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

Abstract

To provide a substrate processing method, a substrate processing device, a semiconductor device manufacturing method, and a program that improve quality of a film formed on a substrate.SOLUTION: A method includes a step of forming a film containing a first element on a substrate by performing, a predetermined number of times, a cycle including a step A of supplying a modifier to the substrate in a processing chamber to form an adsorption layer containing the modifier adsorbed on a part of an exposed portion of the surface of the substrate, a step B of supplying a first film-forming agent containing a first element to the substrate, causing the first film-forming agent to react with the surface of the substrate, and forming a first layer containing the first element on another part of the exposed portion, and a step C of supplying a second film-forming agent that reacts with the first layer to the substrate, causing the second film-forming agent and the first layer to react, and modifying the first layer into a second layer containing the first element, and the adsorption layer suppresses adsorption of by-products generated during the formation of the first layer to at least one of the first layer and the surface of the substrate, and each of the steps includes steps A2 to C2 of evacuating the processing chamber.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

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

[0003] [Patent Document 1] JP 2008-124184 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a technique capable of improving the quality of a film formed on a substrate. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, (a) supplying a modifier to a substrate to form an adsorption layer containing the modifier adsorbed on a portion of an exposed surface of the substrate; (b) supplying a first film-forming agent containing a first element to the substrate, and reacting the first film-forming agent with a surface of the substrate to form a first layer containing the first element on another part of the exposed portion; (c) supplying a second film-forming agent that reacts with the first layer to the substrate, and reacting the second film-forming agent with the first layer to modify the first layer into a second layer containing the first element; a step of forming a film containing the first element on the substrate by performing a cycle including the steps of: There is provided a technique for suppressing, by the adsorption layer, adsorption of by-products generated during the formation of the first layer onto at least one of the first layer and the surface of the substrate. Effect of the Invention

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

[0007] [Figure 1] FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitably used in one embodiment of the present disclosure, showing a processing furnace 202 portion in vertical cross section. [Diagram 2] FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitably used in one embodiment of the present disclosure, showing a processing furnace 202 portion in a cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. 2 is a schematic configuration diagram of a controller 121 of a substrate processing apparatus preferably used in one embodiment of the present disclosure, and is a block diagram showing a control system of the controller 121. [Figure 4] FIG. 1 is a diagram showing a gas supply sequence according to an embodiment of the present disclosure. [Diagram 5] FIG. 5(a) is a diagram showing a modifying agent supply sequence according to one embodiment of the present disclosure; FIG. 5(b) is a diagram showing a raw material supply sequence according to one embodiment of the present disclosure; FIG. 5(c) is a diagram showing an oxidizing agent supply sequence according to one embodiment of the present disclosure; FIG. 5(d) is a diagram showing a raw material supply sequence according to one embodiment of the present disclosure; FIG. 5(e) is a diagram showing a raw material supply sequence according to one embodiment of the present disclosure; and FIG. 5(f) is a diagram showing an oxidizing agent supply sequence according to one embodiment of the present disclosure. [Figure 6] FIG. 1 is a diagram showing Example 1 and Comparative Example 1. [Figure 7] FIG. 13 is a diagram showing a schematic arrangement of wafers in a processing chamber when Example 2 and Comparative Example 2 are produced. [Figure 8] FIG. 8(a) is a diagram showing Example 2, and FIG. 8(b) is a diagram showing Comparative Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0009] (1) Configuration of the substrate processing device 1, the process furnace 202 has a heater 207 as a temperature 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) gas by heat.

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

[0011] Nozzles 249a to 249c serving as first to third supply units are provided in the processing chamber 201 so as to penetrate 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-232c are provided with mass flow controllers (MFCs) 241a-241c, which are flow rate controllers (flow rate control parts), and valves 243a-243c, which are on-off valves, in order from the upstream side of the gas flow. Gas supply pipes 232d-232f are connected to the gas supply pipes 232a-232c downstream of the valves 243a-243c. Gas supply pipes 232d-232f are provided with MFCs 241d-241f and valves 243d-243f, which are provided from the upstream side of the gas flow. Gas supply pipes 232a-232f are made of a metal material, such as SUS.

[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, from the lower part to the upper part of the inner wall of the reaction tube 203, so as to rise upward in the arrangement direction of the wafers 200. That is, the nozzles 249a to 249c are provided in a region horizontally surrounding the wafer arrangement region on the side of the wafer arrangement region in which the wafers 200 are arranged, so as to extend along the wafer arrangement region. In a plan view, the nozzle 249b is disposed so as to face an exhaust port 231a (described later) on a straight line across the center of the wafer 200 loaded into the processing chamber 201. The nozzles 249a and 249c are disposed so as to sandwich a straight line L passing through the nozzle 249b and the center of the exhaust port 231a from both sides along the inner wall of the reaction tube 203 (the outer periphery of the wafer 200). The straight line L is also a straight line passing through the nozzle 249b and the center of the wafer 200. In other words, the nozzle 249c is provided on the opposite side of the nozzle 249a across the line L. The nozzles 249a and 249c are arranged symmetrically with respect to the line L. Gas supply holes 250a to 250c for supplying gas are provided on the side surfaces of the nozzles 249a to 249c, respectively. The gas supply holes 250a to 250c are each opened to face (face) the exhaust port 231a in a plan view, and are capable of supplying gas toward the wafer 200. A plurality of gas supply holes 250a to 250c are provided from the lower part to the upper part 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] An oxidizing agent (oxidizing 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 oxidizing agent is used as one of the film forming agents.

[0017] From the gas supply pipes 232d to 232f, an inert gas is supplied via 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, or the like.

[0018] A modifying agent supply system (reformed gas supply system) is mainly composed of the gas supply pipe 232a, the MFC 241a, and the valve 243a. A raw material supply system (raw material gas supply system) is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. An oxidizing agent supply system (oxidizing gas supply system) is mainly composed of the gas supply pipe 232c, the MFC 241c, and the valve 243c. An inert gas supply system is mainly composed of 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 the valves 243a-243f, MFCs 241a-241f, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a-232f, and is configured so that the supply operation of various substances (various gases) into the gas supply pipes 232a-232f, i.e., the opening and closing operation of the valves 243a-243f and the flow rate adjustment operation by the MFCs 241a-241f, etc. are controlled by a controller 121 described later. The integrated supply system 248 is configured as an integrated or separate type integrated unit, and can be attached and detached to and from the gas supply pipes 232a-232f, etc., in units of integrated units, and is configured so that maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed in units of integrated units.

[0020] An exhaust port 231a for exhausting the atmosphere in the processing chamber 201 is provided at the lower side of the side wall of the reaction tube 203. 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 side wall of the reaction tube 203 from the lower part to the upper part, that is, along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246 as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure adjustment unit). The APC valve 244 can evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating, and further, can 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 included in the exhaust system.

[0021] Below the manifold 209, a seal cap 219 is provided as a furnace port cover body capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is made of a metal material such as SUS, and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a seal member that abuts against the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 is provided for rotating the boat 217, which will be described later. A rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217 through the seal cap 219. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The seal cap 219 is configured to be vertically raised and lowered by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the wafers 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219.

[0022] A rotation mechanism 267 for rotating the boat 217, which will be described later, is installed below the seal cap 219. A rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217 through the seal cap 219. The rotation mechanism 267 is configured to rotate the wafer 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 as a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) for loading and unloading (transporting) the wafer 200 into and out of the processing chamber 201 by lifting and lowering the seal cap 219.

[0023] A shutter 219s is provided below the manifold 209 as a furnace port cover that can airtightly close the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is carried out of the processing chamber 201. The shutter 219s is made of a metal material such as SUS and is formed in a disk shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a seal member that comes into contact with the lower end of the manifold 209. The opening and closing operation (lifting and lowering operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0024] The boat 217 as a substrate support is configured to support a plurality of wafers 200, for example 25 to 200, in multiple stages in a horizontal position and aligned vertically with their centers aligned, i.e., arranged at intervals. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, heat insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported in multiple stages.

[0025] A temperature sensor 263 serving as a temperature detector is installed in the reaction tube 203. By adjusting the power supply to the heater 207 based on temperature information detected by the temperature sensor 263, the temperature distribution in the process chamber 201 becomes a desired one. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[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. A control program for controlling the operation of the substrate processing apparatus, a process recipe in which procedures and conditions of the substrate processing described later are described, etc. are readably stored in the storage device 121c. The process recipe is a combination of procedures in the substrate processing described later, which are executed by the controller 121 in the substrate processing apparatus, so that a predetermined result can be obtained, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. In addition, the process recipe is also simply referred to as a recipe. In this specification, when the word program is used, it may include only a recipe, only a control program, or both. The RAM 121b is configured as a memory area (work area) in which the programs and data 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, and the like.

[0029] The CPU 121a is configured to be able to read and execute a control program from the storage device 121c, and to read a recipe from the storage device 121c in response to an input of an operation command from the input / output device 122, etc. The CPU 121a is configured to be able to control the flow rate adjustment operation of various substances (various gases) by the MFCs 241a to 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, etc., in accordance with the contents of the read recipe.

[0030] The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 in a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory or an SSD. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both of them. The program may be provided to the computer using a communication means such as the Internet or a dedicated line without using the external storage device 123.

[0031] (2) Substrate processing An example of a processing sequence for forming a film on a wafer 200 as a substrate as one step of a manufacturing process of a semiconductor device using the above-mentioned substrate processing apparatus 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] In the processing sequence shown in Figure 4, A step A of supplying a modifying agent to the wafer 200 to form an adsorption layer on the wafer 200, the adsorption layer including the modifying agent physically adsorbed on the surface of the wafer 200; A step B of supplying a raw material containing a first element to the wafer 200 and reacting the raw material with the surface of the wafer 200 to form a first layer containing the first element on the wafer 200; a step C of supplying an oxidizing agent to the wafer 200, reacting the oxidizing agent with the first layer, and modifying the first layer into a second layer containing the first element and oxygen; The cycle including the above is repeated a predetermined number of times (n times, n is an integer of 1 or more).

[0033] In the process sequence shown in FIG. 4, the adsorption of by-products generated during the formation of the first layer to at least one of the first layer and the surface of the wafer 200 is suppressed by the adsorption layer.

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

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

[0036] The term "wafer" used in this specification may mean the wafer itself or a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may mean the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. When it is stated in this specification that "a predetermined layer is formed on a wafer", it may mean that a predetermined layer is formed directly on the surface of the wafer itself or that a predetermined layer is formed on a layer or the like formed on the wafer. When the term "substrate" is used in this specification, it is synonymous with the term "wafer".

[0037] 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 modifier and the film-forming agent (raw material, oxidizer) may include a gaseous substance, may include a liquid substance such as a mist substance, or may include both of them.

[0038] (Wafer charge and boat load) When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209 (shutter open). Thereafter, as shown in FIG. 1, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b. Note that a recessed structure such as a trench or a hole is formed on the surface of the wafer 200. The aspect ratio of the recessed structure, that is, 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.

[0039] (Pressure and temperature regulation) After the boat loading is completed, the inside of the processing chamber 201, i.e., the space in which the wafers 200 are present, is evacuated (reduced pressure exhaust) by the vacuum pump 246 so that the inside of the processing chamber 201 is at a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Also, the wafers 200 in the processing chamber 201 are heated by the heater 207 so that the temperature is a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the inside of the processing chamber 201 has a desired temperature distribution. Also, the rotation mechanism 267 starts rotating the wafers 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0040] (film formation) Thereafter, the following steps A to C are executed in sequence.

[0041] [Step A] In this step, a modifying agent is supplied to the wafer 200 in the processing chamber 201 .

[0042] Specifically, the valve 243a is opened to allow the modifying agent to flow into the gas supply pipe 232a. The modifying agent has a flow rate adjusted by the MFC 241a, is supplied into the processing chamber 201 through the nozzle 249a, and is 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.

[0043] By supplying the modifying agent to the wafer 200 under conditions described below, the modifying agent is physically adsorbed onto the surface of the wafer 200, and an adsorption layer containing the modifier physically 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, some of the adsorption sites present on the surface of the wafer 200 are covered by the adsorption layer, and other adsorption sites are not covered by the adsorption layer and are exposed. Here, the adsorption sites present on the surface of the wafer 200 include, for example, hydroxyl groups (OH groups) that terminate the surface of the wafer 200. In addition, since the modifying agent includes an organic compound as described below, at least a part of the surface of the adsorption layer can be terminated by hydrocarbon groups or the like.

[0044] 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 cover the surface of the wafer 200 discontinuously. As a result, it is possible to reliably expose some of the adsorption sites (OH groups) present on the surface of the wafer 200. However, at this stage, the modifier may be physically adsorbed on the surface of the wafer 200 so that the thickness of the adsorption layer is greater than or equal to one molecular layer (i.e., the surface of the wafer 200 is covered with a continuous layer), and in step A2 described later, some of the modifiers contained in the adsorption layer may be removed from the surface of the wafer 200 to form an adsorption layer having a thickness of less than one molecular layer.

[0045] 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 described later, in this step, it is more preferable to further form an adsorption layer on the bottom surface and sidewall of the inner surface of the recessed structure.

[0046] 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.

[0047] After the supply of the modifying agent to the wafer 200 is completed (stopped), as shown in FIG. 4, it is preferable to perform step A2 in which the inside of the processing chamber 201 is exhausted while the supply of the modifying agent to the processing chamber 201 is stopped, and gas remaining in the processing chamber 201 is removed from the inside of the processing chamber 201. By continuously performing step A2, a part of the modifying agent contained in the adsorption layer can be removed (desorbed) from the surface of the wafer 200, and the density (thickness) of the adsorption layer formed on the wafer 200 can be adjusted to a desired density (thickness). That is, in step A2, the exhaust of the processing chamber 201 can be continued until the thickness of the adsorption layer reaches a desired density. As a result, it is possible to optimize the thickness of the first layer formed per cycle, and adjust the formation rate of the film on the wafer 200 to a relatively large desired size. In step A2, it is preferable to set the exhaust conditions in the processing chamber 201, i.e., the exhaust time, the exhaust speed, etc., so that the formation rate of the film formed on the wafer 200 becomes a desired size.

[0048] As shown in FIG. 4, in step A2, it is preferable to open the valves 243d to 243f and supply the inert gas into the processing chamber 201 through the 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, in step A2, as shown in FIG. 5(a), 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, in step A2, it is preferable to perform 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 (not simultaneously performed) multiple times.

[0049] By performing step A2 in any of these ways, a part of the modifier physically adsorbed on 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 is possible to further optimize the thickness of the first layer formed per cycle and adjust the formation of the film on the wafer 200 to proceed at a higher rate.

[0050] The processing conditions for supplying the modifier in step A are as follows: 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 Treatment temperature: 200 to 500°C, more preferably 200 to 350°C Treatment pressure: 100 to 10,000 Pa, more preferably 100 to 1,000 Pa Examples are given below.

[0051] In this specification, a numerical range such as "100 to 100,000 sccm" means that the lower limit and the upper limit are included in the range. Thus, 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.

[0052] The processing conditions in step A2 are as follows: 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 Examples are given below.

[0053] As the modifier, a gas containing an organic compound can be used. As the gas containing an organic compound, a gas containing at least one selected from the group consisting of an ether compound, a ketone compound, an amine compound, and an organic hydrazine compound can be used. As the gas containing an ether compound, a gas containing at least one of dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, isopropyl ether, furan, tetrahydrofuran, pyran, tetrahydropyran, etc. can be used. As the gas containing a ketone compound, a gas containing at least one of dimethyl ketone, diethyl ketone, methyl ethyl ketone, methyl propyl ketone, etc. can be used. As the gas containing an amine compound, a gas containing at least one of methylamine compounds such as monomethylamine, dimethylamine, and trimethylamine, ethylamine compounds such as monoethylamine, diethylamine, and triethylamine, and methylethylamine compounds such as dimethylethylamine and methyldiethylamine can be used. As the gas containing an organic hydrazine compound, a gas containing at least one of methylhydrazine-based gases such as monomethylhydrazine, dimethylhydrazine, and trimethylhydrazine can be used. As the modifier, one or more of these can be used. In addition, as the modifier, it is preferable to use a gas that is not easily chemically adsorbed to the surface of the wafer 200. In order to form an adsorption layer containing a modifier physically adsorbed on the surface of the wafer 200, for example, a gas that does not substantially chemically react with the adsorption sites (OH groups) on the surface of the wafer 200 can be suitably used.

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

[0055] [Step B] After step A is completed, a source material is supplied to the wafer 200 in the processing chamber 201, that is, to the wafer 200 having an adsorption layer formed on its surface.

[0056] Specifically, the valve 243b is opened to allow the raw material to flow into the gas supply pipe 232b. The raw material is adjusted in flow rate by the MFC 241b, supplied into the processing chamber 201 through the nozzle 249b, and 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 through each of the nozzles 249a to 249c.

[0057] By supplying the raw material to the wafer 200 under conditions to be described later, it is possible to react the raw material with the surface of the wafer 200. As described later, the raw material contains a molecule (hereinafter also referred to as raw material molecule) having a first element and a ligand bonded to 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 the modified layer, i.e., with the adsorption site (OH group) exposed on the surface of the wafer 200. In the course of this reaction, the ligand is desorbed from the first element contained in the raw material, and the first element having dangling species 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 the adsorption layer.

[0058] During the formation of the first layer, a certain by-product is generated. The by-product may include a ligand that is desorbed from the first element by a reaction between the raw material and the adsorption site exposed on the surface of the wafer 200. For example, the by-product may include a molecule in which a part of the ligand is desorbed from a molecule having the first element and a ligand bonded to the first element. For example, a molecule in which a part of the ligand is desorbed from a molecule having the first element and a ligand bonded to the first element may be generated by thermal decomposition of the raw material supplied into the processing chamber 201.

[0059] As described later, the by-products may contain organic ligands (organic substances), and it is undesirable for the by-products to be adsorbed (attached) to the surface of the film formed on the wafer 200 or remain in the film. The adsorption of the by-products to the surface of the film or the remainder of the by-products in the film causes an increase in the thickness of the film. Therefore, the amount of adsorption or the remainder of the by-products may become non-uniform within the wafer surface or within the inner surface (inner wall) of the recessed structure on the wafer, which may cause deterioration in the film thickness uniformity within the wafer surface of the film formed on the wafer 200 or the step coverage of the film formed within the inner surface of the recessed structure. Furthermore, the remainder of the by-products in the film may cause deterioration in the film quality due to an increase in impurities derived from the by-products in the film.

[0060] To address such a problem, according to the present embodiment, the adsorption (attachment) of by-products generated during the formation of the first layer to at least one of the first layer and the surface of the wafer 200 can be suppressed by the adsorption layer formed in advance in step A. This makes it possible to suppress uncontrolled and non-uniform increase in the thickness of the film formed on the wafer 200 caused by the adsorption of by-products, and the residue of by-products in the film.

[0061] One of the reasons why adsorption of by-products to the first layer and the surface of wafer 200 can be suppressed is that the adsorption layer formed in step A reduces the amount of exposure of the surface of wafer 200, i.e., the amount of adsorption sites exposed on the surface of wafer 200 (density per unit area), thereby properly controlling the amount (degree) of reaction between the raw material and the surface of wafer 200, and as a result, the amount of ligands desorbed from the first element, i.e., the amount of by-products containing organic ligands, is reduced.

[0062] Another reason why the adsorption of the first layer and the by-products to the surface of the wafer 200 can be suppressed is that, in addition to the amount of by-products generated during the formation of the first layer being reduced as described above, the adsorption layer formed in advance in step A properly covers and conceals a part of the surface of the wafer 200 so that the by-products do not adhere (physical adsorption), and the adsorption layer acts to suppress the by-products generated during the formation of the first layer from adsorbing (attaching) to the first layer and the surface of the wafer 200. One of the reasons why the adsorption layer acts to suppress the adsorption of the by-products to the first layer and the surface of the wafer 200 is that the modifier physically adsorbed on the surface of the wafer 200, or a part of the modifier desorbed from the surface of the wafer 200, preferentially adsorbs to the by-products rather than to the first layer and the surface of the wafer 200, thereby suppressing the adsorption of the by-products to the first layer. By forming an adsorption layer in advance on the bottom surface and side walls of the inner surface of the recessed structure in step A, it is possible to sufficiently suppress adsorption of by-products to the surface of the wafer 200 and the first layer, even near the bottom surface of the recessed structure where it may be difficult for the modifier to reach.

[0063] The by-products whose adsorption is suppressed are removed by exhaust from the processing chamber 201. In addition, the modifier adsorbed to the by-products is removed from the processing chamber 201 by exhaust in this step or exhaust in a subsequent step.

[0064] 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.

[0065] After the supply of raw materials to wafer 200 has been completed (stopped), it is preferable to perform step B2 in which, as shown in FIG. 4, the inside of processing chamber 201 is evacuated while the supply of raw materials to processing chamber 201 is stopped, and residual gases and the like remaining in processing chamber 201 are removed from inside processing chamber 201.

[0066] By performing step B2, it is possible to remove from the processing chamber 201 an atmosphere containing unreacted raw materials remaining in the processing chamber 201 or raw materials that have contributed to the formation of the first layer, by-products whose adsorption has been suppressed by the adsorption layer, and the like.

[0067] Moreover, 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 into a film with a low concentration of impurities caused by the modifier.

[0068] Furthermore, by performing step B2, it becomes possible to remove the by-products adhering to the adsorption layer from the surface of the wafer 200 together with the modifier contained in the adsorption layer, i.e., the modifier physically adsorbed to the surface of the wafer 200. As a result, it becomes possible to suppress the by-products from remaining in the film formed on the wafer 200, and to make the film have excellent in-wafer film thickness uniformity and step coverage, and have a low concentration of impurities caused by the by-products.

[0069] As shown in FIG. 4, in step B2, it is preferable to open the valves 243d to 243f and supply the 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 wafer 200. Also, preferably, in step B2, as shown in FIG. 5(b), 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. Also preferably, in step B2, 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 (not simultaneously).

[0070] By performing step B2 in any of these ways, a portion of the modifier physically adsorbed on the surface of the wafer 200 can be more efficiently removed from the surface of the wafer 200, and the various effects described above can be more reliably obtained.

[0071] The processing conditions for the raw material supply in step B are as follows: 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 may be similar to the treatment conditions in the step A of supplying the modifier.

[0072] The processing conditions in step B2 may be the same as those in step A2.

[0073] The raw material may be a gas containing a molecule having a first element and a ligand bonded to the first element. The first element may be a metal element, preferably a transition metal element, more preferably a Group 4 element such as zirconium (Zr), hafnium (Hf), or titanium (Ti). The ligand bonded to the first element may be an organic ligand, preferably a hydrocarbon group containing at least one selected from the group consisting of alkyl groups such as methyl, ethyl, propyl, and butyl groups, cyclopentadienyl groups, cyclohexadienyl groups, and cycloheptatrienyl groups.

[0074] As a raw material containing Zr as the first element, for example, a gas containing at least one selected from the group consisting of tetrakisethylmethylaminozirconium (Zr[N(CH3)C2H5]4), tetrakisdiethylaminozirconium (Zr[N(C2H5)2]4), tetrakisdimethylaminozirconium (Zr[N(CH3)2]4), Zr(MMP)4, Zr(O-tBu)4, and trisdimethylaminocyclopentadienylzirconium ((C5H5)Zr[N(CH3)2]3) can be used. As a raw material, one or more of these can be used.

[0075] As a raw material containing Hf as the first element, for example, a gas containing at least one selected from the group consisting of tetrakisethylmethylaminohafnium (Hf[N(CH3)C2H5]4), tetrakisdiethylaminohafnium (Hf[N(C2H5)2]4), tetrakisdimethylaminohafnium (Hf[N(CH3)2]4), Hf(O-tBu)4, Hf(MMP)4, and trisdimethylaminocyclopentadienylhafnium ((C5H5)Hf[N(CH3)2]3) can be used. As a raw material, one or more of these can be used.

[0076] As a raw material containing Ti as the first element, for example, a gas containing at least one selected from the group consisting of tetrakisethylmethylaminotitanium (Ti[N(CH3)C2H5]4), tetrakisdiethylaminotitanium (Ti[N(C2H5)2]4), tetrakisdimethylaminotitanium (Ti[N(CH3)2]4), Ti(O-tBu)4, Ti(MMP)4, and trisdimethylaminocyclopentadienyltitanium ((C5H5)Ti[N(CH3)2]3) can be used. As a raw material, one or more of these can be used.

[0077] [Step C] After step B is completed, an oxidizing agent is supplied to the wafer 200 in the processing chamber 201, that is, to the wafer 200 having the first layer containing the first element formed on the surface thereof.

[0078] Specifically, the valve 243c is opened to allow the oxidizing agent to flow into the gas supply pipe 232c. The flow rate of the oxidizing agent is adjusted by the MFC 241c, and the oxidizing agent is supplied into the processing chamber 201 through the nozzle 249c and exhausted from the exhaust port 231a. At this time, the oxidizing agent is supplied to the wafer 200 (oxidizing agent supply). The oxidizing agent may be supplied in a state diluted with a dilution gas such as an inert gas or another oxygen-containing 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.

[0079] By supplying an oxidizing agent to the wafer 200 under conditions described below, the oxidizing agent reacts with the first layer, and the first layer can be modified (oxidized) into a second layer containing the first element and oxygen (O).

[0080] In addition, by-products may also be generated during the formation of the second layer. The by-products may contain ligands that are desorbed from the first layer due to the reaction between the oxidizing agent and the first layer. These by-products may also contain organic ligands (organic substances) like the by-products generated during the formation of the first layer, and re-adsorption (re-attachment) of the by-products to the second layer and the resulting residue of the by-products in the film formed on the wafer 200 are undesirable.

[0081] To address such a problem, according to the present embodiment, the adsorption of by-products generated during the formation of the second layer to at least one of the second layer and the surface of the wafer 200 can be suppressed by the adsorption layer formed in advance in step A. This is believed to be because, similar to step B, the adsorption layer formed in advance in step A properly covers and conceals part of the surface of the wafer 200, and the adsorption layer acts to suppress (hinder) the re-adsorption (re-attachment) of by-products generated during the formation of the second layer to the second layer.

[0082] The by-products that are prevented from being re-adsorbed are removed by exhaust from inside the processing chamber 201. It is also considered that some of the by-products that are prevented from being adsorbed to the second layer and the surface of the wafer 200 may be adsorbed (attached) to the adsorption layer.

[0083] After the formation of the second layer on the wafer 200 is completed, the valve 243c is closed to stop the supply of the oxidizing agent into the processing chamber 201.

[0084] After the supply of the oxidizing agent to the wafer 200 is completed (stopped), it is preferable to perform step C2 in which the inside of the processing chamber 201 is evacuated while the supply of the oxidizing agent to the processing chamber 201 is stopped, as shown in FIG. 4, and residual gases and the like remaining in the processing chamber 201 are removed from the processing chamber 201.

[0085] By performing step C2, it is possible to remove from the processing chamber 201 an atmosphere containing unreacted oxidizing agent remaining in the processing chamber 201 or oxidizing agent after contributing to the formation of the second layer, and by-products whose adsorption is suppressed by the adsorption layer.

[0086] Moreover, by performing step C2, 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 into a film with a low concentration of impurities caused by the modifier.

[0087] Furthermore, by performing step C2, it is possible to remove the by-products adhering to the adsorption layer from the surface of the wafer 200 together with the modifier contained in the adsorption layer, i.e., the modifier physically adsorbed to the surface of the wafer 200. As a result, it is possible to suppress the by-products from remaining in the film formed on the wafer 200, and to make the film have excellent in-wafer film thickness uniformity and step coverage, and also have a low concentration of impurities caused by the by-products.

[0088] As shown in FIG. 4, in step C2, it is preferable to open the valves 243d to 243f and supply the 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 wafer 200. Also, in step C2, as shown in FIG. 5(c), 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. Also, in step C2, it is preferable to perform 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 (not simultaneously performed) multiple times.

[0089] By performing step C2 in any of these ways, a portion of the modifier physically adsorbed on the surface of the wafer 200 can be more efficiently removed from the surface of the wafer 200, and the various effects described above can be more reliably obtained.

[0090] The processing conditions for supplying the oxidant in step C are as follows: Oxidant supply flow rate: 100 to 100,000 sccm, more preferably 1,000 to 10,000 sccm Oxidizing agent 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 may be similar to the treatment conditions in the step A of supplying the modifier.

[0091] The processing conditions in step C2 may be the same as those in step A2.

[0092] As the oxidizing agent, for example, a gas containing oxygen (O) and hydrogen (H) can be used. As the O and H containing gas, for example, water vapor (HO gas), hydrogen peroxide (HO) gas, hydrogen (H) gas + oxygen (O) gas, H gas + ozone (O) gas, etc. can be used. As the O and H containing gas, one or more of these can be used.

[0093] In this specification, the description of two gases, such as "H2 gas + O2 gas," means a mixed gas of H2 gas and O2 gas. When supplying a mixed gas, the two gases may be mixed (premixed) in a supply pipe and then supplied into the processing chamber 201, or the two gases may be separately supplied into the processing chamber 201 through different supply pipes and mixed (postmixed) in the processing chamber 201.

[0094] [Perform the specified number of times] By performing the cycle of the above-mentioned steps A to C non-simultaneously, i.e., without synchronization, a predetermined number of times (n times, n being an integer of 1 or more), it is possible to form a film containing the first element and O (an oxide film containing the first element) on the wafer 200, i.e., on the surface of the wafer 200 including the inner surface of the recessed structure formed on the surface of the wafer 200. It is preferable to repeat the above-mentioned cycle multiple times. In other words, it is preferable to make the thickness of the second layer formed per cycle thinner than the desired thickness, and to repeat the above-mentioned cycle multiple times until the thickness of the oxide film formed by stacking the second layer reaches the desired thickness.

[0095] (After purging and atmospheric pressure recovery) 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 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 the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (return to atmospheric pressure).

[0096] (Boat unloading and wafer discharging) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafers 200 are carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 while being supported by the boat 217 (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 carried out to the outside of the reaction tube 203, the processed wafers 200 are taken out of the boat 217 (wafer discharge).

[0097] (3) Effects of this mode According to this aspect, one or more of the following effects can be obtained.

[0098] (a) When a cycle including steps A to C is performed a predetermined number of times, the adsorption of by-products generated during the formation of the first layer to at least one of the first layer and the surface of the wafer 200 is suppressed by the adsorption layer, thereby improving the quality of the film formed on the wafer 200. For example, it is possible to improve the in-wafer film thickness uniformity and step coverage of the film formed on the wafer 200. In addition, for example, it is possible to make the film formed on the wafer 200 a film with a low concentration of impurities caused by by-products generated during the formation of the first layer. As an example, the concentration of impurities contained in the film formed on the wafer 200 is lower than the concentration of impurities contained in the film formed on the wafer 200 by performing the cycle including steps B and C but not including step A the same predetermined number of times.

[0099] (b) When a cycle including steps A to C is performed a predetermined number of times, the adsorption of by-products generated during the formation of the second layer to at least one of the second layer and the surface of the wafer 200 is suppressed by the adsorption layer, thereby making it possible to further improve the quality of the film formed on the wafer 200. For example, it is possible to further improve the in-wafer film thickness uniformity and step coverage of the film formed on the wafer 200. In addition, for example, it is possible to make the film formed on the wafer 200 a film with a lower concentration of impurities caused by by-products generated during the formation of the second layer.

[0100] (c) The modifier contained in the adsorption layer is physically adsorbed on the surface of the wafer 200, and therefore is easily desorbed from the surface of the wafer 200 during the cycle including steps A to C. As a result, it is possible to adjust the formation rate of the film formed on the wafer 200 to a desired level, thereby improving the productivity of the film formation process. In addition, it is possible to suppress the modifier from remaining in the film formed on the wafer 200, thereby improving the quality of the film.

[0101] For example, in step A, after supplying the modifying agent to the wafer 200, step A2 is performed to exhaust the inside of the processing chamber 201, thereby making it possible to remove a part of the modifying agent contained in the adsorption layer from the surface of the wafer 200. This makes it possible to adjust the density (thickness) of the adsorption layer formed on the wafer 200 to a desired density (thickness). As a result, it becomes possible to proceed with the formation of a film on the wafer 200 at a desired rate. In addition, it is possible to suppress the residue of the modifying agent in the film formed on the wafer 200, and to make this film a film with a low concentration of impurities caused by the modifying agent.

[0102] Also, for example, in step B, after supplying the raw material to the wafer 200, step B2 is performed to exhaust the inside of the processing chamber 201, thereby making it possible to desorb the modifier contained in the adsorption layer from the surface of the wafer 200, thereby suppressing the modifier from remaining in the film formed on the wafer 200, and making this film a film with a low concentration of impurities caused by the modifier. Also, by removing the by-products attached to the adsorption layer from the surface of the wafer 200 together with the modifier contained in the adsorption layer, it is possible to suppress the by-products from remaining in the film formed on the wafer 200. As a result, it is possible to make this film a film with excellent wafer in-plane uniformity and step coverage, and with a low concentration of impurities caused by by-products generated during the formation of the first layer.

[0103] Also, for example, in step C, after supplying the oxidizing agent to the wafer 200, step C2 is performed to exhaust the inside of the processing chamber 201, thereby making it possible to desorb the modifier contained in the adsorption layer from the surface of the wafer 200, thereby suppressing the modifier from remaining in the film formed on the wafer 200, and making this film a film with a low concentration of impurities caused by the modifier. Also, by removing the by-products attached to the adsorption layer from the surface of the wafer 200 together with the modifier contained in the adsorption layer, it is possible to suppress the by-products from remaining in the film formed on the wafer 200. As a result, it is possible to make this film a film with excellent wafer in-plane uniformity and step coverage, and with a low concentration of impurities caused by by-products generated during the formation of the second layer.

[0104] (d) In step A, by forming a discontinuous adsorption layer (an adsorption layer having a thickness of less than one molecular layer) on the wafer 200, i.e., by leaving some of the adsorption sites (OH groups) present on the surface of the wafer 200 exposed, it becomes possible to bond the first element contained in the raw material to the adsorption sites present on the surface of the wafer 200 in step B. As a result, it becomes possible to proceed with the formation of a film on the wafer 200 at a desired rate.

[0105] (e) The above-mentioned effect is particularly beneficial when a recessed structure is formed on the surface of the wafer 200 and a film is to be formed on the inner surface of the recessed structure.

[0106] This is because, when a film is formed on the inner surface of a recessed structure formed on the surface of the wafer 200, the by-products generated in the recessed structure pass through the opening of the recessed structure when being discharged from the recessed structure, so that the exposure amount of the by-products tends to be greater near the opening of the recessed structure than near the bottom of the recessed structure. Therefore, the by-products are more likely to be adsorbed near the opening of the recessed structure. As a result, the film formed near the opening of the recessed structure is more likely to have a larger film thickness and a higher concentration of impurities due to the by-products than the film formed near the bottom of the recessed structure. In particular, when the recessed structure has an aspect ratio of 10 or more, the above-mentioned problem occurs significantly.

[0107] According to this embodiment, as described above, the adsorption of by-products generated during the formation of the first layer and the second layer to at least one of the first layer, the second layer, and the surface of the wafer 200 can be suppressed by the adsorption layer, and the problem described herein can be solved and the step coverage of the film formed on the inner surface of the recessed structure formed on the wafer 200 can be improved. In addition, when the adsorption layer is formed on at least the bottom surface and the sidewall of the inner surface of the recessed structure in step A, that is, when the adsorption layer is formed not only on the opening but also on the entire inner surface of the recessed structure, the adsorption of by-products can be suppressed not only on the opening but also on the bottom surface and the sidewall of the recessed structure. As a result, it is possible to further improve the step coverage of the film formed on the wafer 200, and it is possible to form a film with a low concentration of impurities caused by by-products on the entire inner surface of the recessed structure.

[0108] (f) The above-mentioned effects can be obtained in the same way even when a predetermined substance (gaseous substance, liquid substance) is arbitrarily selected from the above-mentioned modifying agent group, raw material group, oxidizing agent group, and inert gas group.

[0109] <Other Aspects of the Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0110] 5(d) and the process sequence shown below, in step B, a raw material supply cycle including a step of supplying raw material to the wafer 200 and a step of evacuating the processing chamber 201 while stopping the supply of raw material may be performed multiple times (m times, where m is an integer of 2 or more). The process conditions in each of these steps may be the same as the raw material supply described in the above embodiment and the process conditions in step B2.

[0111] [Modifier → (raw material → exhaust) × m → oxidizer] × n

[0112] When the continuous supply time of the raw material is long, the thermal decomposition of the raw material progresses, and the amount of by-products generated by the thermal decomposition may increase. In order to suppress the increase in the amount of by-products caused by such thermal decomposition, it is desirable to shorten the continuous supply time of the raw material. In this embodiment, the continuous supply time is shortened by supplying the raw material in a time-division manner, and the first layer can be formed while suppressing the generation (increase) of by-products.

[0113] In this case, the modifier contained in the adsorption layer can be desorbed from the surface of the wafer 200 each time the raw material supply cycle is repeated, and the modifier can be further prevented from remaining in the film. In addition, the by-products attached to the adsorption layer can be removed from the surface of the wafer 200 together with the modifier contained in the adsorption layer each time the raw material supply cycle is performed, and the by-products can be further prevented from remaining in the film. As a result, the film formed on the wafer 200 can be made to have excellent in-wafer film thickness uniformity and step coverage, and a lower concentration of impurities caused by the modifier and by-products.

[0114] As shown in FIG. 5(d), in the exhaust step in the raw material supply cycle of this embodiment, it is preferable to open the valves 243d to 243f and supply an inert gas as a purge gas into the processing chamber 201 through the nozzles 249a to 249c.

[0115] Also, for example, as in FIG. 5(e) and the process sequence shown below, the above-mentioned source supply cycle may further include a step of supplying a modifying agent to the wafer 200.

[0116] [Modifier → (raw material → exhaust → modifier → exhaust) × m → oxidizer] × n or [Reformer → (raw material → exhaust → reformer) × m → oxidizer] × n

[0117] When the raw material supply cycle is repeated as described above, the modifier contained in the adsorption layer is desorbed from the surface of the wafer 200 each time the raw material supply cycle is repeated. As a result, the modifier constituting the adsorption layer may be insufficient. In such a case, the modifier is supplied in the raw material supply cycle as well, so that the insufficient modifier can be made up for. This makes it possible to more reliably suppress the adsorption of by-products generated each time the raw material supply cycle is performed to at least one of the first layer and the surface of the wafer 200 by the adsorption layer, thereby making it possible to further improve the quality of the film formed on the wafer 200.

[0118] 5(e), in the exhaust step in the raw material supply cycle of this embodiment, it is preferable to open the valves 243d-243f and supply an inert gas as a purge gas into the processing chamber 201 through the nozzles 249a-249c. In addition, in the raw material supply cycle of this embodiment, the exhaust step after the step of supplying the modifier may not be performed.

[0119] 5(f) and the process sequence shown below, in step C, an oxidant supply cycle including a step of supplying an oxidant to the wafer 200 and a step of evacuating the processing chamber 201 while stopping the supply of the oxidant may be performed multiple times (m times, where m is an integer of 2 or more). The process conditions in each of these steps may be the same as the process conditions in the supply of the oxidant and step C2 described in the above embodiment.

[0120] [Modifier → Raw material → (Oxidizer → Exhaust) × m] × n

[0121] In this case, the modifier contained in the adsorption layer can be desorbed from the surface of the wafer 200 each time the oxidizer supply cycle is repeated, and the modifier can be further suppressed from remaining in the film. Also, the by-products attached to the adsorption layer can be removed from the surface of the wafer 200 together with the modifier contained in the adsorption layer each time the oxidizer supply cycle is performed, and the by-products can be further suppressed from remaining in the film. As a result, the film formed on the wafer 200 can be made to have excellent in-wafer film thickness uniformity and step coverage, and a lower concentration of impurities caused by the modifier and by-products.

[0122] As shown in FIG. 5(f), in the exhaust step in the oxidizing agent supply cycle of this embodiment, it is preferable to open the valves 243d to 243f and supply an inert gas as a purge gas into the processing chamber 201 through the nozzles 249a to 249c.

[0123] It is preferable that the recipes used for each process are prepared individually according to the process contents and stored in the storage device 121c via an electric communication line or an external storage device 123. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process contents from among the multiple recipes stored in the storage device 121c. This makes it possible to form films of various film types, composition ratios, film qualities, and film thicknesses with good reproducibility using a single substrate processing device. It is also possible to reduce the burden on the operator and quickly start each process while avoiding operational errors.

[0124] The above-mentioned recipes may not only be created anew, but may also be prepared by modifying an existing recipe that has already been installed in the substrate processing apparatus. When modifying a recipe, the modified recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the recipe has been recorded. In addition, an existing recipe that has already been installed in the substrate processing apparatus may be directly modified by operating the input / output device 122 provided in the existing substrate processing apparatus.

[0125] In the above-mentioned embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-mentioned embodiment, and can be suitably applied to, for example, a case where a film is formed using a single-wafer type substrate processing apparatus that processes one or several substrates at a time. In addition, in the above-mentioned embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall type processing furnace has been described. The present disclosure is not limited to the above-mentioned embodiment, and can be suitably applied to, for example, a case where a film is formed using a substrate processing apparatus having a cold-wall type processing furnace.

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

[0127] The above-mentioned aspects may be used in appropriate combination. The processing procedures and processing conditions in this case may be the same as those of the above-mentioned aspects. EXAMPLES

[0128] Example 1 In Example 1, a hafnium oxide film (HfO film) was formed on a patterned wafer having a concave structure formed on its surface by using the above-mentioned substrate processing apparatus and the processing sequence shown in Fig. 4. As the modifier, raw material, oxidizer, and inert gas, specific substances were selected from the substance group shown in the above-mentioned embodiment. The processing conditions for each step were set to specific conditions within the range of processing conditions for each step shown in the above-mentioned embodiment.

[0129] As Comparative Example 1, the above-mentioned substrate processing apparatus was used to form a HfO film on a patterned wafer having a recessed structure formed on its surface by a processing sequence in which step A of the processing sequence shown in Fig. 4 was not performed. The same substances as those used in Example 1 were selected as the raw material, oxidizing agent, and inert gas. The processing conditions for each step were set to predetermined conditions within the range of processing conditions for each step in Example 1.

[0130] Then, for Example 1 and Comparative Example 1, the thickness of the HfO film formed in the recessed structure was measured. The film thickness was measured at two locations, the periphery of the opening (TOP) and the periphery of the bottom (BTM) in the recessed structure. Then, the cycle rate at each measurement location, i.e., the thickness (Å / cycle) of the HfO film formed per cycle, was calculated. In addition, a value (Step Coverage) was calculated as an index showing the quality of step coverage by [cycle rate at BTM / cycle rate at TOP]×100(%).

[0131] The results are shown in Figure 6. The left vertical axis in Figure 6 indicates cycle rate (Å / cycle), and the right vertical axis indicates step coverage (%). The horizontal axis in Figure 6 indicates Comparative Example 1 and Example 1, in that order. In the figure, the ◆ mark indicates the cycle rate at TOP, the ■ mark indicates the cycle rate at BTM, and the bar graph indicates step coverage (%).

[0132] 6, it can be seen that the cycle rate in the TOP portion is appropriately suppressed in Example 1, and as a result, the step coverage (%) is improved compared to Comparative Example 1. This is considered to be because, as explained in the above embodiment, the incorporation of by-products into the HfO film can be suppressed by performing Step A at a predetermined timing to form an adsorption layer.

[0133] Example 2 In Example 2, a HfO film was formed on a patterned wafer having a concave structure formed on its surface by using the above-mentioned substrate processing apparatus and the processing sequence shown in Fig. 4. As the modifier, raw material, oxidizer, and inert gas, specific substances were selected from the substance group shown in the above-mentioned embodiment. The processing conditions for each step were set to specific conditions within the range of processing conditions for each step shown in the above-mentioned embodiment.

[0134] As Comparative Example 2, the above-mentioned substrate processing apparatus was used to form a HfO film on a patterned wafer having a recessed structure formed on its surface by a processing sequence in which step A of the processing sequence shown in Fig. 4 was not performed. The same substances as those used in Example 1 were selected as the raw material, oxidizing agent, and inert gas. The processing conditions for each step were set to predetermined conditions within the range of processing conditions for each step in Example 1.

[0135] In both Example 2 and Comparative Example 2, the film formation process was performed with a monitor wafer placed at a position facing the surface (processing surface) of the patterned wafer as shown in Fig. 7. The monitor wafer used was a silicon wafer whose upper surface (the surface not facing the surface of the patterned wafer) and lower surface (the surface facing the surface of the patterned wafer) were both flat (no concave structure was formed), and on each of the upper and lower surfaces was formed a SiO film as a base.

[0136] Then, for Example 2 and Comparative Example 2, the thicknesses of the HfO films (hereinafter, evaluation films) formed on the surfaces of the upper and lower sides of the monitor wafers were measured. The results are shown in Figures 8(a) and 8(b). The vertical axis of Figure 8(a) shows the thickness (Å) of the evaluation film in Example 2, and the horizontal axis shows the distance (mm) from the center of the wafer to the measurement point. The vertical axis of Figure 8(b) shows the thickness (Å) of the evaluation film in Comparative Example 2, and the horizontal axis shows the distance (mm) from the center of the wafer to the measurement point.

[0137] As shown in these figures, it can be seen that the thickness of the evaluation film formed on the underside of the monitor wafer is thinner in Example 2 than in Comparative Example 2. This means that the amount of by-products generated during the film formation process is smaller in Example 2 than in Comparative Example 2. As described above, the reason why the amount of by-products generated in Example 2 is smaller is considered to be due to the following: (1) the adsorption layer formed in step A properly covers the surface of the monitor wafer so that by-products are not adsorbed, and this adsorption layer acts to suppress the adsorption of by-products to the first layer and the second layer, thereby suppressing the adsorption of by-products to the surface of the monitor wafer and the first layer and the second layer formed thereon; and (2) the adsorption layer formed in step A reduces the amount of adsorption sites exposed on the surface of the wafer 200, which properly controls the degree of reaction between the source material and the surface of the wafer 200 in step B, resulting in a reduction in the amount of organic ligands desorbed from Hf.

[0138] <Preferred aspects of the present disclosure> Preferred aspects of the present disclosure will be described below.

[0139] (Appendix 1) (a) supplying a modifier to a substrate and forming an adsorption layer on the substrate, the adsorption layer including the modifier physically adsorbed on a surface of the substrate; (b) supplying a source material containing a first element to the substrate and reacting the source material with a surface of the substrate to form a first layer containing the first element on the substrate; (c) supplying an oxidizing agent to the substrate and reacting the oxidizing agent with the first layer to modify the first layer into a second layer containing the first element and oxygen; a step of forming a film containing the first element and oxygen on the substrate by performing a cycle including the steps of: There is provided a method for manufacturing a semiconductor device or a method for processing a substrate, in which the adsorption layer prevents by-products generated during the formation of the first layer from being adsorbed to at least one of the first layer and the surface of the substrate.

[0140] (Appendix 2) 2. The method according to claim 1, comprising: the source material includes a molecule having the first element and a ligand bound to the first element; A by-product generated during the formation of the first layer includes the ligand released from the first element.

[0141] (Appendix 3) 3. The method according to claim 2, comprising: A by-product generated during the formation of the first layer contains the ligand that is desorbed from the first element as a result of a reaction between the source material and an adsorption site on the surface of the substrate.

[0142] (Appendix 4) 3. The method according to claim 2, comprising: The by-products produced during the formation of the first layer further include molecules having the first element and a ligand bound to the first element, from which a portion of the ligand has been detached.

[0143] (Appendix 5) 5. The method according to claim 4, A molecule having the first element and a ligand bonded to the first element, from which a part of the ligand has been detached, is generated by thermally decomposing the raw material.

[0144] (Appendix 6) The method according to any one of claims 1 to 5, The adsorption layer suppresses adsorption of by-products generated during the formation of the second layer onto at least one of the second layer and the surface of the substrate.

[0145] (Appendix 7) The method according to any one of claims 1 to 6, The adsorbed layer comprises the modifier adsorbed so as to discontinuously cover (at a thickness of less than one molecular layer) the surface of the substrate.

[0146] (Appendix 8) The method according to any one of claims 1 to 7, (a) further includes a step (a2) of evacuating a space in which the substrate is present after supplying the modifying agent to the substrate.

[0147] (Appendix 9) 9. The method according to claim 8, comprising: In (a2), a portion of the modifier contained in the adsorption layer is removed from the surface of the substrate.

[0148] (Appendix 10) 10. The method according to claim 8 or 9, In (a2), evacuation of the space in which the substrate exists is continued until the thickness of the adsorption layer reaches a desired thickness.

[0149] (Appendix 11) Any of the methods according to claims 8 to 10, In (a2), the evacuation conditions (evacuation time, evacuation speed, etc.) of the space in which the substrate exists are set so that the film formation rate becomes a desired magnitude.

[0150] (Appendix 12) The method according to any one of claims 1 to 11, (b) further includes a step (b2) of evacuating a space in which the substrate exists after supplying the source material to the substrate.

[0151] (Appendix 13) 13. The method of claim 12, further comprising: In (b2), by-products adhering to the adsorption layer are removed from the surface of the substrate together with the modifier contained in the adsorption layer.

[0152] (Appendix 14) The method according to any one of claims 1 to 13, (c) further includes a step (c2) of evacuating the space in which the substrate is present after supplying the oxidizing agent to the substrate.

[0153] (Appendix 15) 15. The method according to claim 14, In (c2), by-products adhering to the adsorption layer are removed from the surface of the substrate together with the modifier contained in the adsorption layer.

[0154] (Appendix 16) The method according to any one of claims 1 to 16, A recessed structure is formed on the substrate, and the film is formed on the inner surface of the recessed structure.

[0155] (Appendix 17) 17. The method of claim 16, comprising: In (a), the adsorption layer is formed on at least the bottom surface and side walls of the inner surface of the recessed structure.

[0156] (Appendix 18) The method according to any one of claims 1 to 17, In (b), a raw material supply cycle including a step of supplying the raw material to the substrate and a step of evacuating the space in which the substrate exists while stopping the supply of the raw material is performed a plurality of times.

[0157] (Appendix 19) 19. The method according to claim 18, comprising: The source supply cycle further includes the step of supplying the modifier to the substrate.

[0158] (Appendix 20) The method according to any one of claims 1 to 19, In (c), an oxidant supply cycle including a step of supplying the oxidant to the substrate and a step of evacuating the space in which the substrate exists while stopping the supply of the oxidant is performed a plurality of times.

[0159] (Appendix 21) The method according to any one of claims 1 to 20, The modifier includes an organic compound.

[0160] (Appendix 22) 22. The method according to claim 21, The modifying agent includes at least one selected from the group consisting of an ether compound, a ketone compound, an amine compound, and an organic hydrazine compound.

[0161] (Appendix 23) The method according to any one of claims 1 to 22, The ligand includes an organic ligand.

[0162] (Appendix 24) a processing chamber in which the substrate is processed; a modifying agent supply system that supplies a modifying agent to the substrate in the processing chamber; a source supply system for supplying a source containing a first element to the substrate in the processing chamber; an oxidant supply system for supplying an oxidant to the substrate in the processing chamber; A control unit configured to be able to control the modifying agent supply system, the raw material supply system, and the oxidizing agent supply system so as to perform each process (each step) in the processing chamber in Appendix 1; A substrate processing apparatus having a

[0163] (Appendix 25) A program for causing a substrate processing apparatus to execute each procedure (each step) in appendix 1 by a computer in a processing chamber of the substrate processing apparatus, or a computer-readable recording medium having the program recorded thereon, is provided. [Explanation of symbols]

[0164] 200 wafers (substrates)

Claims

1. (a) supplying a modifier to a substrate to form an adsorption layer containing the modifier physically adsorbed on a portion of an exposed surface of the substrate; (b) supplying a first film-forming agent containing a first element to the substrate, and reacting the first film-forming agent with a surface of the substrate to form a first layer containing the first element on another part of the exposed portion; (c) supplying a second film-forming agent that reacts with the first layer to the substrate, and reacting the second film-forming agent with the first layer to modify the first layer into a second layer containing the first element; a step of forming a film containing the first element on the substrate by performing a cycle including the steps of: A substrate processing method, comprising: a substrate processing unit configured to suppress, by an adsorption layer, adsorption of a by-product generated during formation of the first layer onto at least one of the first layer and a surface of the substrate.

2. the first film-forming agent includes a molecule having the first element and a ligand bonded to the first element; A by-product generated during the formation of the first layer includes the ligand released from the first element. The method of claim 1 .

3. A by-product generated during the formation of the first layer includes the ligand that is desorbed from the first element by a reaction between the first film-forming agent and an adsorption site on the surface of the substrate. The substrate processing method according to claim 2 .

4. The by-products generated during the formation of the first layer further include a molecule having the first element and a ligand bound to the first element, from which a part of the ligand has been detached. The substrate processing method according to claim 2 .

5. The molecule, which is obtained by removing a part of the ligand from the molecule having the first element and the ligand bonded to the first element, is generated by thermally decomposing the first film-forming agent. The substrate processing method according to claim 4 .

6. The adsorption layer suppresses adsorption of by-products generated during the formation of the second layer onto at least one of the second layer and the surface of the substrate. The substrate processing method according to any one of claims 1 to 5.

7. The adsorption layer includes the modifier adsorbed so as to discontinuously cover the surface of the substrate. The substrate processing method according to any one of claims 1 to 6.

8. (a) further includes a step (a2) of evacuating the space in which the substrate is present after supplying the modifying agent to the substrate. The substrate processing method according to any one of claims 1 to 7.

9. In step (a2), a part of the modifier contained in the adsorption layer is removed from the surface of the substrate. The substrate processing method according to claim 8 .

10. In (a2), exhaust conditions for the space in which the substrate is present are set so that the film formation rate becomes a desired value. The substrate processing method according to claim 8 or 9.

11. (b) further includes a step (b2) of removing by-products adhering to the adsorption layer together with the modifier contained in the adsorption layer from the surface of the substrate by evacuating a space in which the substrate is present after the first film-forming agent is supplied to the substrate. The substrate processing method according to any one of claims 1 to 10.

12. A recessed structure is formed on the substrate, and the film is formed on the inner surface of the recessed structure. The substrate processing method according to any one of claims 1 to 11.

13. a modifier supply system for supplying a modifier to the substrate; a first film forming agent supply system that supplies a first film forming agent including a first element to the substrate; a second film forming agent supply system that supplies a second film forming agent to the substrate; (a) supplying a modifier to the substrate to form an adsorption layer containing the modifier physically adsorbed on a portion of an exposed surface of the substrate; (b) supplying the first film-forming agent containing a first element to the substrate, and reacting the first film-forming agent with a surface of the substrate to form a first layer containing the first element on another part of the exposed portion; (c) supplying the second film-forming agent, which reacts with the first layer, to the substrate, and reacting the second film-forming agent with the first layer to modify the first layer into a second layer containing the first element; By performing a cycle including the steps of: a control unit configured to be capable of controlling the modifier supply system, the first film-forming agent supply system, and the second film-forming agent supply system so as to perform a process of forming a film containing the first element on the substrate while suppressing, by the adsorption layer, adsorption of a by-product generated during the formation of the first layer onto at least one of the first layer and a surface of the substrate; A substrate processing apparatus comprising:

14. (a) supplying a modifier to a substrate to form an adsorption layer containing the modifier physically adsorbed on a portion of an exposed surface of the substrate; (b) supplying a first film-forming agent containing a first element to the substrate, and reacting the first film-forming agent with a surface of the substrate to form a first layer containing the first element on another part of the exposed portion; (c) supplying a second film-forming agent that reacts with the first layer to the substrate, and reacting the second film-forming agent with the first layer to modify the first layer into a second layer containing the first element; a step of forming a film containing the first element on the substrate by performing a cycle including the steps of: A method for manufacturing a semiconductor device, comprising the steps of: preventing a by-product generated during formation of the first layer from being adsorbed to at least one of the first layer and a surface of the substrate by the adsorption layer.

15. (a) supplying a modifier to a substrate to form an adsorption layer containing the modifier physically adsorbed on a portion of an exposed surface of the substrate; (b) supplying a first film-forming agent containing a first element to the substrate, and reacting the first film-forming agent with a surface of the substrate to form a first layer containing the first element on another part of the exposed portion; (c) supplying a second film-forming agent that reacts with the first layer to the substrate, and reacting the second film-forming agent with the first layer to modify the first layer into a second layer containing the first element; a step of forming a film containing the first element on the substrate while suppressing, by the adsorption layer, adsorption of by-products generated during the formation of the first layer onto at least one of the first layer and a surface of the substrate, by performing a cycle including the steps of: A program that is executed by a computer in a substrate processing apparatus.

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