Substrate processing device and substrate processing method

Abstract

Provided is a substrate processing device capable of detecting deterioration of a component with high accuracy. A substrate processing device (100) comprises: a substrate holding unit (20) in which a conductive material layer (22) and a protective layer (23) are laminated on a surface of a base member (21) in a portion that may be immersed in a processing liquid (L); and a control unit (40) that detects the occurrence of a defect in the substrate holding unit on the basis of a resistance value and / or a current value when a potential difference is produced between the conductive material layer and the processing liquid.

Description

Substrate Processing Apparatus and Substrate Processing Method

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method.

[0002] An example of a substrate processing apparatus that stores a processing liquid in a processing tank and immerses a substrate in the processing tank using a lifter that holds the substrate to clean the substrate is disclosed in Patent Document 1. The substrate processing apparatus has an inspection means for inspecting deterioration of a resin-coated metallic part constituting the lifter. The inspection means includes a measurement means for measuring a predetermined metal concentration in a liquid that has come into contact with the part to be inspected, and a deterioration determination means for determining the degree of deterioration of the part to be inspected by comparing the metal concentration measured by the measurement means with a predetermined threshold value.

[0003] Japanese Patent Application Laid-Open No. 2019-029471

[0004] However, with the inspection means of the substrate processing apparatus disclosed in Patent Document 1, it is impossible to distinguish whether the metal in the processing liquid adhered to the wafer during preprocessing or is derived from the deterioration of the part to be inspected. Therefore, there is a problem that the deterioration of the part cannot be detected with high accuracy depending on the inspection means.

[0005] One aspect of the present invention aims to realize a substrate processing apparatus and the like that can detect part deterioration with high accuracy.

[0006] To solve the above problems, a substrate processing apparatus according to one aspect of the present invention is a substrate processing apparatus that performs surface treatment by immersing a substrate in a processing liquid, comprising: a processing tank for storing a processing liquid; a substrate holding part that holds the substrate in a predetermined position in the processing liquid in the processing tank, and wherein a conductive material layer and a protective layer are laminated on the surface of a base member in order from the base member side, at least in the portion that can be immersed in the processing liquid; a measuring unit that measures at least one of the current value flowing between the conductive material layer and the processing liquid and the resistance value between the conductive material layer and the processing liquid when a potential difference is generated between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank during the surface treatment; and a control unit that detects the occurrence of a malfunction in the substrate holding part based on at least one of the current value and the resistance value.

[0007] Furthermore, a substrate processing method according to one aspect of the present invention comprises a processing tank for storing a processing liquid, a substrate holding part for holding a substrate in a predetermined position in the processing liquid in the processing tank, and having a conductive material layer and a protective layer laminated on the surface of a base member in order from the base member side, at least in the portion that can be immersed in the processing liquid, and a measuring part for measuring at least one of the current value flowing between the conductive material layer and the processing liquid and the resistance value between the conductive material layer and the processing liquid when a potential difference is generated between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank, during the surface processing, wherein the substrate is immersed in the processing liquid A substrate processing method for surface treatment, comprising the steps of storing the processing liquid in the processing tank and holding the substrate in a predetermined position in the processing liquid with the substrate holding unit, further comprising, in parallel with the step of holding the substrate in the processing liquid, measuring at least one of the current value flowing between the conductive material layer and the processing liquid and the resistance value between the conductive material layer and the processing liquid when a potential difference is generated between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank, during the surface treatment, and detecting the occurrence of a malfunction in the substrate holding unit based on at least one of the current value and the resistance value.

[0008] According to one aspect of the present invention, it is possible to realize a substrate processing apparatus that can detect component degradation with high accuracy.

[0009] This is a schematic cross-sectional view illustrating the overall configuration of the substrate processing apparatus according to Embodiment 1. This is a cross-sectional view illustrating the configuration of the main parts of the substrate processing apparatus according to Embodiment 1. This is a plan view illustrating the configuration of the substrate holding part. This is a block diagram illustrating the configuration of the main parts of the substrate processing apparatus. This is a cross-sectional view illustrating the specific configuration of the substrate holding part and the measurement part. This is a flowchart illustrating a substrate processing method using the substrate processing apparatus. This is a diagram showing the configuration of the main parts of the substrate processing apparatus according to Embodiment 2. This is a diagram showing the configuration of the main parts of the substrate processing apparatus according to Embodiment 3.

[0010] [Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings.

[0011] Figure 1 is a schematic cross-sectional view illustrating the overall configuration of a substrate processing apparatus 100 according to Embodiment 1 of the present invention. Figure 2 is a cross-sectional view illustrating the configuration of the main parts of the substrate processing apparatus 100. Figure 3 is a plan view illustrating the configuration of the substrate holding section 20. Figure 4 is a block diagram illustrating the configuration of the main parts of the substrate processing apparatus 100. Figure 5 is a cross-sectional view illustrating the specific configuration of the substrate holding section 20 and the measurement section 30.

[0012] The substrate processing apparatus 100 performs surface treatment by immersing the substrate W in a processing liquid L. In Figure 1, the processing liquid L is omitted. The substrate W is, for example, a semiconductor wafer. As shown in Figures 1 to 4, the substrate processing apparatus 100 comprises a processing tank 10, a substrate holding unit 20, a measurement unit 30, and a control unit 40.

[0013] The treatment tank 10 stores the treatment liquid L. The treatment tank 10 has a shape that allows the entire substrate W to be immersed in the stored treatment liquid L. The treatment tank 10 may be made of a material that is corrosion-resistant to the treatment liquid L.

[0014] The substrate processing apparatus 100 further comprises a processing liquid supply source 13, a discharge pipe 15, an overflow tank 17, and a drainage liquid recovery unit 19. The processing liquid supply source 13 supplies processing liquid L to the discharge pipe 15. The discharge pipe 15 is located at the bottom of the processing tank 10 and supplies the processing liquid L supplied from the processing liquid supply source 13 into the processing tank 10. The discharge pipe 15 may be a so-called upflow pipe that discharges the processing liquid upwards from the processing tank 10. Alternatively, the discharge pipe 15 may discharge the processing liquid along the bottom surface of the processing tank 10. The overflow tank 17 stores the processing liquid L that overflows from the processing tank 10. The drainage liquid recovery unit 19 recovers the processing liquid L stored in the overflow tank 17.

[0015] In Figure 1, the discharge pipe 15 is shown separated from the treatment tank 10 for better visibility. However, the discharge pipe 15 may be embedded in a part of the treatment tank 10, as shown in Figure 2. Also, the treatment liquid supply source 13 and the wastewater recovery unit 19 are omitted in all figures except Figure 1.

[0016] The processing tank 10 may be a tank known as a CHB (Chemical Bath) that processes the substrate W by circulating a single type of processing liquid L. In this case, the substrate processing apparatus 100 further includes piping and a pump for circulating the processing liquid L, a heater for heating the processing liquid L, and a filter for filtering the processing liquid L. Alternatively, the processing tank 10 may be a tank known as an ONB (One Bath) that performs surface treatment by continuously replacing the processing liquid L with a chemical solution and pure water.

[0017] The substrate holding unit 20 holds the substrate W in a predetermined position within the processing liquid L in the processing tank 10. The predetermined position is the position where the entire substrate W is immersed in the processing liquid L. Specifically, the substrate holding unit 20 is a lifter that can move the substrate W between at least the predetermined position and a position above the predetermined position. More specifically, the substrate holding unit 20 can move the substrate W to a position above the predetermined position where the entire substrate W is outside the processing liquid L. In the following description, the predetermined position may be referred to as the immersion position, and the position where the entire substrate W is outside the processing liquid L may be referred to as the lifting position.

[0018] The substrate holding unit 20 can immerse the substrate W in the processing liquid L by moving the substrate W from the lifting position to the immersion position. Furthermore, the substrate holding unit 20 can lift the substrate W out of the processing liquid L by moving the substrate W from the immersion position to the lifting position.

[0019] The substrate holding section 20 may include a mounting section 26 on which multiple substrates W are placed, and a back plate 27 positioned at one end of the mounting section 26 and extending vertically along the side wall of the processing tank 10. The mounting section 26 may have any shape that can accommodate multiple substrates W. This allows the substrate holding section 20 to hold multiple substrates W and move them between a lifting position and an immersion position. The substrate holding section 20 further includes a drive mechanism 28 for raising and lowering the mounting section 26 and the back plate 27.

[0020] In the example shown in Figure 3, the mounting portion 26 consists of three rod-shaped members extending parallel to the direction in which the substrates W are aligned. The mounting portion 26 supports the ends of the substrates W at three points. The mounting portion 26 is also provided with a comb-shaped portion K, which has multiple grooves arranged at predetermined intervals along its longitudinal direction into which the outer edge of the substrate W fits and holds the substrate W in an upright position. As a result, the substrate holding portion 20 can hold the substrate W in a stable state.

[0021] As shown in Figures 2 and 5, the substrate holding portion 20 has a structure in which a conductive material layer 22 and a protective layer 23 are laminated on the surface of the base member 21 in order from the base member 21 side, at least in the portion that can be immersed in the processing liquid L. The base member 21 may be made of a material having sufficient strength to withstand the weight of the substrate W. The conductive material layer 22 may be made of a material that is conductive and has little effect on the processing liquid L even if it dissolves in the processing liquid L. The protective layer 23 may be made of a material that is less conductive than the conductive material layer 22 and has corrosion resistance to the processing liquid L.

[0022] For example, the base member 21 is made of quartz material, and the protective layer 23 is made of PFA (Perfluoroalkoxy alkanes) or PCTFE (Polychlorotrifluoroethylene). This ensures that the substrate holding portion 20 has the strength to withstand the weight of the substrate W. In addition, the protective layer 23 can protect the base member 21 from treatment liquids L such as hydrofluoric acid.

[0023] The materials constituting the base member 21 and the protective layer 23 are not necessarily limited to the examples described above. For example, the base member 21 may be made of a material other than quartz, such as PEEK (Polyetheretherketone). Also, carbon is an example of a material for the conductive material layer 22, but it is not limited to this.

[0024] The measurement unit 30 measures, during surface treatment, at least one of the following when a potential difference is generated between the conductive material layer 22 and the processing liquid L in which the substrate W is immersed in the processing tank 10: (i) the value of the current flowing between the conductive material layer 22 and the processing liquid L, and (ii) the value of the resistance between the conductive material layer 22 and the processing liquid L.

[0025] The control unit 40 controls various parts of the substrate processing apparatus 100 and controls the operation of the substrate processing apparatus 100. The control unit 40 comprises one or more processors or circuits. The processor or circuit may include, but is not limited to, a central processing unit (CPU), a microprocessing unit (MPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), or a field-programmable gateway (FPGA). In Figure 1, the control unit 40 includes a CPU 41.

[0026] Furthermore, the control unit 40 further includes a memory 42, which is a storage medium. The storage medium may also be referred to as a non-temporary computer-readable medium. The storage medium may include, but is not limited to, a hard disk (HD) or random access memory (RAM).

[0027] As shown in Figure 4, the control unit 40 controls the operation of the substrate holding unit 20. The control unit 40 also detects the occurrence of a malfunction in the substrate holding unit 20 based on the current value and at least one of the measured values ​​measured by the measurement unit 30.

[0028] In this specification, a malfunction of the substrate holding portion 20 refers to the deterioration of the protective layer 23, which exposes the conductive material layer 22 to the processing liquid L. In other words, at the time the malfunction occurs, the base member 21 is not exposed to the processing liquid L. Therefore, there is a time lag between the occurrence of the malfunction and the corrosion of the base member 21 by the processing liquid L.

[0029] As described above, the conductive material layer 22 is made of a conductive material. The protective layer 23 is made of a material with lower conductivity than the conductive material layer 22. Therefore, when the conductive material layer 22 is exposed to the processing liquid L due to deterioration of the protective layer 23, the current flowing between the conductive material layer 22 and the processing liquid L increases, and the resistance between the conductive material layer 22 and the processing liquid L decreases. Consequently, the control unit 40 can detect the occurrence of a malfunction in the substrate holding part 20 with high accuracy during the surface treatment of the substrate W.

[0030] For example, the control unit 40 detects a malfunction in the substrate holding unit 20 when the current value measured by the measurement unit 30 exceeds a predetermined threshold, or when the resistance value measured by the measurement unit 30 falls below a predetermined threshold. The predetermined threshold for the current value may be the upper limit of the current value measured by the measurement unit 30 that is expected when there is no malfunction in the substrate holding unit 20. The predetermined threshold for the resistance value may be the lower limit of the resistance value measured by the measurement unit 30 that is expected when there is no malfunction in the substrate holding unit 20. As a result, the control unit 40 can easily detect a malfunction in the substrate holding unit 20 during the surface treatment of the substrate W based on at least one of the current value and the measured value measured by the measurement unit 30.

[0031] As shown in Figure 5, the measurement unit 30 includes wiring 31 with a terminal 31a that connects to a contact portion 22a in the conductive material layer 22, and an electrode 32 that is placed in the processing liquid L in the processing tank 10. The contact portion 22a and the terminal 31a are positioned so as not to come into contact with the processing liquid L when the substrate holding unit 20 holds the substrate W in the immersion position. Known materials such as metal can be used as the terminal 31a, wiring 31, and electrode 32 without any particular limitations.

[0032] Furthermore, the measurement unit 30 includes a measuring instrument 33. The measuring instrument 33 is at least one of an ammeter that measures the current value flowing between the contact portion 22a and the electrode 32, and a resistance meter that measures the resistance value between the contact portion 22a and the electrode 32. As a result, the control unit 40 can detect a malfunction of the substrate holding portion 20 based on the current value or resistance value measured by the measuring instrument 33. Any known ammeter and / or resistance meter can be used as the measuring instrument 33 without any particular limitations.

[0033] The control unit 40 may output a warning signal in at least one of the following cases: when the current value measured by the measurement unit 30 exceeds a predetermined threshold, or when the resistance value measured by the measurement unit 30 falls below a predetermined threshold. This allows the control unit 40 to output a warning signal when a malfunction occurs in the substrate holding unit 20. The warning signal may be input to a monitor that displays a warning message to an administrator who manages the operation of the substrate processing device 100. Alternatively, the warning signal may be input to a warning device that outputs a warning to the administrator of the substrate processing device 100, for example, by sound, image, or light. The administrator can recognize that a malfunction has occurred in the substrate holding unit 20 when a warning is output from the monitor or warning device.

[0034] Normally, the processing of the substrate W is carried out according to a predetermined production plan. In the substrate processing apparatus 100, if a malfunction occurs in the substrate holding part 20, the manager can recognize it early. Therefore, the manager can take action to prevent disruption to the production plan by planning and executing the replacement of the substrate holding part 20 or the recoating of the conductive material layer 22 with the protective layer 23 during the grace period before the base member 21 is corroded by the processing liquid L, as described above.

[0035] The substrate holding portion 20 may further have a contact portion protection layer 22b. The contact portion protection layer 22b protects the contact portion 22a. Specifically, the surface of the contact portion 22a other than the portion that contacts the terminal 31a is protected by the contact portion protection layer 22b. In this case, the contact portion protection layer 22b prevents deterioration of the contact portion 22a. That is, with this configuration, it becomes possible to use a material other than carbon that has low corrosion resistance to the processing liquid L as the material of the conductive material layer 22, thereby broadening the range of material selection for the conductive material layer 22.

[0036] In the chamber of the substrate processing apparatus 100, the processing liquid L may vaporize or droplets of the processing liquid L may be scattered. In this case, the terminal 31a may be exposed to the atmosphere of the vaporized or scattered processing liquid L. To address this, the terminal 31a may be made to have a corrosion-resistant structure. More specifically, the terminal 31a may have corrosion resistance to at least the processing liquid L. This prevents corrosion of the terminal 31a even when it is exposed to the atmosphere of the vaporized or scattered processing liquid L.

[0037] Specifically, the substrate processing apparatus 100 may further include a terminal sealing member 50 for surrounding the terminal 31a with a predetermined gas while the terminal 31a is in contact with the contact portion 22a. The terminal sealing member 50 includes a covering member that covers at least a portion of the area around the terminal 31a, and a gas supply mechanism that supplies the predetermined gas into the covering member. The predetermined gas is a type of gas that does not corrode the terminal 31a. An example of a gas that does not corrode the terminal 31a is nitrogen (N). ２Examples include, but are not limited to, the following. This prevents vapor from the treatment liquid L from entering the interior of the covering member, thereby preventing corrosion of the terminal 31a.

[0038] The substrate processing apparatus 100 does not necessarily have to include a terminal sealing member 50. For example, the terminal 31a itself may be made of a material that has corrosion resistance to the processing liquid L. For example, the terminal 31a may be made of carbon. Alternatively, the surface of the terminal 31a other than the part that contacts the contact portion 22a may be protected by a terminal protective layer. The terminal protective layer may be made of a material that has corrosion resistance to the processing liquid L. Corrosion of the terminal 31a is also prevented by having the terminal 31a in such a configuration.

[0039] Figure 6 is a flowchart illustrating a substrate processing method using the substrate processing apparatus 100. In the substrate processing method illustrated in Figure 6, the control unit 40 first stores the processing liquid L in the processing tank 10 (S1). Next, the control unit 40 holds the substrate W with the substrate holding unit 20 (S2). In this state, the control unit 40 moves the substrate W from the lifted position to the immersion position (S3) and holds it in the immersion position (S4). As a result, the substrate W is surface-treated by the processing liquid L.

[0040] In parallel with step S4, the control unit 40 performs a step to detect the occurrence of a malfunction in the substrate holding unit 20. Specifically, the control unit 40 measures the resistance value or current value between the conductive material layer 22 and the processing liquid L using the measurement unit 30 (S5). Furthermore, the control unit 40 determines whether or not a malfunction has occurred in the substrate holding unit 20 based on the measured resistance value or current value (S6).

[0041] If a malfunction occurs in the substrate holding unit 20 (YES in S6), the control unit 40 outputs an alarm signal (S7). If no malfunction occurs in the substrate holding unit 20 (NO in S6), the control unit 40 skips step S7.

[0042] After that, the control unit 40 determines whether or not the surface treatment of the substrate W with the processing liquid L has ended (S8). For example, when the period during which the control unit 40 holds the substrate W at the immersion position is equal to or longer than a predetermined time, the control unit 40 determines that the surface treatment has ended. In this case, the substrate processing apparatus 100 further includes a timer that measures the period during which the substrate W is held at the immersion position.

[0043] When the surface treatment of the substrate W has not ended (NO in S8), the control unit 40 continues step S4 and repetitively performs the subsequent processing from step S5 in parallel. However, when the control unit 40 determines that a malfunction has occurred in the substrate holding unit 20 (YES in S6), it may only repeat step S8.

[0044] When the surface treatment of the substrate W has ended (YES in S8), the control unit 40 moves the substrate W from the immersion position to the lifting position by the substrate holding unit 20 (S9). Thereby, the processing method of the substrate W by the substrate processing apparatus 100 ends. As described above, in the substrate processing method by the substrate processing apparatus 100, it is possible to detect the occurrence of a malfunction in the substrate holding unit 20 without stopping the processing of the substrate W.

[0045] (Measurement Example) The inventor of the present application conducted an experiment of measuring the resistance value between the electrodes in a state where electrodes simulating the substrate holding unit 20 and the electrode 32 were immersed in the processing liquid. As the electrode simulating the substrate holding unit 20, an electrode having the surface of carbon coated with a PCTFE film was used. As the electrode simulating the electrode 32, an electrode made of glassy carbon was used. These electrodes were immersed in hydrofluoric acid as the processing liquid in a state where their positional relationship was fixed using a fixing jig. The thickness of the PCTFE film (PCTFE film thickness) in the electrode simulating the substrate holding unit 20 was varied, and the resistance value between these electrodes was measured.

[0046] The measurement results of the resistance values were as follows. - When the PCTFE film thickness was 350 μm, 200 μm, and 100 μm, the resistance value was ∞. - When the PCTFE film thickness was 0 μm, the resistance value was 0.032 MΩ.

[0047] As described above, in the electrode simulating the substrate holding portion 20, it was confirmed that the electrode became conductive when the PCTFE film thickness became 0 μm, that is, when the PCTFE film covering the surface of the carbon disappeared. Therefore, it is expected that in the substrate processing apparatus 100 as well, the measurement unit 30 can detect the deterioration of the substrate holding portion 20 by measuring the resistance value between the conductive material layer 22 and the processing liquid L. Also, when the measurement unit 30 measures the current value between the conductive material layer 22 and the processing liquid L, it is similarly expected that the deterioration of the substrate holding portion 20 can be detected.

[0048] [Embodiment 2] FIG. 7 is a diagram showing the configuration of a main part of a substrate processing apparatus 200 according to Embodiment 2. In FIG. 7, the shapes of some components are simplified. However, the actual shapes of those components are not particularly different from the shapes of the components with the same reference numerals in the substrate processing apparatus 100.

[0049] As shown in FIG. 7, the substrate processing apparatus 200 is different from the substrate processing apparatus 100 in that it includes a measurement unit 30A instead of the measurement unit 30. The measurement unit 30A is different from the measurement unit 30 in that it includes an electrode 34 instead of the electrode 32, and a measuring instrument 35 instead of the measuring instrument 33. The measurement unit 30A measures the capacitance between the electrode 34 and the conductive material layer 22 during the surface treatment of the substrate W.

[0050] The electrode 34 is an electrode that generates a potential difference between the conductive material layer 22 and the processing liquid. The electrode 34 has a structure in which an electrode protection layer 34b is laminated on the surface of the conductive material 34a. The conductive material 34a may have the same configuration as the electrode 32 in the measurement unit 30. The electrode protection layer 34b is a layer of insulator laminated on the surface of the conductive material 34a. The electrode protection layer 34b may be formed of PFA or PCTFE, similarly to the protection layer 23 in the substrate holding portion 20.

[0051] The electrode 34 is immersed in the processing liquid at least during the period when the measurement unit 30A is performing measurements. For example, the electrode 34 may be able to be raised and lowered so that it is immersed in the processing liquid only during the period when the measurement unit 30A is performing measurements, and not immersed in the processing liquid at other times. In the substrate processing apparatus 200, of the electrode 34, the conductive material 34a does not come into direct contact with the processing liquid, and only the electrode protective layer 34b comes into direct contact with the processing liquid.

[0052] The measuring instrument 35 is a capacitance meter for measuring capacitance. In the substrate processing apparatus 200, the measuring instrument 35 measures the capacitance between the electrode 34 and the conductive material layer 22.

[0053] In the substrate processing apparatus 200, the capacitance between the electrode 34 and the conductive material layer 22 increases as the protective layer 23 and / or electrode protective layer 34b deteriorate. For example, the control unit 40 detects the occurrence of a malfunction in the substrate holding unit 20 when the capacitance measured by the measurement unit 30A exceeds a predetermined threshold. The predetermined threshold for capacitance may be the upper limit of the capacitance measured by the measurement unit 30A that is expected when there is no malfunction in the substrate holding unit 20. This allows the control unit 40 to easily detect the occurrence of a malfunction in the substrate holding unit 20 during the surface treatment of the substrate W based on the capacitance measured by the measurement unit 30A.

[0054] (Measurement Example) The inventors of the present invention conducted an experiment to measure the capacitance between electrodes that mimicked the substrate holder 20 and the electrode 34, while they were immersed in a processing solution. Electrodes with a PCTFE film coating on the surface of carbon were used as electrodes mimicking the substrate holder 20 and the electrode 34, respectively. These electrodes were immersed in hydrofluoric acid as the processing solution, with their relative positions fixed using a fixing jig. The PCTFE film thickness on the electrode mimicking electrode 34 was fixed at 350 μm, and the PCTFE film thickness on the electrode mimicking the substrate holder 20 was varied, and the capacitance between these electrodes was measured.

[0055] The capacitance measurement results were as follows. In the following measurement results, the capacitance level value is approximately 1% ≈ 2pF. • When the PCTFE film thickness was 350 μm, the capacitance level was 18%. • When the PCTFE film thickness was 200 μm, the capacitance level was 23.8%. • When the PCTFE film thickness was 100 μm, the capacitance level was 31%.

[0056] As described above, it was confirmed that the capacitance increases as the PCTFE film thickness decreases in the electrode that mimics the substrate holding portion 20. Therefore, it is expected that in the substrate processing apparatus 200 as well, the deterioration of the substrate holding portion 20 can be detected by the measurement unit 30A measuring the capacitance between the conductive material layer 22 and the electrode 34.

[0057] [Embodiment 3] Figure 8 is a diagram showing the configuration of the main parts of the substrate processing apparatus 300 according to Embodiment 3. In Figure 8, as in Figure 7, the shapes of some components have been simplified. As shown in Figure 8, the substrate processing apparatus 300 differs from the substrate processing apparatus 100 in that it has a measurement unit 60 instead of a measurement unit 30. The measurement unit 60 includes a first protective electrode 61 and a second protective electrode 62, and a measuring instrument 35. The measurement unit 60 measures the capacitance between the first protective electrode 61 and the second protective electrode 62 during the surface treatment of the substrate W.

[0058] The first protective electrode 61 has a structure in which an electrode protective layer 61b is laminated on the surface of a conductive material 61a. The second protective electrode 62 has a structure in which an electrode protective layer 62b is laminated on the surface of a conductive material 62a. The conductive materials 61a and 62a may be the same as the conductive material 34a in the electrode 34. The thickness and composition of the electrode protective layers 61b and 62b may be the same as the thickness and composition of the protective layer 23 in the substrate holding portion 20.

[0059] The first protective electrode 61 and the second protective electrode 62 are immersed in the processing liquid in the processing tank 10 for the same period of time that the substrate holding part 20 is immersed in the processing liquid. Specifically, the first protective electrode 61 and the second protective electrode 62 may move up and down in conjunction with the raising and lowering of the substrate holding part 20, and switch between a state of being immersed in the processing liquid and a state of not being immersed in the processing liquid. In a substrate processing apparatus 300 when no malfunction occurs, the conductive materials 61a and 62a of the first protective electrode 61 and the second protective electrode 62 do not come into direct contact with the processing liquid, while the electrode protective layers 61b and 62b come into direct contact with the processing liquid.

[0060] In the substrate processing apparatus 300, the measuring instrument 35 measures the capacitance between the first protective electrode 61 and the second protective electrode 62. In the substrate processing apparatus 300, as the electrode protective layers 61b and 62b deteriorate, the capacitance between the first protective electrode 61 and the second protective electrode 62 decreases.

[0061] As described above, the material and thickness of the electrode protection layers 61b and 62b are the same as those of the protective layer 23 in the substrate holding section 20. Furthermore, the time that the electrode protection layers 61b and 62b are immersed in the processing solution is approximately the same as the time that the protective layer 23 is immersed in the processing solution. For this reason, it is considered that the degree of deterioration of the protective layer 23 in the substrate processing apparatus 300 at a given time is approximately the same as the degree of deterioration of the electrode protection layers 61b and 62b at the same time.

[0062] For example, the control unit 40 detects a malfunction in the substrate holding unit 20 when the capacitance measured by the measurement unit 60 falls below a predetermined threshold. The predetermined threshold for capacitance may be the lower limit of the capacitance measured by the measurement unit 60 that would be expected if there were no malfunction in the substrate holding unit 20. This allows the control unit 40 to easily detect a malfunction in the substrate holding unit 20 during surface treatment of the substrate W based on the capacitance measured by the measurement unit 60. In particular, since the measurement unit 60 detects the occurrence of a malfunction based on the capacitance between the first protective electrode 61 and the second protective electrode 62, it can detect a malfunction in the substrate holding unit 20 where the conductive material layer 22 does not have a contact portion 22a. Therefore, the measurement unit 60 is easily applicable to existing substrate processing equipment.

[0063] (Measurement Example) The inventors of the present invention conducted an experiment to measure the capacitance between electrodes that mimicked the first protective electrode 61 and the second protective electrode 62 while they were immersed in a processing solution. Electrodes with a carbon surface coated with a PCTFE film were used as the electrodes mimicking the first protective electrode 61 and the second protective electrode 62, respectively. These electrodes were immersed in hydrofluoric acid as the processing solution, with their relative positions fixed using a fixing jig. The PCTFE film thickness on the electrodes mimicking the first protective electrode 61 and the second protective electrode 62 was varied while keeping them equal, and the capacitance between these electrodes was measured.

[0064] The capacitance measurement results were as follows. The capacitance level values ​​in the following measurement results are 1% ≈ 2pF, the same as those described in the measurement example of Embodiment 2. • When the PCTFE film thickness was 350 μm, the capacitance level was 18%. • When the PCTFE film thickness was 200 μm, the capacitance level was 42.1%. • When the PCTFE film thickness was 100 μm, the capacitance level was 73.3%.

[0065] As described above, it was confirmed that the capacitance increases as the PCTFE film thickness decreases in electrodes that mimic the first protective electrode 61 and the second protective electrode 62, respectively. Therefore, it is expected that in the substrate processing apparatus 300, the measurement unit 60 can detect the deterioration of the substrate holding unit 20 by measuring the capacitance between the first protective electrode 61 and the second protective electrode 62.

[0066] [Summary] A substrate processing apparatus according to one aspect of the present invention is a substrate processing apparatus that performs surface treatment by immersing a substrate in a processing liquid, comprising: a processing tank for storing a processing liquid; a substrate holding part that holds the substrate in a predetermined position in the processing liquid in the processing tank, and wherein a conductive material layer and a protective layer are laminated on the surface of a base member in order from the base member side, at least in the portion that can be immersed in the processing liquid; a measuring unit that measures at least one of the current value flowing between the conductive material layer and the processing liquid and the resistance value between the conductive material layer and the processing liquid when a potential difference is generated between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank during the surface treatment; and a control unit that detects the occurrence of a malfunction in the substrate holding part based on at least one of the current value and the resistance value.

[0067] Furthermore, in a substrate processing apparatus according to one aspect of the present invention, the measuring unit comprises wiring having terminals connected to contact portions in the conductive material layer, and electrodes disposed in the processing liquid in the processing tank, and also comprises at least one of an ammeter for measuring the current value flowing between the contact portion and the electrode, and a resistance meter for measuring the resistance value between the contact portion and the electrode.

[0068] Furthermore, in a substrate processing apparatus according to one aspect of the present invention, the contact portion is protected by the protective layer.

[0069] Furthermore, in a substrate processing apparatus according to one aspect of the present invention, the terminals are corrosion-resistant.

[0070] Furthermore, a substrate processing apparatus according to one aspect of the present invention further comprises a terminal sealing member for surrounding the terminal with a predetermined gas when the terminal is in contact with the contact portion.

[0071] Furthermore, in a substrate processing apparatus according to one aspect of the present invention, the terminals are formed of carbon.

[0072] Furthermore, in a substrate processing apparatus according to one aspect of the present invention, the surface of the terminal other than the portion that contacts the contact portion is protected by a terminal protective layer.

[0073] Furthermore, in a substrate processing apparatus according to one aspect of the present invention, the control unit outputs a warning signal in at least one of the following cases: when the current value exceeds a predetermined threshold, and when the resistance value falls below a predetermined threshold.

[0074] Furthermore, in a substrate processing apparatus according to one aspect of the present invention, the substrate holding portion includes a mounting portion for placing a plurality of substrates, and a back plate positioned at one end of the mounting portion and extending vertically along the side wall of the processing tank.

[0075] Furthermore, in a substrate processing apparatus according to one aspect of the present invention, the base member is made of a quartz material, and the protective layer is made of PFA or PCTFE.

[0076] Furthermore, a substrate processing method according to one aspect of the present invention comprises a processing tank for storing a processing liquid, a substrate holding part for holding a substrate in a predetermined position in the processing liquid in the processing tank, and having a conductive material layer and a protective layer laminated on the surface of a base member in order from the base member side, at least in the portion that can be immersed in the processing liquid, and a measuring part for measuring at least one of the current value flowing between the conductive material layer and the processing liquid and the resistance value between the conductive material layer and the processing liquid when a potential difference is generated between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank, during the surface processing, wherein the substrate is immersed in the processing liquid A substrate processing method for surface treatment, comprising the steps of storing the processing liquid in the processing tank and holding the substrate in a predetermined position in the processing liquid with the substrate holding unit, further comprising, in parallel with the step of holding the substrate in the processing liquid, measuring at least one of the current value flowing between the conductive material layer and the processing liquid and the resistance value between the conductive material layer and the processing liquid when a potential difference is generated between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank, during the surface treatment, and detecting the occurrence of a malfunction in the substrate holding unit based on at least one of the current value and the resistance value.

[0077] 10 Processing tank 20 Substrate holding section 21 Base member 22 Conductive material layer 22a Contact section 23 Protective layer 26 Mounting section 27 Back plate 30, 30A, 60 Measurement section 31 Wiring 31a Terminals 32, 34 Electrodes 33 Measuring instrument 40 Control section 50 Terminal sealing member 61 First protective electrode 62 Second protective electrode 100, 200, 300 Substrate processing apparatus

Claims

1. A substrate processing apparatus for performing surface treatment by immersing a substrate in a processing liquid, comprising: a processing tank for storing the processing liquid; a substrate holding part for holding the substrate in a predetermined position in the processing liquid in the processing tank, wherein a conductive material layer and a protective layer are laminated on the surface of a base member in order from the base member side, at least in the portion that can be immersed in the processing liquid; a measuring unit for measuring at least one of the following during the surface treatment: (1) the current value flowing between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank when a potential difference is generated between the conductive material layer and the processing liquid in which the substrate is immersed; (2) the resistance value between the conductive material layer and the processing liquid; and (3) the capacitance between an electrode placed in the processing liquid in the processing tank and the conductive material layer; and a control unit for detecting the occurrence of a malfunction in the substrate holding part based on at least one of the current value, the resistance value and the capacitance.

2. The substrate processing apparatus according to claim 1, wherein the measuring unit comprises wiring having terminals connected to contact portions in the conductive material layer, and electrodes disposed in the processing liquid in the processing tank, and further comprises at least one of an ammeter for measuring the current value flowing between the contact portion and the electrode, a resistance meter for measuring the resistance value between the contact portion and the electrode, and a capacitance meter for measuring the capacitance between the contact portion and the electrode.

3. The substrate processing apparatus according to claim 2, wherein the surface of the contact portion other than the portion that contacts the terminal is protected by a contact portion protective layer.

4. The substrate processing apparatus according to claim 2, wherein the terminals are corrosion-resistant.

5. The substrate processing apparatus according to claim 4, further comprising a terminal sealing member for surrounding the terminal with a predetermined gas when the terminal is in contact with the contact portion.

6. The substrate processing apparatus according to claim 4, wherein the terminals are formed of carbon.

7. The substrate processing apparatus according to claim 4, wherein the surface of the terminal other than the portion that contacts the contact portion is protected by a terminal protective layer.

8. The substrate processing apparatus according to claim 1, wherein the control unit outputs a warning signal when the current value exceeds a predetermined threshold and when the resistance value falls below a predetermined threshold, in at least one of these cases.

9. The substrate holding portion includes a mounting portion for mounting a plurality of substrates, and a back plate positioned at one end of the mounting portion and extending vertically along the side wall of the processing tank, as described in claim 1.

10. The substrate processing apparatus according to any one of claims 1 to 9, wherein the base member is made of a quartz material and the protective layer is made of PFA or PCTFE.

11. A substrate processing apparatus for performing surface treatment by immersing a substrate in a processing liquid, comprising: a processing tank for storing a processing liquid; a substrate holding part for holding the substrate in a predetermined position in the processing liquid in the processing tank, wherein a conductive material layer and a protective layer are laminated on the surface of a base member in order from the base member side, at least in the portion that can be immersed in the processing liquid; a first protective electrode and a second protective electrode, which are immersed in the processing liquid when the substrate holding part holds the substrate in a predetermined position in the processing liquid in the processing tank, and which have a structure in which an electrode protective layer having the same thickness and composition as the protective layer of the substrate holding part is laminated on the surface of a conductive material; a measuring unit for measuring the capacitance between the first protective electrode and the second protective electrode during the surface treatment; and a control unit for detecting the occurrence of a malfunction in the substrate holding part based on the capacitance.

12. A substrate processing apparatus comprising: a processing tank for storing a processing liquid; a substrate holding part for holding a substrate in a predetermined position in the processing liquid within the processing tank, wherein a conductive material layer and a protective layer are laminated on the surface of a base member in order from the base member side, at least in the portion that can be immersed in the processing liquid; and a measuring unit for measuring at least one of the following during surface treatment: (1) the current value flowing between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank when a potential difference is generated between the conductive material layer and the processing liquid within the processing tank; (2) the resistance value between the conductive material layer and the processing liquid; and (3) the capacitance between an electrode placed in the processing liquid within the processing tank and the conductive material layer. A substrate processing method for surface treatment of a substrate by immersing the substrate in a processing liquid, comprising the steps of: storing the processing liquid in the processing tank; and holding the substrate in a predetermined position in the processing liquid with the substrate holding part. A substrate processing method further comprising the step of, in parallel with the step of holding the substrate in the processing liquid, measuring during the surface treatment at least one of the following when a potential difference is generated between the conductive material layer and the processing liquid in which the substrate is immersed in the processing tank: (1) the value of the current flowing between the conductive material layer and the processing liquid, (2) the value of the resistance between the conductive material layer and the processing liquid, and (3) the capacitance between the electrode placed in the processing liquid in the processing tank and the conductive material layer, and detecting the occurrence of a defect in the substrate holding part based on at least one of the current value, the resistance value and the capacitance.

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