Substrate processing equipment

Abstract

The present invention relates to a substrate processing device. A quartz heater (41) having a quartz tube (47) is provided in a concentration pipe (39) as part of a first circulation pipe (35). Two ends (36A) and (36B) of a first detour pipe (36) are connected to the upstream end and downstream end of the concentration pipe (39). A non-quartz heater (45) having a non-quartz tube (51) is provided in the first detour pipe (36). When concentrating the phosphoric acid solution in the first tank (T1), the control unit (93) heats the phosphoric acid solution passing through the concentration pipe (39) by using the quartz heater (41) while transporting the phosphoric acid solution to the concentration pipe (39). When the concentration of the phosphoric acid solution in the first tank (T1) is completed, the control unit (93) heats the phosphoric acid solution passing through the first detour pipe (36) by using the non-quartz heater (45).

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus for processing substrates. Examples of such substrates include semiconductor substrates, FPD (Flat Panel Display) substrates, mask glass substrates, optical disk substrates, magnetic disk substrates, ceramic substrates, and solar cell substrates. Examples of FPDs include liquid crystal displays and organic EL (electroluminescence) displays. Background Art

[0002] Conventional substrate processing equipment includes a processing tank, an outer tank, and a circulation line (see, for example, Patent Document 1). The processing tank stores a phosphoric acid solution. Substrates are processed by immersing them in the phosphoric acid solution within the processing tank. The outer tank is located outside the processing tank and receives phosphoric acid solution that overflows from the processing tank. The circulation line is configured to return the phosphoric acid solution discharged from the outer tank to the processing tank. The circulation line is equipped with a circulation pump and a thermostat.

[0003] The substrate processing apparatus also includes a pre-temperature control unit. This pre-temperature control unit contains a container for storing a phosphoric acid solution (processing liquid). Phosphoric acid (phosphoric acid solution) or pure water is supplied to this container from a chemical supply source. The phosphoric acid solution supplied to the container is circulated while its temperature is controlled. The temperature-controlled phosphoric acid solution is then supplied to the processing tank via an external tank and a circulation line.

[0004] For example, a 3D-NAND (Three-Dimensional NOT-AND) device is a non-volatile memory device. During the manufacturing process, a structure consisting of alternating layers of silicon nitride and silicon oxide films is formed on a substrate. The silicon nitride film is then selectively etched using a phosphoric acid solution.

[0005] Adding silicon to a phosphoric acid solution increases the etching rate of the silicon nitride film relative to the silicon oxide film. In other words, when the silicon concentration in the phosphoric acid solution is within an appropriate range, the etching rate of the silicon oxide film is sufficiently lower than that of the silicon nitride film. As a result, the silicon nitride film on the substrate is selectively etched (see, for example, Patent Documents 2 and 3).

[0006] [Background Art Literature]

[0007] [Patent Document]

[0008] [Patent Document 1]

[0009] Japanese Patent Application Publication No. 2018-050001

[0010] [Patent Document 2]

[0011] Japanese Patent Application Laid-Open No. 2020-088003

[0012] [Patent Document 3]

[0013] Japanese Patent Application Laid-Open No. 2015-177139 Summary of the Invention

[0014] [Problems to be solved by the invention]

[0015] However, conventional substrate processing apparatuses have the following problems. The silicon concentration of the phosphoric acid solution supplied from the pre-temperature control unit is assumed to be 0 (zero) ppm or a concentration close to 0 ppm. However, the inventors have confirmed that the silicon concentration of the phosphoric acid solution supplied from the pre-temperature control unit exceeds the assumed concentration and is high. The substrate processing apparatus supplies the phosphoric acid solution to the processing unit (e.g., a processing tank) based on the assumption that the silicon concentration of the phosphoric acid solution is 0 ppm or a concentration close to 0 ppm. However, if the actual silicon concentration is higher, for example, more phosphoric acid solution than the assumed amount may continue to be supplied from the pre-temperature control unit, thereby affecting the processing.

[0016] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate processing apparatus capable of preventing the silicon concentration of a phosphoric acid solution supplied to a processing unit from becoming high.

[0017] [Technical means to solve the problem]

[0018] The inventors have diligently studied to solve the above-mentioned problem and have come to the conclusion that the increase in silicon concentration is caused by the dissolution of silicon from the quartz parts of the heater.

[0019] The present invention, which is based on the above findings, has the following structure. That is, the substrate processing apparatus of the present invention is characterized by comprising: a processing section having a processing tank storing a phosphoric acid solution for immersing a substrate; a tank storing the phosphoric acid solution; a supply flow path for conveying the phosphoric acid solution in the tank to the processing section; a circulation flow path connected at both ends to the tank for returning the phosphoric acid solution flowing from the tank to the tank; a pump provided in the circulation flow path; a quartz heater provided in a concentration flow path as a part of the circulation flow path, having a quartz tube formed of quartz and for passing the phosphoric acid solution; a detour flow path connected at both ends to the upstream and downstream ends of the concentration flow path; a non-quartz a heater disposed in the detour flow path and comprising a non-quartz tube that is not formed of quartz and is used to pass the phosphoric acid solution; and a control unit; when concentrating the phosphoric acid solution in the tank, the control unit heats the phosphoric acid solution passing through the concentrating flow path while conveying the phosphoric acid solution to the concentrating flow path; and when concentrating the phosphoric acid solution in the tank is completed, the control unit conveys the phosphoric acid solution to the detour flow path and heats the phosphoric acid solution passing through the detour flow path using the non-quartz heater, thereby maintaining the temperature of the phosphoric acid solution in the tank.

[0020] According to the substrate processing apparatus of the present invention, a quartz heater is provided in the concentration flow path, which is part of the circulation flow path, and a non-quartz heater is provided in the detour flow path that bypasses the quartz heater. When concentrating the phosphoric acid solution in the tank, the quartz heater is used to heat the phosphoric acid solution passing through the concentration flow path. After concentration of the phosphoric acid solution in the tank is complete, the non-quartz heater is used to heat the phosphoric acid solution passing through the detour flow path to maintain the temperature of the phosphoric acid solution in the tank. The use of the non-quartz heater prevents silicon from dissolving into the phosphoric acid solution, reducing silicon dissolution into the phosphoric acid solution overall. Consequently, it is possible to prevent the phosphoric acid solution supplied to the processing unit from having a high silicon concentration.

[0021] In addition, the substrate processing apparatus preferably further includes a phosphoric acid concentration sensor for measuring the concentration of the phosphoric acid solution in the tank. When the concentration value measured by the phosphoric acid concentration sensor is less than a predetermined threshold value, the control unit concentrates the phosphoric acid solution in the tank. When the concentration value measured by the phosphoric acid concentration sensor is greater than the threshold value, the control unit determines that the concentration of the phosphoric acid solution in the tank is complete and maintains the temperature of the phosphoric acid solution in the tank. Thus, heating by the quartz heater and heating by the non-quartz heater can be switched based on the concentration value measured by the phosphoric acid concentration sensor.

[0022] Furthermore, in the substrate processing apparatus, the control unit preferably uses the quartz heater to heat the phosphoric acid solution flowing through the concentration flow path so that the temperature of the phosphoric acid solution in the tank reaches a predetermined first temperature when concentrating the phosphoric acid solution in the tank. Furthermore, the control unit preferably uses the non-quartz heater to heat the phosphoric acid solution flowing through the detour flow path so that the temperature of the phosphoric acid solution in the tank reaches a second temperature lower than the first temperature when maintaining the temperature of the phosphoric acid solution in the tank. This suppresses the output of the non-quartz heater, thereby preventing damage to the non-quartz tube.

[0023] In the substrate processing apparatus, the first temperature is preferably equal to or higher than the boiling point of the phosphoric acid solution. If the first temperature is equal to or higher than the boiling point of the phosphoric acid solution, concentration can be further promoted.

[0024] In the substrate processing apparatus, the second temperature is preferably 100°C or higher and lower than the boiling point of the phosphoric acid solution. When the temperature of the phosphoric acid solution is lower than 100°C, the phosphoric acid solution absorbs water. By keeping the temperature of the phosphoric acid solution at 100°C or higher, the phosphoric acid solution is prevented from absorbing water.

[0025] Furthermore, the substrate processing apparatus preferably includes a supply channel heater disposed in the supply channel for heating the phosphoric acid solution passing through the supply channel. This can suppress the temperature difference when the temperature of the phosphoric acid solution supplied to the processing unit through the supply channel is lower than the temperature of the phosphoric acid solution within the processing tank of the processing unit.

[0026] The substrate processing apparatus preferably further includes a bubble supply unit disposed on the bottom wall of the tank and having a plurality of holes configured to supply bubbles into the tank through the holes. This facilitates concentration of the phosphoric acid solution.

[0027] Furthermore, in the substrate processing apparatus, preferably, the control unit supplies the phosphoric acid solution to the processing unit via the supply flow path during substrate processing in which the substrate is immersed in the processing tank. This allows the phosphoric acid solution in the processing tank to be replaced gradually, thereby suppressing an increase in the silicon concentration in the phosphoric acid solution within the processing tank.

[0028] Furthermore, in the substrate processing apparatus, preferably, during substrate processing in which a substrate is immersed in the processing tank, the control unit supplies the phosphoric acid solution to the processing unit via the supply flow path while partially discharging the phosphoric acid solution from the processing tank. This allows the phosphoric acid solution in the processing tank to be partially replaced, thereby significantly reducing the silicon concentration in the phosphoric acid solution.

[0029] In the substrate processing apparatus, an example of the non-quartz tube is a fluorine-based resin tube made of fluorine-based resin, which can prevent silicon from eluting from the heater component into the phosphoric acid solution.

[0030] In addition, the substrate processing apparatus is preferably provided with: a second tank interposed in a supply flow path for conveying the phosphoric acid solution from the tank to the processing unit, storing the phosphoric acid solution conveyed from the tank; a second circulation flow path connected at both ends to the second tank, for returning the phosphoric acid solution flowing from the second tank to the second tank; a second pump provided in the second circulation flow path; a second quartz heater provided in a second concentration flow path as a part of the second circulation flow path, having a second quartz tube formed of quartz and for passing the phosphoric acid solution; a second detour flow path connected at both ends to the upstream end and the downstream end of the second concentration flow path; and a second non-quartz heater. The device is provided in the second detour flow path and has a second non-quartz tube that is not formed of quartz and is used to allow the phosphoric acid solution to pass through. When the phosphoric acid solution in the second tank is concentrated, the control unit transports the phosphoric acid solution to the second concentration flow path while heating the phosphoric acid solution passing through the second concentration flow path using the second quartz heater. When concentration of the phosphoric acid solution in the second tank is completed, the control unit transports the phosphoric acid solution to the second detour flow path while heating the phosphoric acid solution passing through the second detour flow path using the second non-quartz heater, thereby maintaining the temperature of the phosphoric acid solution in the second tank.

[0031] After the concentration of the phosphoric acid solution in the second tank is complete and the temperature of the phosphoric acid solution in the second tank is maintained, a second non-quartz heater is used to heat the phosphoric acid solution passing through the second detour flow path. Using the second non-quartz heater prevents silicon from dissolving into the phosphoric acid solution, reducing silicon dissolution into the phosphoric acid solution overall. This prevents the phosphoric acid solution supplied to the processing unit from reaching a high silicon concentration.

[0032] Furthermore, the substrate processing apparatus preferably includes: a second tank interposed in a supply flow path for supplying the phosphoric acid solution from the tank to the processing unit, the supply path storing the phosphoric acid solution supplied from the tank; a second circulation flow path connected at both ends to the second tank, the supply path returning the phosphoric acid solution flowing from the second tank to the second tank; a second pump disposed in the second circulation flow path; and a second quartz heater disposed in the second circulation flow path, the heater having a second quartz tube formed of quartz and for passing the phosphoric acid solution; wherein the control unit, when concentrating the phosphoric acid solution in the tank, heats the phosphoric acid solution passing through the concentration flow path using the quartz heater so that the temperature of the phosphoric acid solution in the tank reaches a predetermined first temperature; and wherein the control unit, in order to maintain the concentration of the phosphoric acid solution, heats the phosphoric acid solution passing through the second circulation flow path using the second quartz heater so that the temperature of the phosphoric acid solution in the second tank reaches a second temperature lower than the first temperature, thereby maintaining the temperature of the phosphoric acid solution in the second tank.

[0033] Furthermore, the substrate processing apparatus preferably includes: a second tank interposed in a supply flow path for supplying the phosphoric acid solution from the tank to the processing unit, the second tank storing the phosphoric acid solution supplied from the tank; a second circulation flow path connected at both ends to the second tank, the second tank returning the phosphoric acid solution flowing into the second tank; a second pump disposed in the second circulation flow path; and a second quartz heater disposed in the second circulation flow path, the second quartz heater having a second quartz tube formed of quartz and for passing the phosphoric acid solution; wherein the control unit, when concentrating the phosphoric acid solution in the second tank, heats the phosphoric acid solution passing through the second circulation flow path using the second quartz heater so that the temperature of the phosphoric acid solution in the second tank reaches a predetermined first temperature; and upon completion of concentration of the phosphoric acid solution in the second tank, the control unit, when concentrating the phosphoric acid solution in the second tank, heats the phosphoric acid solution passing through the second circulation flow path using the second quartz heater so that the temperature of the phosphoric acid solution in the second tank reaches a second temperature lower than the first temperature.

[0034] After the phosphoric acid solution is concentrated, the temperature of the phosphoric acid solution is maintained at a second temperature lower than the first temperature set during concentration. By lowering the heating temperature of the second quartz heater, silicon dissolution from the second quartz tube of the second quartz heater can be suppressed. As a result, overall silicon dissolution into the phosphoric acid solution is reduced. This prevents the phosphoric acid solution supplied to the processing unit from reaching a high silicon concentration.

[0035] In addition, the substrate processing apparatus of the present invention is characterized by comprising: a processing portion having a processing tank storing a phosphoric acid solution for immersing a substrate; a tank storing the phosphoric acid solution; a supply flow path for conveying the phosphoric acid solution in the tank to the processing portion; a circulation flow path connected to the tank at both ends for returning the phosphoric acid solution flowing from the tank to the tank; a pump provided in the circulation flow path; a quartz heater provided in the circulation flow path and having a quartz tube formed of quartz and through which the phosphoric acid solution passes; and a control portion; wherein the control portion uses the quartz heater to heat the phosphoric acid solution passing through the circulation flow path so that the temperature of the phosphoric acid solution in the tank reaches a predetermined first temperature when concentrating the phosphoric acid solution in the tank; and when the concentration of the phosphoric acid solution in the tank is completed, the control portion uses the quartz heater to heat the phosphoric acid solution passing through the circulation flow path so that the temperature of the phosphoric acid solution in the tank reaches a second temperature lower than the first temperature.

[0036] According to the substrate processing apparatus of the present invention, when concentrating the phosphoric acid solution in the tank, a quartz heater is used to heat the phosphoric acid solution passing through the circulation path so that the temperature of the phosphoric acid solution in the tank reaches a first temperature. After the concentration of the phosphoric acid solution in the tank is completed and the temperature of the phosphoric acid solution in the tank is maintained, the quartz heater is used to heat the phosphoric acid solution passing through the circulation path so that the temperature of the phosphoric acid solution in the tank reaches a second temperature lower than the first temperature. Although the quartz heater is used, raising the temperature to the second temperature lower than the first temperature reduces the dissolution of silicon into the phosphoric acid solution at the second temperature compared to the first temperature. This prevents the phosphoric acid solution supplied to the processing unit from reaching a high silicon concentration.

[0037] [Effects of the Invention]

[0038] According to the substrate processing apparatus of the present invention, it is possible to prevent the silicon concentration of the phosphoric acid solution supplied to the processing unit from becoming high. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a diagram showing a substrate processing apparatus according to Examples 1 and 2.

[0040] Figure 2 This is a diagram showing a processing unit.

[0041] Figure 3 (a) is a diagram showing a quartz heater, Figure 3 (b) is a diagram showing a non-quartz heater.

[0042] Figure 4 This is a flowchart for explaining the operation of the pre-temperature adjustment unit of the first embodiment.

[0043] Figure 5This is a flowchart for explaining the operation of the pre-temperature adjustment unit of the second embodiment.

[0044] Figure 6 This is a diagram showing a substrate processing apparatus according to a third embodiment.

[0045] Figure 7 This is a flowchart for explaining the operation of the pre-temperature adjustment unit of the third embodiment.

[0046] Figure 8 This is a graph showing the relationship between the expected silicon concentration and the temperature control time.

[0047] Figure 9 This is a diagram showing a substrate processing apparatus according to a fourth embodiment.

[0048] Figure 10 This is a flowchart for explaining the operation of the pre-temperature adjustment unit of the fourth embodiment.

[0049] Figure 11 This is a diagram showing a substrate processing apparatus according to a fifth embodiment.

[0050] Figure 12 This is a flowchart for explaining the operation of the pre-temperature adjustment unit of the fifth embodiment. DETAILED DESCRIPTION

[0051] [Example 1]

[0052] Hereinafter, Example 1 of the present invention will be described with reference to the accompanying drawings. Figure 1 It is a diagram showing the substrate processing apparatus 1 . Figure 2 It is a diagram showing the processing unit 2A (2B / 2C).

[0053] (1) Configuration of substrate processing apparatus 1

[0054] Reference Figure 1 The substrate processing apparatus 1 is a batch type apparatus that collectively processes a plurality (eg, 50) of substrates W. The substrate processing apparatus 1 includes three processing sections 2A, 2B, and 2C, and a pre-temperature control unit 4. The number of processing sections is not limited to three.

[0055] The structure of the processing unit 2A will be described. The two processing units 2B and 2C are respectively configured in the same manner as the processing unit 2A. Figure 2 The processing section 2A includes a processing tank 6 , an outer tank 7 , a tank heater 8 , a processing section circulation flow path 9 , and an elevator (substrate holding section) 11 .

[0056] Treatment tank 6 is a container for storing phosphoric acid solution. Phosphoric acid solution is a solution containing phosphoric acid and pure water. External tank 7 is located around treatment tank 6. External tank 7 receives phosphoric acid solution that overflows from treatment tank 6. External tank 7 is connected to drain pipe 14. When the level of the phosphoric acid solution in external tank 7 reaches or exceeds the level of inlet 14A of drain pipe 14, the phosphoric acid solution in external tank 7 flows out into drain pipe 14.

[0057] Tank heater 8 is installed on the outer walls of treatment tank 6 and outer tank 7. Tank heater 8 heats the phosphoric acid solution in treatment tank 6 and outer tank 7 from outside of treatment tank 6 and outer tank 7. Tank heater 8 and heater 19, described below, heat the phosphoric acid solution in treatment tank 6 to a predetermined temperature (e.g., 160°C).

[0058] The processing unit circulation flow path 9 includes, for example, piping. The processing unit circulation flow path 9 connects the outer tank 7 and the processing tank 6. Specifically, the processing unit circulation flow path 9 connects the bottom of the outer tank 7 to a discharge pipe 15 provided at the bottom of the processing tank 6. The discharge pipe 15 has a discharge port for discharging the phosphoric acid solution. The processing unit circulation flow path 9 returns the phosphoric acid solution flowing from the outer tank 7 to the processing tank 6 via the discharge pipe 15. Furthermore, the processing unit circulation flow path 9 includes, in order from the outer tank 7 side, a pump 17, a heater 19, a filter 21, and a silicon concentration sensor 23.

[0059] Pump 17 pumps the phosphoric acid solution within treatment unit circulation flow path 9. Heater 19 heats the phosphoric acid solution passing through treatment unit circulation flow path 9. Filter 21 removes particles from the phosphoric acid solution returning to treatment tank 6. Silicon concentration sensor 23 measures the silicon concentration of the phosphoric acid solution passing through treatment unit circulation flow path 9.

[0060] The lifter 11 holds multiple substrates W, to be processed, in an upright position at equal intervals. The lifter 11 includes a backing plate 11A and multiple (three) support members 11B fixed to the bottom of the backing plate 11A. The support members 11B are parallel to each other and extend horizontally. The support members 11B hold multiple substrates W.

[0061] The processing unit 2A also includes multiple bubble supply tubes 25, a gas supply source 27, a supply pipe 28, and an on-off valve V21. Each bubble supply tube 25 is located at or near the bottom of the processing tank 6. Each bubble supply tube 25 has multiple holes through which bubbles are supplied into the phosphoric acid solution. This allows bubbles to enter between the two substrates W, promoting the replacement of the phosphoric acid solution between the two substrates W. Gas (an inert gas such as nitrogen) from the gas supply source 27 is delivered to the multiple bubble supply tubes 25 via the supply pipe 28. The on-off valve V21 controls the supply and stop of gas.

[0062] Furthermore, a discharge pipe 30 is connected to the bottom of the treatment tank 6. The discharge pipe 30 is provided with an on-off valve V22. The discharge pipe 30 is used to discharge the phosphoric acid solution in the treatment tank 6. The on-off valve V22 controls the discharge and stop of the phosphoric acid solution.

[0063] The processing unit 2A includes a temperature sensor TS11 for measuring the temperature of the phosphoric acid solution within the processing tank 6. The processing unit 2A controls the tank heater 8 and heater 19 so that the temperature measured by the temperature sensor TS11 reaches a preset temperature (160°C). Alternatively, at least one of an unconcentrated phosphoric acid solution and deionized water (DIW) may be directly supplied to the processing tank 6. Furthermore, the processing unit 2A may include a phosphoric acid concentration sensor for measuring the phosphoric acid concentration of the phosphoric acid solution within the processing tank 6, the external tank 7, or the processing unit circulation flow path 9.

[0064] (1-1) Configuration of the Pre-temperature Control Unit 4

[0065] Return to Figure 1 . The pre-temperature adjustment unit 4 supplies the phosphoric acid solution to each treatment section 2A, 2B, and 2C. The pre-temperature adjustment unit 4 includes a pre-circulation section 31 and a main circulation section 33. Generally, the phosphoric acid solution circulated on the market has a phosphoric acid concentration of 85% at room temperature. The pre-circulation section 31 heats the phosphoric acid solution having a phosphoric acid concentration of 85%. As a result, the water content of the phosphoric acid solution is blown away, and the phosphoric acid concentration is concentrated to 88-89%. The main circulation section 33 stabilizes the phosphoric acid concentration and the temperature of the phosphoric acid solution. First, the structure of the pre-circulation section 31 is described.

[0066] The pre-circulation section 31 includes a first tank T1, a first circulation pipe 35, a first bypass pipe 36, and a first supply pipe 37. The first circulation pipe 35 corresponds to the circulation flow path of the present invention. The first bypass pipe 36 corresponds to the bypass flow path of the present invention.

[0067] The first tank T1 is a container for storing a phosphoric acid solution. Furthermore, the first tank T1 and the second tank T2 described below are configured to be deaerated. The first tank T1 includes an outlet OL1 and an inlet IL1. The outlet OL1 is located at the bottom of the first tank T1, and the inlet IL1 is located on the top wall of the first tank T1.

[0068] The first circulation pipe 35 has two ends 35A and 35B connected to the first tank T1. Specifically, the first end 35A of the first circulation pipe 35 is connected to the outlet OL1 of the first tank T1, and the second end 35B of the first circulation pipe 35 is connected to the inlet IL1 of the first tank T1. The first circulation pipe 35 is used to return the phosphoric acid solution flowing into the first tank T1 to the first tank T1.

[0069] The concentration pipe 39 is part of the first circulation pipe 35. Two quartz heaters 41 (41A, 41B) are provided in series in the concentration pipe 39. A first pump 43 is provided in the first circulation pipe 35 between the outlet OL1 and the quartz heater 41A. The first pump 43 transports the phosphoric acid solution.

[0070] The first bypass pipe 36 detours the two quartz heaters 41. First end 36A of the first bypass pipe 36 is connected to the first circulation pipe 35 between the first pump 43 and the quartz heater 41A. Furthermore, second end 36B of the first bypass pipe 36 is connected to the first circulation pipe 35 between the quartz heater 41B and a branch pipe 35C described below. The first circulation pipe 35 between first end 36A and second end 36B serves as the concentration pipe 39. Therefore, both ends 36A and 36B of the first bypass pipe 36 are connected to the upstream and downstream ends of the concentration pipe 39.

[0071] The first bypass pipe 36 is provided with a non-quartz heater 45. Figure 3 (a) Figure 3 (b) The configuration of the quartz heater 41 and the non-quartz heater 45 will be described. Figure 3 (a) is a diagram showing a quartz heater 41. Quartz heater 41 includes a quartz tube 47 and a heater body 49. Quartz tube 47 is positioned midway along concentrating piping 39. Quartz tube 47 allows phosphoric acid solution to pass through. Quartz tube 47 is made of quartz. A hollow, cylindrical heater body 49 is provided around the outer periphery of quartz tube 47. Heater body 49 and heater body 53, described below, are comprised of, for example, an electric heater with nichrome wire. Quartz heater 41 heats the phosphoric acid solution passing through concentrating piping 39 (specifically, quartz tube 47).

[0072] Figure 3 (b) is a diagram showing a non-quartz heater 45. The non-quartz heater 45 includes a non-quartz tube 51 and a heater body 53. The non-quartz tube 51 is arranged in the middle of the first detour piping 36. The non-quartz tube 51 is for the phosphoric acid solution to pass through. The non-quartz tube 51 is not formed of quartz. That is, the non-quartz tube 51 is formed of a fluorine-based resin such as PFA (perfluoroalkoxyalkane) or PTFE (polytetrafluoroethylene). Therefore, the non-quartz tube 51 is a fluorine-based resin tube. This prevents silicon from eluting from the heater parts into the phosphoric acid solution. A hollow cylindrical heater body 53 is provided on the outer periphery of the non-quartz tube 51. The non-quartz heater 45 heats the phosphoric acid solution passing through the first detour piping 36 (specifically, the non-quartz tube 51).

[0073] Furthermore, the concentration pipe 39 corresponds to the concentration flow path of the present invention. The quartz heater 41 corresponds to the quartz heater of the present invention. The quartz tube 47 corresponds to the quartz tube of the present invention. The non-quartz heater 45 corresponds to the non-quartz heater of the present invention. The non-quartz tube 51 corresponds to the non-quartz heater of the present invention.

[0074] Return to Figure 1 A branch pipe 35C is provided in the first circulation pipe 35 between the quartz heater 41B and the inlet IL1. The first supply pipe 37 is used to transport the phosphoric acid solution from the first tank T1 to the second tank T2 of the main circulation section 33. The first end of the first supply pipe 37 is connected to the branch pipe 35C. The second end of the first supply pipe 37 is inserted into the second tank T2 and is located near the bottom wall of the second tank T2.

[0075] The pre-temperature control unit 4 also includes a phosphoric acid supply source 55, a pipe 56, a pump 57, and an on-off valve V1. The phosphoric acid supply source 55 is comprised of, for example, a container. The first end of the pipe 56 is connected to the phosphoric acid supply source 55. The second end of the pipe 56 is inserted into the first tank T1 and positioned near the bottom wall of the first tank T1. A sulfuric acid solution having a phosphoric acid concentration of 85% at room temperature is supplied from the phosphoric acid supply source 55 to the first tank T1. The pipe 56 is provided with a pump 57 for conveying the phosphoric acid solution and an on-off valve V1. The on-off valve V1 controls the supply and stop of the phosphoric acid solution.

[0076] In addition, the pre-temperature adjustment unit 4 includes a pure water supply source 59, two pipes 61 and 62, a pump 64, and two opening and closing valves V2 and V3. The pure water supply source 59 is composed of a container, for example. The first end of the pipe 61 is connected to the pure water supply source 59. The second end of the pipe 61 is inserted into the first tank T1 and is arranged near the bottom wall of the first tank T1. The pipe 61 is provided with a pump 64 for conveying pure water (DIW; deionized water), and an opening and closing valve V2. The pipe 61 between the pump 64 and the opening and closing valve V2 is provided with a branch pipe 65. The first end of the pipe 62 is connected to the branch pipe 65. The second end of the pipe 62 is inserted into the second tank T2 and is arranged near the bottom wall of the second tank T2. The pipe 62 is provided with an opening and closing valve V3. The opening and closing valve V2 executes the supply and stop of pure water to the first tank T1. The on-off valve V3 controls the supply and stop of pure water to the second tank T2.

[0077] The pre-circulation section 31 also includes four on-off valves: V4, V5, V6, and V7. On-off valve V4 is provided in the concentration pipe 39 between the first end 36A of the first bypass pipe 36 and the quartz heater 41A. On-off valve V5 is provided in the first bypass pipe 36 between the first end 36A and the non-quartz heater 45. On-off valve V6 is provided in the first circulation pipe 35 between the branch pipe 35C and the inlet IL1. On-off valve V7 is provided in the first supply pipe 37.

[0078] The pre-circulation section 31 opens the on-off valves V4 and V6, closes the on-off valves V5 and V7, and drives the first pump 43. This causes the phosphoric acid solution to circulate in the order of outlet OL1, first pump 43, two quartz heaters 41, branch pipe 35C, and inlet IL1. Furthermore, the pre-circulation section 31 opens the on-off valves V5 and V6, closes the on-off valves V4 and V7, and drives the first pump 43. This causes the phosphoric acid solution to circulate in the order of outlet OL1, first pump 43, non-quartz heater 45, branch pipe 35C, and inlet IL1. The pre-circulation section 31 opens the on-off valves V5 and V7, closes the on-off valves V4 and V6, and drives the first pump 43. Thus, the phosphoric acid solution flows in the order of the outlet OL1, the first pump 43, the non-quartz heater 45, the branch pipe 35C, the first supply pipe 37, and the "second tank T2".

[0079] Furthermore, when supplying the phosphoric acid solution to the second tank T2, the phosphoric acid solution may be passed through the concentration pipe 39 provided with two quartz heaters 41. Specifically, the pre-circulation section 31 may open the on-off valves V4 and V7, close the on-off valves V5 and V6, and drive the first pump 43.

[0080] In addition, the pre-circulation part 31 includes a bubble supply unit 67, a gas supply source 69, a supply pipe 71, and an on-off valve V8. The bubble supply unit 67 is composed of, for example, a plurality of pipes. The bubble supply unit 67 has a plurality of holes for supplying bubbles to the phosphoric acid solution in the first tank T1. The bubble supply unit 67 is arranged on the bottom wall side in the first tank T1. The gas supply source 69 is composed of, for example, a container. The gas (for example, an inert gas such as nitrogen) supplied from the gas supply source 69 is transported to the bubble supply unit 67 via the supply pipe 71. The on-off valve V8 controls the supply and stop of bubbles from the bubble supply unit 67.

[0081] The pre-circulation section 31 also includes a temperature sensor TS1, a phosphoric acid concentration sensor PS1, and a liquid level sensor LS1. The temperature sensor TS1 measures the temperature of the phosphoric acid solution in the first tank T1. The phosphoric acid concentration sensor PS1 measures the phosphoric acid concentration of the phosphoric acid solution in the first tank T1. The phosphoric acid concentration sensor PS1 includes a detection tube 74 and a pressure sensor 75. The pressure sensor 75 measures the pressure of the inert gas (e.g., nitrogen) in the detection tube 74, to which a constant flow rate of inert gas is supplied. The phosphoric acid concentration sensor PS1 calculates the phosphoric acid concentration from the measured pressure based on the correlation between pressure and specific gravity and the correlation between specific gravity and concentration. The liquid level sensor LS1 detects the liquid level of the phosphoric acid solution in the first tank T1.

[0082] Next, the main circulation section 33 will be described. The main circulation section 33 includes a second tank T2, a second circulation pipe 77, a second bypass pipe 78, and three second supply pipes 80, 81, and 82. The second tank T2 is a container for storing phosphoric acid solution. The second tank T2 is interposed between the first supply pipe 37 and the second supply pipe 80, which are used to transport the phosphoric acid solution from the first tank T1 to, for example, the processing unit 2A. The second tank T2 stores the phosphoric acid solution transported from the first tank T1. The second tank T2 includes an outlet OL2 and an inlet IL2. The outlet OL2 is located at the bottom of the second tank T2, and the inlet IL2 is located on the ceiling of the second tank T2.

[0083] The second circulation pipe 77 has two ends 77A and 77B connected to the second tank T2. Specifically, the first end 77A of the second circulation pipe 77 is connected to the outlet OL2 of the second tank T2, and the second end 77B of the second circulation pipe 77 is connected to the inlet IL2 of the second tank T2. The second circulation pipe 77 is used to return the phosphoric acid solution flowing into the second tank T2 to the second tank T2.

[0084] The concentrating pipe 85 is a part of the second circulation pipe 77. The concentrating pipe 85 is provided with a quartz heater 87. The quartz heater 87 is connected to the Figure 3 The quartz heater 41 shown in (a) is constructed in the same manner. A second pump 89 is provided in the second circulation pipe 77 between the outlet OL2 and the quartz heater 87.

[0085] The second detour piping 78 detours the quartz heater 87. The first end 78A of the second detour piping 78 is connected to the second circulation piping 77 between the second pump 89 and the quartz heater 87. In addition, the second end 78B of the second detour piping 78 is connected to the second circulation piping 77 between the quartz heater 87 and the branch pipe 77C described below. The second circulation piping 77 between the first end 78A and the second end 78B is the concentration piping 85. Therefore, the two ends 78A and 78B of the second detour piping 78 are connected to the upstream end and the downstream end of the concentration piping 85. A non-quartz heater 91 is provided in the second detour piping 78. The non-quartz heater 91 is connected to the quartz heater 87. Figure 3 The non-quartz heater 45 shown in (b) is constructed in the same manner.

[0086] The second circulation pipe 77 corresponds to the second circulation flow path of the present invention. The second bypass pipe 78 corresponds to the second bypass flow path of the present invention. The concentration pipe 85 corresponds to the second concentration flow path of the present invention. The quartz heater 87 corresponds to the second quartz heater of the present invention. The quartz tube 47 (see Figure 3 (a)) is the second quartz tube of the present invention. The non-quartz heater 91 corresponds to the second non-quartz heater of the present invention. The non-quartz tube 51 (see Figure 3(b)) is the second non-quartz tube of the present invention.

[0087] Three branch pipes 77C, 77D, and 77E are provided in the second circulation pipe 77 between the quartz heater 87 and the inlet IL2. Three second supply pipes 80, 81, and 82 are used to transport the phosphoric acid solution from the second tank T2 to the three processing units 2A, 2B, and 2C, respectively. The first end of the second supply pipe 80 is connected to the branch pipe 77C. The second end 80B of the second supply pipe 80 is positioned, for example, above the processing tank 6 of the processing unit 2A to supply the phosphoric acid solution to the processing tank 6 of the processing unit 2A.

[0088] Similarly, the first end of the second supply pipe 81 is connected to the branch pipe 77D. The second end 81B of the second supply pipe 81 is positioned, for example, above the treatment tank 6 of the treatment section 2B, to supply the phosphoric acid solution to the treatment tank 6 of the treatment section 2B. The first end of the second supply pipe 82 is connected to the branch pipe 77E. The second end 82B of the second supply pipe 82 is positioned, for example, above the treatment tank 6 of the treatment section 2C.

[0089] The first supply pipe 37 and the second supply pipes 80 to 82 correspond to the supply flow paths of the present invention, which selectively transport the phosphoric acid solution in the first tank T1 to the processing units 2A, 2B, and 2C.

[0090] The main circulation section 33 includes six on-off valves: V9, V10, V11, V12, V13, and V14. On-off valve V9 is located in the concentration piping 85 between the second pump 89 and the quartz heater 87. On-off valve V10 is located in the second detour piping 78 between the second pump 89 and the non-quartz heater 91. On-off valve V11 is located in the second circulation piping 77 between the branch pipe 77E and the inlet IL2. On-off valve V12 is located in the second supply piping 80. On-off valve V13 is located in the second supply piping 81. On-off valve V14 is located in the second supply piping 82.

[0091] The main circulation section 33 opens the on-off valves V9 and V11, closes the on-off valves V10 and V12 to V14, and drives the second pump 89. This causes the phosphoric acid solution to circulate in the order of outlet OL2, second pump 89, quartz heater 87, and inlet IL2. Separately, the main circulation section 33 opens the on-off valves V10 and V11, closes the on-off valves V9 and V12 to V14, and drives the second pump 89. This causes the phosphoric acid solution to circulate in the order of outlet OL2, second pump 89, non-quartz heater 91, and inlet IL2.

[0092] The main circulation section 33, for example, opens the on-off valves V10 and V12, closes the on-off valves V9, V11, V13, and V14, and drives the second pump 89. This causes the phosphoric acid solution to be fed in the order of outlet OL2, second pump 89, non-quartz heater 91, second supply channel 80, and treatment tank 6 of treatment section 2A. Furthermore, when feeding the phosphoric acid solution to treatment section 2B, the on-off valves V10 and V13 are opened, while the on-off valves V9, V11, V12, and V14 are closed. Furthermore, when feeding the phosphoric acid solution to treatment section 2C, the on-off valves V10 and V14 are opened, while the on-off valves V9, V11, V13, and V14 are closed.

[0093] Furthermore, when supplying the phosphoric acid solution to each of the processing units 2A, 2B, and 2C, the phosphoric acid solution may be passed through the concentration pipe 85 provided with the quartz heater 87. Specifically, the main circulation section 33 may, for example, open the on-off valves V9 and V12, close the on-off valves V10, V11, V13, and V14, and drive the second pump 89.

[0094] The main circulation section 33 also includes a temperature sensor TS2, a phosphoric acid concentration sensor PS2, and a liquid level sensor LS2. The temperature sensor TS2 measures the temperature of the phosphoric acid solution in the second tank T2. The phosphoric acid concentration sensor PS2, configured similarly to the phosphoric acid concentration sensor PS1, measures the phosphoric acid concentration of the phosphoric acid solution in the second tank T2. The liquid level sensor LS2 measures the liquid level of the phosphoric acid solution in the second tank T2.

[0095] The substrate processing apparatus 1 includes a control unit 93 and a memory unit (not shown). The control unit 93 controls the various components of the substrate processing apparatus 1. The control unit 93 includes, for example, one or more processors such as a central processing unit (CPU). The memory unit also includes at least one of a ROM (Read-Only Memory), a RAM (Random-Access Memory), and a hard disk. The memory unit stores computer programs for operating the substrate processing apparatus 1.

[0096] (2) Operation of the substrate processing apparatus 1

[0097] Reference Figure 4 , the operation of the substrate processing apparatus 1, mainly the operation of the pre-temperature adjustment unit 4, will be described.

[0098] [Step S01] Supplying phosphoric acid solution (phosphoric acid) to the first tank T1

[0099] The on-off valve V1 is opened. This allows phosphoric acid solution to be supplied from the phosphoric acid supply source 55 to the first tank T1 via the pipe 56. The supply of phosphoric acid solution is based on the liquid level detected by the liquid level sensor LS1. The supplied phosphoric acid solution has a phosphoric acid concentration of 85% (at room temperature). When a specific amount of phosphoric acid solution has been supplied to the first tank T1, the on-off valve V1 is closed, stopping the supply of phosphoric acid solution to the first tank T1.

[0100] [Step S02] Heating and Concentrating

[0101] When the phosphoric acid solution is supplied from the phosphoric acid supply source 55, the preliminary circulation section 31 increases the temperature of the phosphoric acid solution in the first tank T1 while concentrating the phosphoric acid solution.

[0102] The pre-circulation unit 31 concentrates the phosphoric acid solution in the first tank T1 when the concentration value measured by the phosphoric acid concentration sensor PS1 falls below a preset threshold value (e.g., 88%). To concentrate the phosphoric acid solution in the first tank T1, the pre-circulation unit 31 opens the on-off valves V4 and V6, closes the on-off valves V5 and V7, and drives the first pump 43. This causes the phosphoric acid solution to circulate in this order through the outlet OL1, the first pump 43, the two quartz heaters 41 (concentration piping 39), the branch pipe 35C, and the inlet IL1.

[0103] Furthermore, the pre-circulation section 31 heats the phosphoric acid solution passing through the concentration pipe 39 using two quartz heaters 41 while conveying the phosphoric acid solution to the concentration pipe 39. Furthermore, the phosphoric acid solution passing through the two quartz heaters 41 can also be heated to a first temperature (e.g., 160° C.) or higher, as described below.

[0104] Temperature sensor TS1 measures the temperature of the phosphoric acid solution in the first tank T1. The pre-circulation unit 31 uses two quartz heaters 41 to heat the phosphoric acid solution until the temperature measured by temperature sensor TS1 reaches a predetermined first temperature (e.g., 160°C). The two quartz heaters 41 have, for example, twice the heating capacity of a single quartz heater 87, resulting in high output. Therefore, heating and concentration operations can be performed relatively quickly. Furthermore, when concentrating the phosphoric acid solution in the first tank T1, the on-off valve V8 is opened, allowing the bubble supply unit 67 to supply bubbles into the phosphoric acid solution in the first tank T1. This accelerates the concentration of the phosphoric acid solution.

[0105] Furthermore, the first temperature is pre-set to 160°C. In this regard, the first temperature may also be, for example, above 150°C. That is, the first temperature is a temperature below but near the boiling point of the phosphoric acid solution, or above the boiling point of the phosphoric acid solution. The concentration operation is performed by heating the phosphoric acid solution. If the first temperature is below but near the boiling point of the phosphoric acid solution, concentration proceeds relatively quickly. If the first temperature is above the boiling point of the phosphoric acid solution, concentration can be further accelerated. Furthermore, the boiling point of a phosphoric acid solution with a phosphoric acid concentration of 85% at room temperature is 157°C to 158°C.

[0106] In step S02 , the non-quartz heater 45 that is not used for heating the phosphoric acid solution stops heating or is heated in a state close to the heating stop state.

[0107] [Step S03] Maintaining the temperature control state

[0108] After the phosphoric acid concentration of the phosphoric acid solution is concentrated from 85% to, for example, 88% to 89%, the pre-circulation section 31 maintains the temperature of the phosphoric acid solution at 160° C. to ensure the phosphoric acid concentration. This will be described in detail below.

[0109] When the concentration value measured by the phosphoric acid concentration sensor PS1 is equal to or greater than a threshold value (88%), the pre-circulation unit 31 determines that the concentration of the phosphoric acid solution in the first tank T1 is complete, and thus maintains the temperature of the phosphoric acid solution in the first tank T1 at 160°C. This allows switching between heating by the quartz heater 41 and heating by the non-quartz heater 45 based on the concentration value measured by the phosphoric acid concentration sensor PS1.

[0110] First, when the concentration of the phosphoric acid solution in the first tank T1 is complete, the pre-circulation unit 31 switches the circulation route. The pre-circulation unit 31 opens the on-off valves V5 and V6, closes the on-off valves V4 and V7, and drives the first pump 43. This causes the phosphoric acid solution to circulate in this order: outlet OL1, first pump 43, non-quartz heater 45 (first bypass pipe 36), branch pipe 35C, and inlet IL1.

[0111] Furthermore, the pre-circulation section 31 heats the phosphoric acid solution passing through the first bypass pipe 36 using the non-quartz heater 45 while transferring the phosphoric acid solution to the first bypass pipe 36. This maintains the temperature of the phosphoric acid solution in the first tank T1 (160°C). Furthermore, after concentration is complete, the on-off valve V8 is closed, thereby stopping the supply of bubbles from the bubble supply section 67.

[0112] The phosphoric acid solution in the first tank T1, which is in a temperature-controlled state, is in a standby state until an instruction to supply the solution to the second tank T2 is issued. In this description, the concentration threshold of the phosphoric acid solution is set at 88%. However, the threshold may be set to a value greater than the phosphoric acid concentration (85%) of the phosphoric acid solution supplied from the phosphoric acid supply source 55. Alternatively, an upper threshold value may be set such that the phosphoric acid concentration is less than 100%. If the upper threshold value is exceeded, pure water is supplied from the pure water supply source 59 to the first tank T1. In this case, the process returns to step S02.

[0113] In addition, in step S03 , the quartz heater 41 that is not used for heating the phosphoric acid solution stops heating, or performs heating in a state that is close to the heating stop state.

[0114] [Step S04] Supplying phosphoric acid solution to the second tank T2

[0115] The pre-circulation section 31 supplies the phosphoric acid solution from the first tank T1 to the second tank T2. The pre-circulation section 31 opens the on-off valves V5 and V7, closes the on-off valves V4 and V6, and drives the first pump 43. This causes the phosphoric acid solution to flow in the order of outlet OL1, first pump 43, non-quartz heater 45, branch pipe 35C, first supply pipe 37, and second tank T2.

[0116] Furthermore, when the phosphoric acid solution is transferred from the first tank T1 to the second tank T2, the liquid level sensor LS1 detects that the liquid level of the phosphoric acid solution in the first tank T1 has dropped. Therefore, it is necessary to supply the phosphoric acid solution from the phosphoric acid supply source 55 to the first tank T1. In this case, the process proceeds to the next step S05 and then returns to step S01.

[0117] [Step S05] Heating and Concentrating

[0118] When the phosphoric acid solution is supplied to the second tank T2, the main circulation section 33 performs the same operations as those in steps S02 and S03 described above to stabilize the phosphoric acid concentration and temperature of the phosphoric acid solution. Therefore, the main circulation section 33 simultaneously increases the temperature of the phosphoric acid solution in the second tank T2 and concentrates the phosphoric acid solution. This will be described in detail below.

[0119] When the concentration value measured by the phosphoric acid concentration sensor PS2 falls below a preset threshold (e.g., 88%), the main circulation section 33 concentrates the phosphoric acid solution in the second tank T2. To concentrate the phosphoric acid solution in the second tank T2, the main circulation section 33 opens the on-off valves V9 and V11, closes the on-off valves V10 and V12-V14, and drives the second pump 89. This causes the phosphoric acid solution to circulate in this order through the outlet OL2, the second pump 89, the quartz heater 87 (concentration piping 85), and the inlet IL2.

[0120] Furthermore, the main circulation section 33 uses a quartz heater 87 to heat the phosphoric acid solution passing through the concentration pipe 85. A temperature sensor TS2 measures the temperature of the phosphoric acid solution in the second tank T2. The main circulation section 33 uses the quartz heater 87 to heat the phosphoric acid solution so that the temperature measured by the temperature sensor TS2 reaches a predetermined first temperature (e.g., 160°C).

[0121] In step S05 , the non-quartz heater 91 that is not used for heating the phosphoric acid solution stops heating or performs heating in a state that is close to the heating stop state.

[0122] [Step S06] Maintaining the temperature control state

[0123] After the phosphoric acid concentration of the phosphoric acid solution is concentrated to, for example, 88% to 89%, the main circulation section 33 maintains the temperature of the phosphoric acid solution at 160° C. to ensure the phosphoric acid concentration. This will be described in detail below.

[0124] When the concentration value measured by the phosphoric acid concentration sensor PS2 is equal to or higher than the threshold value (88%), the main circulation section 33 determines that the concentration of the phosphoric acid solution in the second tank T2 is complete and maintains the temperature of the phosphoric acid solution in the second tank T2 (160° C.).

[0125] Specifically, upon completion of the concentration of the phosphoric acid solution in the second tank T2, the main circulation section 33 first switches the circulation route. The main circulation section 33 opens the on-off valves V10 and V11, closes the on-off valves V9 and V12-V14, and activates the second pump 89. This causes the phosphoric acid solution to circulate in this order, passing through the outlet OL2, the second pump 89, the non-quartz heater 91 (the second bypass pipe 78), and finally the inlet IL2.

[0126] Furthermore, the main circulation section 33 heats the phosphoric acid solution passing through the second bypass pipe 78 using the non-quartz heater 91 while feeding the phosphoric acid solution to the second bypass pipe 78. This maintains the temperature of the phosphoric acid solution in the second tank T2 (160°C).

[0127] The phosphoric acid solution in the second tank T2, which is in a temperature-controlled state, is in a standby state until a supply instruction to each processing unit 2A, 2B, and 2C is issued. In the description of step S06, the concentration threshold of the phosphoric acid solution is set at 88%. However, the threshold may be set to a value greater than the phosphoric acid concentration (85%) of the phosphoric acid solution supplied from the phosphoric acid supply source 55. Alternatively, an upper threshold value may be set such that the phosphoric acid concentration is less than 100%. If the upper threshold value is exceeded, pure water is supplied from the pure water supply source 59 to the second tank T2. In this case, the process returns to step S05.

[0128] In addition, in step S06 , the quartz heater 87 that is not used for heating the phosphoric acid solution stops heating, or performs heating in a state that is close to the heating stop state.

[0129] [Step S07] Supplying phosphoric acid solution to the processing unit 2A (2B, 2C)

[0130] The main circulation section 33 supplies the phosphoric acid solution from the second tank T2 to each of the processing units 2A, 2B, and 2C. The main circulation section 33 opens the on-off valves V10 and V12, closes the on-off valves V9, V11, V13, and V14, and drives the second pump 89. This sequence conveys the phosphoric acid solution to the outlet OL2, the second pump 89, the non-quartz heater 91, the second supply pipe 80, and finally to the processing tank 6 of the processing unit 2A. The phosphoric acid solution with a low silicon concentration is supplied to the processing tank 6 of the processing unit 2A.

[0131] When the phosphoric acid solution is supplied to the treatment section 2B, the on-off valves V10 and V13 are opened, and the on-off valves V11, V12, and V14 are closed. When the phosphoric acid solution is supplied to the treatment section 2C, the on-off valves V10 and V14 are opened, and the on-off valves V11, V12, and V14 are closed.

[0132] Here, two supply methods are explained. The two supply methods refer to continuous replenishment and local liquid replacement. Figure 2 First, continuous replenishment will be described. In this description, the phosphoric acid solution is supplied to the processing unit 2A. This is also true when the phosphoric acid solution is supplied to either the processing units 2B or 2C.

[0133] Continuous replenishment means that, while substrate processing is being performed with a plurality of substrates W held by the elevator 11 immersed in the processing tank 6 of the processing unit 2A, the pre-temperature control unit 4 continuously supplies the phosphoric acid solution to the processing tank 6 of the processing unit 2A. This gradually replaces the phosphoric acid solution in the processing tank 6, thereby suppressing an increase in the silicon concentration in the phosphoric acid solution within the processing tank 6.

[0134] Each substrate W immersed in processing tank 6 has a structure in which silicon nitride films and silicon oxide films are alternately stacked. Substrate processing involves selectively etching the silicon nitride films using a phosphoric acid solution. Excess phosphoric acid solution in processing section 2A is naturally discharged through drain pipe 14 connected to outer tank 7. When substrate processing is completed, the supply of phosphoric acid solution from pre-temperature control unit 4 is stopped.

[0135] Next, local liquid replacement will be described. Local liquid replacement refers to the process of partially draining the phosphoric acid solution in the processing tank 6 of the processing unit 2A while the substrate W is immersed in the processing tank 6 of the processing unit 2A. The pre-temperature control unit 4 then supplies phosphoric acid solution to the processing tank 6 of the processing unit 2A through the second supply pipe 80.

[0136] Silicon concentration sensor 23 (refer to Figure 2 ) is provided in the processing unit circulation flow path 9 of the processing unit 2A. When the silicon concentration value measured by the silicon concentration sensor 23 exceeds a preset threshold value, the substrate processing apparatus 1 opens the on-off valve V22 and supplies a phosphoric acid solution from the second tank T2 to the processing tank 6 of the processing unit 2A using the pre-temperature control unit 4. By opening the on-off valve V22, the phosphoric acid solution in the processing tank 6 of the processing unit 2A is discharged through the discharge pipe 30. Simultaneously with the discharge, the phosphoric acid solution is supplied to the processing tank 6 of the processing unit 2A using the pre-temperature control unit 4. This partially replaces the phosphoric acid solution in the processing tank 6, thereby significantly reducing the silicon concentration of the phosphoric acid solution.

[0137] Furthermore, the operation of partial liquid replacement may be interrupted during the continuous replenishment operation. In addition, the method of supplying the phosphoric acid solution to each processing unit 2A, 2B, 2C is arbitrary and is not limited to the two supply methods described above.

[0138] When the phosphoric acid solution is being supplied from the second tank T2 to the processing units 2A, 2B, and 2C, the liquid level sensor LS2 detects that the liquid level of the phosphoric acid solution in the second tank T2 has dropped. Therefore, it is necessary to supply the phosphoric acid solution from the first tank T1 to the second tank T2. In this case, the process returns to step S04.

[0139] According to this embodiment, a quartz heater 41 is provided in the first concentration pipe 39, which is part of the first circulation pipe 35. A non-quartz heater 45 is provided in the first bypass pipe 36, which bypasses the quartz heater 41. When concentrating the phosphoric acid solution in the first tank T1, the quartz heater 41 is used to heat the phosphoric acid solution passing through the concentration pipe 39. Furthermore, after the concentration of the phosphoric acid solution in the first tank T1 is completed and the temperature of the phosphoric acid solution in the first tank T1 is maintained, the non-quartz heater 41 is used to heat the phosphoric acid solution passing through the first bypass pipe 36. The use of the non-quartz heater 45 prevents silicon from eluting into the phosphoric acid solution, reducing silicon elution into the phosphoric acid solution overall. This, for example, prevents the phosphoric acid solution supplied to the processing unit 2A from having a high silicon concentration.

[0140] Furthermore, a quartz heater 87 is provided in the second concentration pipe 85, which is part of the second circulation pipe 77. A non-quartz heater 91 is provided in the second bypass pipe 78, which detours the quartz heater 87. When concentrating the phosphoric acid solution in the second tank T2, the quartz heater 87 is used to heat the phosphoric acid solution passing through the concentration pipe 85. Furthermore, after the concentration of the phosphoric acid solution in the second tank T2 is completed and the temperature of the phosphoric acid solution in the second tank T2 is maintained, the second non-quartz heater 91 is used to heat the phosphoric acid solution passing through the second bypass pipe 78. The use of the second non-quartz heater 91 prevents silicon from eluting into the phosphoric acid solution, reducing silicon elution into the phosphoric acid solution overall. This, for example, prevents the phosphoric acid solution supplied to the processing unit 2A from having a high silicon concentration.

[0141] [Example 2]

[0142] Next, a second embodiment of the present invention will be described with reference to the drawings. Explanations overlapping with those of the first embodiment will be omitted.

[0143] In Example 1, in the two steps S03 and S06, the temperature of the phosphoric acid solution was maintained at 160°C. In contrast, in Example 2, the temperature of the phosphoric acid solution was maintained at 120°C.

[0144] The pre-temperature adjustment unit 4 of embodiment 2 has Figure 1 The pre-temperature adjustment unit 4 of the second embodiment has the same structural features as the pre-temperature adjustment unit 4 of the first embodiment shown. Specifically, in the pre-temperature adjustment unit 4 of the second embodiment, the pre-circulation section 31 includes the first bypass pipe 36 and the non-quartz heater 45. In addition, the main circulation section 33 includes the second bypass pipe 78 and the non-quartz heater 91.

[0145] Secondly, refer to Figure 5 The operation of the pre-temperature adjustment unit 4 will be described. Figure 5 Steps S11, S12, S14, S15, and S17 are shown in FIG. Figure 4 The operations of steps S01, S02, S04, S05, and S07 are the same. In step S12, the pre-circulation section 31 heats the phosphoric acid solution passing through the concentration pipe 39 using two quartz heaters 41 so that the temperature of the phosphoric acid solution in the first tank T1 reaches a preset first temperature (160° C.), thereby concentrating the phosphoric acid solution.

[0146] [Step S13] Maintaining the temperature control state

[0147] After the phosphoric acid concentration of the phosphoric acid solution is concentrated from 85% to, for example, 88% to 89%, the pre-circulation section 31 maintains the temperature of the phosphoric acid solution at 120° C. This will be described in detail below.

[0148] When the concentration value measured by the phosphoric acid concentration sensor PS1 is equal to or higher than the threshold value (88%), the pre-circulation section 31 determines that the concentration of the phosphoric acid solution in the first tank T1 is complete and maintains the temperature of the phosphoric acid solution in the first tank T1 (120°C).

[0149] Specifically, upon completion of the concentration of the phosphoric acid solution in the first tank T1, the pre-circulation section 31 first switches the circulation route. The pre-circulation section 31 opens the on-off valves V5 and V6, closes the on-off valves V4 and V7, and activates the first pump 43. This causes the phosphoric acid solution to circulate in this order: outlet OL1, first pump 43, non-quartz heater 45 (first bypass pipe 36), branch pipe 35C, and inlet IL1. Furthermore, while the pre-circulation section 31 transports the phosphoric acid solution to the first bypass pipe 36, it heats the phosphoric acid solution passing through the first bypass pipe 36 using the non-quartz heater 45.

[0150] At this time, the pre-circulation section 31 heats the phosphoric acid solution in the first tank T1 using the non-quartz heater 45 so that the temperature reaches the second temperature (120°C). The second temperature (120°C) is set lower than the first temperature (160°C). In this description, the second temperature is set to 120°C. In this regard, the second temperature can also be set to, for example, 100°C or higher and lower than the boiling point of the phosphoric acid solution. When the temperature of the phosphoric acid solution is lower than 100°C, the phosphoric acid solution absorbs water. Therefore, the phosphoric acid concentration of the phosphoric acid solution decreases. By setting the temperature of the phosphoric acid solution to 100°C or higher, the phosphoric acid solution can be prevented from absorbing water.

[0151] The phosphoric acid solution is transferred from the first tank T1 to the second tank T2 (step S14). The main circulation unit 33 heats the phosphoric acid solution passing through the concentration pipe 85 using the quartz heater 87 so that the temperature of the phosphoric acid solution in the second tank T2 reaches the preset first temperature (160°C) (step S15), thereby concentrating the phosphoric acid solution.

[0152] [Step S16] Maintaining the temperature control state

[0153] After the phosphoric acid concentration of the phosphoric acid solution is concentrated to, for example, 88% to 89%, the main circulation section 33 maintains the temperature of the phosphoric acid solution at 120° C. This will be described in detail below.

[0154] When the concentration value measured by the phosphoric acid concentration sensor PS2 is equal to or higher than the threshold value (88%), the main circulation section 33 determines that the concentration of the phosphoric acid solution in the second tank T2 is complete and maintains the temperature of the phosphoric acid solution in the second tank T2 (120° C.).

[0155] Specifically, upon completion of the concentration of the phosphoric acid solution in the second tank T2, the main circulation section 33 first switches the circulation route. The main circulation section 33 opens the on-off valves V10 and V11, closes the on-off valves V9, and V12-V14, and activates the second pump 89. This causes the phosphoric acid solution to circulate in this order: outlet OL2, second pump 89, non-quartz heater 91 (second bypass pipe 78), and inlet IL2. Furthermore, while the main circulation section 33 transports the phosphoric acid solution to the second bypass pipe 78, it heats the phosphoric acid solution passing through the second bypass pipe 78 using the non-quartz heater 91.

[0156] At this time, the main circulation section 33 is heated using the non-quartz heater 91 so that the temperature of the phosphoric acid solution in the second tank T2 becomes a second temperature (120° C.) lower than the first temperature (160° C.).

[0157] Next, in step S17, the pre-temperature control unit 4 supplies a 120°C phosphoric acid solution to the treatment tank 6. Supplying a 120°C phosphoric acid solution to the 160°C phosphoric acid solution in the treatment tank 6 might have raised concerns about potential treatment issues. However, the phosphoric acid concentration of the phosphoric acid solution from the pre-temperature control unit 4 is the same as that in the treatment tank 6. Therefore, unstable behavior, such as boiling, does not occur. Furthermore, it is believed that as long as the heating capacity of the two heaters 8 and 19 in the treatment tank 6 is sufficient, rapid heating to 160°C is possible, thus ensuring no treatment issues.

[0158] This embodiment, in addition to the effects of Example 1, also offers the following advantages. Specifically, the output of the non-quartz heater 45 can be suppressed. This prevents damage to the non-quartz tube. For example, heating could cause the non-quartz tube to melt. This embodiment prevents this. Furthermore, it increases the number of options for non-quartz heaters.

[0159] [Example 3]

[0160] Next, a third embodiment of the present invention will be described with reference to the accompanying drawings. Explanations overlapping with those of the first and second embodiments will be omitted.

[0161] Figure 6 This is a diagram showing the structure of the substrate processing apparatus 1 according to the third embodiment. In the third embodiment, the main circulation section 33 does not have Figure 1 The second bypass pipe 78, the non-quartz heater 91 and the two opening and closing valves V9 and V10 are shown. In addition, the concentration pipe 85 is not separated in the second circulation pipe 77. Figure 1 The shown configuration is the same.

[0162] Secondly, refer to Figure 7 The operation of the pre-temperature adjustment unit 4 will be described. Figure 7The operations of steps S21 to S24 are respectively Figure 4 The operations in steps S01 to S04 shown are the same.

[0163] In step S24, the phosphoric acid solution is supplied from the first tank T1 to the second tank T2. The phosphoric acid solution in the first tank T1 is maintained at 160°C and is concentrated to 88% to 89%. The process proceeds to step S26.

[0164] [Step S26] Maintaining the temperature control state

[0165] First, the main circulation unit 33 circulates the phosphoric acid solution in the second tank T2. Specifically, the main circulation unit 33 opens the on-off valve V11, closes the on-off valves V12 to V14, and drives the second pump 89. This causes the phosphoric acid solution to circulate in the order of outlet OL2, second pump 89, quartz heater 87, on-off valve V11, and inlet IL2.

[0166] The main circulation section 33 does not raise the temperature of the phosphoric acid solution to the first temperature (160°C). Specifically, the main circulation section 33 uses the quartz heater 87 to heat the phosphoric acid solution passing through the second circulation pipe 77 so that the temperature of the phosphoric acid solution in the second tank T2 reaches the second temperature (120°C). This maintains the temperature of the phosphoric acid solution in the second tank T2 at 120°C. The temperature of the phosphoric acid solution in the second tank T2 is measured by the temperature sensor TS2.

[0167] In addition, the second temperature is set lower than the first temperature. In this description, the second temperature is set to 120°C. In this regard, the second temperature may be set in a range of, for example, 100°C to 140°C. This is because when the temperature of the phosphoric acid solution is lower than 100°C, the phosphoric acid solution absorbs water. In addition, it is believed that when the phosphoric acid solution is heated to 140°C using the quartz heater 87 (41), the amount of silicon (Si) eluted can be suppressed to about 1 / 2 compared to when the phosphoric acid solution is heated to 160°C using the quartz heater 87 (41).

[0168] The second temperature is preferably set to a range of 100° C. to 120° C. This is because it is believed that the amount of silicon (Si) elution can be suppressed to approximately 1 / 10 when the phosphoric acid solution is heated to 120° C. using the quartz heater 87 (41) compared to when the phosphoric acid solution is heated to 160° C. using the quartz heater 87 (41).

[0169] Figure 8 Graph showing the relationship between the temperature control time of the pre-temperature control unit 4 and the expected silicon concentration. Figure 8In the figure, the temperature control time increases as it moves to the right. Furthermore, the expected silicon concentration increases as it moves upward. The expected silicon concentration is calculated using three quartz heaters 41A, 41B, and 87 to raise the temperature of the phosphoric acid solution to 160°C and 120°C, respectively. Figure 8 The expected silicon concentration at 120° C. is approximately 1 / 10 of the expected silicon concentration at 160° C. Furthermore, it is tentatively estimated that the expected silicon concentration at 140° C. is a concentration between the concentrations at 160° C. and 120° C., that is, approximately 1 / 2 of the concentration at 160° C.

[0170] According to this embodiment, after the concentration of the phosphoric acid solution is completed, the temperature of the phosphoric acid solution is maintained at a second temperature lower than the first temperature set during the concentration of the phosphoric acid solution. By lowering the heating temperature of the second quartz heater 87, it is possible to suppress the silicon from the second quartz tube 47 (see Figure 3 (a)) dissolution. Therefore, overall, the dissolution of silicon into the phosphoric acid solution is reduced. Therefore, for example, the silicon concentration in the phosphoric acid solution supplied to the processing unit 2A can be prevented from becoming high.

[0171] In addition, Figure 7 In step S23 shown in FIG. 1 , the phosphoric acid solution in the first tank T1 is maintained at the first temperature (160° C.). Figure 5 As in step S13 of the above, the phosphoric acid solution in the first tank T1 is heated to a second temperature (120° C.) lower than the first temperature using the non-quartz heater 45 .

[0172] In addition, the main circulation part 33 is provided with a quartz heater 87. Alternatively, the quartz heater 87 may be replaced by a Figure 3 The non-quartz heater 45 (91) shown in (b) is provided in the first circulation pipe 35. In addition, the main circulation section 33 may heat the phosphoric acid solution in the second tank T2 to 160°C when the phosphoric acid solution is concentrated using the quartz heater 87, and heat the phosphoric acid solution in the second tank T2 to 120°C while maintaining the temperature control state.

[0173] [Example 4]

[0174] Next, a fourth embodiment of the present invention will be described with reference to the drawings. Explanations overlapping with those of the first to third embodiments will be described. Figure 9 It is a diagram showing the configuration of the pre-temperature adjustment unit 4 of the fourth embodiment.

[0175] In Example 1, the pre-circulation section 31 includes the non-quartz heater 45, and the main circulation section 33 includes the non-quartz heater 91. In this regard, the pre-temperature adjustment unit 4 of Example 4 does not include the two non-quartz heaters 45 and 91.

[0176] Reference Figure 9In the pre-circulation section 31, the ends 35A and 35B of the first circulation pipe 35 are connected to the outlet OL1 and inlet IL1 of the first tank T1, respectively. The first circulation pipe 35 is provided with, in order from the outlet OL1 side, a first pump 43, a quartz heater 41A, a quartz heater 41B, a branch pipe 35C, and an on-off valve V6.

[0177] In the main circulation section 33, the ends 77A and 77B of the second circulation pipe 77 are connected to the outlet OL2 and inlet IL2 of the second tank T2, respectively. The second circulation pipe 77 is provided with a second pump 89, a quartz heater 87, a branch pipe 77C, a branch pipe 77D, a branch pipe 77E, and an on-off valve V11 in the order from the outlet OL2.

[0178] Secondly, refer to Figure 10 The operation of the pre-temperature control unit 4 will be described. A phosphoric acid solution is supplied from the phosphoric acid supply source 55 to the first tank T1 (step S31).

[0179] [Step S32] Heating and Concentrating

[0180] When the concentration value measured by the phosphoric acid concentration sensor PS1 falls below a preset threshold (e.g., 88%), the pre-circulation unit 31 concentrates the phosphoric acid solution in the first tank T1. To concentrate the phosphoric acid solution, the pre-circulation unit 31 first opens the on-off valve V6, closes the on-off valve V7, and drives the first pump 43. This causes the phosphoric acid solution to circulate through the first circulation pipe 35 in this order: outlet OL1, first pump 43, two quartz heaters 41, on-off valve V6, and inlet IL1.

[0181] Furthermore, the pre-circulation section 31 heats the phosphoric acid solution passing through the first circulation pipe 35 using two quartz heaters 41. Furthermore, the pre-circulation section 31 heats the phosphoric acid solution so that the temperature measured by the temperature sensor TS1 reaches a preset first temperature (e.g., 160°C).

[0182] [Step S33] Maintaining the temperature control state

[0183] The phosphoric acid solution continues to circulate. When the concentration value measured by the phosphoric acid concentration sensor PS1 exceeds a threshold value (88%), the pre-circulation unit 31 determines that the concentration of the phosphoric acid solution in the first tank T1 is complete, and maintains the temperature of the phosphoric acid solution in the first tank T1 at 120°C. Specifically, when the concentration of the phosphoric acid solution in the first tank T1 is complete, the pre-circulation unit 31 heats the phosphoric acid solution passing through the first circulation pipe 35 using at least one of the two quartz heaters 41 while transferring the phosphoric acid solution to the first circulation pipe 35.

[0184] At this time, the preliminary circulation unit 31 heats the phosphoric acid solution passing through the first circulation pipe 35 so that the temperature of the phosphoric acid solution in the first tank T1 becomes the second temperature (120° C.). The second temperature is set lower than the first temperature.

[0185] [Step S34] Supplying phosphoric acid solution to the second tank T2

[0186] The pre-circulation unit 31 supplies the phosphoric acid solution from the first tank T1 to the second tank T2. The pre-circulation unit 31 opens the on-off valve V7, closes the on-off valve V6, and drives the first pump 43.

[0187] [Step S35] Heating and Concentrating

[0188] First, the main circulation section 33 opens the on-off valve V11, closes the on-off valves V12, V13, and V14, and drives the second pump 89. Consequently, the phosphoric acid solution circulates through the second circulation pipe 77 in the order of outlet OL2, second pump 89, quartz heater 87, on-off valve V11, and inlet IL2.

[0189] In this state, the main circulation section 33 concentrates the phosphoric acid solution in the second tank T2 when the concentration value measured by the phosphoric acid concentration sensor PS2 falls below a predetermined threshold value (e.g., 88%). At this time, the main circulation section 33 heats the phosphoric acid solution passing through the second circulation pipe 77 using the quartz heater 87. Furthermore, the main circulation section 33 heats the phosphoric acid solution so that the temperature measured by the temperature sensor TS2 reaches a predetermined first temperature (e.g., 160°C).

[0190] [Step S36] Maintaining the temperature control state

[0191] After the phosphoric acid concentration of the phosphoric acid solution is concentrated to, for example, 88% to 89%, the main circulation section 33 maintains the temperature of the phosphoric acid solution (120° C.). This will be described in detail below.

[0192] The phosphoric acid solution continues to circulate. When the concentration value measured by the phosphoric acid concentration sensor PS2 exceeds a threshold value (88%), the main circulation unit 33 determines that the concentration of the phosphoric acid solution in the second tank T2 is complete and maintains the temperature of the phosphoric acid solution in the second tank T2 at a preset temperature (120°C). Specifically, when the concentration of the phosphoric acid solution in the second tank T2 is complete, the main circulation unit 33 heats the phosphoric acid solution passing through the second circulation pipe 77 using the quartz heater 87 while transferring the phosphoric acid solution to the second circulation pipe 77.

[0193] At this time, the main circulation section 33 is heated using the quartz heater 87 so that the temperature of the phosphoric acid solution in the second tank T2 becomes a second temperature (120° C.) lower than the first temperature (160° C.).

[0194] [Step S37] Supplying phosphoric acid solution to the processing unit 2A (2B, 2C)

[0195] The main circulation section 33 supplies the phosphoric acid solution in the second tank T2 to, for example, the processing section 2A. Specifically, the main circulation section 33 opens the on-off valve V12, closes the on-off valves V11, V13, and V14, and drives the second pump 89. This supplies the phosphoric acid solution to the processing tank 6 of the processing section 2A via the second supply pipe 80.

[0196] According to this embodiment, when concentrating the phosphoric acid solution in the first tank T1, two quartz heaters 41 are used to heat the phosphoric acid solution passing through the first circulation channel 35 so that the temperature of the phosphoric acid solution in the first tank T1 reaches a first temperature. After the concentration of the phosphoric acid solution in the first tank T1 is completed and the temperature of the phosphoric acid solution in the first tank T1 is maintained, the quartz heaters 41 are used to heat the phosphoric acid solution passing through the first circulation channel 35 so that the temperature of the phosphoric acid solution in the first tank T1 reaches a second temperature lower than the first temperature. Although the quartz heaters 41 are used, since the temperature is raised to the second temperature lower than the first temperature, the dissolution of silicon into the phosphoric acid solution at the second temperature is reduced compared to the first temperature. This can prevent the silicon concentration in the phosphoric acid solution supplied to the processing unit 2A from becoming high, for example.

[0197] In addition, Figure 9 In the pre-temperature adjustment unit 4 shown, it is also possible to Figure 9 The main loop portion 33 shown is replaced by Figure 1 The main loop portion 33 is shown.

[0198] [Example 5]

[0199] Next, a fifth embodiment of the present invention will be described with reference to the drawings. Explanations overlapping with those of the first to fourth embodiments will be omitted.

[0200] In Example 1, the pre-temperature control unit 4 includes two circulation sections 31 and 33 and prepares the phosphoric acid solution to be supplied to the treatment sections 2A, 2B, and 2C in two stages. In this regard, the pre-temperature control unit 4 may prepare the phosphoric acid solution in one stage.

[0201] Reference Figure 11 The pre-temperature adjustment unit 4 has Figure 1 The pre-circulation section 31 shown in FIG. Specifically, the pre-temperature adjustment unit 4 includes a first tank T1, a first circulation pipe 35, a first bypass pipe 36, and three supply pipes (supply flow paths) 101, 102, and 103. Three branch pipes 35D, 35E, and 35F are provided in the first circulation pipe 35 between the second end 36B of the first bypass pipe 36 and the inlet IL1.

[0202] The three branch pipes 35D, 35E, and 35F are connected to supply pipes 101, 102, and 103, respectively. Supply pipe 101 is used to directly supply the phosphoric acid solution to the treatment tank 6 of treatment unit 2A. The two supply pipes 102 and 103 are used to directly supply the phosphoric acid solution to the two treatment tanks 6 of treatment units 2B and 2C, respectively.

[0203] The pre-temperature adjustment unit 4 of Example 5 includes six on-off valves: V4, V5, V6, V16, V17, and V18. On-off valve V6 is located in the first circulation pipe 35 between the branch pipe 35F and the inlet IL1. On-off valve V16 is located in the supply pipe 101. On-off valve V17 is located in the supply pipe 102. On-off valve V18 is located in the supply pipe 103.

[0204] Secondly, refer to Figure 12 The operation of the pre-temperature adjustment unit 4 of this embodiment will be described. A phosphoric acid solution having a concentration of 85% at room temperature is supplied from the phosphoric acid supply source 55 to the first tank T1 (step S41).

[0205] [Step S42] Heating and Concentrating

[0206] The pre-temperature adjustment unit 4 increases the temperature of the phosphoric acid solution in the first tank T1 while concentrating the phosphoric acid solution.

[0207] When the concentration value measured by the phosphoric acid concentration sensor PS1 falls below a preset threshold (e.g., 88%), the pre-temperature control unit 4 concentrates the phosphoric acid solution in the first tank T1. To concentrate the phosphoric acid solution, the pre-temperature control unit 4 first opens the on-off valves V4 and V6, closes the on-off valves V5 and V16-V18, and drives the first pump 43. This causes the phosphoric acid solution to circulate in this order through the outlet OL1, the first pump 43, the two quartz heaters 41 (concentration piping 39), the on-off valve V6, and the inlet IL1.

[0208] Furthermore, the pre-temperature control unit 4 heats the phosphoric acid solution passing through the concentration pipe 39 using two quartz heaters 41 while feeding the phosphoric acid solution. The two quartz heaters 41 heat the phosphoric acid solution so that the temperature measured by the temperature sensor TS1 reaches a predetermined first temperature (160°C). Furthermore, the temperature sensor TS1 measures the temperature of the phosphoric acid solution in the first tank T1. The concentration operation is completed when the concentration value measured by the phosphoric acid concentration sensor PS1 reaches a predetermined threshold value (e.g., 88%).

[0209] [Step S43] Maintaining the temperature control state

[0210] After the concentration is completed, the pre-temperature adjustment unit 4 maintains the temperature of the phosphoric acid solution at 160° C. to ensure the phosphoric acid concentration. This will be described in detail below.

[0211] When the concentration value measured by the phosphoric acid concentration sensor PS1 exceeds a threshold value (88%), the pre-temperature control unit 4 determines that the concentration of the phosphoric acid solution in the first tank T1 is complete and maintains the temperature of the phosphoric acid solution in the first tank T1 at 160°C. Specifically, the pre-temperature control unit 4 switches the circulation route when the concentration of the phosphoric acid solution in the first tank T1 is complete. The pre-temperature control unit 4 opens the on-off valves V5 and V6, closes the on-off valves V4 and V16-V18, and drives the first pump 43. This causes the phosphoric acid solution to circulate in this order: outlet OL1, first pump 43, non-quartz heater 45 (first bypass pipe 36), on-off valve V6, and inlet IL1.

[0212] The pre-temperature control unit 4 heats the phosphoric acid solution passing through the first bypass pipe 36 using the non-quartz heater 45 while feeding the phosphoric acid solution to the first bypass pipe 36. This maintains the temperature of the phosphoric acid solution in the first tank T1 at 160°C. The phosphoric acid solution in the first tank T1, while maintaining its temperature, remains in a standby state until a supply instruction to any of the three processing units 2A, 2B, and 2C is issued.

[0213] [Step S44] Supplying phosphoric acid solution to the processing unit 2A (2B, 2C)

[0214] The pre-temperature control unit 4, for example, transports the phosphoric acid solution in the first tank T1 to the processing section 2A. The pre-temperature control unit 4 opens the on-off valves V5 and V16, closes the on-off valves V4, V6, V17, and V18, and drives the first pump 43. Consequently, the phosphoric acid solution in the first tank T1 is supplied in the order of outlet OL1, first pump 43, non-quartz heater 45, branch pipe 35D, supply pipe 101, and processing tank 6 of the processing section 2A.

[0215] When phosphoric acid solution is supplied from the first tank T1 to any of the three processing units 2A, 2B, and 2C, the liquid level sensor LS1 detects that the level of the phosphoric acid solution in the first tank T1 has dropped. In this case, the first tank T1 needs to be replenished with phosphoric acid solution from the phosphoric acid supply source 55. Therefore, the process returns to step S41.

[0216] According to this embodiment, the dissolution of silicon into the phosphoric acid solution is reduced as a whole, as in Example 1. Therefore, for example, the silicon concentration in the phosphoric acid solution supplied to the processing unit 2A can be prevented from becoming high.

[0217] The present invention is not limited to the above-described embodiment, and can be implemented in the following modified forms.

[0218] (1) In the fifth embodiment, the phosphoric acid solution is heated by the quartz heater 41 during the concentration operation, and is heated by the non-quartz heater 45 during the temperature control state. In this regard, as described in the fourth embodiment, the non-quartz heater 45 may be omitted, and the phosphoric acid solution may be heated to the first temperature (160° C.) by the quartz heater 41 during the concentration operation, and to the second temperature (120° C.) by the quartz heater 41 during the temperature control state.

[0219] in other words, Figure 9 The pre-temperature control unit 4 of the fourth embodiment shown includes two circulation sections 31 and 33, and prepares the phosphoric acid solution supplied to the treatment sections 2A, 2B, and 2C in two stages. However, the pre-temperature control unit 4 may also prepare the phosphoric acid solution in one stage.

[0220] (2) In each of the above-described embodiments and modification (1), the pre-temperature adjustment unit 4, for example, supplies the phosphoric acid solution directly to the treatment tank 6 when supplying the phosphoric acid solution to the treatment section 2A. Alternatively, the pre-temperature adjustment unit 4 may supply the phosphoric acid solution directly to the outer tank 7 and indirectly to the treatment tank 6 via the outer tank 7 and the treatment section circulation flow path 9.

[0221] (3) In each of the above-mentioned Examples 2 to 4 and the various variations, the phosphoric acid solution is heated to the first temperature (160°C) during the concentration operation and is heated to the second temperature (120°C) while maintaining the temperature control state. The phosphoric acid solution maintained at the second temperature (120°C) is then supplied to the treatment tank 6 storing the phosphoric acid solution heated to 160°C. In this regard, for example, Figure 9 In the figure, heaters 105, 106, and 107 shown by two-dot chain lines may be provided in each of the three supply pipes 80 to 82. For example, heater 105 heats the phosphoric acid solution passing through the second supply pipe 80. The two heaters 106 and 107 heat the two supply pipes 81 and 82, respectively.

[0222] For example, when the temperature of the phosphoric acid solution supplied to the processing unit 2A through the second supply pipe 80 is lower than the temperature of the phosphoric acid solution in the processing tank 6 of the processing unit 2A, the temperature difference can be suppressed. Furthermore, each heater 105 to 107 corresponds to a supply channel heater of the present invention. Each heater 105 to 107 preferably includes a non-quartz heater.

[0223] (4) In each of the aforementioned Examples 2 to 4 and the various variations, the first temperature of the phosphoric acid solution during concentration is set to 160°C in both the pre-circulation section 31 and the main circulation section 33, and the second temperature of the phosphoric acid solution during temperature control is set to 160°C or 120°C. In this regard, the first temperature set in the pre-circulation section 31 may be different from the first temperature set in the main circulation section 33. Similarly, the second temperature set in the pre-circulation section 31 may be different from the second temperature set in the main circulation section 33.

[0224] (5) In each of the above-described embodiments 1 to 4 and the various modifications, the bubble supply portion 67 is provided only in the first tank T1. In this regard, the bubble supply portion 67 may also be provided in the second tank T2.

[0225] (6) In the above-described embodiments and variations, the first end of the first supply pipe 37 is connected to the first circulation pipe 35 via the branch pipe 35C. Furthermore, for example, the first end of the second supply pipe 80 is connected to the second circulation pipe 77 via the branch pipe 77C. In this regard, the first end of the first supply pipe 37 may be directly connected to the first tank T1. Furthermore, the first end of the second supply pipe 80 may be directly connected to the second tank T2.

[0226] [Explanation of Symbols]

[0227] 1 Substrate processing device

[0228] 2A, 2B, 2C Processing Department

[0229] 4 Pre-temperature control unit

[0230] 6 Processing Tanks

[0231] 31 Pre-loop section

[0232] 33 Main loop

[0233] T1 Slot 1

[0234] 35 1st circulation piping

[0235] 36 1st roundabout piping

[0236] 37 1st supply pipe

[0237] 39 Concentration piping

[0238] 41 Quartz Heater

[0239] 43 Pump 1

[0240] 45 Non-quartz heater

[0241] 47 quartz tube

[0242] 51 Non-quartz tube

[0243] 67 Bubble supply unit

[0244] T2 Slot 2

[0245] 77 Second circulation piping

[0246] 78 2nd roundabout piping

[0247] 80, 81, 82 Second supply pipe

[0248] 101, 102, 103 Second supply pipe

[0249] 85 Concentration piping

[0250] 87 Quartz Heater

[0251] 89 Pump 2

[0252] 91 Non-quartz heater

[0253] 93 Control Department.

Claims

1. A substrate processing device, characterized in that have: a processing section having a processing tank storing a phosphoric acid solution for immersing the substrate; a tank for storing the phosphoric acid solution; a supply flow path for conveying the phosphoric acid solution in the tank to the processing unit; a circulation flow path, both ends of which are connected to the tank and used to return the phosphoric acid solution flowing into the tank to the tank; a pump, disposed in the circulation flow path; a quartz heater provided in the concentration flow path which is a part of the circulation flow path, comprising a quartz tube formed of quartz and for allowing the phosphoric acid solution to pass therethrough; a circuitous flow path, both ends of which are connected to the upstream end and the downstream end of the concentration flow path; a non-quartz heater disposed in the circuitous flow path, having a non-quartz tube that is not made of quartz and is used to allow the phosphoric acid solution to pass therethrough; and control unit; and The control unit, when concentrating the phosphoric acid solution in the tank, heats the phosphoric acid solution passing through the concentrating flow path using the quartz heater while feeding the phosphoric acid solution to the concentrating flow path; When concentration of the phosphoric acid solution in the tank is completed, the control unit heats the phosphoric acid solution passing through the bypass flow path using the non-quartz heater while feeding the phosphoric acid solution to the bypass flow path, thereby maintaining the temperature of the phosphoric acid solution in the tank.

2. The substrate processing apparatus according to claim 1, wherein: further comprising a phosphoric acid concentration sensor for measuring the concentration of the phosphoric acid solution in the tank, The control unit concentrates the phosphoric acid solution in the tank when the concentration value measured by the phosphoric acid concentration sensor is lower than a preset threshold value. The control unit determines that concentration of the phosphoric acid solution in the tank is complete when the concentration value measured by the phosphoric acid concentration sensor is equal to or greater than the threshold value, and maintains the temperature of the phosphoric acid solution in the tank.

3. The substrate processing apparatus according to claim 1, wherein The control unit heats the phosphoric acid solution passing through the concentration flow path using the quartz heater so that the temperature of the phosphoric acid solution in the tank reaches a predetermined first temperature when concentrating the phosphoric acid solution in the tank. The control unit heats the phosphoric acid solution passing through the bypass flow path using the non-quartz heater so that the temperature of the phosphoric acid solution in the tank reaches a second temperature lower than the first temperature while maintaining the temperature of the phosphoric acid solution in the tank.

4. The substrate processing apparatus according to claim 3, wherein: The first temperature is equal to or higher than the boiling point of the phosphoric acid solution.

5. The substrate processing apparatus according to claim 3, wherein: The second temperature is 100° C. or higher and lower than the boiling point of the phosphoric acid solution.

6. The substrate processing apparatus according to claim 3, wherein: A supply channel heater is provided, the supply channel heater being provided in the supply channel and heating the phosphoric acid solution passing through the supply channel.

7. The substrate processing apparatus according to claim 1, wherein: The invention further includes a bubble supply portion that is arranged on the bottom wall side of the groove and has a plurality of holes and is configured to supply bubbles into the groove through the plurality of holes.

8. The substrate processing apparatus according to claim 1, wherein: When performing substrate processing in which a substrate is immersed in the processing tank, the control unit supplies the phosphoric acid solution to the processing unit through the supply flow path.

9. The substrate processing apparatus according to claim 1, wherein: During substrate processing in which a substrate is immersed in the processing tank, the control unit supplies the phosphoric acid solution to the processing unit through the supply flow path while discharging a portion of the phosphoric acid solution in the processing tank.

10. The substrate processing apparatus according to claim 1, wherein The non-quartz tube is a fluorine-based resin tube formed of a fluorine-based resin.

11. The substrate processing apparatus according to any one of claims 1 to 10, characterized in that have: a second tank disposed in a supply flow path for conveying the phosphoric acid solution from the tank to the processing unit, and storing the phosphoric acid solution conveyed from the tank; a second circulation flow path connected at both ends to the second tank and used to return the phosphoric acid solution flowing from the second tank to the second tank; a second pump, provided in the second circulation flow path; a second quartz heater provided in a second concentrating flow path which is a part of the second circulation flow path, and having a second quartz tube formed of quartz and for allowing the phosphoric acid solution to pass therethrough; a second detour flow path having both ends connected to the upstream end and the downstream end of the second concentration flow path; as well as a second non-quartz heater, provided in the second detour flow path, including a second non-quartz tube that is not made of quartz and is used for passing the phosphoric acid solution; The control unit, when concentrating the phosphoric acid solution in the second tank, heats the phosphoric acid solution passing through the second concentrating flow path using the second quartz heater while conveying the phosphoric acid solution to the second concentrating flow path; When concentration of the phosphoric acid solution in the second tank is completed, the control unit heats the phosphoric acid solution passing through the second detour flow path using the second non-quartz heater while conveying the phosphoric acid solution to the second detour flow path, thereby maintaining the temperature of the phosphoric acid solution in the second tank.

12. The substrate processing apparatus according to any one of claims 1 to 10, characterized in that have: a second tank disposed in a supply flow path for conveying the phosphoric acid solution from the tank to the processing unit, and storing the phosphoric acid solution conveyed from the tank; a second circulation flow path connected at both ends to the second tank and used to return the phosphoric acid solution flowing from the second tank to the second tank; a second pump, provided in the second circulation flow path; as well as a second quartz heater, provided in the second circulation flow path, having a second quartz tube formed of quartz and used for passing the phosphoric acid solution; and The control unit heats the phosphoric acid solution passing through the concentration flow path using the quartz heater so that the temperature of the phosphoric acid solution in the tank reaches a predetermined first temperature when concentrating the phosphoric acid solution in the tank. In order to maintain the concentration of the phosphoric acid solution, the control unit heats the phosphoric acid solution passing through the second circulation flow path using the second quartz heater so that the temperature of the phosphoric acid solution in the second tank becomes a second temperature lower than the first temperature, thereby maintaining the temperature of the phosphoric acid solution in the second tank.

13. The substrate processing apparatus according to any one of claims 1 to 10, characterized in that have: a second tank disposed in a supply flow path for conveying the phosphoric acid solution from the tank to the processing unit, and storing the phosphoric acid solution conveyed from the tank; a second circulation flow path connected at both ends to the second tank and used to return the phosphoric acid solution flowing from the second tank to the second tank; a second pump, provided in the second circulation flow path; as well as a second quartz heater, provided in the second circulation flow path, having a second quartz tube formed of quartz and used for passing the phosphoric acid solution; and The control unit heats the phosphoric acid solution passing through the second circulation flow path using the second quartz heater so that the temperature of the phosphoric acid solution in the second tank reaches a predetermined first temperature when concentrating the phosphoric acid solution in the second tank. When concentration of the phosphoric acid solution in the second tank is completed, the control unit heats the phosphoric acid solution passing through the second circulation flow path using the second quartz heater so that the temperature of the phosphoric acid solution in the second tank reaches a second temperature lower than the first temperature.

14. A substrate processing device, characterized in that have: a processing section having a processing tank storing a phosphoric acid solution for immersing the substrate; a tank for storing the phosphoric acid solution; a supply flow path for conveying the phosphoric acid solution in the tank to the processing unit; a circulation flow path, both ends of which are connected to the tank and used to return the phosphoric acid solution flowing into the tank to the tank; a pump, disposed in the circulation flow path; a quartz heater, provided in the circulation flow path, having a quartz tube formed of quartz and through which the phosphoric acid solution passes; and Control Department; The control unit heats the phosphoric acid solution passing through the circulation flow path using the quartz heater so that the temperature of the phosphoric acid solution in the tank reaches a predetermined first temperature when concentrating the phosphoric acid solution in the tank. When concentration of the phosphoric acid solution in the tank is completed, the control unit heats the phosphoric acid solution passing through the circulation flow path using the quartz heater so that the temperature of the phosphoric acid solution in the tank reaches a second temperature lower than the first temperature.

Images