Substrate processing method, semiconductor device manufacturing method, substrate processing apparatus, and recording medium

Abstract

The invention provides a substrate processing method, a method of manufacturing a semiconductor device, a substrate processing apparatus, and a recording medium, which control a region where processing of a substrate is easy to proceed and a region where processing of the substrate is obstructed. A first step and a second step are performed for a predetermined number of times, the first step being performed for a predetermined number of times: (a1) a step for supplying a first modification gas, which forms a first modification layer on at least a portion of a substrate, to the substrate; and a step (a2) in which a first removal gas for removing a portion of the first modified layer from the substrate is supplied to the substrate, and a second step is performed at a predetermined number of times after the first step. Supplying a processing gas to the substrate, wherein the processing gas preferentially processes a region where the first modified layer is not formed with respect to a region where the first modified layer is present; and (b2) a step of supplying a reaction gas to the substrate.

Description

Technical Field

[0001] The present invention relates to a substrate processing method, a method for manufacturing a semiconductor device, a substrate processing apparatus and a recording medium. Background Art

[0002] As one of the substrate processing steps (semiconductor device manufacturing steps), a film formed on the surface of a substrate using a substance that inhibits adsorption of other substances to the substrate is sometimes used (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-69407 Summary of the Invention

[0006] The present invention provides a technology capable of controlling areas where processing of a substrate is facilitated and areas where processing is hindered.

[0007] According to one aspect of the present invention, there is provided a technique for performing the first step and the second step a predetermined number of times, wherein:

[0008] The first step is carried out at a specified number of times:

[0009] (a1) step of supplying a first modified gas to the substrate for forming a first modified layer on at least a portion of the substrate; and

[0010] (a2) supplying a first removing gas to the substrate for removing a portion of the first modified layer from the substrate,

[0011] The second step is carried out after the first step as specified above:

[0012] (b1) supplying a processing gas to the substrate that preferentially processes a region where the first modified layer is not formed, relative to a region where the first modified layer is present; and

[0013] In step (b2), a reaction gas is supplied to the substrate.

[0014] Effects of the Invention

[0015] According to the present invention, it is possible to control the area where processing of a substrate is easy and the area where processing is hindered. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of a vertical processing furnace of a substrate processing apparatus, showing a portion of the processing furnace 202 in a vertical cross-sectional view.

[0017] Figure 2 This is a schematic diagram of the vertical processing furnace of the substrate processing device, which shows the processing furnace 202. Figure 1 FIG is an example of an AA line cross-sectional view.

[0018] Figure 3 1 is a schematic configuration diagram of the controller 121 of the substrate processing apparatus, and is a diagram showing the control system of the controller 121 in the form of a block diagram.

[0019] Figure 4A This is a diagram showing a processing procedure in one embodiment of the present invention.

[0020] Figure 4B 1 is a diagram showing an example of the steps in step S10.

[0021] Figure 4C 1 is a diagram showing an example of the steps in step S12.

[0022] Figure 5 4 is a schematic diagram of a cross-sectional portion of the surface of the wafer 200 obtained by executing each step of the processing sequence of FIG. 4 .

[0023] Figure 6 This is a schematic diagram of the vertical processing furnace of the substrate processing device, showing the processing furnace 202 portion when the gas is activated by plasma. Figure 1 FIG is an example of an AA line cross-sectional view.

[0024] Figure 7A This is a diagram showing an example of the processing procedure in Modification Example 1.

[0025] Figure 7B This is a diagram showing an example of step S30 in Modification 1.

[0026] Figure 8 It is a diagram schematically showing a cross-sectional portion of the surface of the chip 200 after performing step S10-1, step S10-2, and step S30-1 respectively, when the modification example 1 is performed in the modes (1) to (3) in which the processing conditions of at least a part of each step are different from each other.

[0027] Figure 9A This is a diagram showing the processing sequence in Modification Example 2.

[0028] Figure 9B 1 is a diagram showing an example of the steps in step S40.

[0029] Figure 10 This is a diagram showing the processing sequence in Modification Example 3.

[0030] Description of Reference Numerals

[0031] 200 wafers (substrates) DETAILED DESCRIPTION

[0032] <One embodiment of the present invention>

[0033] The following mainly refers to Figures 1 to 5 One embodiment of the present invention will be described. The drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings may not necessarily be consistent with reality. Furthermore, the dimensional relationships and ratios of the elements shown in the multiple drawings may not necessarily be consistent with each other.

[0034] (1) Structure of substrate processing apparatus

[0035] like Figure 1 As shown, the processing furnace 202 includes a heater 207. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) the gas using heat.

[0036] A reaction tube 203 is disposed inside the heater 207. A manifold 209 is disposed below the reaction tube 203, with an O-ring 220a interposed between the manifold 209 and the reaction tube 203. The reaction tube 203 and the manifold 209 primarily constitute a processing vessel (reaction container). A processing chamber 201 is formed within the processing container. The processing chamber 201 is configured to accommodate a wafer 200 serving as a substrate. Processing of the wafer 200 is performed within the processing chamber 201.

[0037] Nozzles 249a to 249c are provided in the processing chamber 201. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively.

[0038] Gas supply pipes 232a to 232c are equipped, in order from the upstream side of the gas flow, with mass flow controllers (MFCs) 241a to 241c, serving as flow controllers (flow control units), and valves 243a to 243c, serving as on-off valves. Gas supply pipe 232d is connected to gas supply pipe 232a downstream of valve 243a. Gas supply pipe 232e is connected to gas supply pipe 232b downstream of valve 243b. Gas supply pipe 232f is connected to gas supply pipe 232c downstream of valve 243c. MFCs 241d to 241f and valves 243d to 243f are equipped, in order from the upstream side of the gas flow.

[0039] like Figure 2As shown, nozzles 249a-249c are respectively disposed in the space between the inner wall of reaction tube 203 and wafer 200. Nozzles 249a and 249c are arranged on either side of a straight line L passing through the center of nozzle 249b and exhaust port 231a. Each nozzle 249a-249c is provided with gas supply holes 250a-250c for supplying gas toward wafer 200. Multiple gas supply holes 250a-250c are provided from the bottom to the top of each nozzle 249a-249c.

[0040] The first reforming gas is supplied into the processing chamber 201 via the gas supply pipe 232a, the MFC 241a, the valve 243a, and the nozzle 249a. The first reforming gas in this embodiment is a gas that inhibits the process gas from being adsorbed onto the wafer 200.

[0041] The process gas is supplied into the process chamber 201 through the gas supply pipe 232b, MFC 241b, valve 243b, and nozzle 249b. The process gas in this embodiment is a raw material gas for forming the process layer 152, which reacts with the reaction gas to form a desired film (film formation).

[0042] The first removal gas and the reaction gas are supplied into the processing chamber 201 via the gas supply pipe 232c, the MFC 241c, the valve 243c, and the nozzle 249c. The first removal gas is a gas that removes a portion of the first modified layer 150 formed by the first modifying gas. The reaction gas is a gas that reacts with the processed layer 152 formed by the process gas to form a desired film (first layer 154) (film formation).

[0043] Inert gas is supplied into the processing chamber 201 through gas supply pipes 232d to 232f, MFCs 241d to 241f, valves 243d to 243f, gas supply pipes 232a to 232c, and nozzles 249a to 249c. The inert gas functions as a purge gas, carrier gas, or dilution gas.

[0044] The first reforming gas supply system is primarily comprised of gas supply pipe 232a, MFC 241a, and valve 243a. The processing gas supply system is primarily comprised of gas supply pipe 232b, MFC 241b, and valve 243b. The first removal gas supply system and the reaction gas supply system are primarily comprised of gas supply pipe 232c, MFC 241c, and valve 243c. In other words, gas supply pipe 232c, MFC 241c, and valve 243c serve as both the first removal gas supply system and the reaction gas supply system. Alternatively, for example, the same structure as gas supply pipe 232c, MFC 241c, and valve 243c may be provided, and the first removal gas supply system and the reaction gas supply system may be independent. The inert gas supply system is primarily comprised of gas supply pipes 232d-232f, MFCs 241d-241f, and valves 243d-243f. The nozzles connected to the gas supply pipes constituting each of the above-mentioned supply systems may also be incorporated into each of these supply systems.

[0045] One or all of the various supply systems described above may be configured as an integrated supply system 248 incorporating valves 243a to 243f and MFCs 241a to 241f. The integrated supply system 248 is connected to the gas supply pipes 232a to 232f, respectively, and is configured such that the supply of various substances (gases) into the gas supply pipes 232a to 232f, namely, the opening and closing of the valves 243a to 243f and the flow rate adjustment by the MFCs 241a to 241f, are controlled by the controller 121 described later.

[0046] An exhaust pipe 231 is connected to the lower side wall of the reaction tube 203 and is provided with an exhaust port 231a for exhausting the atmosphere in the processing chamber 201. A vacuum pump 246, which serves as a vacuum exhaust device, is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector for detecting the pressure in the processing chamber 201, an APC (Auto Pressure Controller) serving as a pressure regulator, and a valve 244. The APC valve 244 can perform vacuum exhaust and stop vacuum exhaust in the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is in operation. The APC valve 244 is further configured to adjust the valve opening based on pressure information detected by the pressure sensor 245 when the vacuum pump 246 is in operation, thereby adjusting the pressure in the processing chamber 201. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. It is also conceivable to include the vacuum pump 246 in the exhaust system.

[0047] A sealing cover 219 is provided below the manifold 209. An O-ring 220b is provided on the upper surface of the sealing cover 219. A rotating mechanism 267 is provided below the sealing cover 219. A rotating shaft 255 of the rotating mechanism 267 passes through the sealing cover 219 and is connected to the boat 217. The rotating mechanism 267 is configured to rotate the wafer 20 by rotating the boat 217. The boat elevator 115 is configured as a transport device (transport mechanism) that moves the wafer 200 into and out of the processing chamber 201 by raising and lowering the sealing cover 219.

[0048] A gate 219s is provided below the manifold 209 to airtightly seal the lower opening of the manifold 209 when the boat 217 is unloaded from the processing chamber 201. An O-ring 220c is provided on the upper surface of the gate 219s. The opening and closing movements (such as lifting and rotating movements) of the gate 219s are controlled by a gate opening and closing mechanism 115s.

[0049] The boat 217, serving as a substrate support, is configured to support, for example, 25 to 200 wafers 200 in a horizontal position in multiple layers. In this specification, the term "25 to 200 wafers" indicates that both the lower and upper limits are included in the range. Thus, for example, "25 to 200 wafers" means "25 to 200 wafers." The same applies to other numerical ranges. Underneath the boat 217, multiple layers of heat shields 218 made of a heat-resistant material such as quartz or SiC are supported.

[0050] A temperature sensor 263 is provided within the reaction tube 203 as a temperature detector. By adjusting the power supplied to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature within the processing chamber 201 or on the wafer 200 can be adjusted to a desired temperature distribution. The temperature sensor 263 is provided along the inner wall of the reaction tube 203.

[0051] like Figure 3As shown, the controller 121 as a control unit is configured as a computer having 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 and output device 122 configured as, for example, a touch panel is connected to the controller 121. In addition, an external storage device 123 can be connected to the controller 121. In addition, the substrate processing apparatus can be configured to have one control unit or to have multiple control units. That is, for the control for performing the processing sequence described later, one control unit can be used or multiple control units can be used. In addition, the multiple control units can be configured as a control system interconnected by a wired or wireless communication network, or the entire control system can be used to perform the control for implementing the processing sequence described later. When the term "control unit" is used in this specification, it may include not only one control unit but also a plurality of control units and a control system composed of a plurality of control units.

[0052] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. In the storage device 121c, a control program for controlling the actions of the substrate processing device, a process recipe that records the steps and conditions of the substrate processing described later, etc., are recorded and saved in a readable manner. The process recipe is a combination of a method of using the controller 121 to make the substrate processing device perform each step in the substrate processing described later and obtain a specified result, and functions as a program. Hereinafter, process recipes and control programs, etc. are collectively referred to as programs. In addition, process recipes are also referred to as recipes. When the term program is used in this specification, there are cases where only one side of the recipe is included, only one side of the control program is included, or both sides are included. RAM121b is configured as a storage area (work area) for temporarily holding programs and data read by CPU121a.

[0053] The I / O port 121d is connected to the 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, gate opening and closing mechanism 115s, and the like.

[0054] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a recipe from the storage device 121c based on input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, flow rate adjustment of various substances (gases) by the MFCs 241a to 241f, opening and closing of the valves 243a to 243h, opening and closing of the APC valve 244 and pressure adjustment by the APC valve 244 based on the pressure sensor 245, starting and stopping of the vacuum pump 246, temperature adjustment of the heater 207 based on the temperature sensor 263, rotation and rotation speed adjustment of the boat 217 by the rotation mechanism 267, lifting and lowering of the boat 217 by the boat elevator 115, and opening and closing of the gate 219s by the gate opening and closing mechanism 115s.

[0055] The controller 121 is constructed by installing the above-mentioned program recorded and stored in the external storage device 123 into the computer. The external storage device 123 includes, for example, magnetic disks such as HDDs, optical disks such as CDs, optical magnetic disks such as MOs, semiconductor memories such as USB memories and SSDs. The storage device 121c and the external storage device 123 constitute a computer-readable recording medium. Hereinafter, they will be collectively referred to as recording media. When the term recording medium is used in this specification, there are cases where only the storage device 121c is included, only the external storage device 123 is included, or both are included. In addition, the provision of the program to the computer can also be carried out without using the external storage device 123, but using communication means such as the Internet or a dedicated line.

[0056] (2) Substrate processing

[0057] Main Use Figure 4A 、 Figure 4B 、 Figure 4C 、 Figure 5 A method for processing a substrate using the aforementioned substrate processing apparatus as part of a semiconductor device manufacturing process will be described. Specifically, an example processing sequence for forming a film on a wafer 200 serving as a substrate having recessed portions such as trenches, grooves, and cavities formed on its surface as three-dimensional structures will be described. In the following description, the operations of the various components comprising the substrate processing apparatus are controlled by a controller 121.

[0058] In the processing sequence of this method, the first step and the second step are performed a predetermined number of times, wherein,

[0059] The first step is performed a predetermined number of times: (a1) supplying a first modifying gas to the wafer 200 for forming the first modified layer 150 on at least a portion of the wafer 200; and (a2) supplying a first removing gas to the wafer 200 for removing a portion of the first modified layer 150 from the wafer 200.

[0060] The second process is performed a specified number of times after the first process: (b1) process, supplying processing gas to the chip 200 for treating the area where the first modified layer 150 is not formed preferentially relative to the area where the first modified layer 150 exists; and (b2) process, supplying reaction gas to the chip 200.

[0061] That is, Figure 4A As shown in FIG. 1 , the first step is performed in step S10. In the first step, as shown in FIG. Figure 4B As shown, in step S10-1, step (a1) is executed, and in step S10-2, a purge process is performed in the processing chamber 201. In step S10-3, step (a2) is executed, and in step S10-4, a purge process is performed in the processing chamber 201. In step S10-5, it is determined whether steps S10-1 to S10-4 have been performed a predetermined number of times. If the determination is negative, the process returns to step S10-1. If the determination is positive, the first process is terminated and the process proceeds to step S12 to execute the second process.

[0062] In the second step, if Figure 4C As shown, in step S12-1, step (b1) is executed, and in step S12-2, a purge process is performed within the processing chamber 201. In step S12-3, step (b2) is executed, and in step S12-4, a purge process is performed within the processing chamber 201. In step S12-5, it is determined whether steps S12-1 to S12-4 have been performed a predetermined number of times. If the determination is negative, the process returns to step S12-1. If the determination is positive, the second step is terminated and the process proceeds to step S14.

[0063] In step S14 , it is determined whether the first step and the second step have been executed a predetermined number of times. If the determination is negative, the process returns to step S10 . If the determination is positive, the present process ends.

[0064] The term "wafer" as used in this specification may refer to the wafer itself or a laminate of a wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" as used in this specification may refer to the surface of the wafer itself or the surface of a predetermined layer, etc., formed on the wafer. When the term "a predetermined layer is formed on the wafer" is used in this specification, it may refer to forming the predetermined layer directly on the surface of the wafer itself or forming the predetermined layer on top of a layer, etc., formed on the wafer. The same applies to the use of the term "substrate" in this specification, which is synonymous with the use of the term "wafer."

[0065] The term "layer" used in this specification includes at least one of a continuous layer and a discontinuous layer. For example, a stacked layer may include a continuous layer, a discontinuous layer, or both.

[0066] In this specification, when describing the first raw material gas, the first adsorption inhibitory gas, the second raw material gas, the second adsorption inhibitory gas and the reaction gas being adsorbed or reacted relative to the surface of the chip 200, it not only includes the state in which they are adsorbed or reacted relative to the surface of the chip 200 in an undecomposed state, but also includes the state in which intermediates generated by their decomposition or the detachment of their ligands are adsorbed or reacted relative to the surface of the chip 200.

[0067] (Wafer loading and boat loading)

[0068] Load multiple wafers 200 into the boat 217 (wafer loading). The gate 219s is moved by the gate opening and closing mechanism 115s, and the lower end opening of the manifold 209 is opened (gate opening). After that, the boat 217 supporting the multiple wafers 200 is lifted by the boat elevator 115 and moved into the processing chamber 201 (boat loading). At this time, the sealing cover 219 seals the lower end of the manifold 209 with the help of the O-ring 220b. Like this, Figure 1 As shown, a wafer 200 is prepared (provided) into a processing chamber 201 .

[0069] (Pressure adjustment and temperature adjustment)

[0070] After the boat is loaded, vacuum pump 246 is used to perform vacuum exhaust (decompression exhaust) in the processing chamber 201, that is, the space where the wafer 200 is located, so that the pressure (vacuum degree) is desired. At this time, the pressure in the processing chamber 201 is measured by pressure sensor 245, and feedback control is performed on APC valve 244 based on the measured pressure information. In addition, heater 207 is used to heat the wafer 200 in the processing chamber 201 so that the processing temperature is desired. At this time, feedback control is performed on the power supplied to heater 207 based on the temperature information detected by temperature sensor 263 so that the temperature distribution in the processing chamber 201 is desired. In addition, the rotation of wafer 200 by rotating mechanism 267 is started. The exhaust in the processing chamber 201, the heating and rotation of wafer 200 are all continued for at least the period until the processing of wafer 200 is completed.

[0071] (Film forming treatment)

[0072] After that, execute the following contents in sequence.

[0073] [a1]

[0074] In this step, a first modifying gas is supplied to the wafer 200 in the processing chamber 201 , and in this embodiment, to the wafer 200 having recessed portions on its surface, so as to form the first modified layer 150 on at least a portion thereof.

[0075] Specifically, valve 243a is opened to allow the first reforming gas to flow into gas supply pipe 232a. The first reforming gas is flow-regulated by MFC 241a, supplied into processing chamber 201 via nozzle 249a, and exhausted from exhaust port 231a. At this time, the first reforming gas is supplied to wafer 200 from the side of wafer 200 (first reforming gas supply). Alternatively, valves 243d-243f may be opened to allow inert gas to be supplied into processing chamber 201 via nozzles 249a-249c, respectively.

[0076] As the processing conditions when supplying the first reforming gas in this step, the following are exemplified:

[0077] Processing temperature: 350-700°C, preferably 500-600°C

[0078] Processing pressure: 1-10000 Pa, preferably 10-1333 Pa

[0079] First reforming gas supply flow rate: 0.01 to 3 slm, preferably 0.1 to 1 slm

[0080] First reforming gas supply time: 10 to 120 seconds, preferably 20 to 60 seconds

[0081] Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm

[0082] In this specification, the processing temperature refers to the temperature of the wafer 200 or the temperature within the processing chamber 201, and the processing pressure refers to the pressure within the processing chamber 201. Furthermore, the processing time refers to the duration of the processing. Furthermore, the supply flow rate refers to the flow rate of the gas supplied to the processing chamber 201. Furthermore, the supply flow rate includes a value of 0 slm, which indicates that the substance (gas) is not supplied to the processing chamber 201. This also applies to the following description.

[0083] By supplying the first reforming gas to the wafer 200 under the above-mentioned processing conditions, the first reforming gas can be adsorbed on the adsorption sites on the surface of the wafer 200 (see Figure 5 Specifically, as a result, the first modified gas can be discontinuously adsorbed on at least a portion of the upper surface and inner surface (the side wall and bottom surface inside the recess) of the recess (see Figure 5 (a)). More specifically, this allows the first modifying gas to be adsorbed over the entire surface of the recess, from the opening side to the deep side. Hereinafter, the "opening side of the recess" will be referred to as the "opening side," and the "deep side of the recess" will be referred to as the "deep side." Furthermore, in this specification, the "deep side of the recess" refers to areas, such as the bottom of the recess, that are difficult for the gas supplied to the wafer 200 to reach compared to the opening side, and the surrounding area.

[0084] As the first modified gas, a halogen-containing gas containing at least one of Cl, F, Br, and I can be used. The halogen-containing gas has at least one of a Cl group, a F group, a Br group, and an I group as a functional group. As the first adsorption-inhibiting gas, for example, single-substance gases of halogens such as fluorine (F2), chlorine (Cl2), bromine (Br2), and iodine (I2), interhalogen compound gases such as chlorine fluoride (ClF3) gas, bromine chloride (BrCl) gas, iodine chloride (ICl) gas, iodine fluoride (IF5) gas, bromine fluoride (BrF3) gas, and iodine bromide (IBr) gas, hydrogen chloride (HCl) gas, hydrogen fluoride (HF) gas, hydrogen bromide (HBr) gas, and hydrogen iodide (HI) gas, or a combination of these gases can be used.

[0085] Alternatively, a gas containing an organic compound can be used as the first reformed gas. The gas containing an organic compound may include at least one selected from the group consisting of ether compounds, ketone compounds, amine compounds, organic hydrazine compounds, and compounds having a cyclic structure in their molecular structure. The gas containing an ether compound may include at least one selected from dimethyl ether, ethyl ether, methyl ethyl ether, dipropyl ether, isopropyl ether, furan, tetrahydrofuran, pyran, and tetrahydropyran. The gas containing a ketone compound may include at least one selected from dimethyl ketone, diethyl ketone, methyl ethyl ketone, and methyl acetone. The gas containing an amine compound may include at least one selected from methylamine compounds such as monomethylamine, dimethylamine, and trimethylamine; ethylamine compounds such as monoethylamine, diethylamine, and triethylamine; and methylethylamine compounds such as dimethylethylamine and methyldiethylamine. The gas containing an organic hydrazine compound may include at least one selected from methylhydrazine-based gases such as monomethylhydrazine, dimethylhydrazine, and trimethylhydrazine. As the gas containing a compound having a cyclic structure, cyclopentyl methyl ether, anisole, oxetane, and other gases having a cyclic structure containing at least one of a cycloalkyl group, a benzene ring structure, and carbon in the molecular structure can be used. As the first adsorption-inhibiting gas, one or more of these can be used.

[0086] Alkyl-containing gas containing an alkyl group can also be used. As the first reformed gas, methane (CH4) gas, ethane (C2H6) gas, propane (C3H8) gas, etc. can be used.

[0087] As the inert gas, rare gases such as nitrogen (N2), argon (Ar), helium (He), neon (Ne), and xenon (Xe) can be used. As the inert gas, one or more of these can be used. This also applies to the steps described below.

[0088] After the first modifying gas is adsorbed onto the surface of wafer 200 (the upper surface and inner surface of the recess), valve 243a is closed to stop the supply of the first modifying gas into processing chamber 201. Then, processing chamber 201 is evacuated to remove gaseous substances remaining in processing chamber 201. At this time, valves 243d to 243f are opened to supply an inert gas into processing chamber 201 via nozzles 249a to 249c. The inert gas supplied from nozzles 249a to 249c acts as a purge gas, thereby purging (purging) the space where wafer 200 is located, i.e., the interior of processing chamber 201.

[0089] [a2]

[0090] After step a1 is completed, the first removal gas is supplied to the wafer 200 in the processing chamber 201 .

[0091] Specifically, valve 243c is opened to allow the first purge gas to flow into gas supply pipe 232c. The first purge gas is flow-regulated by MFC 241c, supplied into processing chamber 201 via nozzle 249c, and exhausted from exhaust port 231a. At this point, the first purge gas is supplied to wafer 200 (first purge gas supply). Alternatively, valves 243d through 243f may be opened to allow inert gas to be supplied into processing chamber 201 via nozzles 249a through 249c, respectively.

[0092] As the processing conditions when the first removal gas is supplied in this step, the following are exemplified:

[0093] Processing temperature: 400-900°C, preferably 500-800°C

[0094] Processing pressure: 1-2666 Pa, preferably 10-1333 Pa

[0095] Processing gas supply flow rate: 0.001~2slm, preferably 0.01~1slm

[0096] Processing gas supply time: 1 to 40 seconds, preferably 2 to 20 seconds

[0097] Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm

[0098] Other processing conditions can be the same as those when the first reforming gas is supplied in step a1.

[0099] By supplying the first removal gas to the wafer 200 under the above-mentioned processing conditions, a portion of the first modified layer 150 on the surface of the wafer 200 can be removed. Figure 5 As shown in (b), the upper surface of the recess and a portion of the first modified layer 150 on the opening side of the recess can be removed.

[0100] As the first removal gas, for example, a gas containing a reducing gas, an oxidizing gas, a nitriding gas, a sulfiding gas, a selenidating gas, a telluridating gas, etc. can be used. As the reaction gas, one or more of these can be used.

[0101] As the reducing gas, for example, one or more gases including hydrogen (H2), deutanol (D2) gas, borane (BH3) gas, diborane (B2H6) gas, carbon monoxide (CO) gas, ammonia (NH3), monosilane (SiH4) gas, disilane (Si2H6) gas, trisilane (Si3H8) gas, germane (GeH4) gas, digermane (Ge2H6) gas, etc. can be used. In addition, as the reaction gas, for example, an oxidizing gas containing oxygen (O) gas can be used. As the oxidizing gas, for example, one or more gases including oxygen (O2), ozone (O3), water vapor (H2O), a mixed gas of H2 and O2, water peroxide (H2O2), nitrous oxide (N2O), etc. can be used. As the nitriding gas, for example, one or more hydrogen nitride-based gases such as ammonia (NH3), diimide (N2H2) gas, hydrazine (N2H4) gas, N3H8 gas, etc. can be used. As the sulfiding gas, for example, a gas containing hydrogen sulfide (H2S), hydrogen disulfide (H2S2), ammonium disulfide ((NH4)2S), dimethyl sulfide ((CH3)2S), etc. can be used. As the sulfiding gas, more than one of them can be used. As the selenization gas, for example, a gas containing hydrogen selenide (H2Se), hydrogen diselenide (H2Se2), dimethyl selenium ((CH3)2Se), etc. can be used. As the selenization gas, more than one of them can be used. As the telluride gas, for example, a gas containing hydrogen telluride (H2Te), hydrogen ditelluride (H2Te2), dimethyl tellurium ((CH3)2Te), etc. can be used. As the telluride gas, more than one of them can be used.

[0102] After a portion of the first modified layer 150 on the surface of the wafer 200 (the upper surface and inner surface of the recessed portion) is removed, the valve 243c is closed to stop the supply of the first removal gas into the processing chamber 201. Then, the processing chamber 201 is purged in the same step as that performed after step a1.

[0103] [Number of times the prescribed regulations are implemented a]

[0104] By performing the first step a predetermined number of times (n1 times, where n1 is an integer greater than or equal to 1 or 2), wherein the first step comprises step a1, purge treatment, step a2, and purge treatment in this order, a partially removed first modified layer 150 can be formed on the surface of the wafer 200 (the inner surface of the recess). The purge step can be omitted from the first step. Furthermore, at least a portion of step a1 and step a2 can be performed simultaneously.

[0105] [b1]

[0106] The processing gas is supplied to the wafer 200 in the processing chamber 201. That is, the processing gas is supplied to the wafer 200 after the first modified layer 150 is formed on the upper surface and inner surface of the recess and a portion of the first modified layer 150 is removed.

[0107] Specifically, valve 243b is opened to allow process gas to flow into gas supply pipe 232b. The process gas is flow-regulated by MFC 241b, supplied into process chamber 201 via nozzle 249b, and exhausted from exhaust port 231a. At this point, process gas is supplied to wafer 200 (process gas supply). Alternatively, valves 243d-243f may be opened to allow inert gas to be supplied into process chamber 201 via nozzles 249a-249c, respectively.

[0108] As the processing conditions when supplying the processing gas in this step, the following are exemplified:

[0109] Processing temperature: 400-900°C, preferably 500-800°C

[0110] Processing pressure: 1-5000 Pa, preferably 10-1333 Pa

[0111] Processing gas supply flow rate: 0.01~2slm, preferably 0.1~1slm

[0112] Processing gas supply time: 5 to 50 seconds, preferably 6 to 30 seconds

[0113] Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm

[0114] The other processing conditions can be the same as those when the first reforming gas is supplied in step a1.

[0115] By supplying the processing gas to the wafer 200 under the above-mentioned processing conditions, the processing gas can be adsorbed on the portion of the surface of the wafer 200 where the first modified layer 150 is partially removed, thereby forming a processing layer 152 (see Figure 5 (c)).

[0116] As a processing gas, for example, a silane-based gas containing silicon (Si) can be used. As a silane-based gas, for example, a gas containing Si and halogen, i.e., a halosilane-based gas, can be used. Halogen includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. In other words, a halosilane-based gas has at least one of the following halogen groups as a functional group: a chlorine (Cl) group, a fluorine (F) group, a bromine (Br) group, an iodine (I) group, etc.

[0117] As the processing gas, for example, chlorosilane-based gases such as monochlorosilane (SiH3Cl) gas, dichlorosilane (SiH2Cl2) gas, trichlorosilane (SiHCl3) gas, tetrachlorosilane (SiCl4) gas, hexachlorodisilane (Si2Cl6) gas, and octachlorotrisilane (Si3Cl8) gas can be used. At least one of these chlorosilane-based gases can be used as the processing gas.

[0118] As the processing gas, in addition to chlorosilane-based gases, for example, fluorosilane-based gases such as tetrafluorosilane (SiF4) gas, trifluorosilane (SiHF3) gas, and difluorosilane (SiH2F2) gas, bromosilane-based gases such as tetrabromosilane (SiBr4) gas, tribromosilane (SiHBr3) gas, and dibromosilane (SiH2Br2) gas, and iodosilane-based gases such as tetraiodosilane (SiI4) gas, triiodosilane (SiHI3) gas, and diiodosilane (SiH2I2) gas can also be used. At least one of these gases can be used as the processing gas.

[0119] In addition, as a processing gas, for example, a gas containing Si as the first element and an organic ligand can be used. As a gas containing Si and an organic ligand, for example, aminosilane-based gases such as tetrakis(dimethylamino)silane (Si[N(CH3)2]4) gas, tris(dimethylamino)silane (Si[N(CH3)2]3H) gas, bis(diethylamino)silane (Si[N(C2H5)2]2H2) gas, bis(tert-butylamino)silane (SiH2[NH(C4H9)]2) gas, and (diisopropylamino)silane (SiH3[N(C3H7)2]) gas can also be used. In addition, as a processing gas, a gas containing Si as the first element and a hydrogen (H) group can be used. As a gas containing Si and an H group, for example, monosilane (SiH4) and disilane (Si2H6) can be used. As the first raw material gas, one or more of these can be used.

[0120] As a processing gas, for example, a gas containing Si and an alkyl group as an organic ligand, i.e., an alkylsilane-based gas, can also be used. The alkyl group may be linear or branched. Examples of the alkyl group include methyl, ethyl, n-propyl, n-butyl, isopropyl, isobutyl, sec-butyl, and tert-butyl.

[0121] In addition, for example, one or more of tungsten (W), titanium (Ti), molybdenum (Mo), tantalum (Ta), cobalt (Co), yttrium (Y), ruthenium (Ru), hafnium (Hf), zirconium (Zr), aluminum (Al), boron (B), gallium (Ga), indium (In), phosphorus (P), carbon (C), etc. can be used.

[0122] As the processing gas, for example, a gas containing the first element and a halogen element can be used. Examples of such gases include tungsten hexachloride (WCl6), tungsten hexafluoride (WF6), titanium tetrachloride (TiCl4), titanium tetrafluoride (TiF4), molybdenum pentachloride (MoCl5), molybdenum pentafluoride (MoF5), molybdenum dioxide dichloride (MoO2Cl2), molybdenum oxychloride tetrachloride (MoOCl4), tantalum pentachloride (TaCl5), tantalum pentafluoride (TaF5), cobalt difluoride (CoF2), cobalt dichloride (CoCl2), yttrium trifluoride (YF3), yttrium trichloride (YCl3), ruthenium trichloride (RuCl3), ruthenium trifluoride (RuF3), hafnium tetrachloride (HfCl4), hafnium tetrafluoride (HfF4), zirconium tetrachloride (ZrCl4), zirconium tetrafluoride (ZrF4), aluminum trichloride (AlCl3), and aluminum trifluoride (AlF3). In addition, as the first gas, for example, boron trifluoride (BF3), boron trichloride (BCl3), gallium trifluoride (GaF3), gallium trichloride (GaCl3), indium trifluoride (InF3), indium trichloride (InCl3), phosphorus trifluoride (PF3), phosphorus pentafluoride (PF5), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), carbon tetrafluoride (CF4), carbon tetrachloride (CCl4), trifluoromethane (CHF3), fluoromethane (CH3F), chloroform (CHCl3), chloromethane (CH3Cl), etc. can be used. As the processing gas, for example, a gas containing the first element and a Br group or a gas containing the first element and an I group can also be used.

[0123] In addition, as the processing gas, for example, a gas containing the first element and an organic ligand, or a gas containing the first element and a hydrogen group can be used. As the organic ligand, for example, an alkyl group, a cycloalkyl group, an alkoxy group, a phenyl group, or a cyclopentyl group can be used. As the first raw material gas, for example, hexakis(dimethylamino)ditungsten (W2[N(CH3)2]6), bis(tert-butylimide)bis(dimethylamide)tungsten ((t-C4H9NH)2W=(Nt-C4H9)2), tetrakis(ethylmethylamino)titanium (Ti[N(C2H5)(CH3)]4), bis(ethylcyclopentadienyl)ruthenium (Ru(CH2CH3)Cp)2), bis(cyclopentadienyl)ruthenium (Ru(Cp)2), tetrakis(ethylmethylamino)hafnium (Hf[N(CH3)(CH2CH3)]4), tetrakis(diethylamino)hafnium (Hf[N(CH2CH3)2]4), tetrakis(dimethylamino)hafnium (Hf[N(CH3)2]4), tris(dimethylamino)cyclopentadienyl hafnium ((Cp)Hf[N(CH3)2]3), tetrakis(ethylmethylamino)zirconium (Zr[N(CH3)Cp]4), tetrakis(diethylamino)zirconium (Zr[N(CH2CH3)2]4), tetrakis(dimethylamino)zirconium (Zr[N(CH3)2]4), tris(dimethylamino)cyclopentadienyl zirconium ((Cp)Zr[N(CH3)2]3), trimethylaluminum (Al(CH3)3), borane (BH3), trimethylgallium (Ga(CH3)3), trimethylindium (In(CH3)3), phosphine (PH3), methane (CH4), etc.

[0124] Here, the first modified gas is a gas that blocks the adsorption of the processing gas onto the wafer 200. Specifically, the functional groups contained in the first modified gas that are formed on (exposed to) the upper surface and inner surface of the recess block the adsorption of the processing gas onto the wafer 200 (the upper surface and inner surface of the recess). As a result, the processing gas is not adsorbed onto the first modified layer 150 on the surface of the wafer 200, but is adsorbed onto the portion of the first modified layer 150 that has been removed. For example, in this embodiment, Figure 5 As shown in (c), the processing gas is adsorbed onto the upper surface and opening side of the recess on the wafer 200. Furthermore, the gas supplied to the wafer 200 typically easily reaches the upper surface and opening side of the recess on the wafer 200, but has difficulty reaching the deep side of the recess. Therefore, by adjusting the processing conditions of step a1 and / or step a2, controlling the distribution of the first modified layer 150 formed on the wafer 200, controlling the distribution of the first modified layer 150 removed from the wafer 200, and so on, the position of the processing gas adsorbed on the wafer 200 can be controlled.

[0125] Here, in this specification, the phrase "the processing gas is not adsorbed onto the first modified layer 150" includes not only the case where the processing gas is not adsorbed onto the first modified layer at all, but also the case where very little processing gas is adsorbed onto the first modified layer. For example, it also includes the case where the processing gas is adsorbed onto about 1% of the first modified layer on the chip 200, and preferably the case where the processing gas is adsorbed onto less than 1% of the first modified layer.

[0126] By performing steps a1, a2, and b1, a layer for adsorbing the first reforming gas and the processing gas can be formed on the adsorption site provided on the surface of the wafer 200.

[0127] After step b1, valve 243b is closed to stop the supply of the process gas into the process chamber 201. Then, the process chamber 201 is purged in the same step as that performed after step a1.

[0128] [b2]

[0129] After step b1 is completed, a reaction gas is supplied to the wafer 200 .

[0130] Specifically, valve 243c is opened to allow the reactant gas to flow into gas supply pipe 232c. The reactant gas is flow-regulated by MFC 241c, supplied into processing chamber 201 via nozzle 249c, and exhausted from exhaust port 231a. At this point, the reactant gas is supplied to wafer 200 (reactant gas supply). Alternatively, valves 243d-243f may be opened to allow inert gas to be supplied into processing chamber 201 via nozzles 249a-249c, respectively.

[0131] As the processing conditions when supplying the reaction gas in this step, the following are exemplified:

[0132] Processing pressure: 1-4000Pa, preferably 10-1000Pa

[0133] Reaction gas supply flow rate: 0.1-10 slm, preferably 1-5 slm

[0134] Reaction gas supply time: 1 to 120 seconds, preferably 10 to 60 seconds.

[0135] The other processing conditions can be the same as those when the first reforming gas is supplied in step a1.

[0136] By supplying the reaction gas to the wafer 200 under the above-mentioned processing conditions, at least a portion of the processing layer 152 formed on the inner surface of the recess reacts with the reaction gas to form the first layer 154 (see Figure 5 (d)).

[0137] For example, the aforementioned gases including reducing gas, oxidizing gas, nitriding gas, sulfiding gas, selenizing gas, and tellurizing gas can be used as the reactive gas. More than one of these gases can be used as the reactive gas. Here, the first removal gas and the reactive gas can have the same molecular structure. Alternatively, the first removal gas and the reactive gas can have different molecular structures. Furthermore, in step b2, at least a portion of the first modified layer 150 on the wafer 200 can be removed using the reactive gas in parallel with the formation of the first layer 154.

[0138] After step b2, valve 243c is closed to stop the supply of the reaction gas into the processing chamber 201. Then, the processing chamber 201 is purged in the same step as that performed after step a1.

[0139] [Number of times of implementation of regulationsb]

[0140] By performing the second step a predetermined number of times (n2 times, where n2 is an integer greater than or equal to 1 or 2), wherein the second step is performed in the order of step b1, purge treatment, step b2, and purge treatment, a first layer 154 of a predetermined thickness can be formed on the surface (inner surface of the recess) of the wafer 200. Furthermore, the purge step can be omitted in the second step. Furthermore, steps b1 and part of step b2 can be performed simultaneously, or the processing gas and the reaction gas can be reacted in the gas phase. Alternatively, step b2 can be omitted and step b1 can be performed n2 times. In this case, a processing layer 152 of a predetermined thickness can be formed on the surface (inner surface of the recess) of the wafer 200.

[0141] [Number of times of implementation]

[0142] By performing the first cycle of performing the first and second steps in this order a predetermined number of times (n times, where n is an integer greater than or equal to 1 or 2), a film 160 having a desired composition can be formed on the upper surface of the wafer 200 and the opening side of the recess. For example, by step a1 of the second cycle, as shown in FIG. Figure 5 As shown in (e), the surface including the first layer 154 forms the first modified layer 150 on the upper surface and the concave portion of the wafer 200. By the process of step a2, as shown in FIG. Figure 5 As shown in (f), the upper surface of the wafer 200 and a portion of the first modified layer 150 on the opening side of the recess are removed, and by step b1, as shown in FIG. Figure 5 As shown in (g), a processing layer 152 is formed on the upper surface of the wafer 200 and the opening side of the recess. Figure 5As shown in (h), a first layer 154 having a greater thickness is formed on the upper surface of the wafer 200 and the opening side of the recess. By further repeating the first cycle, the opening gradually becomes narrower, as shown in FIG. Figure 5 As shown in (i), an air gap G can be formed.

[0143] (Post-purge and atmospheric pressure recovery)

[0144] After the film formation process is completed, an inert gas is supplied as a purge gas into the processing chamber 201 from the nozzles 249a to 249c and exhausted from the exhaust port 231a. This purges the processing chamber 201, removing any remaining gas and reaction byproducts (post-purge). Subsequently, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to normal pressure (return to atmospheric pressure).

[0145] (Boat unloading and wafer unloading)

[0146] The sealing cover 219 is then lowered by the boat elevator 115, opening the lower end of the manifold 209. The boat 217 is then unloaded from the reaction tube 203 (boat unloading). After the boat is unloaded, the gate 219s moves, sealing the lower end of the manifold 209 via the O-ring 220c and the gate 219s (gate closing). The processed wafers 200 are then removed from the boat 217 (wafer unloading).

[0147] (3) Effects of this method

[0148] According to this aspect, in addition to the above-described effects, one or more of the following effects can be obtained.

[0149] (a) By performing step a2 after step a1, the distribution of the first modified layer 150 within the recess of the wafer 200 can be controlled. This allows for control of the areas that are most easily processed in the second step. For example, the following distribution of the first modified layer can be formed.

[0150] (1) The density of the first modified layer formed in the central portion of the recessed portion is higher than that in the opening portion and the deep portion of the recessed portion.

[0151] (2) The density of the first modified layer formed in the deep portion of the recessed portion compared to the opening portion of the recessed portion.

[0152] (3) The density of the first modified layer is substantially uniform from the opening to the deep portion of the recess.

[0153] (b) The first removal gas and the reaction gas can be gases with the same molecular structure. In this case, the reaction gas supply system and the first removal gas supply system can be shared, thereby simplifying the device structure.

[0154] (c) The first removal gas and the reaction gas may be gases having different molecular structures. In this case, gases having different reactivities can be used separately in step a2 and step b2. For example, when an oxide film is formed as the film 160, O2 can be used as the first removal gas, and O3 having a higher reactivity than O2 can be used as the reactive gas. In addition, when an oxynitride film is formed as the film 160, NH3 can be used as the first removal gas, and O3 having a higher reactivity than N2O can be used as the reactive gas. That is, a gas having a lower reactivity than the reactive gas can be used as the first removal gas. In these cases, it is possible to suppress the excessive oxidation (modification) of the processing layer 152, the first layer 154, and the base film already formed on the wafer 200.

[0155] On the other hand, for example, when an oxide film is formed as film 160, O3 can be used as the first removing gas and O2 can be used as the reactive gas. Furthermore, when an oxynitride film is formed as film 160, NH3 can be used as the first removing gas and O3 can be used as the reactive gas. In other words, a gas with a higher reactivity than the reactive gas can be used as the first removing gas. This allows oxidation (modification) of the process layer 152, first layer 154, or the underlying film of the process layer 152 or first layer 154 already formed on wafer 200, also in step a2.

[0156] (d) The amount of reaction gas aerated into wafer 200 in step (b2) is preferably greater than the amount of first reforming gas aerated into wafer 200 in step (a2). This facilitates the reaction gas to reach the deeper portion of the recess. Furthermore, when the first removal gas and the reaction gas have the same molecular structure, a reaction between the first removal gas (reaction gas) and the first reforming gas is more likely to occur. This facilitates the reaction to proceed sufficiently even in the deeper portion of the recess, thereby facilitating uniform treatment throughout the entire recess.

[0157] Furthermore, by satisfying at least one of the following conditions 1 to 6, the amount of reaction gas aerated into the wafer 200 in step (b2) can be made greater than the amount of first reformed gas aerated into the wafer 200 in step (a2).

[0158] 1. The supply time of the reaction gas in step b2 is made longer than the supply time of the first reforming gas in step a1.

[0159] 2. Make the processing pressure in step b2 higher than that in step a1.

[0160] 3. The flow rate of the reaction gas supplied in step b2 is made greater than the flow rate of the first reforming gas supplied in step a1.

[0161] 4. The inert gas supply flow rate in step b2 is made smaller than the inert gas supply flow rate in step a1.

[0162] 5. The partial pressure of the reaction gas in the processing chamber 201 in step b2 is made higher than the partial pressure of the first reforming gas in the processing chamber 201 in step a1.

[0163] 6. The molar fraction of the reaction gas in the gas in the processing chamber 201 in step b2 is made greater than the molar fraction of the first reforming gas in step a1.

[0164] (e) Preferably, the upper and inner surfaces of the recessed portion where the first modifying gas is adsorbed are in a state where the first functional groups derived from the first modifying gas are exposed. In step (a2), at least a portion of the first functional groups, which constitute at least a portion of the first modified layer, are replaced with second functional groups having a higher reactivity with the process gas than the first functional groups. In this case, the first modified layer can be removed in a short time. Therefore, a decrease in the number of substrates that can be processed per unit time (productivity) can be suppressed.

[0165] (f) It is preferred that either of the following (1) and (2) holds true.

[0166] (1) The first reforming gas and the processing gas contain halogen elements.

[0167] (2) The first reforming gas and the processing gas are organic compounds or have organic ligands.

[0168] In such a case, the first modified layer is likely to hinder the adsorption of the process gas onto the wafer 200. This allows for more precise control of the portion where the process is most likely to be performed in the second step.

[0169] (g) When forming a film on the wafer 200 in the second step, the first reforming gas preferably does not contain the main constituent element of the film. This allows the film to be formed preferentially on the region where the first reformed layer is not formed, rather than on the region where the first reformed layer is formed.

[0170] (h) The first removal gas may also contain a gas activated by plasma. Figure 6 An example of the structure of the processing furnace 202 in such a case will be described. Figure 1 Elements that are substantially the same as those described in are denoted by the same reference numerals, and description thereof is omitted. Figure 6 yes Figure 1An example of a cross-sectional view of the processing furnace 202 taken along line AA is shown. A buffer chamber 237 is provided within the reaction tube 203, which is partitioned by a partition wall 237a. A nozzle 249c is disposed within the buffer chamber 237. Two rod-shaped electrodes 269 and 270, each made of a conductive material, are provided within the buffer chamber 237, extending from the lower portion of the inner wall of the reaction tube 203 into the buffer chamber 237 and extending upward (in the forward direction relative to the drawing) toward the upper portion of the reaction tube 203. The rod-shaped electrodes 269 and 270 are arranged parallel to the nozzle 249c. The rod-shaped electrodes 269 and 270 are covered from top to bottom by an electrode protection tube 275. One of the rod-shaped electrodes 269 and 270 is connected to a high-frequency power supply 273 via a matching unit 272, while the other is connected to a ground wire, which serves as a reference potential. By applying high-frequency (RF) power between rod-shaped electrodes 269 and 270 from high-frequency power supply 273, the first removal gas can be activated by plasma in plasma generation region 224 between rod-shaped electrodes 269 and 270. Rod-shaped electrodes 269 and 270 and electrode protection tube 275 primarily constitute a plasma excitation unit (activation mechanism) that excites (activates) the gas into a plasma state.

[0171] When the first removal gas is activated by plasma, its reactivity can be increased, then decreased (deactivated) over time. This can further increase the difference in ease of removal of the first modified layer between areas easily accessible by the first removal gas and areas difficult to reach. For example, this can make removal of the first modified layer near the opening of the recess easier, while removal of the first modified layer in the center and deep side of the recess more difficult. This allows for more precise control over the areas that are easily accessible during the second step.

[0172] (i) It is preferable that the number of repetitions N of the first and second steps is two or more. By repeating the steps two or more times, the target position can be easily processed.

[0173] Modifications

[0174] The processing sequence in this embodiment can be changed as shown in the following modified examples. These modified examples can be combined arbitrarily. Unless otherwise specified, the processing steps and processing conditions in each step of each modified example can be the same as the processing steps and processing conditions in each step of the above-mentioned processing sequence.

[0175] (Variation 1)

[0176] like Figure 7A As shown in the processing sequence, after the execution of the first step and before the execution of the second step, the third step (S30) is executed. Figure 7BAs shown, in step S30-1, step (c) is executed. Step (c) involves supplying a second modifying gas, which forms the second modified layer 158, to at least a portion of the region on the wafer 200 where the first modified layer 150 is not formed. In step S30-2, a purge process is performed within the processing chamber 201. In step S30-3, a determination is made as to whether step (c) has been performed a predetermined number of times. If the determination is negative, the process returns to step S30-1. If the determination is positive, the third step is terminated and the process proceeds to step S12 to execute the second step.

[0177] (A) Effects of Modification 1

[0178] In this modification, at least part of the effects of the above-described embodiment is also obtained. In addition, in this modification, one or more of the following effects are obtained.

[0179] (a) By performing the third step in this manner, the distribution of the modified layer (one or both of the first modified layer and the second modified layer) within the pattern can be more finely controlled. Specifically, a modified layer having the following distribution can be formed.

[0180] (1) The density of the first modified layer 150 and the second modified layer 158 can be made substantially uniform from the opening to the deep portion of the concave portion. In this case, in the first step, the first modified layer 150 is formed to the deep portion of the concave portion ( Figure 8 (a) of (1), while removing at least a portion of the first modified layer 150 on the opening side ( Figure 8 (1) (b)), in the third step, the second modified layer 158 is formed on the portion where at least a portion of the first modified layer 150 on the opening side is removed ( Figure 8 (c) of (1).

[0181] (2) The density of the first modified layer and the second modified layer formed in the opening and deep portion of the concave portion can be increased compared to the central portion of the concave portion. In this case, in the first step, the first modified layer 150 is formed to the deep portion of the concave portion ( Figure 8 (2) (a)), and at the same time, at least a portion of the first modified layer 150 is removed to a position deeper than the middle of the concave portion ( Figure 8 (2) (b)), in the third step, a second modified layer 158 is formed on the opening side ( Figure 8 (c) of (2).

[0182] (3) When the molecular structures of the first modified gas and the second modified gas are different, modified layers having different adsorption barrier effects on the processing gas can be formed on the deep side, near the center, and on the opening side of the concave portion. For example, a second modified layer for the processing gas can be formed on the opening side, a first modified layer having a smaller adsorption barrier effect than the second modified layer can be formed near the center, and it is difficult to form the first and second modified layers on the deep side. In this case, in the first step, the first modified layer 150 is formed to a position deeper than the middle portion of the concave portion (not formed to the bottom) ( Figure 8 (3) (a)), while removing at least a portion of the first modified layer 150 on the opening side ( Figure 8 (3) (b)), in the third step, the second modified layer 158 is formed on the portion where at least a portion of the first modified layer 150 on the opening side is removed ( Figure 8 (c) of (3). As a result, the ease of processing can be increased in a stepped manner toward the deep side of the recess where the gas is difficult to reach. Therefore, the processing in the recess can be performed uniformly (a film of uniform thickness can be easily formed). For example, as the first modified layer and the second modified layer, consider the case where layers containing X1 groups and X2 groups as functional groups of halogen elements X1 and X2 that are different from each other are formed respectively. In this case, by making the atomic number of X2 smaller than the atomic number of X1 (for example, using Cl and F as X1 and X2, respectively), the adsorption barrier effect of the second modified layer can be made greater than the adsorption barrier effect of the first modified layer.

[0183] (b) The amount of the second modified gas aerated into the wafer 200 in step (c) is preferably smaller than the amount of the first modified gas aerated into the wafer 200 in step (a1). In this case, since the second modified gas is supplied to the opening side of the recessed portion after the first modified layer has been removed in step (b2), the formation of the second modified layer is less likely to be obstructed by the first modified layer. Therefore, the aforementioned effect (control of the distribution of the modified film) is easily achieved.

[0184] (c) When the first reformed gas and the second reformed gas are gases having the same molecular structure, the first reformed gas supply system and the second reformed gas supply system can be made common, thereby simplifying the device structure.

[0185] (d) Preferably, in step (a2), at least a portion of the first functional groups on wafer 200, which form at least a portion of the first modified layer, are replaced with second functional groups having a higher reactivity with the process gas than the first functional groups, and in step (c), at least a portion of the second functional groups are replaced with third functional groups, which form at least a portion of the second modified layer, which have a lower reactivity with the process gas than the second functional groups. In this case, the first modified layer can be removed and the second modified layer can be formed in a shorter time. Therefore, a decrease in the number of substrates that can be processed per unit time (productivity) can be suppressed.

[0186] (e) It is preferred that either of the following (1) and (2) holds true.

[0187] (1) The first reformed gas, the processing gas, and the second reformed gas contain halogen elements.

[0188] (2) The first reformed gas, the processing gas, and the second reformed gas are organic compounds or have organic ligands.

[0189] In such a case, the first modified layer and the second modified layer are likely to hinder the adsorption of the processing gas onto the wafer 200. This allows for more precise control of the portion where the processing is likely to be performed in the second step.

[0190] (f) When forming a film on the wafer 200 in the second step, the first and second modifying gases preferably do not contain the main constituent elements of the film. This facilitates preferential film formation in regions where at least one of the first and second modified layers is not formed, compared to regions where at least one of the first and second modified layers is formed.

[0191] (g) The first removal gas may also contain a gas activated by plasma. When the first removal gas is activated by plasma, the reactivity of the first removal gas can be increased, and its reactivity can be reduced (deactivated) over time. As a result, the difference in the ease of removing the first modified layer between the parts that are easy for the first removal gas to reach and the parts that are difficult to reach can be further increased. For example, the first modified layer near the opening of the recess can be more easily removed, and the first modified layer in the central part and deep side of the recess can be more difficult to remove. Therefore, the parts that are easy to process in the second step can be further finely controlled.

[0192] (Variation 2)

[0193] like Figure 9A As shown in the processing sequence, after the first and second steps are executed for a predetermined number of times, the fourth step (S40) is executed. Figure 9BAs shown, in step S40-1, step (d) is executed. Step (d) is a process of supplying a second removal gas to remove a portion of the first modified layer 150 from the wafer 200. In step S40-2, a purge process is performed within the processing chamber 201. In step S40-3, it is determined whether step (c) has been performed a predetermined number of times. If the determination is negative, the process returns to step S40-1. If the determination is positive, the fourth step ends.

[0194] (A) Effects of Modification 2

[0195] In this modification, at least part of the effects of the above-mentioned embodiment and modification is also obtained. In addition, in this modification, one or more effects shown below are obtained.

[0196] (a) When the first modified layer 150 remains on the substrate after the second step, it is difficult to perform the second step on this portion compared to other portions. This may cause a decrease in the uniformity of the treatment in the region to be treated on the wafer 200. For example, when a film is formed in step b, the uniformity of the formed film may be reduced due to the generation of portions (pinholes) where the film is not sufficiently formed or the increase in the surface roughness of the film. In the fourth step, by supplying the second removal gas, at least a portion of the first modified layer remaining on the wafer 200 after the second step can be removed. Therefore, the uniformity of the film in the region to be treated on the wafer 200 (uniformity of the treatment) can be improved.

[0197] (b) The first removal gas and the second removal gas may be gases having the same molecular structure. Alternatively, the second removal gas and the reaction gas may be gases having the same molecular structure. Alternatively, the first removal gas, the second removal gas, and the reaction gas may be gases having the same molecular structure. This allows two or more systems, namely, the first removal gas supply system, the second removal gas supply system, and the reaction gas supply system, to be shared. Consequently, the device structure can be simplified.

[0198] (c) The first and second removal gases can be gases with different molecular structures. Alternatively, the second removal gas and the reaction gas can be gases with different molecular structures. Alternatively, the first, second, and reaction gases can be gases with different molecular structures. This allows gases with different reactivities to be used separately in two or more of step a2, step b2, and step d. This allows for control over the promotion and suppression of modification in the treatment layer 152, first layer 154, and base film.

[0199] (d) The amount of the second removal gas aerated into wafer 200 in step (d) is preferably greater than the amount of the first removal gas aerated into wafer 200 in step (a2). This facilitates the second removal gas to reach the deep side of the recess. Furthermore, a reaction between the second removal gas and first modified layer 150 is more likely to occur. Therefore, even in the deep side of the recess, first modified layer 150 can be removed more easily. Consequently, uniform treatment can be performed over the entire recess.

[0200] (e) The amount of the second removal gas aerated into the wafer 200 in step (d) is preferably greater than the amount of the reaction gas aerated into the wafer 200 in step (b2). This facilitates the second removal gas to reach the deep side of the recess. Furthermore, a reaction between the second removal gas and the first modified layer is more likely to occur. Therefore, even in the deep side of the recess, the first modified layer 150 can be removed more easily. Consequently, uniform treatment can be performed across the entire recess.

[0201] (f) Preferably, in step (a2), at least a portion of the first functional groups on the wafer 200, which constitute at least a portion of the first modified layer 150, are replaced with second functional groups having a higher reactivity with the process gas than the first functional groups, and in step (c), at least a portion of the second functional groups are replaced with third functional groups, which constitute at least a portion of the second modified layer 158, which have a lower reactivity with the process gas than the second functional groups. This replacement allows the first modified layer 150 to be removed.

[0202] (Variation 3)

[0203] like Figure 10 As shown in the processing sequence, after the first step, the third step, and the second step are performed a predetermined number of times, the fourth step (S40) is performed, and this is repeated a predetermined number of times to terminate the process. In this modification 3, the second removal gas is a gas that removes at least a portion of the first modified layer 150 and at least a portion of the second modified layer 158.

[0204] (A) Effects of Modification 3

[0205] In this modification, at least part of the effects of the above-described embodiment and modifications 1 and 2 are also obtained. In addition, in this modification, one or more of the following effects are obtained.

[0206] (a) As described in Modification 1, the distribution of one or both of the first modified layer and the second modified layer within the pattern can be more finely controlled. Furthermore, as described in Modification 2, both can improve the uniformity of processing within the desired region on the wafer 200 during the fourth step.

[0207] <Other aspects of the present invention>

[0208] Although the embodiment of the present invention has been specifically described above, the present invention is not limited to the above embodiment and various modifications can be made without departing from the gist of the invention.

[0209] For example, the above embodiment describes the case where a film is formed in step b, but the present invention is not limited to this context. By using the technology of the present invention, it is possible to control the areas on wafer 200 where processing is facilitated and the areas where processing is hindered. For example, the technology of the present invention can also be applied when etching a film on wafer 200 in step b. In such cases, by controlling the distribution of one or both of the first modified layer 150 and the second modified layer 158, it is possible to control the areas where etching is facilitated and the areas where etching is hindered.

[0210] The recipe used in each process is preferably prepared individually according to the process content and recorded and stored in the storage device 121c via an electrical communication line or an external storage device 123. Furthermore, when each process is started, the CPU 121a preferably selects an appropriate recipe based on the process content from the multiple recipes recorded and stored in the storage device 121c. This allows films of various film types, component ratios, film qualities, and film thicknesses to be formed with good reproducibility in a single substrate processing apparatus. Furthermore, this reduces the burden on operators, prevents operational errors, and allows each process to be started quickly.

[0211] The above recipes are not limited to newly created ones; for example, they can also be prepared by modifying an existing recipe already installed in a substrate processing apparatus. When modifying a recipe, the modified recipe can be installed in the substrate processing apparatus via an electrical communication line or a recording medium containing the recipe. Alternatively, the input / output device 122 of an existing substrate processing apparatus can be operated to directly modify an existing recipe installed in the apparatus.

[0212] In the above-mentioned embodiment, an example of forming a film using a batch-type substrate processing device that processes multiple substrates at a time is described. The present invention is not limited to the above-mentioned embodiment. For example, it can also be well applied when forming a film using a cluster-type substrate processing device that processes one or more substrates at a time. In addition, in the above-mentioned embodiment, an example of forming a film using a substrate processing device having a hot-wall type processing furnace is described. The present invention is not limited to the above-mentioned embodiment. It can also be well applied when forming a film using a substrate processing device having a cold-wall type processing furnace. In addition, in the above-mentioned embodiment, an example of activating a gas by heat or plasma is described. However, the present invention is not limited to this. For example, it can also be well applied when activating a gas by irradiating it with electromagnetic waves using a lamp or the like. When using these substrate processing devices, each process can also be performed with the same processing steps and processing conditions as the above-mentioned embodiment and modified example, and the same effect as the above-mentioned embodiment and modified example can be obtained.

[0213] The above-mentioned embodiments and modifications can be used in combination as appropriate. The processing steps and processing conditions in this case can be, for example, the same as those in the above-mentioned embodiments and modifications.

Claims

1. A substrate processing method, characterized in that: The first step and the second step are performed a predetermined number of times, wherein: The first step is performed a predetermined number of times: (a1) supplying a first modified gas to the substrate for forming a first modified layer on at least a portion of the substrate; and (a2) supplying a first removing gas to the substrate for removing a portion of the first modified layer from the substrate, The second step is performed a predetermined number of times after the first step: (b1) supplying a processing gas to the substrate that preferentially processes a region where the first modified layer is not formed, relative to a region where the first modified layer is present; and In step (b2), a reaction gas is supplied to the substrate.

2. The substrate processing method according to claim 1, wherein: The first removal gas and the reaction gas have the same molecular structure.

3. The substrate processing method according to claim 1, wherein: The first removal gas and the reaction gas are gases having different molecular structures.

4. The substrate processing method according to claim 1, wherein: The amount of the first removal gas aerated toward the substrate in the step (a2) is smaller than the amount of the reaction gas aerated toward the substrate in the step (b2).

5. The substrate processing method according to claim 1, wherein: After the first step and before the second step, a third step is further included. The third step includes the step (c) of supplying a second modified gas to the substrate for forming a second modified layer in at least a portion of a region on the substrate where the first modified layer is not formed.

6. The substrate processing method according to claim 5, wherein: The amount of the second reformed gas aerated toward the substrate in the step (c) is smaller than the amount of the first reformed gas aerated toward the substrate in the step (a1).

7. The substrate processing method according to claim 5, wherein: The molecular structure of the second reformed gas is the same as the molecular structure of the first reformed gas.

8. The substrate processing method according to claim 1, wherein: The second step is performed multiple times. The substrate processing method further includes a fourth step of performing step (d) of supplying a second removal gas to the substrate to remove at least a portion of the first modified layer from the substrate after performing the second step a predetermined number of times.

9. The substrate processing method according to claim 5, wherein: There is also a process (d), which supplies a second removal gas to the substrate to remove at least a portion of the first modified layer and at least a portion of the second modified layer from the substrate after the first process, the third process and the second process are performed a specified number of times.

10. The substrate processing method according to claim 8 or 9, characterized in that: The molecular structure of the second removing gas is the same as the molecular structure of the first removing gas.

11. The substrate processing method according to claim 8 or 9, characterized in that: The amount of the second removal gas aerated toward the substrate in the step (d) is set to be greater than the amount of the first removal gas aerated toward the substrate in the step (a2).

12. The substrate processing method according to claim 8 or 9, characterized in that: The molecular structure of the second removal gas is the same as the molecular structure of the reaction gas.

13. The substrate processing method according to claim 8 or 9, characterized in that: The amount of the second removal gas aerated toward the substrate in the step (d) is set to be greater than the amount of the reaction gas aerated toward the substrate in the step (b2).

14. The substrate processing method according to claim 1, wherein: The formation of the first modified layer in step (a1) includes forming a first functional group on the substrate. The removal of the first modified layer in the step (a2) includes replacing a portion of the first functional groups on the substrate with second functional groups having a higher reactivity with the process gas than the first functional groups.

15. The substrate processing method according to claim 1, wherein: Either (1) or (2) below holds true: (1) The first reforming gas and the processing gas contain halogen elements, (2) The first reformed gas and the processing gas are organic compounds or have organic ligands.

16. The substrate processing method according to claim 1, wherein: In the second step, a film containing a predetermined element contained in the processing gas as a main constituent element is formed on the substrate. The step (a1) is performed under the condition that a substance containing the predetermined element is not formed on the substrate.

17. The substrate processing method according to claim 1, wherein: The first removing gas includes a gas activated by plasma.

18. A method for manufacturing a semiconductor device, characterized in that: Perform the first and second steps a specified number of times. Wherein, the first step is performed a predetermined number of times: (a1) supplying a first modified gas to the substrate for forming a first modified layer on at least a portion of the substrate; and (a2) supplying a first removing gas to the substrate for removing a portion of the first modified layer from the substrate, The second step is performed a predetermined number of times after the first step: (b1) supplying a processing gas to the substrate that preferentially processes a region where the first modified layer of the first substance is not formed, relative to a region where the first modified layer is formed on the substrate; and In step (b2), a reaction gas is supplied to the substrate.

19. A substrate processing device, characterized in that: have: a first modifying gas supply system for supplying a first modifying gas for forming a first modified layer on at least a portion of the substrate; a first removing gas supply system for supplying a first removing gas for removing a portion of the first modified layer from the substrate; a processing gas supply system for supplying a processing gas for preferentially treating a region where the first modified layer is not formed, relative to a region where the first modified layer is present; a reaction gas supply system that supplies a reaction gas; and The control unit is configured to control the first reforming gas supply system, the first removal gas supply system, the processing gas supply system, and the reaction gas supply system so as to perform the following process: The first process and the second process are performed a predetermined number of times, wherein: The first process includes performing the following steps a predetermined number of times: (a1) supplying the first reforming gas to the substrate; and (a2) supplying the first removal gas to the substrate, The second process is performed a predetermined number of times after the first process: (b1) supplying the process gas to the substrate; and (b2) A process of supplying the reaction gas to the substrate.

20. A recording medium, which is a computer-readable recording medium and has a program recorded thereon, characterized in that: The program uses a computer to cause the substrate processing apparatus to execute the steps of performing the first step and the second step a predetermined number of times, wherein: The first step is performed a specified number of times: (a1) step of supplying a first modified gas to the substrate for forming a first modified layer on at least a portion of the substrate; (a2) supplying a first removing gas to the substrate for removing a portion of the first modified layer from the substrate, The second step is performed a specified number of times after the first step: (b1) step of supplying a processing gas to the substrate that preferentially processes a region where the first modified layer is not formed, relative to a region where the first modified layer is present; and In step (b2), a reaction gas is supplied to the substrate.

Images