Sulfuric acid heating unit and substrate processing device

Abstract

To exhibit corrosion resistance to high temperature sulfuric acid and enable reduction of a use amount of fluorine resin.SOLUTION: A sulfuric acid heating unit (120t) includes: a pipe (122) in which sulfuric acid flows; a heater (124) which heats sulfuric acid flowing in the pipe (122); and a housing (126) which houses the pipe (122) and the heater (124). At least a part of the housing (122) includes stainless steel.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a sulfuric acid heating unit and a substrate processing apparatus. [Background technology]

[0002] 2. Description of the Related Art Substrate processing apparatuses for processing substrates are known. Substrate processing apparatuses are preferably used for processing semiconductor substrates. Typically, substrate processing apparatuses process substrates using a processing liquid.

[0003] In order to remove the resist remaining on the substrate after dry etching, substrate processing equipment may process the substrate with a sulfuric acid / hydrogen peroxide mixture (SPM liquid), which is a mixture of sulfuric acid and hydrogen peroxide. High-temperature SPM liquid can effectively remove the resist. High-temperature SPM liquid is prepared by mixing high-temperature sulfuric acid and hydrogen peroxide.

[0004] When high-temperature sulfuric acid is used, the use of highly corrosion-resistant fluororesin for components used to prepare the high-temperature sulfuric acid has been considered (Patent Document 1). In the substrate processing apparatus of Patent Document 1, the SPM liquid used in the substrate processing is collected and stored, and the temperature control tank that heats the sulfuric acid stored in the blending tank is made of highly corrosion-resistant fluororesin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-021198 A Summary of the Invention [Problem to be solved by the invention]

[0006] It is generally known that when sulfuric acid adheres to a metal, the metal corrodes. In particular, the higher the temperature of sulfuric acid, the more corrosive the metal tends to become. For this reason, highly corrosion-resistant fluororesins have been used for components that may be exposed to high-temperature sulfuric acid.

[0007] However, in recent years, there has been a demand to reduce the amount of fluororesin used from the viewpoints of the environment and costs.

[0008] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a sulfuric acid heating unit and a substrate processing apparatus that are resistant to corrosion by high-temperature sulfuric acid and can reduce the amount of fluororesin used. [Means for solving the problem]

[0009] According to one aspect of the present invention, a sulfuric acid heating unit includes piping through which sulfuric acid flows, a heater that heats the sulfuric acid flowing through the piping, and a housing that accommodates the piping and the heater, at least a portion of the housing comprising stainless steel.

[0010] In one embodiment, the housing includes a bottom member located below the piping and the heater, and a wall member extending vertically from the bottom member, and at least one of the bottom member and the wall member includes stainless steel.

[0011] In one embodiment, the housing further includes a ceiling member extending from the wall member and facing the bottom member, the ceiling member including stainless steel.

[0012] In one embodiment, the housing includes a bottom member located below the piping and the heater, a wall member extending vertically from the bottom member, and a bracket connecting to the wall member, the bracket comprising stainless steel.

[0013] According to another aspect of the present invention, a substrate processing apparatus includes the above-described sulfuric acid heating unit, and a substrate processing unit that processes a substrate with a processing liquid containing sulfuric acid heated in the sulfuric acid heating unit.

[0014] In one embodiment, the substrate processing apparatus further includes a processing liquid box arranged around the substrate processing unit and supplying the sulfuric acid or the processing liquid to the substrate processing unit, the processing liquid box having the sulfuric acid heating unit.

[0015] In one embodiment, the substrate processing apparatus further includes a processing liquid box arranged around the substrate processing unit and supplying the sulfuric acid or the processing liquid to the substrate processing unit, and a processing liquid cabinet supplying the sulfuric acid to the processing liquid box, the processing liquid cabinet having the sulfuric acid heating unit. Effect of the Invention

[0016] According to the present invention, corrosion resistance to high-temperature sulfuric acid is exhibited and the amount of fluororesin used can be reduced. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; [Diagram 2] 2 is a schematic diagram of a substrate processing unit in the substrate processing apparatus of the present embodiment. FIG. [Diagram 3] 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; [Figure 4] FIG. 2 is a schematic diagram showing a piping configuration in the substrate processing apparatus of the present embodiment. [Diagram 5] 1A is a schematic perspective view of a sulfuric acid heating unit in the substrate processing apparatus of the present embodiment, and FIG. 1B is a schematic exploded perspective view of the sulfuric acid heating unit in the substrate processing apparatus of the present embodiment. [Figure 6] 1 is a graph showing heating conditions in a sulfuric acid corrosion test of samples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of a sulfuric acid heating unit and a substrate processing apparatus according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference symbols and will not be described repeatedly. In this specification, to facilitate understanding of the invention, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other may be described. Typically, the X-axis and the Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction.

[0019] First, an embodiment of a substrate processing apparatus 100 according to the present invention will be described with reference to Fig. 1. Fig. 1 is a schematic plan view of the substrate processing apparatus 100 of the present embodiment.

[0020] The substrate processing apparatus 100 processes a substrate W. The substrate processing apparatus 100 processes the substrate W by performing at least one of etching, surface treatment, property imparting, treatment film formation, removal of at least a portion of a film, and cleaning on the substrate W.

[0021] The substrate W is used as a semiconductor substrate. The substrate W includes a semiconductor wafer. For example, the substrate W has a substantially circular plate shape. Here, the substrate processing apparatus 100 processes the substrates W one by one.

[0022] 1, the substrate processing apparatus 100 includes a plurality of substrate processing units 10, a processing liquid cabinet 110, a processing liquid box 120, a plurality of load ports LP, an indexer robot IR, a center robot CR, and a controller 101. The controller 101 controls the load port LP, the indexer robot IR, and the center robot CR. The controller 101 includes a control unit 102 and a memory unit 104.

[0023] Each of the load ports LP accommodates a plurality of stacked substrates W. The indexer robot IR transports the substrates W between the load port LP and the center robot CR. The center robot CR transports the substrates W between the indexer robot IR and the substrate processing units 10. Each of the substrate processing units 10 discharges a processing liquid onto the substrate W to process the substrate W. The processing liquid includes a chemical liquid, a cleaning liquid, a removing liquid and / or a water repellent. The processing liquid cabinet 110 accommodates the processing liquid. The processing liquid cabinet 110 may accommodate a gas.

[0024] Specifically, the substrate processing units 10 form a plurality of towers TW arranged to surround the center robot CR in a plan view. The towers TW include a tower TWA, a tower TWB, a tower TWC, and a tower TWD. Each of the towers TWA to TWD includes a plurality of substrate processing units 10 (three substrate processing units 10 in FIG. 1) stacked vertically.

[0025] The processing liquid box 120 includes processing liquid boxes 120A to 120D corresponding to the towers TWA to TWD, respectively. Here, the processing liquid box 120A is disposed opposite the processing liquid box 120B across the towers TWA and TWB. The processing liquid box 120C is disposed opposite the processing liquid box 120D across the towers TWC and TWD. Furthermore, the processing liquid box 120A is disposed opposite the processing liquid box 120D across a space in which the center robot CR can move. Furthermore, the processing liquid box 120B is disposed opposite the processing liquid box 120C across a space in which the center robot CR can move.

[0026] The liquid in the processing liquid cabinet 110 is supplied, via any one of the processing liquid boxes 120, to all the substrate processing units 10 included in the tower TW corresponding to the processing liquid box 120. Also, the gas in the processing liquid cabinet 110 is supplied, via any one of the processing liquid boxes 120, to all the substrate processing units 10 included in the tower TW corresponding to the processing liquid box 120.

[0027] In the substrate processing apparatus 100, a boundary wall is disposed between an area where the center robot CR and the substrate processing units 10 are installed and an area where the processing liquid cabinets 110 are installed.

[0028] Typically, the processing liquid cabinet 110 has a storage tank (tank) for preparing a processing liquid. The processing liquid cabinet 110 may have a storage tank for one type of processing liquid or may have storage tanks for multiple types of processing liquid. The processing liquid cabinet 110 also has a pump, a valve, a heater, and / or a filter for distributing the processing liquid.

[0029] The processing liquid cabinet 110 includes a first processing liquid cabinet 110A and a second processing liquid cabinet 110B. For example, the first processing liquid cabinet 110A and the second processing liquid cabinet 110B are disposed apart from each other. Alternatively, the first processing liquid cabinet 110A and the second processing liquid cabinet 110B may be disposed adjacent to each other.

[0030] For example, the first processing liquid cabinet 110A supplies sulfuric acid to the processing liquid box 120. Typically, the first processing liquid cabinet 110A heats the sulfuric acid and supplies the heated sulfuric acid to the processing liquid box 120.

[0031] The second processing liquid cabinet 110B supplies the processing liquid box 120 with hydrogen peroxide.

[0032] The processing liquid box 120 supplies sulfuric acid and hydrogen peroxide solution to the substrate processing unit 10 .

[0033] The control device 101 controls various operations of the substrate processing apparatus 100. The control device 101 controls the substrate processing unit 10 to process the substrate W.

[0034] The control device 101 includes a control unit 102 and a storage unit 104. The control unit 102 has a processor. The control unit 102 has, for example, a central processing unit (CPU). Alternatively, the control unit 102 may have a general-purpose computer.

[0035] The storage unit 104 stores data and computer programs. The data includes recipe data. The recipe data includes information indicating a plurality of recipes. Each of the plurality of recipes defines the processing content and processing procedure for the substrate W.

[0036] The storage unit 104 includes a main storage device and an auxiliary storage device. The main storage device is, for example, a semiconductor memory. The auxiliary storage device is, for example, a semiconductor memory and / or a hard disk drive. The storage unit 104 may include a removable medium. The control unit 102 executes a computer program stored in the storage unit 104 to perform a substrate processing operation.

[0037] The substrate processing apparatus 100 of this embodiment is preferably used for forming semiconductor elements. For example, the substrate processing apparatus 100 is preferably used for processing a substrate W used as a semiconductor element having a stacked structure. The semiconductor element is a so-called 3D structure memory (storage device). As an example, the substrate W is preferably used as a NAND type flash memory.

[0038] Next, the substrate processing unit 10 in the substrate processing apparatus 100 of this embodiment will be described with reference to Fig. 2. Fig. 2 is a schematic diagram of the substrate processing unit 10 in the substrate processing apparatus 100.

[0039] The substrate processing unit 10 includes a chamber 11, a substrate holding part 20, and a processing liquid supply part 30. The chamber 11 accommodates a substrate W. The substrate holding part 20 holds the substrate W.

[0040] The chamber 11 is substantially box-shaped with an internal space. The chamber 11 accommodates the substrate W. Here, the substrate processing apparatus 100 is a single-wafer type that processes the substrate W one by one, and the chamber 11 accommodates the substrate W one by one. The substrate W is accommodated in the chamber 11 and is processed in the chamber 11. The chamber 11 accommodates at least a part of each of the substrate holder 20 and the processing liquid supply unit 30.

[0041] The substrate holding unit 20 holds the substrate W. The substrate holding unit 20 holds the substrate W horizontally so that the top surface (front surface) Wa of the substrate W faces upward and the back surface (bottom surface) Wb of the substrate W faces vertically downward. The substrate holding unit 20 also rotates the substrate W while holding it. For example, the top surface Wa of the substrate W has a laminated structure in which a recess is formed. The substrate holding unit 20 rotates the substrate W while holding it.

[0042] For example, the substrate holding unit 20 may be of a clamping type that clamps an end of the substrate W. Alternatively, the substrate holding unit 20 may have any mechanism that holds the substrate W from its back surface Wb. For example, the substrate holding unit 20 may be of a vacuum type. In this case, the substrate holding unit 20 holds the substrate W horizontally by adsorbing the center of the back surface Wb of the substrate W, which is the non-device forming surface, to its upper surface. Alternatively, the substrate holding unit 20 may combine a clamping type that brings multiple chuck pins into contact with the peripheral end surface of the substrate W with a vacuum type.

[0043] For example, the substrate holding unit 20 includes a spin base 21, a chuck member 22, a shaft 23, an electric motor 24, and a housing 25. The chuck member 22 is provided on the spin base 21. The chuck member 22 chucks the substrate W. Typically, the spin base 21 is provided with a plurality of chuck members 22.

[0044] The shaft 23 is a hollow shaft. The shaft 23 extends vertically along the rotation axis Ax. The spin base 21 is coupled to the upper end of the shaft 23. The substrate W is placed above the spin base 21.

[0045] The spin base 21 is disk-shaped and supports the substrate W horizontally. The shaft 23 extends downward from the center of the spin base 21. The electric motor 24 applies a rotational force to the shaft 23. The electric motor 24 rotates the shaft 23 in a rotational direction, thereby rotating the substrate W and the spin base 21 about the rotation axis Ax. The housing 25 surrounds the shaft 23 and the electric motor 24.

[0046] The processing liquid supply unit 30 supplies a sulfuric acid / hydrogen peroxide mixture (SPM liquid) to the substrate W. Typically, the processing liquid supply unit 30 supplies the SPM liquid to the upper surface Wa of the substrate W. At least a part of the processing liquid supply unit 30 is accommodated in the chamber 11.

[0047] The processing liquid supply unit 30 supplies high-temperature SPM liquid to the substrate W. The SPM liquid may be heated to a temperature between 90° C. and 240° C. inclusive.

[0048] The processing liquid supply unit 30 includes a pipe 32a, a valve 34a, a pipe 32b, a valve 34b, and a nozzle 36. The nozzle 36 discharges a mixture of sulfuric acid and hydrogen peroxide onto the upper surface Wa of the substrate W.

[0049] Here, the nozzle 36 is connected to the pipes 32a and 32b. Sulfuric acid is supplied to the pipe 32a from a supply source. The valve 34a opens and closes a flow path in the pipe 32a. The valve 34a adjusts the opening of the pipe 32a to adjust the flow rate of sulfuric acid supplied to the pipe 32a. Specifically, the valve 34a includes a valve body (not shown) having a valve seat therein, a valve element that opens and closes the valve seat, and an actuator (not shown) that moves the valve element between an open position and a closed position.

[0050] The hydrogen peroxide solution is supplied to the pipe 32b from a supply source. The valve 34b opens and closes the flow path in the pipe 32b. The valve 34b adjusts the opening of the pipe 32b to adjust the flow rate of the hydrogen peroxide solution supplied to the pipe 32b. Specifically, the valve 34b includes a valve body (not shown) having a valve seat therein, a valve element that opens and closes the valve seat, and an actuator (not shown) that moves the valve element between an open position and a closed position.

[0051] Here, sulfuric acid that has flowed through pipe 32a and hydrogen peroxide solution that has flowed through pipe 32b are mixed in nozzle 36 to generate sulfuric acid / hydrogen peroxide solution (SPM liquid). By mixing sulfuric acid and hydrogen peroxide solution, the temperature of the sulfuric acid / hydrogen peroxide solution increases further than the higher temperature of either the sulfuric acid or the hydrogen peroxide solution.

[0052] The nozzle 36 may be configured to be movable relative to the substrate W. The processing liquid supply unit 30 may further include a nozzle moving unit 38. The nozzle moving unit 38 may raise and lower the nozzle 36, or may rotate the nozzle 36 horizontally around a rotation axis. The nozzle moving unit 38 raises and lowers the nozzle 36. For example, the nozzle moving unit 38 includes a ball screw mechanism and an electric motor that provides a driving force to the ball screw mechanism. In addition, the nozzle moving unit 38 rotates the nozzle 36 horizontally. For example, the nozzle moving unit 38 includes an electric motor.

[0053] When valve 34a is open to allow sulfuric acid to flow through pipe 32a and valve 34b is open to allow hydrogen peroxide to flow through pipe 32b, a sulfuric acid / hydrogen peroxide mixture is generated in which sulfuric acid and hydrogen peroxide are mixed in nozzle 36. The sulfuric acid / hydrogen peroxide mixture is supplied to substrate W from nozzle 36. When valve 34a is closed to allow sulfuric acid to not flow through pipe 32a and valve 34b is open to allow hydrogen peroxide to flow through pipe 32b, processing liquid supply unit 30 supplies hydrogen peroxide to substrate W from nozzle 36. When valve 34a is open to allow sulfuric acid to flow through pipe 32a and valve 34b is closed to allow hydrogen peroxide to not flow through pipe 32b, processing liquid supply unit 30 supplies sulfuric acid to substrate W from nozzle 36.

[0054] The substrate processing unit 10 further includes a cup 90. The cup 90 collects the processing liquid scattered from the substrate W. The cup 90 moves up and down. For example, the cup 90 moves up vertically to the side of the substrate W during the period in which the processing liquid supply unit 30 supplies the processing liquid to the substrate W. In this case, the cup 90 collects the processing liquid scattered from the substrate W due to the rotation of the substrate W. Furthermore, when the period in which the processing liquid supply unit 30 supplies the processing liquid to the substrate W ends, the cup 90 moves down vertically from the side of the substrate W.

[0055] As described above, the control device 101 includes the control unit 102 and the memory unit 104. The control unit 102 controls the substrate holder 20, the processing liquid supply unit 30, and / or the cup 90. In one example, the control unit 102 controls the electric motor 24, the valves 34a, 34b, the nozzle moving unit 38, and / or the cup 90.

[0056] The substrate processing apparatus 100 of this embodiment is suitable for use in the manufacture of a semiconductor device having a semiconductor. Typically, in a semiconductor device, a conductive layer and an insulating layer are laminated on a base material. The substrate processing apparatus 100 is suitable for use in cleaning and / or processing (e.g., etching, changing characteristics, etc.) the conductive layer and / or insulating layer during the manufacture of the semiconductor device.

[0057] 2, the processing liquid supply unit 30 supplies a processing liquid containing any one of sulfuric acid, hydrogen peroxide solution, and SPM liquid to the substrate W. However, this embodiment is not limited to this. The processing liquid supply unit 30 may supply another processing liquid to the substrate W. For example, the processing liquid supply unit 30 may be capable of sequentially supplying a plurality of types of processing liquids having different uses to the substrate W. Alternatively, the processing liquid supply unit 30 may be capable of simultaneously supplying a plurality of types of processing liquids having different uses to the substrate W.

[0058] Next, the flow of liquid in the substrate processing apparatus 100 of this embodiment will be described with reference to Figures 1 to 3. Figure 3 is a schematic diagram of the substrate processing apparatus 100 of this embodiment. In Figure 3, the flow of sulfuric acid is indicated by a dashed line, and the flow of hydrogen peroxide solution is indicated by a dashed double-dashed line.

[0059] As shown in FIG. 3, the substrate processing apparatus 100 includes a substrate processing unit 10, a processing liquid cabinet 110, and a processing liquid box 120. The processing liquid box 120 is a processing liquid box.

[0060] The processing liquid cabinet 110 includes a first processing liquid cabinet 110A and a second processing liquid cabinet 110B. In Fig. 3, the processing liquid cabinet 110 shows the first processing liquid cabinet 110A and the second processing liquid cabinet 110B adjacent to each other.

[0061] The processing liquid box 120 includes a processing liquid box 120A and a processing liquid box 120B. The processing liquid box 120A is disposed opposite to the processing liquid box 120B with the towers TWA and TWB interposed therebetween.

[0062] The first processing liquid cabinet 110A supplies sulfuric acid to the processing liquid box 120. Typically, the first processing liquid cabinet 110A heats the sulfuric acid and supplies the heated sulfuric acid to the processing liquid box 120. For example, the first processing liquid cabinet 110A heats the sulfuric acid to a temperature higher than room temperature and equal to or lower than 140°C.

[0063] The concentration of sulfuric acid may be adjusted in the first processing liquid cabinet 110A. For example, the mass concentration of sulfuric acid supplied from the first processing liquid cabinet 110A to the processing liquid box 120 is 90% or more. The mass concentration of sulfuric acid may be 94% or more and 98% or less, or 96% or more and 98% or less.

[0064] The second processing liquid cabinet 110B supplies the hydrogen peroxide solution to the processing liquid box 120.

[0065] The processing liquid box 120 includes a first unit 120s and a second unit 120t. Here, the first unit 120s has a substantially rectangular parallelepiped shape extending in the vertical direction. The second unit 120t has a substantially rectangular parallelepiped shape extending in the horizontal direction. The second unit 120t is disposed above the first unit 120s. At least a portion of the second unit 120t is supported by the first unit 120s. For example, the second unit 120t is supported by the first unit 120s and the tower TW of the substrate processing unit 10.

[0066] The volume of the second unit 120t is smaller than the volume of the first unit 120s. The length of the second unit 120t along the vertical direction is smaller than the length of the first unit 120s along the vertical direction. The length of the second unit 120t along the horizontal direction is larger than the length of the first unit 120s along the horizontal direction.

[0067] The first unit 120s is supplied with hydrogen peroxide solution from the second processing liquid cabinet 110B.

[0068] The second unit 120t is supplied with sulfuric acid from the first processing liquid cabinet 110A. In detail, the second unit 120t is supplied with sulfuric acid heated in the first processing liquid cabinet 110A from the first processing liquid cabinet 110A.

[0069] The sulfuric acid is heated in the second unit 120t. For example, the sulfuric acid is heated to 150° C. or more and 230° C. or less in the second unit 120t. The temperature of the sulfuric acid heated in the second unit 120t may be 190° C. or more and 220° C. or less.

[0070] Thereafter, the sulfuric acid is supplied from the second unit 120t to the first unit 120s. In particular, the sulfuric acid heated in the second unit 120t is supplied from the second unit 120t to the first unit 120s.

[0071] Sulfuric acid is supplied from the first unit 120s to the substrate processing unit 10. In addition, hydrogen peroxide solution is supplied from the first unit 120s to the substrate processing unit 10.

[0072] When sulfuric acid and hydrogen peroxide are supplied from the first unit 120s to the nozzle 36 of the substrate processing unit 10, a sulfuric acid / hydrogen peroxide mixture is generated in which the sulfuric acid and hydrogen peroxide are mixed in the nozzle 36. The sulfuric acid / hydrogen peroxide mixture is supplied to the substrate W from the nozzle 36. When only sulfuric acid is supplied from the first unit 120s to the nozzle 36 of the substrate processing unit 10, the nozzle 36 supplies sulfuric acid to the substrate W. When only hydrogen peroxide is supplied from the first unit 120s to the nozzle 36 of the substrate processing unit 10, the nozzle 36 supplies hydrogen peroxide to the substrate W.

[0073] 3, the SPM liquid, which is a mixture of sulfuric acid and hydrogen oxide water, is generated in the nozzle 36, but the present embodiment is not limited to this. The SPM liquid, which is a mixture of sulfuric acid and hydrogen oxide water, may be generated in the first unit 120s of the processing liquid box 120, and the SPM liquid may be supplied to the nozzle 36 from the first unit 120s.

[0074] As described above, in the substrate processing apparatus 100 of this embodiment, sulfuric acid is heated in each of the first processing liquid cabinet 110A and the second unit 120t, and the SPM liquid is produced using the heated sulfuric acid.

[0075] Until now, metal materials are easily corroded by high-temperature sulfuric acid, so fluororesin, which has high corrosion resistance against high-temperature sulfuric acid, has been used for the first processing liquid cabinet 110A and the second unit 120t. However, in recent years, there has been a demand to reduce the amount of fluororesin used from the viewpoints of the environment and costs.

[0076] The present inventors have found that stainless steel has corrosion resistance to hot sulfuric acid, and therefore, by using stainless steel in a place where hot sulfuric acid may leak, it is possible to suppress corrosion by the sulfuric acid even if hot sulfuric acid leaks.

[0077] In the substrate processing apparatus 100 of the present embodiment, at least one of the first processing liquid cabinet 110A and the second unit 120t for heating sulfuric acid contains stainless steel, which can reduce the amount of fluororesin used.

[0078] Next, a substrate processing apparatus 100 according to the present embodiment will be described with reference to Figures 1 to 4. Figure 4 is a schematic diagram of the substrate processing apparatus 100 according to the present embodiment.

[0079] As shown in Fig. 4, the substrate processing apparatus 100 includes a substrate processing unit 10, a processing liquid cabinet 110, and a processing liquid box 120. Fig. 4 shows the substrate processing unit 10 of the tower TWB and the corresponding processing liquid box 120B.

[0080] The processing liquid cabinet 110 includes a first processing liquid cabinet 110A and a second processing liquid cabinet 110B. In Figure 4, the first processing liquid cabinet 110A and the second processing liquid cabinet 110B are also shown adjacent to each other.

[0081] Sulfuric acid is supplied to the first processing liquid cabinet 110A. The first processing liquid cabinet 110A prepares sulfuric acid and supplies the sulfuric acid at a predetermined flow rate to the processing liquid box 120B. For example, the first processing liquid cabinet 110A filters the sulfuric acid to remove foreign matter. Furthermore, the first processing liquid cabinet 110A heats the sulfuric acid. The first processing liquid cabinet 110A heats the sulfuric acid and supplies the high-temperature sulfuric acid to the processing liquid box 120.

[0082] In detail, sulfuric acid is supplied to the first processing liquid cabinet 110A from a sulfuric acid supply unit 130. The sulfuric acid supply unit 130 has a pipe 132 and a valve 134. Sulfuric acid flows through the pipe 132. The valve 134 is provided in the pipe 132. The valve 134 adjusts the opening degree of the pipe 132 to adjust the flow rate of the sulfuric acid flowing through the pipe 132.

[0083] The first processing liquid cabinet 110A includes a tank 111a, a pipe 112a, a pump 113a, a heater 114a, a filter 115a, a pipe 116a, a valve 117a, a pipe 118a1, a valve 119a, and a housing 110ha. The housing 110ha accommodates the tank 111a, the pipe 112a, the pump 113a, the heater 114a, the filter 115a, the pipe 116a, the valve 117a, the pipe 118a1, and the valve 119a.

[0084] The tank 111a stores the sulfuric acid supplied from the pipe 132 of the sulfuric acid supply unit 130. The pipe 112a is a tubular member through which the sulfuric acid flows. The pipe 112a connects the tank 111a to the pipe 116a and the pipe 118a1.

[0085] A pump 113a, a heater 114a, and a filter 115a are arranged in the pipe 112a.

[0086] The pump 113a is provided in the pipe 112a. The pump 113a pumps sulfuric acid into the pipe 112a. Specifically, the pump 113a is driven to pump sulfuric acid. As a result, the sulfuric acid flows through the pipe 112a. In this embodiment, the pump 113a is driven by gas pressure. The pump 113a is controlled by the control device 101 (control unit 102).

[0087] The heater 114a is provided in the pipe 112a. Specifically, the heater 114a is provided downstream of the pump 113a. In this embodiment, the heater 114a is provided downstream of the pump 113a. The heater 114a heats the sulfuric acid flowing through the pipe 112a. For example, the heater 114a heats the sulfuric acid to a temperature higher than room temperature and equal to or lower than 140° C. Therefore, the sulfuric acid heated by the heater 114a flows through the pipe 112a. Similarly, the sulfuric acid heated by the heater 114a flows through the pipe 116a.

[0088] The filter 115a is provided in the pipe 112a. The filter 115a removes foreign matter from the sulfuric acid flowing through the pipe 112a. Specifically, the filter 115a is provided downstream of the pump 113a and removes foreign matter from the sulfuric acid sent out from the pump 113a. In this embodiment, the filter 115a is disposed between the heater 114a and the connection point between the pipe 112a and the pipe 116a. Therefore, clean sulfuric acid from which foreign matter has been removed flows through the pipe 112a and the pipe 116a.

[0089] The pipe 116a is a tubular member through which sulfuric acid flows. The upstream end of the pipe 116a is connected to the pipe 112a. The downstream end of the pipe 116a is connected to the tank 111a. The sulfuric acid in the tank 111a flows through the pipe 112a and the pipe 116a and returns to the tank 111a. In detail, the sulfuric acid flows from the pipe 112a to the upstream end of the pipe 116a, and flows through the pipe 116a. As a result, the sulfuric acid flows out from the downstream end of the pipe 116a and returns to the tank 111a. In this way, the sulfuric acid circulates through the tank 111a, the pipe 112a, and the pipe 116a.

[0090] Valve 117a is provided in pipe 116a. Valve 117a controls starting and stopping of flow of the processing liquid in pipe 116a. Valve 117a is an open / close valve that can be opened and closed. When valve 117a is opened, sulfuric acid flows through pipe 116a. When valve 117a is closed, the flow of sulfuric acid in pipe 116a stops. The opening and closing operation of valve 117a is controlled by control device 101 (control unit 102).

[0091] The pipe 116a and the valve 117a are housed in a housing 110ha of the first processing liquid cabinet 110A. When sulfuric acid circulates in the processing liquid cabinet 110, the sulfuric acid flows through the pipe 116a.

[0092] The pipe 118a1 is a tubular member through which sulfuric acid flows. The upstream end of the pipe 118a1 is connected to the pipe 112a.

[0093] The valve 119a is provided in the pipe 118a1. The valve 119a controls the start and stop of the flow of sulfuric acid through the pipe 118a1. The valve 119a is an open / close valve that can be opened and closed. When the valve 119a is open, the sulfuric acid flows through the pipe 118a1. When the valve 119a is closed, the flow of sulfuric acid through the pipe 118a1 stops. The opening and closing operation of the valve 119a is controlled by the control device 101 (control unit 102). The pipe 118a1 and the valve 119a are housed in a housing 110ha of the first processing liquid cabinet 110A.

[0094] Sulfuric acid flows from the first processing liquid cabinet 110A to the second unit 120t. The substrate processing apparatus 100 has a connection pipe 162a that connects the first processing liquid cabinet 110A and the second unit 120t. The connection pipe 162a is a tubular member through which sulfuric acid flows. An upstream end of the connection pipe 162a is connected to the pipe 118a1. The sulfuric acid flows from the first processing liquid cabinet 110A to the second unit 120t through the connection pipe 162a. For example, the connection pipe 162a is disposed outside the processing liquid cabinet 110 and the processing liquid box 120.

[0095] The second unit 120t has a pipe 122, a heater 124, and a housing 126. The pipe 122 and the heater 124 are housed in the housing 126. Sulfuric acid flows through the pipe 122. A downstream end of the connection pipe 162a is connected to the pipe 122.

[0096] The pipe 122 is a tubular member through which sulfuric acid flows. The sulfuric acid flowing from the first processing liquid cabinet 110A flows into the pipe 122. The sulfuric acid flowing through the pipe 122 of the second unit 120t flows out to the first unit 120s.

[0097] The heater 124 is provided in the pipe 122. Specifically, the heater 124 heats the sulfuric acid flowing through the pipe 122. The heater 124 heats the sulfuric acid to a temperature higher than that of the heater 114a. For example, the heater 124 heats the sulfuric acid to a temperature not lower than 150° C. and not higher than 230° C. Thus, the sulfuric acid heated by the heater 124 flows through the pipe 122.

[0098] The sulfuric acid from the second unit 120t flows into the first unit 120s. The first unit 120s has a pipe 122a through which the sulfuric acid from the second unit 120t flows. The pipe 122a is a tubular member through which the sulfuric acid flows. An upstream end of the pipe 122a of the first unit 120s is connected to the pipe 122 of the second unit 120t.

[0099] The pipe 122a is connected to the nozzle 36 of the substrate processing unit 10 via the pipe 32a. The valve 34a is provided in the pipe 32a. The valve 34a controls the start and stop of the flow of sulfuric acid in the pipe 32a. The valve 34a is an open / close valve that can be opened and closed. When the valve 34a is opened, sulfuric acid flows through the pipe 32a, and sulfuric acid or a processing liquid containing sulfuric acid is supplied to the substrate W via the nozzle 36. When the valve 34a is closed, the flow of sulfuric acid in the pipe 32a stops. The opening and closing operation of the valve 34a is controlled by the control device 101 (control unit 102). The pipe 32a and the valve 34a are housed in a housing 120hs of the first unit 120s.

[0100] The substrate processing apparatus 100 further includes a connection pipe 162b connecting the first unit 120s and the first processing liquid cabinet 110A. The connection pipe 162b is a tubular member through which sulfuric acid flows. An upstream end of the connection pipe 162b is connected to the pipe 122a. A downstream end of the connection pipe 162b is connected to the first processing liquid cabinet 110A. The sulfuric acid flows from the first unit 120s to the first processing liquid cabinet 110A through the connection pipe 162b. For example, the connection pipe 162b is disposed outside the processing liquid cabinet 110 and the processing liquid box 120.

[0101] The first processing liquid cabinet 110A further includes a pipe 118a2. An upstream end of the pipe 118a2 is connected to the connection pipe 162b. A downstream end of the pipe 118a2 is connected to the tank 111a.

[0102] As described above, the sulfuric acid stored in the tank 111a circulates in the first processing liquid cabinet 110A. When the pump 113a is driven with the valve 117a open and the valve 119a closed, the sulfuric acid stored in the tank 111a flows through the pipes 112a and 116a and circulates to the tank 111a.

[0103] Also, the sulfuric acid stored in the tank 111a circulates from the first processing liquid cabinet 110A through the second unit 120t and the first unit 120s of the processing liquid box 120 to the tank 111a of the first processing liquid cabinet 110A. When the pump 113a is driven with the valves 117a and 34a closed and the valve 119a open, the sulfuric acid stored in the tank 111a circulates to the tank 111a through the pipe 112a, the pipe 118a1, the connection pipe 162a, the pipe 122, the pipe 122a, the connection pipe 162b, and the pipe 118a2. In this way, the sulfuric acid stored in the tank 111a in the first processing liquid cabinet 110A circulates to the tank 111a in the first processing liquid cabinet 110A through the second unit 120t and the first unit 120s of the processing liquid box 120.

[0104] Hydrogen peroxide solution is supplied to the second processing liquid cabinet 110B. The second processing liquid cabinet 110B prepares hydrogen peroxide solution and supplies the hydrogen peroxide solution at a predetermined flow rate to the processing liquid box 120. For example, the second processing liquid cabinet 110B filters the hydrogen peroxide solution to remove foreign matter.

[0105] In detail, hydrogen peroxide solution is supplied to the second processing liquid cabinet 110B from a hydrogen peroxide supply unit 140. The hydrogen peroxide supply unit 140 has a pipe 142 and a valve 144. The hydrogen peroxide solution flows through the pipe 142. The valve 144 is provided in the pipe 142. The valve 144 adjusts the opening degree of the pipe 142 to adjust the flow rate of the hydrogen peroxide solution flowing through the pipe 142.

[0106] The second processing liquid cabinet 110B includes a tank 111b, a pipe 112b, a pump 113b, a filter 115b, a pipe 116b, a valve 117b, a pipe 118b1, a valve 119b, and a housing 110hb. The housing 110hb accommodates the tank 111b, the pipe 112b, the pump 113b, the filter 115b, the pipe 116b, the valve 117b, the pipe 118b1, and the valve 119b.

[0107] Tank 111b stores hydrogen peroxide solution supplied from pipe 142 of hydrogen peroxide supply unit 140. Pipe 112b is a tubular member through which hydrogen peroxide solution flows. Pipe 112b connects tank 111b to pipes 116b and 118b1. Pump 113b and filter 115b are disposed in pipe 112b.

[0108] Pump 113b is provided in pipe 112b. Pump 113b pumps hydrogen peroxide into pipe 112b. Specifically, hydrogen peroxide is pumped from pump 113b by being driven. As a result, hydrogen peroxide flows through pipe 112b. In this embodiment, pump 113b is driven by gas pressure. Pump 113b is controlled by control device 101 (control unit 102).

[0109] Filter 115b is provided in pipe 112b. Filter 115b removes foreign matter from the hydrogen peroxide solution flowing through pipe 112b. Specifically, filter 115b is provided downstream of pump 113b and removes foreign matter from the hydrogen peroxide solution pumped out from pump 113b. Here, filter 115b is disposed between pump 113b and the connection point between pipe 112b and pipe 116b. Therefore, clean hydrogen peroxide solution from which foreign matter has been removed flows through pipe 112b and pipe 116b.

[0110] Pipe 116b is a tubular member through which hydrogen peroxide flows. The upstream end of pipe 116b is connected to pipe 112b. The downstream end of pipe 116b is connected to tank 111b. The hydrogen peroxide flows and circulates through pipes 112b and 116b. More specifically, hydrogen peroxide flows from pipe 112b to the upstream end of pipe 116b, and then flows through pipe 116b. As a result, hydrogen peroxide flows out from the downstream end of pipe 116b, and the hydrogen peroxide returns to tank 111b.

[0111] Valve 117b is provided in pipe 116b. Valve 117b controls the start and stop of the flow of hydrogen peroxide solution in pipe 116b. Valve 117b is an open / close valve that can be opened and closed. When valve 117b is open, hydrogen peroxide solution flows through pipe 116b. When valve 117b is closed, the flow of hydrogen peroxide solution in pipe 116b stops. The opening and closing operation of valve 117b is controlled by control device 101 (control unit 102).

[0112] The pipe 116b and the valve 117b are housed in a housing 110hb of the second treatment liquid cabinet 110B. The pipe 116b circulates the hydrogen peroxide solution inside the second treatment liquid cabinet 110B.

[0113] The pipe 118b1 is a tubular member through which hydrogen peroxide flows. The upstream end of the pipe 118b1 is connected to the pipe 112b.

[0114] Valve 119b is provided in pipe 118b1. Valve 119b controls the start and stop of the flow of hydrogen peroxide solution in pipe 118b1. Valve 119b is an open / close valve that can be opened and closed. When valve 119b is open, hydrogen peroxide solution flows through pipe 118b1. When valve 119b is closed, the flow of hydrogen peroxide solution in pipe 118b1 stops. The opening and closing operation of valve 119b is controlled by control device 101 (control unit 102). Pipe 118b1 and valve 119b are housed in housing 110hb of second treatment liquid cabinet 110B.

[0115] The substrate processing apparatus 100 has a connection pipe 164a that connects the second processing liquid cabinet 110B and the first unit 120s. The connection pipe 164a is a tubular member through which hydrogen peroxide flows. An upstream end of the connection pipe 164a is connected to the pipe 118b1. The hydrogen peroxide flows from the second processing liquid cabinet 110B to the first unit 120s through the connection pipe 164a. For example, the connection pipe 164a is disposed inside the processing liquid cabinet 110.

[0116] The hydrogen peroxide solution flows from the second processing liquid cabinet 110B to the first unit 120s. The first unit 120s has a pipe 122b through which the hydrogen peroxide solution flows from the second processing liquid cabinet 110B. The pipe 122b is a tubular member through which the hydrogen peroxide solution flows. An upstream end of the pipe 122b of the first unit 120s is connected to the connection pipe 164a.

[0117] The pipe 122b is connected to the nozzle 36 of the substrate processing unit 10 via a pipe 32b.

[0118] Valve 34b is provided in pipe 32b. Valve 34b controls starting and stopping of the flow of hydrogen peroxide solution in pipe 32b. Valve 34b is an open / close valve that can be opened and closed. When valve 34b is opened, hydrogen peroxide solution flows through pipe 32b, and hydrogen peroxide solution or a processing liquid containing hydrogen peroxide solution is supplied to substrate W via nozzle 36. When valve 34b is closed, the flow of hydrogen peroxide solution in pipe 32b stops. The opening and closing operation of valve 34b is controlled by control device 101 (control unit 102). Pipe 32b and valve 34b are housed in housing 120hs of first unit 120s.

[0119] The substrate processing apparatus 100 further includes a connection pipe 164b connecting the first unit 120s and the second processing liquid cabinet 110B. The connection pipe 164b is a tubular member through which hydrogen peroxide flows. An upstream end of the connection pipe 164b is connected to the pipe 122b. A downstream end of the connection pipe 164b is connected to the second processing liquid cabinet 110B. The hydrogen peroxide flows from the first unit 120s to the second processing liquid cabinet 110B through the connection pipe 164b. For example, the connection pipe 164b is disposed inside the processing liquid cabinet 110.

[0120] The second processing liquid cabinet 110B further includes a pipe 118b2. An upstream end of the pipe 118b2 is connected to the connection pipe 162b. A downstream end of the pipe 118b2 is connected to the tank 111b.

[0121] The hydrogen peroxide solution stored in the tank 111b circulates in the second treatment liquid cabinet 110B. When the pump 113b is driven with the valve 117b open and the valve 119b closed, the hydrogen peroxide solution stored in the tank 111b flows through the pipes 112b and 116b and circulates to the tank 111b.

[0122] Moreover, the hydrogen peroxide solution stored in the tank 111b of the second processing liquid cabinet 110B flows from the second processing liquid cabinet 110B through the first unit 120s of the processing liquid box 120 and circulates to the tank 111b of the second processing liquid cabinet 110B. When the pump 113b is driven with the valves 117b and 34b closed and the valve 119b open, the hydrogen peroxide solution stored in the tank 111b flows through the pipe 112b, the pipe 118b1, the connection pipe 164a, the pipe 122b, the connection pipe 164b, and the pipe 118b2 and circulates to the tank 111b. In this way, the hydrogen peroxide solution stored in the tank 111b in the second processing liquid cabinet 110B circulates to the tank 111b in the second processing liquid cabinet 110B through the first unit 120s of the processing liquid box 120.

[0123] Here, high-temperature sulfuric acid is supplied to the second unit 120t. In addition, the sulfuric acid is further heated in the second unit 120t. Therefore, if the high-temperature sulfuric acid leaks from the second unit 120t, the housing 126 of the second unit 120t may be corroded by the high-temperature sulfuric acid.

[0124] As described above, the present inventors have found that stainless steel has corrosion resistance to hot sulfuric acid, and therefore, when stainless steel is used for the second unit 120t from which hot sulfuric acid may leak, it is possible to suppress corrosion by hot sulfuric acid.

[0125] As described above, the second unit 120t has the pipe 122, the heater 124, and the housing 126. Sulfuric acid flows through the pipe 122. The heater 124 is attached to the pipe 122. The heater 124 heats the sulfuric acid flowing through the pipe 122. The housing 126 accommodates the pipe 122 and the heater 124.

[0126] In this embodiment, the housing 126 of the second unit 120t includes stainless steel. This makes it possible to prevent the housing 126 of the second unit 120t from corroding even if high-temperature sulfuric acid leaks from inside the second unit 120t. The second unit 120t is an example of a sulfuric acid heating unit.

[0127] The housing 126 has a bottom member 126a and a wall member 126b. The bottom member 126a extends on a horizontal plane. The bottom member 126a is located below the pipe 122 and the heater 124. The bottom member 126a is located above the upper surface of the first unit 120s.

[0128] The wall member 126b extends in a vertical direction relative to the bottom member 126a. The wall member 126b extends in a vertical direction relative to the bottom member 126a from a side portion of the bottom member 126a. The wall member 126b surrounds at least a portion of the periphery of the pipe 122 and the heater 124.

[0129] In this embodiment, at least one of the bottom member 126a and the wall member 126b includes stainless steel. It is preferable that both the bottom member 126a and the wall member 126b include stainless steel.

[0130] The housing 126 may further include a ceiling member 126c. The ceiling member 126c extends in a horizontal plane facing the bottom member 126a. The ceiling member 126c extends from an upper portion of the wall member 126b in a direction perpendicular to the wall member 126b. The ceiling member 126c may include stainless steel.

[0131] Next, the second unit 120t in the substrate processing apparatus 100 of the present embodiment will be described with reference to Fig. 1 to Fig. 5. Fig. 5(a) is a schematic perspective view of the second unit 120t in the substrate processing apparatus 100 of the present embodiment, and Fig. 5(b) is a schematic exploded perspective view of the second unit 120t in the substrate processing apparatus 100 of the present embodiment. In Fig. 5(b), the frame member 126s and the electrical component 127 are omitted in order to avoid overly complicating the drawing.

[0132] 5(a) and 5(b), the second unit 120t includes a pipe 122, a heater 124, and a housing 126. As described above, sulfuric acid from the second processing liquid cabinet 110B flows into the pipe 122 of the second unit 120t. The sulfuric acid flowing through the pipe 122 of the second unit 120t flows out to the first unit 120s.

[0133] High-temperature sulfuric acid flows through the pipe 122. The pipe 122 is connected to a heater 124. The heater 124 heats the sulfuric acid flowing through the pipe 122. The heater 124 heats the sulfuric acid to 150° C. or higher and 230° C. or lower.

[0134] In this way, the sulfuric acid is heated in the second unit 120t, and the second unit 120t is an example of a sulfuric acid heating unit. The housing 126 of the second unit 120t includes stainless steel. This makes it possible to prevent the second unit 120t from corroding even if high-temperature sulfuric acid leaks from inside the second unit 120t.

[0135] The housing 126 has a frame member 126s, a bottom member 126a, and a wall member 126b. The frame member 126s has a frame shape made up of plates of different lengths and widths. The frame member 126s supports the bottom member 126a and the wall member 126b from below vertically. The frame member 126s is disposed on the upper surface of the first unit 120s.

[0136] The bottom member 126a is supported by a frame member 126s. The bottom member 126a extends on a horizontal plane. The bottom member 126a is disposed on the upper surface of the frame member 126s. The pipes 122 and the heater 124 are located above the bottom member 126a.

[0137] The wall member 126b extends in a vertical direction relative to the bottom member 126a. The wall member 126b extends in a vertical direction relative to the bottom member 126a from a side portion of the bottom member 126a.

[0138] The wall member 126b includes a first member 126b1, a second member 126b2, a third member 126b3, and a fourth member 126b4. The first member 126b1 to the fourth member 126b4 each extend in a vertical direction relative to the bottom member 126a. The first member 126b1 to the fourth member 126b4 surround the periphery of the pipe 122 and the heater 124.

[0139] An end portion on one side of the first member 126b1 is connected to an end portion on the other side of the second member 126b2. An end portion on one side of the second member 126b2 is connected to an end portion on the other side of the third member 126b3. An end portion on one side of the third member 126b3 is connected to an end portion on the other side of the fourth member 126b4. An end portion on one side of the fourth member 126b4 is connected to an end portion on the other side of the first member 126b1.

[0140] The housing 126 may further include a ceiling member 126c. The ceiling member 126c extends in a horizontal plane opposite the bottom member 126a. The ceiling member 126c extends from an upper portion of the wall member 126b in a direction perpendicular to the wall member 126b. The ceiling member 126c is located above the pipes 122 and the heater 124.

[0141] The housing 126 further includes a bracket 126d1 and a bracket 126d2. The bracket 126d1 connects the second member 126b2 and the fourth member 126b4. The bracket 126d1 supports the heater 124 from vertically below. The bracket 126d1 includes stainless steel.

[0142] The bracket 126d2 supports the ceiling member 126c from below. The bracket 126d2 connects the ceiling member 126c to at least one of the second member 126b2 and the fourth member 126b4. The bracket 126d2 may support the heater 124 from above. The bracket 126d2 includes stainless steel.

[0143] The second unit 120t further includes an electrical component 127. The electrical component 127 controls valves, sensors, etc. installed in the heater 124 and the pipes 122. The electrical component 127 is disposed on the frame member 126s. The electrical component 127 is disposed at a position away from the space surrounded by the first member 126b1 to the fourth member 126b4.

[0144] In this embodiment, at least a portion of the housing 126 includes stainless steel. This makes it possible to prevent the housing 126 from corroding even if high-temperature sulfuric acid leaking from the pipe 122 adheres to the housing 126.

[0145] For example, the bottom member 126a includes stainless steel, which can prevent the bottom member 126a from corroding even if high-temperature sulfuric acid leaking from the pipe 122 adheres to the bottom member 126a.

[0146] Alternatively, the wall member 126b includes stainless steel, which can prevent the wall member 126b from corroding even if high-temperature sulfuric acid leaking from the pipe 122 adheres to the wall member 126b.

[0147] In this embodiment, at least one of the bottom member 126a and the wall member 126b may contain stainless steel. This can prevent corrosion of at least one of the bottom member 126a and the wall member 126b. It is preferable that both the bottom member 126a and the wall member 126b contain stainless steel.

[0148] In this embodiment, the ceiling member 126c also preferably contains stainless steel, which can prevent the ceiling member 126c from corroding even if high-temperature sulfuric acid leaking from the pipe 122 adheres to the ceiling member 126c.

[0149] In the present embodiment, at least one of the brackets 126d1 and 126d2 includes stainless steel, which can prevent the ceiling member 126c from corroding even if high-temperature sulfuric acid leaking from the pipe 122 adheres to at least one of the brackets 126d1 and 126d2.

[0150] In the above description with reference to Figures 1 to 5, the second unit 120t has been described as an example of the sulfuric acid heating unit of this embodiment, but this embodiment is not limited thereto. The first processing liquid cabinet 110A may be the sulfuric acid heating unit of this embodiment. Alternatively, both the second unit 120t and the first processing liquid cabinet 110A may be the sulfuric acid heating unit of this embodiment.

[0151] In this case, the housing 110ha (FIG. 4) of the first processing liquid cabinet 110A contains stainless steel, which can prevent the housing 110ha of the first processing liquid cabinet 110A from corroding even if high-temperature sulfuric acid leaks into the first processing liquid cabinet 110A.

[0152] In the present embodiment, in the housing 110ha of the first processing liquid cabinet 110A, at least one of the bottom member and the wall member preferably includes stainless steel. Alternatively, in the housing 110ha of the first processing liquid cabinet 110A, the ceiling member may include stainless steel.

[0153] Stainless steel is an alloy steel that contains iron and at least chromium. Stainless steel contains iron and chromium. For example, stainless steel contains 10.5% or more chromium. The carbon concentration in stainless steel is 1.2% or less.

[0154] The stainless steel may contain at least one of nickel and molybdenum in addition to iron and chromium, or may contain at least one of nickel (Ni), molybdenum (Mo), copper (Cu), nitrogen (N), carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), and tantalum (Ta) in addition to iron and chromium.

[0155] The stainless steel may be any of austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, austenitic-ferritic stainless steel, and precipitation hardening stainless steel.

[0156] For example, the stainless steel may be an austenitic stainless steel. The austenitic stainless steel contains nickel and nickel in addition to iron. The stainless steel may contain 18% to 20% chromium and 8% to 10.5% nickel in addition to iron. In one example, the stainless steel may be SUS304. Alternatively, the stainless steel may contain 16% to 18% chromium, 10% to 14% nickel, and 2.0% to 3.0% molybdenum in addition to iron. In one example, the stainless steel may be SUS316L. Alternatively, the stainless steel may contain 19% to 21% chromium, 17.5% to 19.5% nickel, and 6.0% to 7.0% molybdenum in addition to iron. The stainless steel may be SUS312L.

[0157] Alternatively, the stainless steel may be a ferritic stainless steel. The ferritic stainless steel contains nickel. The stainless steel may contain 16% to 18% chromium in addition to iron. In one example, the stainless steel may be SUS430.

[0158] The stainless steel may be a duplex stainless steel that is a mixture of austenitic stainless steel and ferritic stainless steel in a ratio of 1:1. The stainless steel may be SUS821L1 or SUS329J4L.

[0159] In the above description, the second unit 120t of the processing liquid box 120 is located above the first unit 120s, but this embodiment is not limited to this. The second unit 120t may be disposed adjacent to the first unit 120s in the horizontal direction.

[0160] In the above description, the second unit 120t and the first processing liquid cabinet 110A are sulfuric acid heating units, but the first unit 120s may be a sulfuric acid heating unit. Typically, however, a chemical solution other than sulfuric acid and hydrogen peroxide solution flows through the first unit 120s. For this reason, it is preferable that the housing 120hs of the first unit 120s is made of a material other than stainless steel. For example, it is preferable that the housing 120hs of the first unit 120s is made of fluororesin. EXAMPLES

[0161] It was confirmed that stainless steel has corrosion resistance to hot sulfuric acid.

[0162] A thin plate made of fluororesin (alternating copolymer resin of ethylene and chlorotrifluoroethylene: ECTFE) was prepared as sample X. The size and weight of sample X were measured. The size of sample X was 50.01 mm in length, 20.01 mm in width, and 4.86 mm in thickness, and the weight of sample X was 8.171 g.

[0163] (Sulfuric acid immersion) After putting sulfuric acid with a concentration of 96% into a beaker, sample X was entirely immersed in the sulfuric acid in the beaker. Then, while sample X was immersed in the sulfuric acid in the beaker, the heater was turned on to heat the sulfuric acid, and the temperature of the sulfuric acid was raised from room temperature to 190°C over 30 minutes, as shown in Figure 6. After that, the temperature was kept at 190°C for 30 seconds, the heater was turned off, and the sulfuric acid was allowed to cool naturally, and the temperature of the sulfuric acid dropped to 40°C over 30 minutes. The temperature of the sulfuric acid was measured using a thermocouple.

[0164] After immersing Sample X in sulfuric acid for one day, the size and weight of Sample X were measured again. By immersing Sample X in sulfuric acid, the size of Sample X changed from 50.01 mm in length, 20.01 mm in width, and 4.86 mm in thickness to 50.00 mm in length, 20.00 mm in width, and 4.88 mm in thickness. The weight of Sample X increased by 0.005 g (0.06%) from 8.171 g to 8.176 g.

[0165] The table below shows the change in size of sample X due to immersion in sulfuric acid.

[0166] [Table 1]

[0167] [Table 2]

[0168] After that, Sample X was immersed in sulfuric acid for four weeks, and then the appearance of Sample X was visually inspected. No cracks, stickiness, or roughness were found in Sample X. However, Sample X and the sulfuric acid discolored.

[0169] The results of the visual inspection of sample X are shown in the table below.

[0170] [Table 3]

[0171] The ECTFE of sample X is known to have corrosion resistance against sulfuric acid. The test results of samples A to H were evaluated with reference to the test results of sample X.

[0172] (Sample A) A thin plate made of SUS304 was prepared as sample A. The size and weight of sample A were measured. The size of sample A was 50.16 mm in length, 25.07 mm in width, and 2.94 mm in thickness, and the weight of sample A was 28.2233 g.

[0173] (Sample A immersed in sulfuric acid) After pouring sulfuric acid with a concentration of 96% into a beaker, sample A was entirely immersed in the sulfuric acid in the beaker. Then, while sample A was immersed in the sulfuric acid in the beaker, the heater was turned on to heat the sulfuric acid and raise the temperature of the sulfuric acid from room temperature to 190°C over 30 minutes, as shown in Figure 6. After that, the temperature was maintained at 190°C for 30 seconds, the heater was turned off, and the sulfuric acid was allowed to cool naturally, and the temperature of the sulfuric acid dropped to 40°C over 30 minutes.

[0174] After one day had passed since sample A was immersed in sulfuric acid, the size and weight of sample A were measured again. By immersing in sulfuric acid, the size of sample A changed from 50.16 mm in length, 25.07 mm in width, and 2.94 mm in thickness to 50.16 mm in length, 25.06 mm in width, and 2.95 mm in thickness. The weight of sample X decreased by 0.008 g from 28.2233 g to 28.2148 g.

[0175] The table below shows the change in size and the change in weight of sample A due to immersion in sulfuric acid.

[0176] [Table 4]

[0177] [Table 5]

[0178] (Samples B-D) Samples B to D were prepared, and the corrosion of the samples by sulfuric acid was confirmed in the same manner as for sample A.

[0179] (Sample B) A thin plate made of SUS430 was prepared as sample B. The size and weight of sample B were measured. The size of sample B was 49.98 mm, width 25.14 mm, and thickness 2.90 mm, and the weight of sample B was 26.8479 g.

[0180] After immersing sample B in sulfuric acid and changing the temperature of the sulfuric acid, the size and weight of sample B were measured again one day. By immersing in sulfuric acid, the size of sample B changed from 49.98 mm in length, 25.14 mm in width, and 2.90 mm in thickness to 49.99 mm in length, 25.13 mm in width, and 2.90 mm in thickness. The weight of sample B decreased by 0.033 g from 26.8479 g to 26.8151 g.

[0181] The table below shows the change in size and the change in weight of sample B due to immersion in sulfuric acid.

[0182] [Table 6]

[0183] [Table 7]

[0184] (Sample C) A thin plate made of NSSC2120 was prepared as sample C. The size and weight of sample C were measured. The size of sample C was 49.94 mm in length, 25.04 mm in width, and 2.95 mm in thickness, and the weight of sample C was 27.8210 g.

[0185] After immersing sample C in sulfuric acid and changing the temperature of the sulfuric acid, the size and weight of sample C were measured again one day later. The size of sample C changed from 49.94 mm in length, 25.04 mm in width, and 2.95 mm in thickness to 49.94 mm in length, 25.03 mm in width, and 2.94 mm in thickness. The weight of sample B decreased by 0.007 g from 27.8210 g to 27.8143 g.

[0186] The table below shows the change in size and the change in weight of sample C due to immersion in sulfuric acid.

[0187] [Table 8]

[0188] [Table 9]

[0189] (Sample D) A thin plate made of NSSC2351 was prepared as Sample D. The size and weight of Sample D were measured. The size of Sample D was 49.98 mm in length, 25.14 mm in width, and 2.90 mm in thickness, and the weight of Sample D was 27.6328 g.

[0190] After immersing Sample D in sulfuric acid and changing the temperature of the sulfuric acid, the size and weight of Sample D were measured again one day later. The size of Sample D changed from 49.98 mm in length, 25.14 mm in width, and 2.90 mm in thickness to 49.99 mm in length, 25.13 mm in width, and 2.90 mm in thickness. The weight of Sample D decreased by 0.006 g from 27.6328 g to 27.6266 g.

[0191] The table below shows the change in size and the change in weight of sample D due to immersion in sulfuric acid.

[0192] [Table 10]

[0193] [Table 11]

[0194] As with sample X, samples A to D were also immersed in sulfuric acid for four weeks, and then visually inspected to see that they had no cracks, stickiness, or roughness. However, samples A to D discolored, and the sulfuric acid also discolored.

[0195] (corrosion rate) The corrosion rate was calculated from the results of samples A to D according to (Equation 1). Corrosion rate [mm / year] = ΔW / (S t)×8.761 / ρ (Formula 1) Here, ΔW is the weight loss (g) before and after the immersion test, and S is the surface area (m 2 ), t is the test period (hours), and ρ is the specific gravity of the sample (g / cm 3 The corrosion rates of samples A to D are shown below.

[0196] [Table 12]

[0197] Generally, a corrosion rate of 1.00 [mm / year] or less is required as an index of corrosion resistance that can withstand use, but the corrosion rates of all of Samples A to D were below the threshold, and it was found that all of Samples A to D had corrosion resistance to high-temperature sulfuric acid. In addition, it is preferable that the corrosion rate is 0.12 [mm / year] or less.

[0198] The corrosion rates of Samples E to H were calculated in the same manner as for Samples A to D. The materials of Samples A to H are shown below. Sample A: SUS304 Sample B: SUS430 Sample C: NSSC2120 Sample D: NSSC2351 Sample E: MAT21 Sample F: SUS316L Sample G: SUS312L Sample H: SUS329J4L

[0199] The corrosion rates of samples A to H are shown below.

[0200] [Table 13]

[0201] As described above, the corrosion rate of all of the samples A to H was below the threshold value, and it was found that all of the samples A to H had corrosion resistance to high-temperature sulfuric acid. Therefore, it was confirmed that the corrosion of stainless steel in high-temperature sulfuric acid can be suppressed.

[0202] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all components shown in the embodiments. Furthermore, components across different embodiments may be appropriately combined. The drawings are mainly shown schematically for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various changes are possible within a range that does not substantially deviate from the effects of the present invention.

[0203] For example, in the above description, the substrate W is a semiconductor wafer, but the substrate W is not limited to a semiconductor wafer. For example, the substrate W may be a substrate for a liquid crystal display device, a substrate for a field emission display (FED), a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, or a substrate for a solar cell. [Industrial Applicability]

[0204] The present invention can be suitably used in a sulfuric acid heating unit and a substrate processing apparatus. [Explanation of symbols]

[0205] 10 Substrate Processing Unit 20 Board holding part 30 Processing liquid supply unit 100 Substrate processing apparatus 110 Processing liquid cabinet 120 Processing liquid box W substrate

Claims

1. The pipes through which sulfuric acid flows, A heater that heats the sulfuric acid flowing through the pipe; a housing for accommodating the piping and the heater; Equipped with A sulfuric acid heating unit, wherein at least a portion of the housing comprises stainless steel.

2. The housing includes: a bottom member located below the piping and the heater; a wall member extending vertically from the bottom member; Including, The sulfuric acid heating unit of claim 1 , wherein at least one of the bottom member and the wall member comprises stainless steel.

3. The housing further includes a ceiling member extending from the wall member and facing the bottom member, The sulfuric acid heating unit of claim 2 , wherein the ceiling member comprises stainless steel.

4. The housing includes: a bottom member located below the piping and the heater; a wall member extending vertically from the bottom member; A bracket for connection to the wall member; Including, The sulfuric acid heating unit of claim 1 , wherein the bracket comprises stainless steel.

5. A sulfuric acid heating unit according to any one of claims 1 to 4, a substrate processing unit for processing a substrate with a processing liquid containing sulfuric acid heated in the sulfuric acid heating unit; The substrate processing apparatus includes:

6. a processing liquid box arranged around the substrate processing unit and supplying the sulfuric acid or the processing liquid to the substrate processing unit; The substrate processing apparatus according to claim 5 , wherein the processing liquid box includes the sulfuric acid heating unit.

7. a processing liquid box arranged around the substrate processing unit and supplying the sulfuric acid or the processing liquid to the substrate processing unit; a processing solution cabinet for supplying the sulfuric acid to the processing solution box; Further equipped with The substrate processing apparatus according to claim 5 , wherein the processing liquid cabinet includes the sulfuric acid heating unit.

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