Substrate processing method and substrate processing apparatus

Abstract

To peel a resist film at a lower temperature.SOLUTION: A substrate processing method includes the steps of: forming a liquid film of a process liquid containing sulfuric acid on an upper surface of a substrate; generating Caro's acid in the liquid film by diffusing an active species generated in association with plasma generation into the liquid film of the process liquid and further cutting a side chain of a base polymer in a resist film on the upper surface of the substrate by Caro's acid; and removing the resist film from the substrate by heating the resist film containing the base polymer whose side chain is cut to a melting temperature, which is a temperature for melting the resist film.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a substrate processing technology. Substrates to be processed include, for example, semiconductor wafers, glass substrates for liquid crystal displays, substrates for flat panel displays (FPDs) such as organic electroluminescence (EL) displays, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, glass substrates for photomasks, ceramic substrates, substrates for field emission displays (FEDs), and substrates for solar cells. [Background technology]

[0002] Conventionally, techniques for removing a resist film formed on the upper surface of a substrate have been proposed. For example, Patent Document 1 discloses a technique in which a mixed solution of sulfuric acid and hydrogen peroxide is supplied to the upper surface of a substrate, and Caro's acid generated in the mixed solution is used to remove the resist film formed on the upper surface of the substrate.

[0003] On the other hand, as an alternative technology with a smaller environmental impact than the above-mentioned technology, Patent Document 2 discloses a technology for stripping a resist film by generating active species using atmospheric pressure plasma and dissolving the active species into a liquid film covering the upper surface of a substrate. This technology makes it possible to remove the resist film without using hydrogen peroxide water. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-88208 [Patent Document 2] Japanese Patent Publication No. 2020-4561 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the higher the temperature of the liquid film, the easier it is to strip the resist film from within the liquid film. Therefore, even when generating activated species using atmospheric pressure plasma and using these activated species to strip the resist film, a method is used in which the resist film is kept at as high a temperature as possible.

[0006] On the other hand, if a method of maintaining the resist film at a temperature higher than necessary is adopted, there are problems such as accelerated evaporation of the liquid film, resulting in areas where the stripping process does not progress, and heat causing damage to the substrate.

[0007] The technology disclosed in the present specification has been made in consideration of the problems described above, and is a technology for stripping a resist film at a lower temperature. [Means for solving the problem]

[0008] A substrate processing method according to a first aspect of the technology disclosed in the present specification is a substrate processing method for removing a resist film formed on an upper surface of a substrate under atmospheric pressure, the method comprising the steps of: holding the substrate horizontally under atmospheric pressure; forming a liquid film of a treatment liquid containing sulfuric acid on the upper surface of the horizontally held substrate; arranging a plasma generating unit for generating plasma from an electrode above the horizontally held substrate; generating the plasma from the plasma generating unit under atmospheric pressure, diffusing active species generated by the generation of the plasma into the liquid film of the treatment liquid to generate Caro's acid in the liquid film; and further cleaving side chains of a base polymer in the resist film on the upper surface of the substrate with the Caro's acid; and removing the resist film from the substrate by heating the resist film to a melting temperature at which the resist film containing the base polymer whose side chains have been cleaved is melted.

[0009] A substrate processing method according to a second aspect of the technology disclosed in the present specification is related to the substrate processing method according to the first aspect, and the step of cleaving the side chain of the base polymer includes a first temperature-raising process of the electrode accompanying the generation of the plasma, and a second temperature-raising process of the electrode at a temperature higher than that in the first temperature-raising process, wherein in the first temperature-raising process of the electrode, ozone is generated as the active species in the atmosphere between the plasma generating unit and the liquid film of the processing liquid formed on the upper surface of the substrate, and the active species diffuse into the liquid film of the processing liquid, and in the second temperature-raising process of the electrode, the side chain of the base polymer in the resist film is cleaved by Caro's acid generated in the liquid film of the processing liquid by the diffusion of the active species.

[0010] A substrate processing method according to a third aspect of the technology disclosed in the present specification is related to the substrate processing method according to the second aspect, and the first heating process of the electrode is a process of raising the temperature of the electrode to 100°C.

[0011] A substrate processing method that is a fourth aspect of the technology disclosed in the present specification is related to the substrate processing method that is the second or third aspect, and the second heating process of the electrode is a process of raising the temperature of the electrode to the melting temperature of the resist film.

[0012] A substrate processing method that is a fifth aspect of the technology disclosed in the present specification is related to the substrate processing method that is any one of the first to fourth aspects, and the step of removing the resist film from the substrate is a step of removing the resist film from the substrate by heating the resist film to the melting temperature with radiant heat from at least one of the electrode and the plasma.

[0013] A substrate processing method according to a sixth aspect of the technology disclosed in the present specification is related to the substrate processing method according to any one of the first to fifth aspects, wherein the base polymer has a PHS-tBOC structure, and the step of cleaving the side chain of the base polymer is a step of cleaving the side chain between the PHS and the tBOC.

[0014] A substrate processing apparatus that is a seventh aspect of the technology disclosed in the present specification is a substrate processing apparatus for removing a resist film formed on the upper surface of a substrate under atmospheric pressure, and includes: a holding unit that holds the substrate horizontally under atmospheric pressure; a processing liquid nozzle that ejects a processing liquid containing sulfuric acid onto the upper surface of the horizontally held substrate; and a plasma generating unit that is positioned above the horizontally held substrate and generates plasma from an electrode. The plasma generating unit generates the plasma under atmospheric pressure, and active species generated by the generation of the plasma diffuse into a liquid film of the processing liquid on the upper surface of the substrate, thereby generating Caro's acid in the liquid film. The Caro's acid cleaves side chains of a base polymer in the resist film on the upper surface of the substrate, and the resist film containing the base polymer whose side chains have been cleaved is heated to its melting temperature by radiant heat from at least one of the electrode and the plasma. [Effects of the Invention]

[0015] According to at least the first and seventh aspects of the technology disclosed herein, the side chains of the base polymer can be cleaved by Caro's acid generated by the diffusion of active species, which reduces the melting temperature of the resist film, allowing the resist film to be stripped at a lower melting temperature than when the side chains of the base polymer are not cleaved.

[0016] Furthermore, objects, features, aspects, and advantages associated with the technology disclosed herein will become more apparent from the detailed description and accompanying drawings set forth below. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a plan view schematically showing an example of the configuration of a substrate processing system according to an embodiment of the present invention; [Figure 2] 2 is a diagram conceptually illustrating an example of the configuration of a control unit illustrated in FIG. 1. FIG. [Figure 3] 1 is a side view schematically showing an example of the configuration of a substrate processing apparatus according to an embodiment of the present invention. [Figure 4] 10 is a flowchart illustrating an example of an operation of the substrate processing apparatus. [Figure 5] 10A to 10C are diagrams for explaining the operation of the substrate processing apparatus according to the embodiment. [Figure 6] 10A to 10C are diagrams for explaining the operation of the substrate processing apparatus according to the embodiment. [Figure 7] FIG. 1 is a diagram conceptually showing the decomposition process of a KrF resist film. [Figure 8] FIG. 10 is a diagram showing an example of an image of a KrF resist film. [Figure 9] FIG. 1 is a diagram conceptually showing the decomposition process of a KrF resist film. [Figure 10] FIG. 10 is a diagram showing an example of an image of a KrF resist film. [Figure 11] FIG. 1 is a diagram conceptually showing the decomposition process of a KrF resist film. [Figure 12] FIG. 10 is a diagram showing an example of an image of a KrF resist film. [Figure 13] FIG. 1 is a diagram conceptually showing the decomposition process of a KrF resist film. [Figure 14] FIG. 1 is a diagram conceptually showing the decomposition process of a KrF resist film. [Figure 15] FIG. 10 is a diagram showing an example of an image of a KrF resist film. [Figure 16] 1 is a side view schematically showing an example of the configuration of a substrate processing apparatus according to an embodiment of the present invention. [Figure 17] FIG. 2 is a cross-sectional view schematically illustrating an example of the configuration of a portion of a plasma generating unit. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments will be described with reference to the accompanying drawings. In the following embodiments, detailed features will be shown for the purpose of explaining the technology, but these are merely examples and are not necessarily essential features for enabling the embodiments to be implemented.

[0019] The drawings are schematic, and for the sake of convenience, components may be omitted or simplified as appropriate. The relative sizes and positions of components shown in different drawings are not necessarily accurately depicted and may be changed as appropriate. Hatching may also be used in drawings such as plan views that are not cross-sectional views to facilitate understanding of the embodiments.

[0020] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0021] Furthermore, in the description given in this specification, when a certain component is described as "comprising," "including," or "having," unless otherwise specified, this is not an exclusive expression that excludes the presence of other components.

[0022] Furthermore, although ordinal numbers such as "first" or "second" may be used in the descriptions in this specification, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and the contents of the embodiments are not limited to the order that may result from these ordinal numbers.

[0023] Furthermore, in the description given in this specification, expressions such as "positive direction of the ... axis" or "negative direction of the ... axis" refer to the direction along the arrow of the ... axis shown in the figure as the positive direction, and the direction opposite to the arrow of the ... axis shown in the figure as the negative direction.

[0024] Furthermore, in the explanations given in this specification, expressions indicating relative or absolute positional relationships, such as "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," unless otherwise specified, include cases where the positional relationship is strictly indicated, and cases where the angle or distance is displaced within a tolerance or within a range where equivalent functionality is obtained.

[0025] Furthermore, in the explanations given in this specification, expressions indicating an equal state, such as "identical," "equal," "uniform," or "homogeneous," unless otherwise specified, include cases indicating a strictly equal state and cases where there is a difference within a tolerance or within a range where the same level of functionality is obtained.

[0026] Furthermore, in the explanations given in this specification, expressions such as "moving an object in a specific direction" include, unless otherwise specified, moving an object parallel to the specific direction and moving an object in a direction that has a component in the specific direction.

[0027] Furthermore, in the description provided in this specification, terms that indicate specific positions or directions, such as "top," "bottom," "left," "right," "side," "bottom," "front," or "back," may be used, but these terms are used for convenience to facilitate understanding of the contents of the embodiments and have no relation to the positions or directions when the embodiments are actually implemented.

[0028] Furthermore, in the description of the present specification, when "the upper surface of ..." or "the lower surface of ..." is used, it is intended to include not only the upper surface or lower surface of the target component itself, but also a state in which another component is formed on the upper surface or lower surface of the target component. For example, when it is described as "B provided on the upper surface of A," it does not preclude another component "C" from being interposed between A and B.

[0029] First Embodiment The substrate processing apparatus and the substrate processing method according to this embodiment will be described below.

[0030] <Configuration of the substrate processing system> 1 is a plan view schematically illustrating an example of the configuration of a substrate processing system 1 according to the present embodiment. The substrate processing system 1 includes a load port 400, an indexer robot 402, a center robot 406, a control unit 90, and at least one substrate processing apparatus 100 (four substrate processing apparatuses in FIG. 1).

[0031] Each substrate processing apparatus 100 is for processing a substrate W (wafer), and at least one of them corresponds to a substrate processing apparatus using a plasma generation apparatus. The substrate processing apparatus is a single-wafer processing apparatus that can be used for substrate processing, and specifically, is an apparatus that performs a process of removing organic matter adhering to the substrate W or performs metal etching on the substrate W. The organic matter adhering to the substrate W is, for example, a used resist film. The resist film is, for example, one that has been used as an implantation mask for an ion implantation process.

[0032] Here, substrates to be processed include, for example, semiconductor wafers, glass substrates for liquid crystal display devices, substrates for flat panel displays (FPDs) such as organic electroluminescence (EL) display devices, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, glass substrates for photomasks, ceramic substrates, substrates for field emission displays (i.e., FEDs), and substrates for solar cells.

[0033] The substrate processing apparatus 100 may include a chamber 80. In this case, the atmosphere in the chamber 80 may be controlled by a control unit 90, allowing the substrate processing apparatus 100 to perform processing in a desired atmosphere.

[0034] The control unit 90 can control the operation of each component in the substrate processing system 1 (such as the spin motor 10D of the spin chuck 10, the processing liquid supply source 29, the valve 25, the gas supply source 70, or the AC power supply 40, which will be described later). The carrier C is a container that stores substrates W. The load port 400 is a container holding mechanism that holds multiple carriers C. The indexer robot 402 can transport substrates W between the load port 400 and the substrate platform 404. The center robot 406 can transport substrates W between the substrate platform 404 and the substrate processing apparatus 100.

[0035] The indexer robot 402 , the substrate placement unit 404 , and the center robot 406 transport the substrates W between the respective substrate processing apparatuses 100 and the load port 400 .

[0036] The unprocessed substrate W is taken out of the carrier C by the indexer robot 402. Then, the unprocessed substrate W is transferred to the center robot 406 via the substrate placement part 404.

[0037] The center robot 406 carries the unprocessed substrate W into the substrate processing apparatus 100. Then, the substrate processing apparatus 100 processes the substrate W.

[0038] The substrate W that has been processed in the substrate processing apparatus 100 is removed from the substrate processing apparatus 100 by the center robot 406. Then, the processed substrate W passes through another substrate processing apparatus 100 as necessary, and is then transferred to the indexer robot 402 via the substrate placement unit 404. The indexer robot 402 loads the processed substrate W into the carrier C. In this manner, the substrate W is processed.

[0039] Fig. 2 is a diagram conceptually illustrating an example of the configuration of the control unit 90 shown in Fig. 1. The control unit 90 may be configured by a general computer having electric circuits. Specifically, the control unit 90 includes a central processing unit (CPU) 91, a read-only memory (ROM) 92, a random access memory (RAM) 93, a storage device 94, an input unit 96, a display unit 97, and a communication unit 98, as well as a bus line 95 interconnecting these units.

[0040] The ROM 92 stores a basic program. The RAM 93 is used as a work area when the CPU 91 performs predetermined processing. The storage device 94 is composed of a non-volatile storage device such as a flash memory or a hard disk drive. The input unit 96 is composed of various switches or a touch panel, and receives input setting instructions such as processing recipes from an operator. The display unit 97 is composed of, for example, a liquid crystal display device and lamps, and displays various information under the control of the CPU 91. The communication unit 98 has a data communication function via a local area network (LAN), etc.

[0041] The storage device 94 has preset therein a plurality of modes for controlling each component in the substrate processing system 1 of FIG. 1. When the CPU 91 executes the processing program 94P, one of the above-described modes is selected, and each component is controlled in that mode. The processing program 94P may be stored in a recording medium. By using this recording medium, the processing program 94P can be installed in the control unit 90. Furthermore, some or all of the functions executed by the control unit 90 do not necessarily have to be realized by software, but may be realized by hardware such as a dedicated logic circuit.

[0042] FIG. 3 is a side view schematically showing an example of the configuration of the substrate processing apparatus 100 according to the present embodiment.

[0043] 3 may be surrounded by the chamber 80 in FIG. 1. The pressure inside the chamber 80 is approximately atmospheric pressure (for example, 0.5 atmospheres or more and 2 atmospheres or less). In other words, the plasma processing described below is atmospheric pressure plasma processing performed at atmospheric pressure.

[0044] The substrate processing apparatus 100 includes a spin chuck 10 that holds a single substrate W in a horizontal position under atmospheric pressure and rotates the substrate W about a vertical rotation axis Z1 passing through the center of the substrate W, a cylindrical processing cup 12 that surrounds the spin chuck 10 about the rotation axis Z1 of the substrate W, a processing liquid nozzle 20 that discharges a processing liquid onto the upper surface of the substrate W, a processing liquid supply source 29 that supplies the processing liquid to the processing liquid nozzle 20, a valve 25 that switches on and off the supply of the processing liquid from the processing liquid supply source 29 to the processing liquid nozzle 20, and a plasma generator 55. The plasma generator 55 is disposed above the substrate W to cover the entire substrate W and includes a plasma generator 30 as an atmospheric pressure plasma source that generates plasma under atmospheric pressure, an AC power supply 40 that applies an AC voltage to the plasma generator 30, and a support 60 that supports the plasma generator 30.

[0045] Here, various liquids can be used as the processing liquid depending on the purpose of substrate processing in the substrate processing apparatus 100. For example, as an etching liquid, a liquid containing hydrochloric acid, hydrofluoric acid, phosphoric acid, nitric acid, sulfuric acid, sulfate, peroxosulfuric acid, peroxosulfate, hydrogen peroxide, tetramethylammonium hydroxide, or a mixed solution (SC1) of ammonia and hydrogen peroxide can be used. As a cleaning liquid, a liquid containing a mixed solution (SC1) of ammonia and hydrogen peroxide, or a mixed aqueous solution (SC2) of hydrochloric acid and hydrogen peroxide can be used. As a cleaning liquid and a rinsing liquid, deionized water (DIW) can be used.

[0046] This embodiment mainly describes a process for removing a resist film formed on the upper surface of a substrate W. In this case, the processing liquid is assumed to be a liquid containing at least one of sulfuric acid, sulfate, peroxosulfuric acid, and peroxosulfate, or a liquid containing hydrogen peroxide.

[0047] When multiple types of processing liquids are expected, multiple processing liquid nozzles 20 may be provided corresponding to the respective processing liquids. The processing liquid nozzles 20 supply the processing liquid to the substrate W so that a liquid film of the processing liquid is formed on the upper surface of the substrate W.

[0048] The processing liquid nozzle 20 is movable by an arm mechanism (not shown). Specifically, the processing liquid nozzle 20 is attached to an arm member whose angle can be adjusted by an actuator or the like, so that the processing liquid nozzle 20 can swing, for example, in the radial direction of the substrate W.

[0049] The spin chuck 10 includes a disk-shaped spin base 10A that vacuum-sucks the underside of a horizontally oriented substrate W, a rotation shaft 10C that extends downward from the center of the spin base 10A, and a spin motor 10D that rotates the rotation shaft 10C to rotate the substrate W held by the spin base 10A. Note that instead of the spin chuck 10, a clamping chuck may be used that includes multiple chuck pins that protrude upward from the outer periphery of the upper surface of the spin base and that clamp the peripheral edge of the substrate W with the chuck pins. Here, the term "horizontal orientation" does not necessarily mean strictly horizontal, but also includes orientations at some angle from horizontal.

[0050] The plasma generating unit 30 comprises a plate-shaped dielectric member 30A made of a dielectric material such as quartz, a plurality of electrode rods 30B arranged in a comb shape on the upper surface of the dielectric member 30A, a plurality of electrode rods 30C arranged in a comb shape on the lower surface of the dielectric member 30A, a holding unit 30D made of a resin (e.g., polytetrafluoroethylene (PTFE)) or ceramics, etc., and holding the plurality of electrode rods 30B and the plurality of electrode rods 30C at one end, a dielectric tube 30E made of a dielectric material such as quartz and covering each of the electrode rods 30B, a dielectric tube 30F made of a dielectric material such as quartz and covering each of the electrode rods 30C, a collective electrode 30G made of aluminum or the like and connected in common to the plurality of electrode rods 30B, and a collective electrode 30H made of aluminum or the like and connected in common to the plurality of electrode rods 30C. The collection electrodes 30G and 30H are arranged, for example, so that they together form a circle in a plan view, and a plurality of electrode bars 30B and a plurality of electrode bars 30C are housed within the circle.

[0051] The electrode rods 30B and 30C are rod-shaped and made of, for example, tungsten. However, the shapes of the electrode rods 30B and 30C are not limited to rod shapes. Furthermore, the plurality of electrode rods 30B and the plurality of electrode rods 30C are arranged alternately so as not to overlap in a planar view. In other words, the electrode rods 30B and the electrode rods 30C are arranged alternately in a planar view.

[0052] The dielectric tubes 30E covering the respective electrode rods 30B are held by the holding portions 30D at the ends of the electrode rods 30B that are not held by the holding portions 30D. The dielectric tubes 30F covering the respective electrode rods 30C are held by the holding portions 30D at the ends of the electrode rods 30C that are not held by the holding portions 30D.

[0053] As a result, one end of electrode rod 30B is held directly by holding portion 30D, and the other end is held by holding portion 30D via dielectric tube 30E. Similarly, one end of electrode rod 30C is held directly by holding portion 30D, and the other end is held by holding portion 30D via dielectric tube 30F.

[0054] When an AC voltage is applied between the collection electrode 30G and the collection electrode 30H by the AC power supply 40, an AC voltage is applied between each electrode rod 30B connected to the collection electrode 30G and each electrode rod 30C connected to the collection electrode 30H. As a result, a dielectric barrier discharge occurs between the electrode rod 30B and the electrode rod 30C. Then, gas is converted into plasma around the discharge path of the discharge, and a plasma space is formed that spreads two-dimensionally along the surface of the dielectric member 30A separating the electrode rod 30B from the electrode rod 30C.

[0055] When the plasma space is formed, a gas such as O2 (oxygen), Ne, CO2, air, an inert gas, or a combination thereof may be supplied to the space below the plasma generating unit 30 (i.e., the space above the substrate W). The inert gas may be, for example, N2 or a rare gas. The rare gas may be, for example, He or Ar.

[0056] The support part 60 is movable in the Z-axis direction in Fig. 3 by a drive mechanism (not shown) while supporting the plasma generation part 30. The support part 60 is made of resin (for example, PTFE), ceramics, or the like.

[0057] In FIG. 3, the processing liquid nozzle 20 and the plasma generating unit 30 are provided separately, but the processing liquid nozzle 20 may be provided integrally with the plasma generating unit 30, and both may be supported by the support unit 60.

[0058] <Operation of the substrate processing apparatus> Next, the operation of the substrate processing apparatus will be described. The substrate processing method by the substrate processing apparatus according to this embodiment includes the steps of: performing chemical processing on the substrate W transported to the substrate processing apparatus 100; cleaning the substrate W after the chemical processing; drying the substrate W after the cleaning processing; and unloading the substrate W after the drying processing from the substrate processing apparatus 100.

[0059] Hereinafter, the process of removing organic matter (e.g., a used resist film) adhering to the substrate W during or after chemical liquid processing, which is included in the operation of the substrate processing apparatus, will be described with reference to FIGS. 4, 5 and 6 (i.e., a process belonging to the process of performing chemical liquid processing or the process of performing cleaning processing among the above processes). Here, FIG. 4 is a flowchart showing an example of the operation of the substrate processing apparatus. Also, FIGS. 5 and 6 are diagrams for explaining the operation of the substrate processing apparatus according to this embodiment.

[0060] First, the spin chuck 10 holds the substrate W (step ST01 in FIG. 4). Then, the spin chuck 10 is driven to rotate the substrate W.

[0061] 5, the processing liquid 101 is supplied from the processing liquid supply source 29 to the processing liquid nozzle 20, and the processing liquid 101 is discharged from the processing liquid nozzle 20 onto the upper surface of the substrate W while the substrate W is rotating (step ST02 in FIG. 4). At this time, the position of the processing liquid nozzle 20 on the upper surface of the substrate W is adjusted by a nozzle arm or the like (not shown). Note that, although the present embodiment shows a case where the processing liquid 101 is discharged while the substrate W is rotating, the substrate W does not have to be rotating.

[0062] As the processing liquid 101 is discharged from the processing liquid nozzle 20, a liquid film 101A of the processing liquid 101 is formed on the upper surface of the substrate W (step ST03 in FIG. 4), as shown in an example in FIG. 5. Here, the thickness of the liquid film 101A is, for example, not less than 0.1 mm and not more than 2.0 mm, and preferably about 0.2 mm.

[0063] Meanwhile, when a predetermined AC voltage is applied between the collection electrodes 30G and 30H from the AC power supply 40, plasma is generated on the surface of the dielectric member 30A in the plasma generating unit 30 (step ST04 in FIG. 4). Specifically, a plasma space is formed that spreads two-dimensionally along the surface of the dielectric member 30A. The action of the plasma in the plasma space generates active species in the gas near the space. The active species include charged ions and electrically neutral radicals. For example, if the gas contains O2, the action of the plasma in the plasma generating unit 30 generates oxygen radicals, which are a type of active species.

[0064] Here, the plasma generating unit 30 may wait at a predetermined waiting position (for example, a position sufficiently spaced from the substrate W in the positive Z-axis direction, as shown in FIG. 5) during the plasma generation stage as described above, and may then move to a processing position near the substrate W (for example, a position sufficiently close to the substrate W on the positive Z-axis side of the substrate W, as shown in FIG. 6) after a suitably uniform plasma has been generated on the surface of the dielectric member 30A. In this embodiment, uniform processing can be achieved by applying the plasma to the liquid film 101A on the surface of the substrate W while the uniform plasma is generated. Note that a position sufficiently close to the substrate W is, for example, a position 2 mm away from the substrate W, and at this position, the plasma can be sufficiently applied to the thin liquid film 101A formed on the upper surface of the substrate W.

[0065] Then, as shown in FIG. 6, activated species generated by the action of plasma 102 in plasma generating unit 30 are supplied to liquid film 101A (step ST05 in FIG. 4).

[0066] The active species are supplied to the liquid film 101A, whereby the active species activate the processing liquid 101. As a specific example, the active species act on the sulfuric acid liquid film 101A on the upper surface of the substrate W. This improves the processing performance of the processing liquid 101. Specifically, the reaction between the active species and sulfuric acid produces Caro's acid, which has high processing performance (here, oxidizing power). Caro's acid is also called peroxosulfuric acid. The Caro's acid acts on the resist film on the substrate W, thereby oxidizing and removing the resist film.

[0067] Furthermore, when the active species include oxygen radicals, the removal of the resist film on the substrate W is promoted by the oxidizing power of the oxygen radicals.

[0068] In the above description, the operation of the processing liquid nozzle 20 is followed by the operation of the plasma generating unit 30, but the order of operations is not limited to this, and for example, the operation of the processing liquid nozzle 20 and the operation of the plasma generating unit 30 may be performed almost simultaneously.

[0069] Furthermore, in this embodiment, the plasma generating unit 30 is arranged to cover the entire upper surface of the substrate W, but if the plasma generating unit 30 is arranged to cover only a portion of the substrate W, the position of the plasma generating unit 30 on the upper surface of the substrate W may be moved in the rotational direction and radial direction of the substrate W along the upper surface of the substrate W as the substrate W rotates by a driving mechanism not shown.

[0070] Furthermore, the formation of the liquid film 101A is initiated by starting the supply of the processing liquid 101 onto the upper surface of the substrate W, and is stopped by stopping the supply of the processing liquid 101 onto the upper surface of the substrate W. However, even after the supply of the processing liquid 101 from the processing liquid nozzle 20 is stopped, the liquid film 101A can be maintained as long as the substrate W is not rotating at a high speed (for example, by rotating the substrate W at a low speed to form a puddle of the processing liquid film, or by forming a liquid film of the processing liquid without rotating the substrate W). The supply of active species to the liquid film 101A is performed after the supply of the processing liquid 101 is stopped, while the liquid film 101A is maintained. The supply of active species to the liquid film 101A may be performed after the supply of the processing liquid 101 is started and before the supply of the processing liquid 101 is stopped.

[0071] After the above-described removal process, a rinsing step (cleaning step) and a drying step are usually performed on the substrate W. For example, the rinsing step is performed by discharging deionized water (DIW) onto the substrate W, and the drying step is performed by drying with isopropyl alcohol (IPA). However, a spin-off drying step in which the substrate W is rotated at high speed or an N2 blowing step in which nitrogen gas is discharged onto the upper surface of the substrate may also be performed.

[0072] <Mechanism of Resist Film Decomposition> In this embodiment, the mechanism of resist film decomposition will be described with reference to Fig. 7 to Fig. 15, taking a KrF resist film as an example. Fig. 7, Fig. 9, Fig. 11, Fig. 13, and Fig. 14 are diagrams conceptually showing the decomposition process of a KrF resist film. Fig. 8, Fig. 10, Fig. 12, and Fig. 15 are diagrams showing examples of images of a KrF resist film.

[0073] The KrF resist film is a resist film formed from a copolymer of polyhydroxystyrene (PHS) as a base polymer and tert-butyl methacrylate (tBOC group), PBOCSt (poly(4-tert-butoxycarbonyloxystyrene)).

[0074] As shown in Fig. 7, the KrF resist film 200 formed on the upper surface of the substrate W includes an inner layer and a hardened layer 201 formed on the surface of the inner layer. The hardened layer 201 is formed by incorporating a dopant into the PHS. Fig. 8 is an example of an image of the KrF resist film 200 in the state shown in Fig. 7.

[0075] 4, a liquid film 101A of, for example, sulfuric acid is formed on the upper surface of the substrate W on which the KrF resist film 200 is formed. Furthermore, in step ST05 in FIG. 4, activated species generated by the action of the plasma 102 are supplied to the liquid film 101A.

[0076] At room temperature, activated species (e.g., ozone) generated by the action of plasma 102 hardly diffuse into the sulfuric acid liquid film 101A. However, the temperature of liquid film 101A is increased by radiant heat from at least one of plasma 102 generated near liquid film 101A and plasma generating unit 30 (particularly, electrode rod 30B and electrode rod 30C) generating plasma 102, thereby promoting the diffusion of activated species (e.g., ozone) into liquid film 101A. During this temperature increase process, it is assumed that the temperature of liquid film 101A is increased to 100°C, at which ozone decomposes. However, assuming that the amount of heat from the radiant heat decreases before it reaches liquid film 101A, the temperature of electrode rod 30B, for example, may be increased to a temperature higher than 100°C.

[0077] Caro's acid (ie, strong sulfuric acid oxidizing species) is produced on the surface of the sulfuric acid liquid film 101A by the active species (for example, ozone) diffused into the liquid film 101A.

[0078] Next, when the temperature of the KrF resist film 200 (i.e., the temperature of the liquid film 101A covering the KrF resist film 200) rises to 230°C or higher and 240°C or lower due to radiant heat from at least one of the plasma 102 and the plasma generating unit 30, the tBOC group in the base polymer is eliminated by the action of Caro's acid (i.e., a strong sulfuric acid oxidizing species). That is, the side chain between PHS and tBOC in the base polymer is cleaved. This reaction is shown, for example, as follows: PBOCSt → PHS + tBOC + CH.

[0079] 9, the water-soluble PHS 202 begins to selectively dissolve in Caro's acid (H2SO5) generated in the liquid film 101A by the reaction between the active species and sulfuric acid. At this time, the hardened layer 201 has not yet peeled off. FIG. 10 is an example of an image of the KrF resist film 200 in the state shown in FIG.

[0080] Furthermore, when the temperature of the KrF resist film 200 reaches 240°C or higher and 250°C or lower due to radiant heat from at least one of the plasma 102 and the plasma generating unit 30, the PHS reaches its melting temperature. Therefore, as shown in FIG. 11, the melted PHS 203 is decomposed by Caro's acid (H2SO5) 300. The hardened layer 201 also begins to peel. FIG. 12 is an example of an image of the KrF resist film 200 in the state shown in FIG. 11. Assuming that the amount of heat decreases before the radiant heat reaches the liquid film 101A, the temperature of the electrode rod 30B may be raised to a temperature higher than the melting temperature of the PHS.

[0081] Furthermore, when the temperature of the KrF resist film reaches 250°C or higher due to radiant heat from at least one of the plasma 102 and the plasma generating unit 30, most of the hardened layer 201 peels off, leaving only the portions corresponding to the pattern edges with strong adhesion, as shown in Fig. 13, and the peeling of the KrF resist film is completed as shown in Fig. 14. Fig. 15 is an example of an image of the state shown in Fig. 14.

[0082] The melting temperature of a standard KrF resist film is 320°C. On the other hand, after the side chains of the base polymer (the solubility parameter portion of the resist polymer) are cleaved by the action of Caro's acid (i.e., a strong oxidizing species of sulfuric acid), the melting temperature of the (low-molecular) KrF resist film drops to about 260°C, which is equivalent to that of PHS resin.

[0083] As a result, the PHS starts to dissolve at 230° C. or higher as described above, and further, the hardened layer 201 starts to peel at 240° C. or higher. That is, the peelability of the KrF resist film 200 at low temperatures is improved.

[0084] Generally, the higher the temperature of the liquid film 101A, the more the KrF resist film 200 is peeled off. However, in the absence of the action of Caro's acid (ie, strong oxidizing species of sulfuric acid), it is difficult to peel off the KrF resist film 200 in the above temperature range.

[0085] In this embodiment, both the temperature rise process when diffusing the activated species into the liquid film 101A and the temperature rise process when peeling off the KrF resist film 200 are performed by radiant heat from the plasma 102 and the plasma generating part 30, but if the amount of heat is insufficient, a separate heater or the like may be used to raise the temperature.

[0086] <Second embodiment> 16 is a side view schematically illustrating an exemplary configuration of the substrate processing apparatus 100A according to the present embodiment. In FIG. 16, some components are shown in a transparent state for convenience. The substrate processing operation by the substrate processing apparatus 100A is similar to that of the substrate processing apparatus 100 described in the first embodiment. For example, a liquid film of a processing liquid is formed on the upper surface of the substrate W (step ST03 in FIG. 4), activated species generated by the action of plasma in the plasma generating unit 130 (described later) are supplied to the liquid film (step ST05 in FIG. 4), and the KrF resist film 200 is then stripped off by Caro's acid in the liquid film.

[0087] 16 may be surrounded by chamber 80 in FIG. 1. The pressure inside chamber 80 is approximately atmospheric pressure (for example, 0.5 atmospheres or more and 2 atmospheres or less). In other words, the plasma processing described below is atmospheric pressure plasma processing performed at atmospheric pressure.

[0088] The substrate processing apparatus 100A includes a spin chuck 10, a processing cup 12, a processing liquid nozzle 20, a processing liquid supply source 29, a valve 25, and a plasma generator 55A. The plasma generator 55A is disposed above the substrate W so as to cover the entire substrate W, and includes a plasma generator 130 serving as an atmospheric pressure plasma source that generates plasma under atmospheric pressure, an AC power supply 40 that applies an AC voltage to the plasma generator 130, and a support 60 that supports the plasma generator 130.

[0089] The plasma generating unit 130 includes a plate-shaped dielectric member 32A made of a dielectric material such as quartz, a plurality of electrode rods 30J housed in the dielectric member 32A and arranged in a comb shape, a plurality of electrode rods 30K housed in the dielectric member 32A and arranged in a comb shape, a holder 30L made of resin (e.g., polytetrafluoroethylene (PTFE)) or ceramics and holding one end of each of the plurality of electrode rods 30J and the plurality of electrode rods 30K, a collection electrode 30M made of aluminum or the like and connected in common to the plurality of electrode rods 30J, and a collection electrode 30N made of aluminum or the like and connected in common to the plurality of electrode rods 30K. The collection electrodes 30M and 30N are arranged, for example, to form a circle in a plan view, and the plurality of electrode rods 30J and the plurality of electrode rods 30K are housed within the circle.

[0090] The electrode rods 30J and 30K are rod-shaped and made of, for example, tungsten. However, the shapes of the electrode rods 30J and 30K are not limited to rod shapes. Furthermore, the plurality of electrode rods 30J and the plurality of electrode rods 30K are arranged alternately so as not to overlap in a planar view. In other words, the electrode rods 30J and the electrode rods 30K are arranged alternately in a planar view.

[0091] On the other hand, in the side view shown in Fig. 16, the plurality of electrode bars 30J and the plurality of electrode bars 30K are arranged to overlap each other. Note that in the side view shown in Fig. 16, the plurality of electrode bars 30J and the plurality of electrode bars 30K do not have to overlap each other, and may be arranged, for example, shifted in the Z-axis direction in Fig. 16.

[0092] The dielectric member 32A has a planar top and bottom surface with no irregularities, which makes it easy to clean off any deposits on the bottom surface of the dielectric member 32A that may occur during plasma processing.

[0093] Fig. 17 is a cross-sectional view schematically showing an example of the configuration of a portion of the plasma generating unit 130. Fig. 17 corresponds to the A-A' cross section in Fig. 16. Note that the number of electrode bars 30J and electrode bars 30K is not limited to the number shown in Fig. 17.

[0094] As shown in FIG. 17, the dielectric member 32A has a plurality of accommodating holes 32B extending in the X-axis direction from the plate-shaped side surface, and the electrode rods 30J and 30K are accommodated in the corresponding accommodating holes 32B. The accommodating holes 32B are formed by alternately extending inward from the ends (side surfaces) of the dielectric member 32A in the positive and negative X-axis directions. Therefore, the electrode rods 30J are inserted from the end on the positive X-axis side, and the electrode rods 30K are inserted from the end on the negative X-axis side. In this way, the electrode rods 30J and 30K are arranged surrounded by the dielectric member 32A. As shown in FIG. 17, the accommodating holes 32B are formed near the bottom surface of the dielectric member 32A.

[0095] When an AC voltage is applied between the collection electrode 30M and the collection electrode 30N by the AC power supply 40, an AC voltage is applied between each electrode rod 30J connected to the collection electrode 30M and each electrode rod 30K connected to the collection electrode 30N. As a result, a dielectric barrier discharge occurs between the electrode rod 30J and the electrode rod 30K. Then, gas is converted into plasma around the discharge path of the discharge, and a plasma space is formed that spreads two-dimensionally along the surface of the dielectric member 32A (including the inside of the accommodating hole 32B) that separates the electrode rod 30J and the electrode rod 30K. Here, because the accommodating hole 32B is formed in a position close to the bottom surface of the dielectric member 32A, the plasma 102 is mainly formed on the bottom surface of the dielectric member 32A.

[0096] When the plasma space is formed, a gas such as O2 (oxygen), Ne, CO2, air, an inert gas, or a combination thereof may be supplied to the space below the plasma generating unit 130 (i.e., the space above the substrate W). The inert gas may be, for example, N2 or a rare gas. The rare gas may be, for example, He or Ar.

[0097] The action of the plasma 102 generates active species in the gas near the space. The active species include charged ions and electrically neutral radicals. For example, if the gas contains O2, the action of the plasma in the plasma generating unit 130 generates oxygen radicals, which are a type of active species.

[0098] Here, the plasma generating unit 130 may wait at a predetermined waiting position during the stage of generating the plasma 102 as described above, and after a suitably uniform plasma 102 is generated on the lower surface of the dielectric member 32A, it may move to a processing position near the substrate W. In this embodiment, the plasma 102 may be allowed to act on the liquid film on the surface of the substrate W in a state where the uniform plasma 102 is generated, thereby enabling uniform processing.

[0099] In this embodiment, the plasma generating unit 130 is arranged to cover the entire upper surface of the substrate W, but if the plasma generating unit 130 is arranged to cover only a portion of the substrate W, the position of the plasma generating unit 130 on the upper surface of the substrate W may be moved in the rotational direction and radial direction of the substrate W along the upper surface of the substrate W as the substrate W rotates by a driving mechanism not shown.

[0100] <Effects of the above-described embodiments> Next, examples of effects obtained by the above-described embodiments will be described. Note that in the following description, the effects will be described based on the specific configurations exemplified in the above-described embodiments, but these may be replaced with other specific configurations exemplified in the present specification as long as the same effects are obtained. In other words, for convenience, only one of the corresponding specific configurations may be described as a representative below, but the representatively described specific configuration may be replaced with another corresponding specific configuration.

[0101] Furthermore, the replacement may be made across multiple embodiments, i.e., configurations illustrated in different embodiments may be combined to produce the same effect.

[0102] According to the embodiment described above, in the substrate processing method, the substrate W is held horizontally under atmospheric pressure. Then, a liquid film 101A of the processing liquid 101 containing sulfuric acid is formed on the upper surface of the horizontally held substrate W. Then, a plasma generating unit 30 (or plasma generating unit 130; the same applies hereinafter) for generating plasma 102 from an electrode is disposed above the horizontally held substrate W. Here, the electrode corresponds to, for example, at least one of electrode rod 30B, electrode rod 30C, electrode rod 30J, electrode rod 30K, etc. Then, the plasma 102 is generated from the plasma generating unit 30 under atmospheric pressure, and active species generated by the generation of the plasma 102 are diffused into the liquid film 101A of the processing liquid 101, thereby generating Caro's acid 300 in the liquid film 101A. Furthermore, the Caro's acid 300 cleaves the side chains of the base polymer in the resist film on the upper surface of the substrate W. Here, the resist film corresponds to, for example, a KrF resist film 200. Then, the KrF resist film 200 is heated to a melting temperature, which is a temperature for melting the KrF resist film 200 containing the base polymer whose side chains have been cleaved. By doing so, the KrF resist film 200 is removed from the substrate W.

[0103] According to this configuration, the side chains of the base polymer can be cleaved by Caro's acid 300 generated by the diffusion of activated species. This lowers the melting temperature of the KrF resist film 200, allowing the KrF resist film 200 to be stripped at a lower melting temperature than would be the case if the side chains of the base polymer were not cleaved. Furthermore, because the KrF resist film 200 can be stripped at a low temperature, the KrF resist film 200 (i.e., the liquid film 101A covering the KrF resist film 200) can be sufficiently heated to its melting temperature even when a device for heating the KrF resist film 200 (e.g., the electrode rod 30B when using radiant heat) is located away from the substrate W. This prevents problems caused by bringing these heat sources closer to the substrate W (e.g., heat-induced damage to the substrate W, accelerated evaporation of the liquid film 101A, or reduced uniformity of the plasma processing).

[0104] Unless otherwise specified, the order in which the processes are performed can be changed.

[0105] Furthermore, even if other configurations shown as examples in this specification are appropriately added to the above configuration, that is, even if other configurations in this specification that were not mentioned as the above configuration are appropriately added, the same effect can be achieved.

[0106] Furthermore, according to the embodiment described above, the process of severing the side chains of the base polymer includes a first temperature-raising process of the electrode rod 30B accompanying the generation of plasma 102, and a second temperature-raising process of the electrode rod 30B in which the temperature is higher than that in the first temperature-raising process. During the first temperature-raising process of the electrode rod 30B, ozone is generated as an activated species in the air between the plasma generating unit 30 and the liquid film 101A of the processing liquid 101 formed on the upper surface of the substrate W, and the activated species diffuse into the liquid film 101A of the processing liquid 101. During the second temperature-raising process of the electrode rod 30B, the side chains of the base polymer in the KrF resist film 200 are sever- ed by Caro's acid 300 generated in the liquid film 101A of the processing liquid 101 due to the diffusion of the activated species. With this configuration, ozone can be generated as an active species and effectively diffused into the liquid film 101A during the first temperature increase process, and the side chains of the base polymer can be cleaved by Caro's acid produced by the diffusion of the active species during the second temperature increase process.

[0107] Furthermore, according to the embodiment described above, the first temperature-raising process of the electrode rod 30B is a process of raising the temperature of the electrode rod 30B to 100° C. With this configuration, it is possible to prevent ozone from being decomposed during the first temperature-raising process, and to promote the diffusion of active species into the liquid film 101A.

[0108] Furthermore, according to the embodiment described above, the second temperature-raising process of the electrode rod 30B is a process of raising the temperature of the electrode rod 30B to the melting temperature of the KrF resist film 200. With this configuration, by raising the temperature of the electrode rod 30B to the melting temperature that has been lowered by severing the side chains of the base polymer, the KrF resist film 200 can be smoothly peeled off after the side chains of the base polymer are sever- ed.

[0109] Furthermore, according to the embodiment described above, the step of removing the KrF resist film 200 from the substrate W is a step of removing the KrF resist film 200 from the substrate W by heating the KrF resist film 200 to its melting temperature with radiant heat from at least one of the electrode rod 30B and the plasma 102. With this configuration, the temperature of the KrF resist film 200 (i.e., the temperature of the liquid film 101A covering the KrF resist film 200) can be efficiently increased using the radiant heat from at least one of the electrode rod 30B and the plasma 102. Furthermore, because the melting temperature of the KrF resist film 200 is lowered by cleavage of the side chains, the heating temperatures of the electrode rod 30B and the plasma 102 can be kept low.

[0110] Furthermore, according to the embodiment described above, the base polymer has a PHS-tBOC structure. The step of cleaving the side chain of the base polymer is a step of cleaving the side chain between the PHS and tBOC. With this configuration, cleavage of the side chain of the PHS-tBOC structure reduces the melting temperature of the KrF resist film 200 to approximately 260°C, which is equivalent to that of PHS resin. Therefore, the strippability of the KrF resist film 200 at low temperatures is improved.

[0111] According to the embodiment described above, the substrate processing apparatus includes a holder, a processing liquid nozzle 20, and a plasma generator 30. The holder corresponds to, for example, a spin chuck 10. The spin chuck 10 holds the substrate W horizontally under atmospheric pressure. The processing liquid nozzle 20 ejects a processing liquid 101 containing sulfuric acid onto the upper surface of the horizontally held substrate W. The plasma generator 30 is disposed above the horizontally held substrate W and generates plasma 102 from an electrode rod 30B. The plasma generator 30 generates plasma 102 under atmospheric pressure. Active species generated by the generation of plasma 102 diffuse into a liquid film 101A of the processing liquid 101 on the upper surface of the substrate W, thereby generating Caro's acid 300 in the liquid film 101A. The Caro's acid 300 cleaves side chains of the base polymer in a KrF resist film 200 on the upper surface of the substrate W. Then, the KrF resist film 200 containing the base polymer whose side chains have been cut is heated to its melting temperature by radiant heat from at least one of the electrode rod 30B and the plasma 102.

[0112] With this configuration, the side chains of the base polymer can be cleaved by Caro's acid generated by the diffusion of the active species, which lowers the melting temperature of the KrF resist film 200, allowing the KrF resist film 200 to be peeled off at a lower melting temperature than when the side chains of the base polymer are not cleaved.

[0113] Furthermore, even if other configurations shown as examples in this specification are appropriately added to the above configuration, that is, even if other configurations in this specification that were not mentioned as the above configuration are appropriately added, the same effect can be achieved.

[0114] <Modifications of the above-described embodiments> In the embodiments described above, the material, composition, dimensions, shape, relative positional relationship, or implementation conditions of each component may also be described, but these are merely examples in all aspects and are not limiting.

[0115] Therefore, countless modifications and equivalents not shown as examples are contemplated within the scope of the technology disclosed in the present specification, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component in at least one embodiment and combining it with a component in another embodiment.

[0116] Furthermore, in the embodiments described above, when a material name is mentioned without any particular specification, it is assumed that the material may contain other additives, such as an alloy, unless a contradiction arises. [Explanation of symbols]

[0117] 20 Processing liquid nozzle 30 Plasma generating unit 30D holding part 30L holding part 100 Substrate processing apparatus 100A substrate processing equipment 101 Processing liquid 101A Liquid film 102 Plasma 130 Plasma generating unit 300 Caro's acid W substrate

Claims

1. A substrate processing method for removing a resist film formed on an upper surface of a substrate under atmospheric pressure, comprising: holding the substrate horizontally under atmospheric pressure; forming a liquid film of a treatment liquid containing sulfuric acid on the upper surface of the substrate held horizontally; a step of arranging a plasma generating unit for generating plasma from an electrode above the substrate held horizontally; generating the plasma from the plasma generating unit under atmospheric pressure, diffusing active species generated by the generation of the plasma into the liquid film of the processing liquid to generate Caro's acid in the liquid film, and further cleaving side chains of a base polymer in the resist film on the upper surface of the substrate with the Caro's acid; and removing the resist film from the substrate by heating the resist film to a melting temperature that is a temperature for melting the resist film containing the base polymer whose side chains have been cleaved. Substrate processing method.

2. 2. The substrate processing method according to claim 1, the step of scission of the side chain of the base polymer includes a first temperature-raising process of the electrode accompanying the generation of the plasma, and a second temperature-raising process of the electrode in which the temperature is higher than that in the first temperature-raising process, In the first temperature increase process of the electrode, ozone is generated as the active species in the atmosphere between the plasma generating unit and the liquid film of the processing liquid formed on the upper surface of the substrate, and the active species diffuses into the liquid film of the processing liquid, during the second temperature increase process of the electrode, the side chain of the base polymer in the resist film is cleaved by the Caro's acid generated in the liquid film of the treatment liquid due to diffusion of the active species; Substrate processing method.

3. 3. The substrate processing method according to claim 2, The first temperature-raising process of the electrode is a process of raising the temperature of the electrode to 100°C. Substrate processing method.

4. 4. The substrate processing method according to claim 2 or 3, the second temperature-raising process of the electrode is a process of raising the temperature of the electrode to the melting temperature of the resist film; Substrate processing method.

5. 5. A substrate processing method according to claim 1, the step of removing the resist film from the substrate is a step of removing the resist film from the substrate by heating the resist film to the melting temperature with radiant heat from at least one of the electrode and the plasma. Substrate processing method.

6. 6. A substrate processing method according to claim 1, the base polymer has a PHS-tBOC structure, the step of cleaving the side chain of the base polymer is a step of cleaving the side chain between the PHS and the tBOC; Substrate processing method.

7. A substrate processing apparatus for removing a resist film formed on an upper surface of a substrate under atmospheric pressure, a holder that holds the substrate horizontally under atmospheric pressure; a processing liquid nozzle that discharges a processing liquid containing sulfuric acid onto the upper surface of the substrate that is held horizontally; a plasma generating unit that is disposed above the horizontally held substrate and that generates plasma from an electrode; the plasma generating unit generates the plasma under atmospheric pressure, active species generated in association with the generation of the plasma diffuse into a liquid film of the processing liquid on the upper surface of the substrate, thereby generating Caro's acid in the liquid film; the Caro's acid cleaves a side chain of a base polymer in the resist film on the upper surface of the substrate; the resist film including the base polymer whose side chains have been cleaved is heated to a melting temperature by radiant heat from at least one of the electrode and the plasma; Substrate processing equipment.

Images