Substrate processing method and substrate processing apparatus

Abstract

The present application aims to provide a substrate processing method and a substrate processing apparatus which effectively suppress pattern collapse of a concavo-convex pattern. The substrate processing method of the example embodiment includes: a step of replacing a liquid in a concave portion of a substrate in which a concavo-convex pattern is formed on a surface with a reinforcing material in a solid state (S04, S05); and a step of subjecting the substrate to a molecular reduction treatment (S06) which reduces the number of intermolecular bonds in the reinforcing material while maintaining the reinforcing material in the solid state.

Description

Technical Field

[0001] This invention relates to a substrate processing method and a substrate processing apparatus. Background Technology

[0002] Patent document 1 discloses a substrate drying method (substrate processing method) that removes liquid from a substrate on which an uneven pattern is formed on its surface to dry the substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-243869 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] This invention provides a substrate processing method and a substrate processing apparatus that effectively suppress pattern collapse of raised and recessed patterns.

[0008] Technical solutions for solving technical problems

[0009] One aspect of the substrate processing method of the present invention includes: a step of replacing liquid in a recess of a substrate having a raised or recessed pattern formed on its surface with a solid reinforcing material; and a step of performing a low-molecular-weight treatment on the substrate, wherein the low-molecular-weight treatment maintains the reinforcing material in a solid state while reducing the number of intermolecular bonds contained in the reinforcing material.

[0010] Invention Effects

[0011] According to the present invention, a substrate processing method and a substrate processing apparatus that effectively suppress pattern collapse of raised and recessed patterns can be provided. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the general structure of a substrate processing system.

[0013] Figure 2 This is a schematic diagram illustrating the internal structure of a coating and developing apparatus.

[0014] Figure 3 This is a schematic diagram illustrating the structure of a developing unit.

[0015] Figure 4 This is a schematic diagram illustrating the structure of an irradiation unit.

[0016] Figure 5 This is a schematic diagram illustrating the structure of a plasma processing device.

[0017] Figure 6 This is a block diagram illustrating the functional structure of the control device.

[0018] Figure 7 This is a block diagram illustrating the hardware structure of the control device.

[0019] Figure 8 This is a flowchart illustrating an example of a developing process.

[0020] Figure 9 (a)~ Figure 9 (d) is a schematic diagram illustrating the situation inside the recess in an example of the developing process.

[0021] Figure 10 This is a diagram showing an example of the chemical formula of the polymer contained in the reinforcing material.

[0022] Figure 11 (a) is a schematic diagram illustrating an example of exposure processing. Figure 11 (b) is a schematic diagram illustrating an example of the development process of a modified example.

[0023] Figure 12 (a) and Figure 12 (b) is a schematic diagram illustrating an example of the development process.

[0024] Figure 13 This is a schematic diagram illustrating an example of the developing process.

[0025] Figure 14 This is a schematic diagram illustrating another example of the development process for a modified example. Detailed Implementation

[0026] Hereinafter, various illustrative embodiments will be described. In the description, the same reference numerals are used to refer to the same elements or elements having the same function, and repeated descriptions are omitted.

[0027] [Substrate Processing System]

[0028] First, refer to Figure 1 and Figure 2This section describes the general structure of a substrate processing system 1 (substrate processing apparatus). The substrate processing system 1 is a system for forming a photosensitive coating on a substrate, exposing the photosensitive coating, and developing the photosensitive coating. The substrate to be processed is, for example, a semiconductor wafer W. The photosensitive coating is, for example, a resist film. The substrate processing system 1 includes a coating and developing apparatus 2, an exposure apparatus 3, a plasma processing apparatus 10, and a control apparatus 100. The exposure apparatus 3 is an apparatus for exposing the resist film (photosensitive coating) formed on the wafer W (substrate). Specifically, the exposure apparatus 3 uses methods such as immersion exposure to irradiate the exposed portion of the resist film with energy lines for exposure. Before the exposure process performed by the exposure apparatus 3, the coating and developing apparatus 2 coats the surface of the wafer W (substrate) with a resist (solution) to form a resist film. Furthermore, the coating and developing apparatus 2 performs a development process on the resist film after the exposure process. After the resist film is developed, the plasma processing apparatus 10 applies plasma to the surface Wa (refer to) of the wafer W. Figure 3 The etching process using plasma is performed. For example, the plasma processing apparatus 10 uses a resist pattern formed by developing a resist film as a mask to perform etching on the wafer W.

[0029] (Coating and developing apparatus)

[0030] like Figure 1 and Figure 2 As shown, the coating and developing apparatus 2 (substrate processing apparatus) has a carrier block 4, a processing block 5, and an interface block 6.

[0031] The carrier block 4 handles the introduction and removal of wafers W from the coating and developing apparatus 2. For example, the carrier block 4 can support multiple carriers C for wafers W and includes a built-in transport device A1 with a transfer arm. The carriers C, for example, hold multiple circular wafers W. The transport device A1 removes wafers W from the carriers C and delivers them to the processing block 5, and receives wafers W from the processing block 5 and returns them to the carriers C. The processing block 5 has multiple processing modules 11, 12, 13, and 14.

[0032] Processing module 11 includes a coating unit U1, a heat treatment unit U2, and a transport device A3 for transporting wafer W to these components. Processing module 11 forms a lower layer film on the surface of wafer W using the coating unit U1 and the heat treatment unit U2. The coating unit U1 applies a processing solution for forming the lower layer film onto wafer W. The heat treatment unit U2 performs various heat treatments accompanying the formation of the lower layer film.

[0033] Processing module 12 includes a coating unit U1, a heat treatment unit U2, and a transport device A3 for transporting the wafer W to these components. Processing module 12 forms a resist film on a lower layer film using the coating unit U1 and the heat treatment unit U2. The coating unit U1 coats the lower layer film with a resist solution used for resist film formation. The heat treatment unit U2 performs various heat treatments accompanying the formation of the resist film. Thus, a resist film is formed on the surface of the wafer W.

[0034] Processing module 13 includes a coating unit U1, a heat treatment unit U2, and a transport device A3 for transporting wafer W to these components. Processing module 13 uses the coating unit U1 and the heat treatment unit U2 to form an upper layer film on the resist film. The coating unit U1 applies a processing solution for upper layer film formation to the resist film. The heat treatment unit U2 performs various heat treatments accompanying the formation of the upper layer film.

[0035] Processing module 14 includes a developing unit U3, a heat treatment unit U4, an irradiation unit U5, and a transport device A3 for transporting the wafer W to these mechanisms. Processing module 14 utilizes the developing unit U3, heat treatment unit U4, and irradiation unit U5 to perform a series of processes, including the development of the exposed resist film. The developing unit U3 partially removes the resist film (performs the development process) by applying (supplying) a developing solution to the surface of the exposed wafer W. In other words, the developing unit U3 forms a resist pattern as a raised and recessed pattern on the surface of the wafer W. The developing unit U3 supplies rinsing fluid to the surface of the wafer W to wash away the developing solution. Furthermore, after replacing the rinsing fluid in the recesses of the resist pattern with processing fluid, the developing unit U3 forms a reinforcing material (see reference) within these recesses. Figure 9 (b)). The heat treatment unit U4 performs various heat treatments accompanying the development process. Specific examples of heat treatments accompanying the development process include heat treatment before development (PEB: Post Exposure Bake) and heat treatment after development (PB: Post Bake). The irradiation unit U5 has the function of irradiating energy lines onto the surface of the wafer W, performing part of the process for removing the rinsing solution.

[0036] A shelf unit U10 is provided on the side of the carrier block 4 within the processing block 5. The shelf unit U10 is divided into multiple small compartments arranged in the vertical direction. A conveying device A7, including a lifting arm, is provided near the shelf unit U10. The conveying device A7 moves the wafer W up and down between the small compartments of the shelf unit U10.

[0037] A shelf unit U11 is provided on the side of the interface block 6 within the processing block 5. The shelf unit U11 is divided into multiple small compartments arranged in the vertical direction.

[0038] Interface block 6 facilitates the exchange of wafer W between itself and exposure apparatus 3. For example, interface block 6 includes a built-in transport device A8, which includes an exchange arm and is connected to exposure apparatus 3. Transport device A8 delivers wafer W, which is positioned in shelf unit U11, to exposure apparatus 3. Transport device A8 receives wafer W from exposure apparatus 3 and returns it to shelf unit U11.

[0039] (Developing unit)

[0040] Next, refer to Figure 3 An example of the developing unit U3 will be explained below. Figure 3 As shown, the developing unit U3 has a rotation holding part 20 and liquid supply parts 30a, 30b, and 30c (three liquid supply parts).

[0041] The rotation holding unit 20 includes a rotation drive unit 21, a shaft 22, and a holding unit 23. The rotation drive unit 21 operates based on an action signal from the control device 100, causing the shaft 22 to rotate. The rotation drive unit 21 may include a power source such as a motor. The holding unit 23 is located at the front end of the shaft 22. A wafer W can be positioned on the holding unit 23. The holding unit 23 holds the wafer W in a substantially horizontal position by means of, for example, suction. In this case, the rotation holding unit 20 rotates the wafer W about a central axis (rotation axis) perpendicular to the surface Wa of the wafer W, while the wafer W is in a substantially horizontal position. Figure 3 In the example, the rotation holding part 20 causes the wafer W to rotate counterclockwise at a predetermined speed when viewed from above.

[0042] The liquid supply unit 30a supplies developer L1 to the surface Wa of the wafer W. Developer L1 is a solution used to form a resist pattern by developing a resist film R. For example, by supplying developer L1 to the resist film R, the portions of the resist film R that have been irradiated by the energy lines for exposure (areas exposed during the exposure process) react and are removed. That is, a negative resist pattern (resist material) can also be used. Examples of developer L1 for removing exposed areas include organic solvents. Alternatively, by supplying developer L1 to the resist film R, the portions of the resist film R that have not been irradiated by the energy lines for exposure (areas not exposed during the exposure process) react and are removed. That is, a positive resist pattern (resist material) can also be used. Examples of developer L1 for removing unexposed areas include alkaline solutions.

[0043] The liquid supply unit 30b supplies rinsing solution L2 to the surface Wa (where a resist film R with a resist pattern is formed) of the wafer W. The rinsing solution L2 can be any liquid capable of washing away the developer L1. For example, the rinsing solution L2 can also be water (pure water). The liquid supply units 30a and 30b constitute a developing unit for developing the resist film R.

[0044] The liquid supply unit 30c (replacement processing unit) supplies processing liquid L3 to the surface Wa of the wafer W. Processing liquid L3 is a solution used to form a reinforcing material within the recesses of the resist pattern. Processing liquid L3 can also be a solution that can be supplied to the wafer W in a liquid state and dried and cured by a predetermined process (e.g., rotation of the wafer W). For example, processing liquid L3 can also be a solution formed by dissolving a polymer in a solvent. The polymer may also contain at least one of polymethyl acrylate, polymethacrylic acid, polyvinyl alcohol, ultraviolet-curing resin (UV-curing resin), and polymethyl methacrylate (PMMA). When using polymethyl acrylate, polymethacrylic acid, or polyvinyl alcohol, water can also be used as the solvent. When using polymethyl methacrylate, other solvents that can be used include acetone, isopropanol (IPA), methanol, ethanol, xylene, acetic acid, methyl isobutyl ketone (MIBK), methyl isobutyl carbinol (MIBC), butyl acetate, or propylene glycol methyl ether acetate (PGMEA).

[0045] Liquid supply units 30a, 30b, and 30c each have a liquid source 31, a valve 33, a nozzle 34, and a piping 35. The liquid source 31 of each liquid supply unit 30a, 30b, and 30c supplies liquid to the nozzles 34 via the valve 33 and the piping 35. The nozzles 34 of each liquid supply unit 30a, 30b, and 30c are respectively positioned above the wafer W with their release ports facing the surface Wa of the wafer W. The nozzles 34 release the liquid supplied from the liquid source 31 towards the surface Wa of the wafer W. The piping 35 connects the liquid source 31 to the nozzles 34. The valve 33 switches the flow path within the piping 35 between an open and closed state. Furthermore, the developing unit U3 may also have a drive mechanism (not shown) that reciprocates the nozzles 34 in the horizontal direction.

[0046] Although detailed structural illustrations are omitted, the heat treatment unit U4 has a structure capable of heat-treating the wafer W. For example, the heat treatment unit U4 has an openable and closable chamber forming a processing space for heat treatment, and a hot plate housed within the chamber that supports and heats the wafer W. The chamber is opened and closed according to instructions from the control device 100. The hot plate, for example, has a built-in heater, and its temperature is controlled by the control device 100.

[0047] (Irradiation unit)

[0048] Next, refer to Figure 4 An example of irradiation unit U5 will be explained below. Figure 4 As shown, the irradiation unit U5 has an irradiation section 42 (low molecular weight treatment section).

[0049] The irradiation unit 42 irradiates the surface Wa (reinforcing material) of the wafer W with energy lines. The energy lines can be particle beams such as electron beams or electromagnetic waves. The irradiation unit 42 can irradiate with any energy line as long as it can reduce the number of intermolecular bonds in the reinforcing material. For example, the irradiation unit 42 can also irradiate with energy lines that can reduce the degree of polymerization of polymers contained in the reinforcing material. Specific examples of energy lines include ultraviolet light with wavelengths from 100 nm to 400 nm. The wavelength of the energy line can also be from 170 nm to 180 nm. Furthermore, the wavelength of the energy line is not limited to the above values; for example, the wavelength of the energy line to be used can be selected according to the type of reinforcing material.

[0050] Irradiation unit U5 irradiates ultraviolet light onto the surface Wa of the horizontally supported wafer W from a position above irradiation section 42. For example, irradiation section 42 has a light source that emits ultraviolet light. Specific examples of the light source include a krypton fluoride excimer light source emitting ultraviolet light with a wavelength of 172 nm, an argon fluoride excimer light source emitting ultraviolet light with a wavelength of 193 nm, and a krypton chloride excimer light source emitting ultraviolet light with a wavelength of 222 nm. Irradiation section 42 is configured to emit energy lines emitted from the light source downwards toward the wafer W.

[0051] (Plasma processing device)

[0052] Next, refer to Figure 5An example of the plasma processing apparatus 10 will be described below. The plasma processing apparatus 10 performs plasma processing on the wafer W using a resist pattern as a mask. In other words, the plasma processing apparatus 10 etches a portion of the wafer W by performing a plasma-based etching process on the wafer W. Additionally, the plasma processing apparatus 10 can also perform a plasma-based etching process on the reinforcing material formed in the recesses of the resist pattern. Here, "performing plasma processing" or "performing plasma-based etching" in this specification means exposing the surface Wa of the wafer W to a gas in a plasma state for a predetermined time.

[0053] The plasma processing device 10 is connected to the coating and developing device 2 via the conveying mechanism 19 (see reference). Figure 2 The transport mechanism 19 transports the wafer W between the coating and developing apparatus 2 and the plasma processing apparatus 10. The plasma processing apparatus 10 is, for example, a parallel-plate type apparatus. Figure 5 As shown, the plasma processing apparatus 10 includes a processing unit 60, a power supply unit 80, and an exhaust unit 90. The processing unit 60 includes a processing container 68, an electrostatic chuck 61, a base 63, a support platform 64, and an upper electrode 73.

[0054] The processing container 68 is conductive and is formed in a generally cylindrical shape. A grounding wire 69 is electrically connected to the processing container 68, grounding it. An electrostatic chuck 61 and a base 63 are disposed within the processing container 68, supporting the wafer W to be processed. The electrostatic chuck 61 is a generally circular plate-shaped component, formed, for example, by sandwiching electrodes for the electrostatic chuck between a pair of ceramic pieces. The base 63 functions as a lower electrode and is disposed on the lower surface of the electrostatic chuck 61. The base 63 is formed in a generally circular plate shape, for example, from a metal such as aluminum. A support platform 64 is provided at the bottom of the processing container 68, and the base 63 is supported on the upper surface of this support platform 64. Electrodes (not shown) are disposed inside the electrostatic chuck 61, and the wafer W is held in the electrostatic chuck 61 by the electrostatic force generated by applying a DC voltage to these electrodes. A coolant flow path (not shown) for coolant flow is provided inside the support platform 64, and the temperature of the wafer W held by the electrostatic chuck 61 can be controlled by controlling the temperature of the coolant.

[0055] The power supply unit 80 includes high-frequency power supplies 81 and 83 and matching devices 82 and 84. The high-frequency power supply 81 for generating plasma is electrically connected to the base 63 via the matching device 82. The high-frequency power supply 81 is configured to output high-frequency electrical power at frequencies, for example, 27 MHz to 100 MHz. Furthermore, the internal impedance and load impedance of the high-frequency power supply 81 are matched via the matching device 82.

[0056] A high-frequency power supply 83 is electrically connected to the base 63 via a matching adapter 84 to introduce ions into the wafer W by applying a bias voltage to the wafer W. The high-frequency power supply 83 is configured to output high-frequency electrical power at frequencies, for example, 400 kHz to 13.56 MHz. Like the matching adapter 82, the matching adapter 84 is a component that matches the internal impedance of the high-frequency power supply 83 with the load impedance. The operation of the high-frequency power supplies 81 and 83 and the matching adapters 82 and 84 is controlled by the control device 100.

[0057] An upper electrode 73 is disposed on the upper part of the processing container 68. The upper electrode 73 is positioned opposite to the base 63. The upper electrode 73 is supported on the upper part of the processing container 68 and grounded through the processing container 68. A gas diffusion chamber 76, which is formed in a generally circular plate shape, is formed in the center of the interior of the upper electrode 73. At the lower part of the upper electrode 73, a plurality of gas release holes 77 are formed to supply processing gas to the interior of the processing container 68.

[0058] A gas supply pipe 78 is connected to the gas diffusion chamber 76. In the gas supply pipe 78... Figure 5 A gas supply source 79 is connected, and the gas supply source 79 supplies processing gas to the gas diffusion chamber 76 via a gas supply pipe 78. The processing gas supplied to the gas diffusion chamber 76 is introduced into the processing container 68 through a gas release port 77. The processing gas supplied from the gas supply source 79 may also contain inactive gases. Rare gases (e.g., argon) or nitrogen may also be used as inactive gases.

[0059] An exhaust section 90 is disposed below the processing container 68. The exhaust section 90 has an exhaust port 91, an exhaust chamber 92, an exhaust pipe 93, and an exhaust device 94. The exhaust port 91 is provided on the bottom surface of the processing container 68. An exhaust chamber 92 is formed below the exhaust port 91, and the exhaust device 94 is connected to the exhaust chamber 92 via the exhaust pipe 93. By driving the exhaust device 94 (e.g., an exhaust pump), exhaust can be vented from the processing container 68 through the exhaust port 91, and the pressure inside the processing container 68 can be reduced to a specified vacuum level.

[0060] (Control device)

[0061] Next, the specific structure of the control device 100 will be illustrated. The control device 100 controls the substrate processing system 1 partially or entirely. The control device 100 is configured to perform the following processes: replacing the liquid in the recess 202 of the wafer W on which a raised and recessed pattern is formed with a solid reinforcing material 220a; and performing a low-molecular-weight reduction process on the wafer W, which maintains the reinforcing material 220a in a solid state while reducing the number of intermolecular bonds contained in the reinforcing material 220a. Here, "solid state" in this specification refers to a state in which the main components in the processing liquid L3 or other liquids become non-flowing after the solvent contained in the liquid evaporates.

[0062] like Figure 6 As shown, the control device 100, as a functional structure (hereinafter referred to as a "functional module"), includes a heat treatment control unit 101, a development control unit 102, a low-molecular-weight control unit 103, and an etching control unit 104. The heat treatment control unit 101 controls the heat treatment unit U4. The development control unit 102 controls the valves 33 and the rotary drive unit 21 of the liquid supply units 30a, 30b, and 30c within the development unit U3. The low-molecular-weight control unit 103 controls the irradiation unit 42 within the irradiation unit U5. The etching control unit 104 controls the exhaust device 94 and the high-frequency power supplies 81 and 83 within the plasma processing apparatus 10. The processes performed by the heat treatment control unit 101, the development control unit 102, the low-molecular-weight control unit 103, and the etching control unit 104 are equivalent to the processes performed by the control device 100. Details regarding the processes performed by each functional module will be explained later.

[0063] The control device 100 comprises one or more control computers. For example, the control device 100 has... Figure 7 The circuit 120 shown has one or more processors 121, memory 122, storage 123, and input / output ports 124. Memory 123 has a computer-readable storage medium, such as a hard disk. The storage medium stores a program for causing the control device 100 to execute the substrate processing flow described later. The storage medium can be a retrievable medium such as non-volatile semiconductor memory, a hard disk, or an optical disk. Memory 122 temporarily stores the program loaded from the storage medium of memory 123 and the calculation results of processor 121. Processor 121 and memory 122 cooperate to execute the program, thereby constituting the functional modules described above. Input / output ports 124 input and output electrical signals between themselves and the components controlled, according to instructions from processor 121.

[0064] When the control device 100 is composed of multiple control computers, the heat treatment control unit 101, the development control unit 102, the low molecular weight control unit 103, and the etching control unit 104 can each be implemented by a separate control computer. Alternatively, each of these functional modules can be implemented by a combination of two or more control computers. In these cases, the multiple control computers, in a communicably connected state, cooperate to execute the substrate processing flow described later. Furthermore, the hardware structure of the control device 100 is not necessarily limited to each functional module being composed of a program. For example, each functional module of the control device 100 can also be composed of dedicated logic circuits or ASICs (Application Specific Integrated Circuits) that integrate them.

[0065] [Substrate Processing Flow]

[0066] Next, as an example of a substrate processing method, the substrate processing flow executed in the substrate processing system 1 will be described. The control device 100 controls the substrate processing system 1 according to, for example, the following flow to perform substrate processing including coating and developing. First, the control device 100 controls the transport device A1 to transport the wafer W in the carrier C to the shelf unit U10, and controls the transport device A7 to place the wafer W in the small cell of the processing module 11.

[0067] Next, the control device 100 controls the transport device A3 to transport the wafer W from the shelf unit U10 to the coating unit U1 and the heat treatment unit U2 within the processing module 11. Additionally, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a lower layer film on the surface Wa of the wafer W. Afterward, the control device 100 controls the transport device A3 to return the wafer W with the lower layer film formed to the shelf unit U10, and controls the transport device A7 to place the wafer W in a small compartment for the processing module 12.

[0068] Next, the control device 100 controls the transport device A3 to transport the wafer W from the shelf unit U10 to the coating unit U1 and the heat treatment unit U2 within the processing module 12. Additionally, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a resist film R on the lower layer of the wafer W. Afterward, the control device 100 controls the transport device A3 to return the wafer W to the shelf unit U10 and controls the transport device A7 to place the wafer W in a small compartment in the processing module 13.

[0069] Next, the control device 100 controls the conveying device A3 to convey the wafer W from the shelf unit U10 to the respective units within the processing module 13. Additionally, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form an upper film on the resist film R of the wafer W. Afterward, the control device 100 controls the conveying device A3 to convey the wafer W to the shelf unit U11.

[0070] Next, the control device 100 controls the transport device A8 to deliver the wafer W housed in the shelf unit U11 to the exposure device 3. Then, in the exposure device 3, the resist film R formed on the wafer W is exposed. Afterward, the control device 100 receives the exposed wafer W from the exposure device 3 and controls the transport device A8 to place the wafer W in the small compartment of the processing module 14 in the shelf unit U11.

[0071] Next, the control device 100 controls the transport device A3 to transport the wafer W from the shelf unit U11 to the heat treatment unit U4 of the processing module 14. Then, the control device 100 controls the execution of a series of processing steps including heat treatment and development treatment accompanied by development treatment (hereinafter referred to as the "development process"). Details of this development process will be described later. By executing the development process, a resist pattern is formed on the surface Wa of the wafer W. Afterwards, the control device 100 controls the plasma processing device 10 to perform plasma etching on the wafer W using the resist pattern as a mask. The substrate processing including the coating and development treatment is thus completed.

[0072] (Developing process)

[0073] Next, refer to Figures 8-10 An example of the developing process will be explained. Figure 8 This is a flowchart illustrating an example of the developing process. First, the control device 100 executes step S01. In step S01, the heat treatment control unit 101 controls the heat treatment unit U4 to perform heat treatment on the wafer W, which has undergone exposure treatment, at a predetermined temperature for a predetermined time. Then, the control device 100 controls the transport device A3 to transport the wafer W, which has undergone pre-development heat treatment, to the developing unit U3.

[0074] Next, the control device 100 executes step S02. In step S02, the development control unit 102 controls the development unit U3 to supply developer L1 to the resist film R formed on the surface Wa of the wafer W. For example, the development control unit 102 controls the rotation drive unit 21 to rotate the wafer W at a predetermined speed, while opening the valve 33 of the liquid supply unit 30a to release developer L1 from the nozzle 34. As a result, the development process of the resist film R is performed, and a resist pattern 200 having multiple protrusions 201 and multiple recesses 202 is formed on the surface Wa of the wafer W (see reference). Figure 9 (a) In this context, the portion of the resist film R that is not removed (e.g., the portion that is not exposed to light during the exposure process) becomes a protrusion 201, and the portion of the resist film R that is removed (the space between adjacent protrusions 201) becomes a recess 202.

[0075] Next, the control device 100 executes step S03. In step S03, the development control unit 102 controls the development unit U3 to supply rinsing fluid L2 to the surface Wa of the wafer W. For example, while controlling the rotation drive unit 21 to rotate the wafer W at a predetermined speed, the development control unit 102 opens the valve 33 of the liquid supply unit 30b to release rinsing fluid L2 from the nozzle 34. Figure 9 As shown in (a), the developing control unit 102 determines whether the rotation drive unit 21 continues to rotate the wafer W or stops the rotation of the wafer W based on the degree to which a portion of the released rinsing fluid L2 (rinsing fluid 210) remains on the surface Wa of the wafer W. At this time, as... Figure 9 As shown in example (a), each recess 202 can be completely filled with the flushing fluid 210. That is, the height of the flushing fluid 210 (the shortest distance between the upper surface of the flushing fluid 210 and the surface Wa) can be greater than the height of the protrusion 201. Furthermore, the height of the flushing fluid 210 is not limited to... Figure 9 In example (a), at least a portion of the recess 202 is filled with the flushing fluid 210.

[0076] Next, the control device 100 executes step S04. In step S04, the developing control unit 102 controls the developing unit U3 to supply processing liquid L3 to the wafer W on which rinsing liquid 210 remains. Specifically, the developing control unit 102 causes the developing unit U3 to start supplying processing liquid L3 to the surface Wa of the wafer W when rinsing liquid 210 remains in each of the plurality of recesses 202 (for example, when rinsing liquid 210 remains in approximately all of the recesses 202). For example, the developing control unit 102 controls the rotation drive unit 21 to rotate the wafer W at a predetermined speed while opening the valve 33 of the liquid supply unit 30c, causing the developing unit U3 to start releasing processing liquid L3 from the nozzle 34. Afterward, the developing control unit 102 causes the developing unit U3 to continue rotating the wafer W and supplying processing liquid L3 to the surface Wa of the wafer W for a predetermined time. As a result, the rinsing liquid 210 on the surface Wa is squeezed out of the wafer W, and the rinsing liquid 210 is replaced by processing liquid L3. For example, after replacement, the recess 202 can be completely filled with liquid (a portion of the treatment fluid L3). Alternatively, at least a portion of the recess 202 can be filled with the treatment fluid L3.

[0077] Next, the control device 100 executes step S05. In step S05, the development control unit 102 controls the development unit U3 to dry the processing liquid L3 embedded in the recess 202. For example, the development control unit 102 controls the rotation drive unit 21 to rotate the wafer W until the liquid processing liquid L3 becomes solid. Thus, as Figure 9 As shown in (b), a solid reinforcing material 220a is formed within the recess 202. For example, when the processing liquid L3 contains a polymer, by rotating the wafer W to dry it, the solvent contained in the processing liquid L3 evaporates, and a large amount of polymer dispersed in the solvent complexes. As a result, a solid reinforcing material 220a is formed within the recess 202. As described above, the liquid supply section 30c of the developing unit U3 and the rotation holding section 20 constitute a replacement processing section.

[0078] By performing steps S04 and S05, the rinsing fluid 210 within the recess 202 is replaced by solid reinforcing material 220a. At this time, as... Figure 9 As shown in example (b), the reinforcing member 220a can also be formed within the recess 202 in such a way that almost all the space within the recess 202 is filled. As another example, the reinforcing member 220a can also be formed within the recess 202 to a height approximately equal to the height of the protrusion 201. Furthermore, the height of the reinforcing member 220a is not limited to... Figure 9In example (b), at least a portion of the recess 202 may be filled with reinforcing material 220a. Alternatively, reinforcing material 220a may be formed at a height exceeding the height of the protrusion 201 (the depth of the recess 202). After performing step S05, control device 100 controls transport device A3 to transport the wafer W with reinforcing material 220a formed in the recess 202 to irradiation unit U5.

[0079] Next, the control device 100 executes step S06. In step S06, the low-molecular-weight control unit 103 controls the irradiation unit U5 to irradiate the reinforcing material 220a with energy lines. For example, the low-molecular-weight control unit 103 controls the irradiation unit 42 to irradiate the entire surface Wa of the wafer W with energy lines. The type of energy line is determined according to the type of processing liquid L3 (the type of polymer contained in the reinforcing material 220a). By irradiating the reinforcing material 220a with energy lines, the number of intermolecular bonds contained in the reinforcing material 220a is reduced while the reinforcing material 220a remains in a solid state (the reinforcing material 220a does not become liquid). For example, if the reinforcing material 220a contains polymers, the degree of polymerization of the polymers is reduced. As an example, each polymer contained in the reinforcing material 220a may be decomposed into multiple polymers with a degree of polymerization (e.g., tens to hundreds) that is less than the degree of polymerization of the polymer (e.g., thousands to tens of thousands). Furthermore, the polymers contained in the reinforcing material 220a can also be decomposed into multiple monomers with one constituent unit, multiple dimers with two constituent units, or multiple trimers with three constituent units.

[0080] In this way, the depolymerization control unit 103 performs a depolymerization treatment on the wafer W by irradiating the reinforcing material 220a with an energy line, thereby maintaining the reinforcing material 220a in a solid state while reducing the number of intermolecular bonds (e.g., the degree of polymerization of the polymer) contained in the reinforcing material 220a. Thus, as... Figure 9 As shown in (c), a reinforcing material 220a (hereinafter referred to as "reinforcing material 220b") that has undergone a low-molecular-weight treatment is formed in the recess 202. When performing the low-molecular-weight treatment, the low-molecular-weight control unit 103 reduces the number of intermolecular bonds contained in the reinforcing material 220a to a degree that the reinforcing material 220b is more easily sublimated than the resist pattern 200 (the protrusion 201).

[0081] Here, "sublimation" as used in this specification refers to the transformation of the reinforcing material 220b from a solid state to a gaseous state without passing through a liquid state. This "sublimation" includes not only a change in state from a solid to a gaseous state (a change from a solid phase to a gaseous phase), but also a change in state from a solid to a gaseous state accompanied by a chemical change. For example, a change in state from a solid to a gaseous state accompanied by a chemical change includes the case where the reinforcing material 220b is etched by performing an etching process using plasma. Here, "ease of sublimation" means the ease of sublimation (e.g., the amount sublimated per unit time) under the environment used to sublimate the reinforcing material 220b. For example, a state where the reinforcing material 220b is more easily sublimated than the resist pattern 200 means that, under the conditions of plasma treatment used to etch the reinforcing material 220b, the reinforcing material 220b is more etched than the resist pattern 200.

[0082] Figure 10 The diagram illustrates the change in the number of bonds (degree of polymerization) within a polymer when the treatment solution L3 contains a polymer containing polymethyl methacrylate. The degree of polymerization of each polymer contained in reinforcing material 220a is represented by "L+M+N+…" (L, M, and N are positive integers). In irradiation unit U5, by irradiating reinforcing material 220a with an energy line, several of the "C-CH2" bonds in the main chain that bind the monomers are broken. As a result, compounds with monomers constituting unit "L" (e.g., polymers with a degree of polymerization of "L"), compounds with monomers constituting unit "M", and compounds with monomers constituting unit "N" are formed in reinforcing material 220b. For example, in the case where multiple polymers with reduced degrees of polymerization are formed by irradiation with an energy line, the substance changes from a stable state to a property that is more easily sublimated due to the reduced degree of polymerization.

[0083] After performing step S06, the control device 100 controls the conveying device A3 to convey the wafer W with the reinforcing material 220b formed thereon to the heat treatment unit U4. Then, the control device 100 executes step S07. In step S07, the heat treatment control unit 101 controls the heat treatment unit U4 to perform heat treatment on the wafer W, which has undergone development treatment by supplying developer L1, at a predetermined temperature for a predetermined time. Then, the control device 100 controls the conveying device A3 to return the heat-treated wafer W to the shelf unit U10, and controls the conveying devices A7 and A1 to return the wafer W to the carrier C. Afterward, the control device 100 controls the conveying mechanism 19 to convey the wafer W in the carrier C to the plasma processing device 10.

[0084] Next, the control device 100 executes step S08. In step S08, the etching control unit 104 controls the plasma processing apparatus 10 to perform plasma etching on the reinforcing material 220b. In step S08, firstly, the wafer W is placed on the electrostatic chuck 61 of the plasma processing apparatus 10 with the surface Wa, where the resist pattern 200 is formed, facing upwards. Then, the etching control unit 104 controls the plasma processing apparatus 10 to supply a plasma-generating processing gas from the gas supply source 79 into the processing container 68. The processing gas can be determined based on, for example, the type of polymer contained in the processing liquid L3. Afterwards, the etching control unit 104 controls the power supply unit 80 to continuously apply high-frequency electrical power to the base 63, which serves as the lower electrode, using high-frequency power supplies 81 and 83. As a result, a high-frequency electric field is formed between the upper electrode 73 and the electrostatic chuck 61.

[0085] A high-frequency electric field is generated within the processing container 68 to produce plasma of the processing gas, and this plasma is used to etch the reinforcing material 220b. At this time, because the reinforcing material 220a is subjected to a low-molecular-weight treatment to form the reinforcing material 220b, the reinforcing material 220b becomes a state that is more easily sublimated than the resist pattern 200. Therefore, the resist pattern 200 (protrusion 201) is not etched, while the reinforcing material 220b is etched. Thus, as... Figure 9 As shown in (d), the reinforcing material 220b within the recess 202 is sublimated and removed. In this way, the plasma processing apparatus 10 is configured as a removal section that sublimates and removes the reinforcing material (reinforcing material 220b) that has undergone low-molecular-weight treatment. Through the above, a series of developing processes are completed.

[0086] Through steps S04 to S08, the rinsing solution 210 is removed from the surface Wa of the wafer W. During this development process, the rinsing solution 210 released onto the surface Wa of the wafer W is temporarily replaced by reinforcing material 220a (220b), which is removed by etching (sublimation), thereby removing the rinsing solution 210 from the surface Wa of the wafer W. Observing the state within the recess 202, it changes from a state containing liquid (rinsing solution 210) to a state containing solid (reinforcing material 220a, 220b), and then changes from a state containing solid to a state containing gas (atmosphere, etc.).

[0087] [Effects of the Implementation Method]

[0088] The substrate processing method of this embodiment described above includes: a step of replacing the liquid in the recess 202 of the wafer W on which a raised and recessed pattern is formed on the surface Wa with a solid reinforcing material 220a; and a step of performing a low molecular weighting process on the wafer W to reduce the number of intermolecular bonds contained in the reinforcing material 220a while maintaining the reinforcing material 220a in a solid state.

[0089] The substrate processing system 1 includes: a replacement processing unit that replaces the liquid in the recess 202 of the wafer W on which a raised and recessed pattern is formed with a solid reinforcing material 220a; and a depolymerization processing unit that performs a depolymerization process on the wafer W that maintains the reinforcing material 220a in a solid state while reducing the number of intermolecular bonds contained in the reinforcing material 220a.

[0090] In this substrate processing method and substrate processing system 1, the liquid within the recess 202 of the raised / lowered pattern is replaced with a solid reinforcing material 220a, and the reinforcing material 220a is subjected to a low-molecular-weight treatment. By low-molecular-weighting the reinforcing material 220a, a wafer W can be formed in which the reinforcing material 220a (reinforcing material 220b) can be removed while retaining the raised / lowered pattern. By removing the reinforcing material 220b, the material is removed from the recess 202, and therefore the rinsing fluid 210 and other liquids are removed from the recess 202.

[0091] When removing liquids such as rinsing fluid 210 from the recesses (drying), a process is performed in which the wafer W is rotated at a predetermined speed to remove the liquid by centrifugal force. In this case, the recesses 202 change from a state containing liquid (rinsing fluid) to a state containing gas (atmosphere). During this changeover, the pattern (protrusion 201) may collapse due to surface tension because liquid may remain in a portion of the recesses 202. In the substrate processing method and substrate processing system 1 of this embodiment, there is no change from a state containing liquid to a state containing gas within the recesses 202, so pattern collapse due to liquid remaining in a portion of the recesses of the raised pattern is less likely to occur. That is, the substrate processing method and substrate processing system 1 are effective in suppressing pattern collapse.

[0092] In the above embodiments, during the de-molecularization process, the number of intermolecular bonds in the reinforcing material 220a is reduced to a level where the reinforcing material 220b is more easily sublimated than the embossed pattern. In this case, a wafer W can be formed in which the reinforcing material 220b can be removed more reliably while retaining the embossed pattern.

[0093] The substrate processing method of the above embodiments further includes a step of sublimating and removing the reinforcing material (reinforcing material 220b) that has undergone low-molecular-weight treatment. Because the reinforcing material 220b has undergone low-molecular-weight treatment, it is more prone to sublimation than the raised pattern. Therefore, the raised pattern can be retained while the reinforcing material 220b is sublimated and removed. In this method, when removing the liquid within the recess 202 (drying it), since the substance within the recess 202 transforms in the order of liquid, solid, and gas, pattern collapse caused by the transition from a state containing liquid to a state containing gas within the recess 202 can be suppressed.

[0094] In the above embodiments, the step of sublimating and removing the reinforcing material 220b includes performing a plasma etching process on the reinforcing material 220b. In this case, since the reinforcing material 220b has undergone a low-molecular-weight treatment, the solid-state reinforcing material 220b can be sublimated by using a plasma etching process while retaining the raised and recessed patterns. The plasma etching process on the reinforcing material 220b is performed by the plasma processing apparatus 10. Therefore, not only can the wafer W be etched using the resist pattern 200 as a mask, but the etching process on the reinforcing material 220b can also make full use of the plasma processing apparatus 10, thus simplifying the structure of the substrate processing system 1.

[0095] In the above embodiment, the step of replacing the liquid in the recess 202 with the reinforcing material 220a includes: replacing the liquid in the recess 202 with the processing liquid L3 by supplying the processing liquid L3 to the surface Wa of the wafer W; and drying the processing liquid L3 to form the reinforcing material 220a in the recess 202. In this case, it is easy to change the state of the recess 202 from a state containing liquid to a state containing solid.

[0096] In the above embodiments, the embossed pattern includes a plurality of recesses 202. The step of supplying the processing liquid L3 to the surface Wa of the wafer W includes starting the supply of the processing liquid L3 to the surface Wa of the wafer W while liquid remains in each of the plurality of recesses 202. In this case, the possibility of liquid remaining in a portion of the plurality of recesses 202 is reduced, and pattern collapse caused by the replacement of liquid (e.g., rinsing liquid 210) from the recesses 202 to the processing liquid L3 can be suppressed.

[0097] In the above embodiments, the reinforcing material 220a (processing liquid L3) comprises a polymer containing at least one of polymethyl methacrylate, polymethacrylic acid, polyvinyl alcohol, UV-curable resin, and polymethyl methacrylate. In this case, the degree of polymerization of the polymer contained in the reinforcing material 220b is lower than that of the polymer contained in the reinforcing material 220a. Since the material becomes more reactive due to the reduced degree of polymerization, the reinforcing material 220a can be reacted (sublimated) and removed without reacting with the embossed pattern.

[0098] The possibility of supplying a processing solution containing easily reactive polymers with low degrees of polymerization has also been considered. However, such a processing solution is unstable, both before and after supply, making its processing difficult. In the above embodiment, by decomposing polymers with high degrees of polymerization (e.g., thousands to tens of thousands) into polymers with low degrees of polymerization (e.g., tens to hundreds), the processing of the processing solution becomes easier during supply. Furthermore, when the processing solution is dried, the polymers with high degrees of polymerization intertwine to form a solid reinforcing material 220a, making it easy to transform the substance within the recess 202 from liquid to solid. In addition, depending on the type of substance contained in the processing solution, forming a thin film on the surface of the protrusion 201 may reduce the roughness of the resist pattern 200.

[0099] The above describes one embodiment, but the present invention is not necessarily limited to the above embodiment, and various modifications can be made without departing from its spirit.

[0100] (Variation Example 1)

[0101] In the depolymerization process, heat energy can be supplied to the wafer W in addition to the applied energy line. The control device 100 can also apply heat energy to the reinforcing material 220a in addition to the irradiation energy line during the process in step S06, thereby performing a depolymerization process on the reinforcing material 220a. For example, the depolymerization control unit 103 can apply heat energy to the reinforcing material 220a by placing the wafer W on the hot plate 43 (described later) in the irradiation unit U5 and heating the wafer W. In this case, the irradiation unit U5 can also have a heating unit 41 (depolymerization processing unit) (see...). Figure 4 ).

[0102] The heating unit 41 heats the reinforcing material 220a formed within the recess 202 of the resist pattern 200. As the reinforcing material 220a heats, the resist pattern 200 (protrusion 201) is also heated. For example, the heating unit 41 includes a heating plate 43 and a lifting mechanism 44. The heating plate 43 supports a horizontally arranged wafer W and is a plate-shaped heating element used to heat the wafer W. For example, the heating plate 43 may have multiple heaters built into it as a heat source. Specific examples of heaters include electric heating wire heaters, etc.

[0103] The lifting mechanism 44 moves the wafer W up and down above the hot plate 43. For example, the lifting mechanism 44 has multiple (e.g., three) lifting pins 45 and a lifting drive 46. The multiple lifting pins 45 protrude upwards through the hot plate 43. The lifting drive 46 moves the multiple lifting pins 45 up and down, causing their front ends to protrude and embed into the upper part of the hot plate 43. Thus, the wafer W can be moved up and down on the hot plate 43.

[0104] Alternatively, the low-molecular-weight control unit 103 can control the heating unit 41 to heat the wafer W using the hot plate 43 when the lifting pin 45 is lowered by the lifting drive unit 46. Alternatively, the low-molecular-weight control unit 103 can control the irradiation unit 42 to irradiate the surface Wa with energy lines when the wafer W is raised by driving the lifting drive unit 46 (approaching the irradiation unit 42). Furthermore, the heating unit 41 and the irradiation unit 42 do not necessarily have to be configured as a single unit; they can also be configured as independent units.

[0105] (Variation Example 2)

[0106] In the depolymerization process, heat energy can be supplied to the wafer W instead of energy lines. The control device 100 (depolymerization control unit 103) can also supply heat energy to the wafer W instead of energy line irradiation, thereby performing depolymerization treatment on the reinforcing material 220a. In this case, the irradiation unit 42 can be omitted from the irradiation unit U5. Alternatively, the control device 100 can also supply heat energy to the reinforcing material 220a in the heat treatment unit U4 instead of the aforementioned irradiation unit U5, thereby performing depolymerization treatment. Furthermore, the control device 100 controls the heat treatment unit U4 so that the heat treatment after development and the depolymerization treatment are performed in parallel.

[0107] When heat is supplied to the reinforcing material 220a containing a polymer of polymethyl methacrylate, similar to the case of irradiation, a portion of the "C-CH2" bonds are broken, thereby reducing the number of intermolecular bonds (see reference). Figure 10 In this way, by supplying heat energy, multiple compounds are formed with a reduced number of intermolecular bonds, and the substance changes from a stable state to a state where it is more easily sublimated.

[0108] In the above-described modifications 1, 2, and embodiments, the raised / recessed pattern is a resist pattern 200 formed by developing an exposed resist film R. The low-molecular-weight treatment includes supplying at least one of heat energy and energy lines to the resist pattern 200 and the reinforcing material 220a. In this case, when rinsing the developing solution L1 with the rinsing solution L2, pattern collapse caused by the removal of the rinsing solution L2 can be suppressed.

[0109] (Variation Example 3)

[0110] To sublimate the reinforcing material, plasma etching can be used instead, or the wafer W can be placed in a depressurized space. In step S08, the control device 100 can also sublimate (evaporate) the reinforcing material 220b by placing the wafer W with the forming reinforcing material 220b within the processing container 68 of the plasma processing apparatus 10, instead of using plasma etching. That is, the control device 100 can also perform a process to sublimate the reinforcing material 220b by placing the wafer W in a depressurized space. Alternatively, the control device 100 can sublimate a portion of the reinforcing material 220b by placing the wafer W within the depressurized space (processing container 68) of the plasma processing apparatus 10, and then sublimate the remaining portion of the reinforcing material 220b by using plasma etching. In these cases, not only can the plasma processing apparatus 10 be fully utilized in etching the wafer W using the resist pattern 200 as a mask, but also in etching the reinforcing material 220b, thus simplifying the structure of the substrate processing system 1.

[0111] The substrate processing system 1 can also replace the plasma processing device 10 and have a decompression unit (removal section) capable of forming a decompressed space (essentially a vacuum space), which can also be used to remove the reinforcing material 220b. This decompression unit can also be installed within the coating and developing apparatus 2. In this case, the entire development process described above can be performed in the coating and developing apparatus 2. When the reinforcing material 220b is sublimated in the decompression space, the control device 100 reduces the number of intermolecular bonds (e.g., the degree of polymerization of the polymer) in the low-molecular-weight treatment of step S06, so that when the wafer W is placed in the decompression space after the low-molecular-weight treatment, the reinforcing material 220b becomes more easily sublimated than the resist pattern 200.

[0112] In the substrate processing method of Modification Example 3, the step of sublimating and removing the reinforcing material 220b includes sublimating the reinforcing material 220b by placing the wafer W in a depressurized space. Since the reinforcing material 220b has undergone a low-molecular-weight treatment, by placing the wafer W in a depressurized space, the solid reinforcing material 220b can be preserved while retaining the raised and recessed patterns, without evaporating in a liquid state.

[0113] (Variation Example 4)

[0114] Alternatively, a resist film R containing a crosslinking agent that promotes crosslinking during irradiation or heating with energy lines in the low molecular weight reduction process can be used. In this case, in step S06, when the entire surface Wa of the wafer W is irradiated with energy lines or when the entire wafer W is heated, the reinforcing material 220a is subjected to a low molecular weight reduction process, and a crosslinking reaction is promoted within the protrusion 201 formed from the resist film R, which is then cured.

[0115] In the substrate processing method of this modified example 4, the resist pattern 200 contains a crosslinking agent that promotes crosslinking, supplied with at least one of the heat energy and energy lines used in the low molecular weight reduction process. In this case, the protrusion 201 is cured along with the supply of energy lines or heat energy for performing the low molecular weight reduction process. Therefore, the selectivity ratio (contrast) between the reinforcing material 220b and the resist pattern 200 is improved, making it easier to remove the reinforcing material 220b within the recess 202 while retaining the resist pattern 200. In addition, the energy supplied for the low molecular weight reduction process can also be effectively used for the curing of the protrusion 201.

[0116] (Variation Example 5)

[0117] When using a negative resist pattern, a low-molecular-weight reduction process can be performed to improve the etch resistance of the resist pattern, in addition to reducing the number of intermolecular bonds within the reinforcing material. This "etch resistance" refers to the degree to which the resist pattern 200 (protrusion 201) is difficult to wear and etch. By improving etch resistance during the low-molecular-weight reduction process, the progress of wear and etch of the protrusion 201 can be suppressed (e.g., the amount etched is reduced) during the etching process following the low-molecular-weight reduction process, compared to the case where this low-molecular-weight reduction process is not performed. Examples of the above-described etching process following the low-molecular-weight reduction process include etching processes for sublimating the reinforcing material and etching processes for wafers W using the resist pattern 200 as a mask. Furthermore, it is believed that even if the developer, which is an organic solvent, penetrates into the surface portion of the resist pattern 200 and softens it during the development process, the softened portion of the surface layer is solidified due to the energy supplied during the low-molecular-weight reduction process.

[0118] The following is for reference Figure 11(a)~ Figure 13 This section describes in detail one example of the substrate processing flow of Modified Example 5. In the substrate processing flow of Modified Example 5, the control device 100 controls the coating and developing device 2 to perform the same process as described above, including the developing process (see [reference]). Figure 8 The substrate is processed in the same way.

[0119] exist Figure 11 (a) illustrates the exposure process. In this exposure process, energy lines are irradiated (exposed) from an exposure light source 221 onto the resist film R on the surface Wa of the wafer W. During the exposure process, a mask 222 is positioned between the light source 221 and the wafer W to block the irradiation of the energy lines. The mask 222 has openings 222a corresponding to predetermined portions of the resist film R to be removed. In this case, energy lines are irradiated into the region Ra directly below the opening 222a in the resist film R (the region overlapping the opening 222a when the surface Wa is viewed from a direction orthogonal to the surface Wa). Additionally, due to light diffusion or dimensional errors in the mask 222, a small amount of energy lines are also irradiated into the region Rb surrounding region Ra. In this case, region Rb receives an amount of energy lines sufficient to prevent removal during the development process.

[0120] After the exposure process, the control device 100, similar to step S02 described above, controls the developing unit U3 to supply the developing solution L1 to the exposed resist film R. By supplying the developing solution L1 to the resist film R, the areas Ra (areas that are sufficiently exposed) that were irradiated by the energy lines used for exposure during the exposure process are removed. Thus, similar to the development process described above, a resist pattern 200A having multiple protrusions 201A and multiple recesses 202A is formed on the surface Wa. Areas Rb that were irradiated by the energy lines used for exposure but whose irradiation was insufficient are not removed by the developing solution L1 and are retained, forming the surface (including the surface portion) of the protrusions 201A. For example, as... Figure 11 As shown in (b), region Rb forms a side surface and a portion of the upper surface connected to the side surface in the protrusion 201A.

[0121] After the resist pattern 200A is formed, the control device 100, similar to steps S03 and S04 above, sequentially supplies the rinsing solution L2 and the processing solution L3 to the surface Wa of the wafer W. Figure 12As shown in (a), when the developer L1 in the recess 202A is replaced by the rinsing liquid L2 by supplying rinsing liquid L2, the height of the rinsing liquid L2 on the surface Wa can be greater than the height of the protrusion 201A. That is, the distance between the upper surface of the rinsing liquid L2 and the surface Wa can also be greater than the distance between the upper surface of the protrusion 201A and the wafer W. In addition, when the rinsing liquid L2 in the recess 202A is replaced by the processing liquid L3 by supplying processing liquid L3, the height of the processing liquid L3 on the surface Wa can also be greater than the height of the protrusion 201A before the processing liquid L3 becomes solid. By making the height of the rinsing liquid L2 or the processing liquid L3 greater than the height of the protrusion 201A, the entire space of each recess 202A in the entire surface Wa of the wafer W is filled with liquid. Therefore, pattern collapse caused by uneven filling of liquid between adjacent recesses 202A (difference in surface tension) can be suppressed.

[0122] After the recess 202A is replaced with the processing liquid L3, the control device 100, similar to step S05, controls the developing unit U3 to form a reinforcing material 220a within the recess 202A. At this time, the height of the reinforcing material 220a formed within the recess 202A can also be higher than that of the protrusion 201A. The height position of the upper surface of the reinforcing material 220a (the height position of the upper surface of the processing liquid L3 before the formation of the reinforcing material 220a) can also be set to a level where the energy line to be irradiated in the next process can reach the protrusion 201A.

[0123] After the reinforcing material 220a is formed in the recess 202A, the control device 100 can, in the same manner as in step S06, control the irradiation unit U5 to supply energy lines to the resist pattern 200 (protrusion 201A) and the reinforcing material 220a. By supplying this energy line, the number of intermolecular bonds contained in the reinforcing material 220a can be reduced, and the etching resistance of the region Rb on the surface including the resist pattern 200A (protrusion 201A) can be improved.

[0124] Figure 12 The irradiation section 42 shown in (b) is configured to irradiate both the region Rb of the protrusion 201A and the reinforcing material 220a with energy lines. The type of energy line irradiated from the irradiation section 42 is preset to reduce the number of intermolecular bonds in the reinforcing material 220a and to improve the etching resistance of the region Rb. For example, the type of energy line irradiated from the irradiation section 42 is set so that a chemical reaction different from the chemical reaction caused by irradiation with the exposure energy line can occur in the resist film R (protrusion 201A). By supplying energy lines to the reinforcing material 220a, a reinforcing material (reinforcing material 220b) that has undergone low-molecular-weight treatment is formed; by supplying energy lines to the region Rb, the etching resistance of the region Rb is improved. Alternatively, Figure 12The irradiation section 42 shown in (b) also irradiates energy lines in a direction that is inclined relative to the direction orthogonal to the surface Wa, so that the energy lines irradiated from the light source also reach the lower part of the side surface (the part constituting the side surface in region Rb) of the protrusion 201A.

[0125] Alternatively, the control device 100 can control the irradiation unit U5, etc., to replace the irradiation of the energy line, or on this basis, supply heat energy to the reinforcing material 220a and the resist pattern 200A (protrusion 201A) formed in the recess 202A. It is also possible to reduce the number of intermolecular bonds in the reinforcing material 220a and improve the etching resistance of the region Rb by supplying this heat energy.

[0126] After the reinforcing material 220b is formed in the recess 202A, the control device 100, similar to step S08, controls the plasma processing device 10, etc., to remove the reinforcing material 220b. Thus, as... Figure 13 As shown, a resist pattern 200A is formed on the surface Wa in a state where liquid and solid have been removed from the recess 202A. Because the etching resistance of region Rb is improved, the progress of wear and erosion in region Rb can be suppressed during the processing of this step S08, or during the etching process of the wafer W after the development process.

[0127] In the substrate processing method of the above-described modified example 5, the developing process includes the step of forming a resist pattern 200A by removing the region Ra in the resist film R that was exposed during the exposure process. In this substrate processing method, the number of intermolecular bonds in the reinforcing material 220a is reduced during the low-molecularization process, and the etching resistance of the region Rb on the surface containing the resist pattern 200A is improved. During the etching process, the portion of the protrusion that has been slightly irradiated by the energy lines used for exposure may wear or erode, potentially reducing the etching accuracy using the resist pattern. In this regard, in the above method, since the etching resistance of region Rb is improved, the reduction in etching accuracy caused by swelling of the slightly exposed portion of the protrusion 201A can be prevented.

[0128] (Variation Example 6)

[0129] A resist pattern containing a material that undergoes a dehydration condensation reaction upon supplying energy lines or heat can also be used. This resist pattern containing a material undergoing a dehydration condensation reaction (hereinafter referred to as "resist pattern 200B") may also contain a metal to improve etching resistance. Alternatively, regarding resist pattern 200B, the result of the development process used to form this pattern is that it has properties more susceptible to moisture influence compared to the ambient temperature of the wafer W. Resist pattern 200B may also be negative, similar to resist pattern 200A in Variation 5.

[0130] exist Figure 14 The diagram shows a surface Wa in which a resist pattern 200B comprising multiple protrusions 201B and multiple recesses 202B is formed, and then a reinforcing member 220a is formed in the recesses 202B. The height of the reinforcing member 220a formed in the recesses 202B can be the same as the height of the protrusions 201B, or it can be exposed on the upper surface of the protrusions 201B. The control device 100 controls the irradiation unit U5, including the irradiation section 42, to irradiate the resist pattern 200B (protrusions 201B) and the reinforcing member 220a with energy lines. Since the upper surface of the protrusions 201B is exposed, irradiation of the energy lines to the protrusions 201B becomes easier.

[0131] Alternatively, the control device 100 can control the irradiation unit U5, etc., to supply heat energy to the resist pattern 200B (protrusion 201B) and the reinforcing material 220a instead of the energy line. By supplying energy lines or heat energy to the resist pattern 200B (protrusion 201B), cross-linking based on dehydration condensation is promoted within the resist pattern 200B (protrusion 201B), resulting in the curing of the protrusion 201B.

[0132] In the substrate processing method of the above-described modified example 6, the resist pattern 200B contains a material that promotes cross-linking based on dehydration condensation by being supplied with at least one of heat energy and energy lines during the low-molecular-weight treatment. In this case, the protrusion 201B cures along with the supply of energy lines or heat energy for performing the low-molecular-weight treatment. Therefore, the selectivity ratio (contrast) between the reinforcing material 220b and the resist pattern 200B is improved, making it easier to remove the reinforcing material 220b within the recess 202B while retaining the resist pattern 200B. Furthermore, the energy supply for the low-molecular-weight treatment can also be effectively utilized during the curing of the protrusion 201B.

[0133] (Other variations)

[0134] When the developing unit U3 replaces the rinsing fluid in the recess 202 with a solid reinforcing material, it may do so without drying the rinsing fluid in the recess 202 (without emptying the recess 202), and instead replace the rinsing fluid with the reinforcing material. For example, the developing unit U3 may also supply a polymer-containing powdered substance to the rinsing fluid on the surface Wa, and remove the rinsing fluid after the solids have precipitated. Alternatively, the developing unit U3 may dissolve the polymer-containing powdered substance in the rinsing fluid on the surface Wa, and then dry the rinsing fluid containing the dissolved substance, thereby solidifying the rinsing fluid.

[0135] The heights of the reinforcing materials 220a and 220b formed within the recess 202 can be the same as or lower than the resist pattern 200 (protrusion 201). Alternatively, the heights of the reinforcing materials 220a and 220b can be higher than the protrusion 201. In this case, the reinforcing materials 220a (220b) within the recess 202 can be interconnected by a film-like reinforcing material located above the protrusion 201. The reinforcing materials 220a and 220b only need to fill at least a portion of the recess 202.

[0136] The substrate processing system 1 can have any structure as long as it includes a replacement processing unit that replaces the liquid in the recess 202 with a solid reinforcing material, a low-molecular-weight treatment unit that performs low-molecular-weight treatment on the reinforcing material, and a control device that can control them. In the substrate processing system 1, the plasma processing device 10 can also be provided in the coating and developing device 2.

[0137] The substrate being processed is not limited to semiconductor wafers; it can be, for example, a glass substrate, a mask substrate, or an FPD (Flat Panel Display).

[0138] Explanation of reference numerals in the attached figures

[0139] 1……Substrate processing system, 2……Coating and developing apparatus, U3……Developing unit, U5……Irradiation unit, 10……Plasma processing apparatus, 200, 200A, 200B……Resist pattern, 201, 201A, 201B……Raised portion, 202, 202A, 202B……Recessed portion, 220a, 220b……Reinforcing material, W……Wa wafer, Wa……Surface.

Claims

1. A substrate processing method, characterized in that, include: The step of replacing the liquid in the recess of the embossed pattern on the surface of a substrate with a solid state of reinforcing material, wherein the embossed pattern is an embossed pattern containing a metal resist. The step of performing a low-molecularization treatment on the substrate, wherein the low-molecularization treatment maintains the reinforcing material in a solid state while reducing the number of intermolecular bonds contained in the reinforcing material; Following the step of performing the low-molecular-weight treatment, the substrate containing the reinforcing material maintained in a solid state is conveyed to the removal section; and After the substrate is transported to the removal section, the reinforcing material that has undergone the low-molecular-weight treatment is removed by sublimation using the removal section. The depolymerization treatment supplies at least one of heat energy and energy lines to the embossed pattern and the reinforcing material, thereby reducing the number of intermolecular bonds in the reinforcing material and improving the etching resistance of the region including the surface of the convex portion of the embossed pattern.

2. The substrate processing method as described in claim 1, characterized in that: During the aforementioned low molecular weighting treatment, the number of intermolecular bonds in the reinforcing material is reduced to a level where the reinforcing material is more easily sublimated than the embossed pattern.

3. The substrate processing method as described in claim 1, characterized in that: The step of sublimating and removing the reinforcing material includes sublimating the reinforcing material by placing the substrate in a depressurized space.

4. The substrate processing method as described in claim 3, characterized in that: The step of sublimating and removing the reinforcing material includes performing an etching process on the reinforcing material using plasma.

5. The substrate processing method according to any one of claims 1 to 4, characterized in that: The steps for replacing with reinforcing material include: The steps of replacing the liquid in the recess with a treatment liquid by supplying a treatment liquid to the surface of the substrate; and The step of drying the treatment solution to form the reinforcing material in the recess.

6. The substrate processing method as described in claim 5, characterized in that: The embossed pattern includes a plurality of the recesses. The step of supplying the processing liquid to the surface of the substrate includes starting the supply of the processing liquid to the surface of the substrate while liquid remains in each of the plurality of recesses.

7. The substrate processing method according to any one of claims 1 to 4, characterized in that: The raised or recessed pattern is a resist pattern formed by developing an exposed resist film.

8. The substrate processing method as described in claim 7, characterized in that: It also includes the step of causing a dehydration condensation reaction of the resist pattern by supplying at least one of thermal energy and energy lines.

9. The substrate processing method as described in claim 7, characterized in that: The developing process includes the step of forming the resist pattern by removing the areas of the resist film that were exposed during the exposure process.

10. The substrate processing method according to any one of claims 1 to 4, characterized in that: The reinforcing material comprises a polymer containing at least one of polymethyl acrylate, polymethacrylate, polyvinyl alcohol, and polymethyl methacrylate.

11. A substrate processing apparatus, characterized in that, include: The liquid supply unit supplies developing solution to the resist film on the surface of the substrate to form a raised pattern of metal-containing resist on the surface of the substrate. and The replacement processing unit replaces the liquid in the recesses of the embossed pattern with a solid reinforcing material; The low-molecular-weight treatment section performs a low-molecular-weight treatment on the substrate, wherein the low-molecular-weight treatment maintains the reinforcing material in a solid state while reducing the number of intermolecular bonds in the reinforcing material; and The removal section, after performing the low-molecular-weight treatment using the low-molecular-weight treatment section, removes the reinforcing material that has undergone the low-molecular-weight treatment by sublimation. The replacement processing unit performs the following process: replacing the liquid in the recess with a processing liquid by supplying a processing liquid to the surface of the substrate; The process of drying the treatment solution to form the reinforcing material within the recess. In the low molecular weight reduction process, the low molecular weight reduction unit supplies at least one of heat energy and energy lines to the embossed pattern and the reinforcing material, so as to reduce the number of intermolecular bonds contained in the reinforcing material and improve the etching resistance of the area including the surface of the convex portion of the embossed pattern.

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