raw material having an organic ligand, the effect of suppressing the adsorption of the raw material by the adsorption layer can be enhanced.

[0113] (g) The above-mentioned effects can be similarly obtained when a predetermined substance (gaseous substance, liquid substance) is arbitrarily selected from the above-mentioned raw material group, reactant group, and inert gas group.

[0114] Second Embodiment (Another Aspect of the Present Disclosure) In the first embodiment described above, an example was described in which a compound having the rational formula R-O-R', where R is a branched alkyl group, and R' is a linear hydrocarbon chain, is used as the modifier. In contrast, in another aspect of the present disclosure, a compound having the rational formula R-O-R', where at least one of R and R' is an allyl group (i.e., a 2-propenyl group) can be used as the modifier. Note that the elements other than the modifier in this aspect can be the same as those in the first embodiment described above. In this aspect as well, a gas containing these compounds can be used as the modifier.

[0115] Here, the double bond in the allyl group is expected to improve the physical adsorption (i.e., the ease with which physical adsorption occurs) of the modifier to the wafer surface compared to a single bond. That is, by using a compound in which at least one of R and R' is an allyl group as the modifier, it is expected that the physical adsorption of the modifier can be improved.

[0116] Furthermore, as the modifier in this embodiment, a compound in which both R and R′ are allyl groups can be more preferably used. That is, as the modifier in this embodiment, an ether compound having the structural formula shown in Figure 8(a), i.e., a (di)allyl ether, can be used.

[0117] As described above, the double bond of the allyl group is expected to improve the physical adsorption of the modifier to the wafer surface. Therefore, by using a compound in which both R and R′ are allyl groups as a modifier, it is expected that the physical adsorption of the modifier can be further improved.

[0118] Furthermore, as the modifier in this embodiment, a compound in which the above-mentioned R is an allyl group and the above-mentioned R' is a ligand other than an allyl group can be used. The ligand other than an allyl group as the above-mentioned R' can be, for example, a linear hydrocarbon chain, preferably a C1-C10 linear alkyl, more preferably a C1-C3 linear alkyl. As the modifier in this embodiment, for example, an ether compound having the structural formula shown in FIG. 8(b), i.e., allyl methyl ether, or an ether compound having the structural formula shown in FIG. 8(c), i.e., allyl ethyl ether, can be used.

[0119] As the modifier in this embodiment, it is preferable to use a compound having a molecular weight in the range of 40 to 130, more preferably in the range of 70 to 110, similar to the modifier in the above-mentioned embodiment.

[0120] Other Embodiments (Other Aspects of the Present Disclosure) The first and second embodiments of the present disclosure have been specifically described above. However, 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.

[0121] In the first embodiment, an example has been described in which step A2 is performed to remove gases and the like remaining in the processing chamber 201 from the processing chamber 201 after the supply of the modifying agent to the wafer 200 is completed. In contrast to this, for example, as in the processing sequence shown in Figure 5, step A2 may not be performed (i.e., not implemented) after the supply of the modifying agent to the wafer 200 is completed, and the supply of raw materials to the wafer 200 may be started (i.e., the step of supplying the modifying agent and the step of supplying the raw materials are performed consecutively). In this case, the processing time can be shortened and the throughput of substrate processing can be improved.

[0122] In the first embodiment, an example has been described in which step A of supplying a modifying agent to the wafer 200 and step B of supplying a raw material to the wafer 200 are performed asynchronously. However, as shown in the processing sequence of FIG. 6, for example, the supply of raw material to the wafer 200 may be started (i.e., step B may be started) before the supply of the modifying agent to the wafer 200 is stopped (i.e., before step A is completed). That is, step D may be performed in which the modifying agent and raw material are simultaneously supplied to the wafer 200. In this case, the processing time can be further shortened and the throughput of substrate processing can be improved.

[0123] It is preferable that the recipes used for each process are individually prepared according to the process content and stored in the storage device 121c via an electric communication line or the external storage device 123. When starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from among the multiple recipes stored in the storage device 121c. This makes it possible to reproducibly form films with various film types, composition ratios, film qualities, and film thicknesses using a single substrate processing apparatus. It also reduces the burden on the operator, avoids operational errors, and enables each process to be started quickly.

[0124] The above-mentioned recipes may not necessarily be newly created, but may be prepared by modifying an existing recipe already installed in the substrate processing apparatus. When modifying a recipe, the modified recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the 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.

[0125] 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.

[0126] When using these substrate processing apparatuses, each process can be performed under the same process procedures and conditions as in the above-described embodiment, and the same effects as in the above-described embodiment can be obtained.

[0127] The above-described embodiments can be used in combination as appropriate. In this case, the processing procedures and processing conditions can be the same as those of the above-described embodiments, for example.

[0128] 200 wafers (substrates)

Claims

1. A substrate processing method comprising: (a) supplying a modifier to a substrate having a recessed structure; and (b) supplying a raw material containing a predetermined element to the substrate, by repeating this cycle a predetermined number of times to form a film containing the predetermined element on the substrate, wherein the modifier is a compound having the rational formula R-O-R', where R is a branched alkyl group and R' is a linear hydrocarbon chain.

2. The substrate processing method according to claim 1, wherein R is any one selected from the group consisting of an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group, or a substituent thereof.

3. The substrate processing method according to claim 1, wherein R' is a linear alkyl group.

4. The substrate processing method according to claim 1, wherein R' is a linear hydrocarbon chain containing an unsaturated bond.

5. The method for processing a substrate according to claim 3, wherein R' is a C1-C10 alkyl.

6. The substrate processing method according to claim 1, wherein R is a tert-butyl group and R' is a methyl group or an ethyl group.

7. The substrate processing method according to any one of claims 1 to 6, wherein the modifying agent is a compound having a molecular weight in the range of 40 or more and 130 or less.

8. The substrate processing method according to any one of claims 1 to 6, wherein the modifying agent is a compound having a molecular weight in the range of 70 or more and 110 or less.

9. The substrate processing method according to any one of claims 1 to 6, wherein the source material is a compound containing an organic ligand bonded to an atom of the predetermined element.

10. The substrate processing method according to any one of claims 1 to 6, wherein the raw material is a compound containing an amino group that bonds to an atom of the predetermined element.

11. A substrate processing method according to any one of claims 1 to 6, wherein in (a), the modifying agent in a non-thermally decomposed state is physically adsorbed onto the substrate.

12. The substrate processing method according to any one of claims 1 to 6, wherein the surface of the substrate to which the modifying agent is supplied in (a) is OH-terminated.

13. The substrate processing method according to any one of claims 1 to 6, wherein the predetermined element is a metal element or a semi-metal element.

14. A substrate processing method according to any one of claims 1 to 6, wherein the cycle further includes the step of: (c) supplying to the substrate a reactant that reacts with at least a portion of the molecules of the precursor adsorbed to the substrate in (b).

15. The method of claim 14, wherein the reactant is an oxygen-containing gas.

16. The method of claim 14, wherein the reactant is a nitrogen-containing gas.

17. The substrate processing method according to any one of claims 1 to 6, wherein in the cycle, (a) is initiated before (b).

18. The substrate processing method according to any one of claims 1 to 6, wherein in the cycle, (a) and (b) are performed non-simultaneously.

19. The substrate processing method according to claim 17, wherein the cycle further includes, between (a) and (b), the step of: (d) evacuating the space in which the substrate is present while the supply of the modifier and the raw material to the substrate is stopped.

20. A method for manufacturing a semiconductor device, comprising: (a) supplying a modifier to a substrate having a recessed structure; and (b) supplying a raw material containing a predetermined element to the substrate, by repeating this cycle a predetermined number of times to form a film containing the predetermined element on the substrate, wherein the modifier is a compound having the rational formula R-O-R', where R is a branched alkyl group and R' is a linear hydrocarbon chain.

21. A program that causes a substrate processing apparatus to execute, by a computer, a procedure comprising: (a) a procedure for supplying a modifier to a substrate having a recessed structure; and (b) a procedure for supplying a raw material containing a predetermined element to the substrate, by repeating this cycle a predetermined number of times to form a film containing the predetermined element on the substrate, wherein the modifier is a compound having the rational formula R-O-R', where R is a branched alkyl group and R' is a linear hydrocarbon chain.

22. A substrate processing apparatus comprising: a modifier supply system that supplies a modifier to a substrate; a raw material supply system that supplies a raw material containing a predetermined element to the substrate; and a control unit configured to be able to control the modifier supply system and the raw material supply system so as to perform a process of forming a film containing the predetermined element on the substrate by performing a cycle including: (a) a process of supplying the modifier to the substrate having a concave structure, and (b) a process of supplying the raw material containing the predetermined element to the substrate a predetermined number of times, wherein the modifier is a compound having the rational formula R-O-R', where R is a branched alkyl group and R' is a linear hydrocarbon chain.

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