Substrate processing apparatus and substrate processing method

Abstract

Embodiments relate to a substrate processing apparatus and a substrate processing method. According to one embodiment, a substrate processing apparatus includes a mixing section that mixes a first liquid containing a metal element and a second liquid exhibiting alkalinity to generate a third liquid containing the metal element and exhibiting alkalinity. The apparatus also includes a supply section that supplies the third liquid to a substrate. The apparatus also includes a first flow path that transports the third liquid from the mixing section to the supply section without passing through a filter that removes particles from the third liquid.

Description

[0001] Related applications

[0002] This application claims priority to Japanese Patent Application No. 2021-36542 (filed on March 8, 2021). This application incorporates the entire contents of that basic application by reference. Technical Field

[0003] Embodiments of this disclosure relate to a substrate processing apparatus and a substrate processing method. Background Technology

[0004] When supplying a metal element to a substrate by supplying a liquid containing a metal element to the substrate, it is preferable to use a method that can appropriately supply the metal element to the substrate. Summary of the Invention

[0005] The embodiments provide a substrate processing apparatus and a substrate processing method capable of appropriately supplying metal elements to a substrate.

[0006] According to one embodiment, the substrate processing apparatus includes a mixing unit that mixes a first liquid containing a metal element and a second liquid exhibiting alkalinity to generate a third liquid containing the metal element and exhibiting alkalinity. The apparatus further includes a supply unit for supplying the third liquid to a substrate. The apparatus also includes a first flow path that conveys the third liquid from the mixing unit to the supply unit without passing through a filter, wherein the filter is a filter for removing particles from the third liquid. Attached Figure Description

[0007] Figure 1 This is a schematic diagram showing the configuration of the substrate processing apparatus according to the first embodiment.

[0008] Figure 2 This is a schematic diagram showing the configuration of the substrate processing apparatus according to the second embodiment.

[0009] Figure 3 This is a flowchart illustrating the operation of the substrate processing apparatus according to the second embodiment.

[0010] Figure 4 This is a graph illustrating the operation of the substrate processing apparatus according to the second embodiment. Detailed Implementation

[0011] Embodiments of the present invention will now be described with reference to the accompanying drawings. Figures 1 to 4 In this text, identical components are labeled with the same number, and redundant descriptions are omitted.

[0012] (First Embodiment)

[0013] Figure 1 This is a schematic diagram showing the configuration of the substrate processing apparatus according to the first embodiment. Figure 1 The substrate processing apparatus is used to process substrate W using a chemical solution.

[0014] Figure 1 The substrate processing apparatus includes a metal aqueous solution tank 1, an ammonia tank 2, a pure water tank 3, a dilution tank 4, a mixing tank 5, a platform 6, a nozzle 7, a recovery tank 11, a retention filter 12, a flow meter 13, a control unit 14, valves 21 and 22. The metal aqueous solution tank 1, pure water tank 3, and dilution tank 4 are examples of a first liquid supply unit, and the ammonia tank 2 is an example of a second liquid supply unit. The mixing tank 5 is an example of a mixing unit, and the nozzle 7 is an example of a supply unit. The recovery tank 11 is an example of a recovery unit, and the retention filter 12 is an example of a filter.

[0015] Additionally, the ammonia tank 2 is equipped with a pH meter 2a and a detector 2b. The mixing tank 5 is equipped with a pH meter 5a, an absorbance meter 5b, a stirrer 5c, and a motor 5d. The pH meter 5a and absorbance meter 5b are examples of the measuring unit. The recovery tank 11 is equipped with a pH meter 11a, an absorbance meter 11b, and a waste liquid recovery mechanism 11c.

[0016] Figure 1 The substrate processing apparatus also includes flow paths P1, P2, P3, P4, P5, P11, P12, and P13. Flow paths P1, P2, P3, P4, P5, P11, P12, and P13 are formed, for example, by piping. Flow path P5 is an example of a first flow path, flow paths P11 and P12 are examples of second flow paths, and flow path P13 is an example of a third flow path.

[0017] The following is for reference Figure 1 This section describes the detailed contents of the substrate processing apparatus of this embodiment.

[0018] The metal aqueous solution tank 1 is used to contain a metal aqueous solution containing a metal element. Examples of this metal element are transition metal elements and rare earth metal elements. For example, the metal aqueous solution of this embodiment contains nickel (Ni), cobalt (Co), copper (Cu), iron (Fe), tungsten (W), aluminum (Al), palladium (Pd), rhodium (Rh), platinum (Pt), gold (Au), silver (Ag), lead (Pb), manganese (Mn), ruthenium (Ru), chromium (Cr), titanium (Ti), niobium (Nb), iridium (Ir), or tantalum (Ta) as the metal element. In addition, the metal aqueous solution of this embodiment contains the metal element in ionic form. The metal aqueous solution is, for example, an aqueous solution of nitric acid, hydrochloric acid, acetic acid, formic acid, sulfuric acid, oxalic acid, aminosulfonic acid, or carbonic acid containing metal ions. For example, in the case where the metal aqueous solution is an aqueous solution of nickel acetate (Ni(COOH)2), the metal element is Ni, and the ion is Ni. 2+Ions. The aqueous metal solution in the aqueous metal solution tank 1 is transported to the dilution tank 4 via the flow path P1.

[0019] Ammonia tank 2 is used to contain high-concentration ammonia solution. Ammonia solution is an aqueous solution of ammonia (NH3) and exhibits alkalinity. The pH of this ammonia solution is, for example, 10 or higher, preferably 10 or higher and 12 or lower, more preferably 11 or higher and 12 or lower. Furthermore, the concentration of ammonia in this ammonia solution is, for example, 28 wt% or higher. The ammonia solution in ammonia tank 2 is conveyed to mixing tank 5 via flow path P2. The ammonia solution in ammonia tank 2 is an example of a second liquid.

[0020] pH meter 2a measures the pH of the ammonia solution in ammonia tank 2 and outputs the measurement result to control unit 14. Detector 2b detects ammonia gas and outputs an alarm when ammonia gas is detected. Since the substrate processing apparatus of this embodiment processes ammonia solution, ammonia gas may be generated within the substrate processing apparatus. Detector 2b is configured to notify the user of ammonia gas generation. The alarm can be output in any manner, such as an alarm sound, alarm screen, alarm email, alarm light, or alarm indicator. In this embodiment, detector 2b is installed outside the casing of the substrate processing apparatus to detect ammonia gas leakage. Alternatively, detector 2b may output a signal indicating that ammonia gas has been detected to control unit 14, in which case control unit 14 may also output an alarm.

[0021] Pure water tank 3 is used to contain pure water. This pure water is, for example, high-purity pure water, i.e., ultrapure water. The pure water in pure water tank 3 is transported to dilution tank 4 via flow path P3.

[0022] Dilution tank 4 dilutes the aqueous metal solution from aqueous metal solution tank 1 with pure water from pure water tank 3, thereby generating an aqueous metal solution with a lower concentration of the metal element. For example, dilution tank 4 can generate Ni. 2+ The concentration of ions is 1.0 × 10⁻⁶. -4 1.0 × 10 mol / L or higher -1 Aqueous solutions of metals with concentrations below mol / L. At this point, the Ni concentration in the aqueous metal solution... 2+ The concentration of ions is controlled, for example, by control unit 14. The aqueous metal solution generated in dilution tank 4 is conveyed to mixing tank 5 via flow path P4. The aqueous metal solution generated in dilution tank 4 is an example of the first liquid.

[0023] Mixing tank 5 mixes the aqueous metal solution from dilution tank 4 and ammonia water from ammonia water tank 2 to generate a solution containing a metal element and exhibiting alkalinity. In this embodiment, the aqueous metal solution reacts with ammonia water to generate an ammonia complex containing a metal element. Thus, the solution in this embodiment becomes an aqueous solution containing an ammonia complex. For example, if the aqueous metal solution is an aqueous nickel acetate solution, the solution becomes an aqueous solution containing Ni element in the ammonia complex (hexaamminenickel complex).<hexammine nickel complex> (Aqueous solution). The liquid generated in the mixing tank 5 is conveyed to the nozzle 7 via the flow path P5. The liquid generated in the mixing tank 5 is an example of the third liquid. The mixing tank 5 in this embodiment is formed as a closed mixing tank.

[0024] pH meter 5a measures the pH of the medicinal solution in mixing tank 5 and outputs the measurement result to control unit 14. This pH measurement result is used by control unit 14 to control the pH of the medicinal solution in mixing tank 5. Control unit 14 controls the pH of the medicinal solution in mixing tank 5, for example, to make the pH of the medicinal solution in mixing tank 5 10 or higher, preferably 10 or higher and 12 or lower, more preferably 11 or higher and 12 or lower. For example, if the pH measurement value obtained by pH meter 5a is less than 11, control unit 14 raises the pH of the medicinal solution in mixing tank 5 to a value of 11 or higher. Specifically, control unit 14 controls the pH to make the pH measurement value obtained by pH meter 5a 11 or higher. More detailed descriptions of the pH control performed by control unit 14 will follow.

[0025] The absorbance meter 5b measures the absorbance of the pharmaceutical solution in the mixing tank 5 and outputs the measurement result to the control unit 14. This absorbance measurement result is used by the control unit 14 to control the metal concentration of the pharmaceutical solution in the mixing tank 5. An example of this metal concentration is the concentration of Ni atoms in the pharmaceutical solution. The absorbance of the pharmaceutical solution can be used to evaluate the metal concentration of the solution. The control unit 14 controls the metal concentration of the pharmaceutical solution in the mixing tank 5, for example, making the metal concentration of the pharmaceutical solution in the mixing tank 5 1.0 × 10⁻⁶. -4 1.0 × 10 mol / L or higher -1 Below mol / L. For example, the metal concentration corresponding to the absorbance measured by absorbance meter 5b is less than 1.0 × 10⁻⁶. -4 At a concentration of mol / L, the control unit 14 increases the metal concentration of the drug solution in the mixing tank 5 to 1.0 × 10⁻⁶ mol / L. - 4 Values ​​above mol / L. Specifically, the control unit 14 controls the absorbance measured by the absorbance meter 5b to ensure that the metal concentration corresponding to the measured absorbance value is 1.0 × 10⁻⁶. -4 mol / L or higher. More detailed information on the control of metal concentration by control unit 14 will be described later.

[0026] The mixer 5c stirs the pharmaceutical solution within the mixing tank 5 by rotating within the mixing tank 5. This allows for the homogenization of the pH and metal concentration of the pharmaceutical solution within the mixing tank 5. An electric motor 5d is mounted on the mixer 5c and enables the mixer 5c to rotate. The rotation of the electric motor 5d is controlled, for example, by a control unit 14.

[0027] Platform 6 is used to support substrate W and rotate substrate W. The rotation of platform 6 is controlled by control unit 14.

[0028] Nozzle 7 is used to supply the liquid medicine from mixing tank 5 to substrate W. In this embodiment, nozzle 7 dispenses the liquid medicine onto the upper surface of substrate W on rotating platform 6. Thus, substrate W is treated with the liquid medicine. In this embodiment, by supplying the liquid medicine to substrate W, metal elements in the liquid medicine can be supplied to substrate W. For example, metal atoms in the liquid medicine can be attached to the surface of substrate W or introduced into the interior of substrate W. In this embodiment, substrate W contains an amorphous silicon layer, and Ni atoms in the liquid medicine are attached to the surface of the amorphous silicon layer. In this case, the concentration of Ni atoms on the surface of the amorphous silicon layer can be controlled, for example, by adjusting the concentration of Ni atoms in the liquid medicine. The dispensing operation of liquid medicine by nozzle 7 is controlled, for example, by control unit 14.

[0029] Furthermore, in this embodiment, the chemical solution is supplied to the substrate W using a spin coating method with nozzle 7, but other methods can also be used to supply the chemical solution. For example, the chemical solution can also be supplied to the substrate W by spraying or impregnating with the chemical solution. In addition, the substrate W is processed as a single piece in this embodiment, but it can also be processed in batches.

[0030] The recovery tank 11 recovers the liquid medicine supplied to the substrate W. Thus, the liquid medicine supplied to the substrate W can be reused. The liquid medicine recovered from the recovery tank 11 is conveyed to the interception filter 12 via the flow path P11.

[0031] pH meter 11a measures the pH of the drug solution in the recovery tank 11 and outputs the measurement result to the control unit 14. Absorbance meter 11b measures the absorbance of the drug solution in the recovery tank 11 and outputs the measurement result to the control unit 14. Waste liquid recovery mechanism 11c is a mechanism for recovering the drug solution (waste liquid) supplied to the substrate W. In this embodiment, the drug solution is ejected from nozzle 7 onto the substrate W on platform 6 and recovered into the recovery tank 11 via waste liquid recovery mechanism 11c.

[0032] A trap filter 12 is disposed between flow path P11 and flow path P12 to recover powder from the liquid medicine flowing from recovery tank 11 to mixing tank 5. Specifically, the trap filter 12 of this embodiment removes particles from the liquid medicine. Thus, the liquid medicine after particle removal can be supplied to the mixing tank 5. These particles are, for example, metal oxides generated in the liquid medicine. The liquid medicine passing through the trap filter 12 is conveyed to the mixing tank 5 via flow path P12 for reuse within the mixing tank 5.

[0033] A flow meter 13 is installed in the flow path P12 to measure the flow rate of the liquid medicine flowing through the downstream flow path P12 of the intercepting filter 12. If the intercepting filter 12 is clogged due to particles, the flow rate measured by the flow meter 13 will decrease. Therefore, the flow rate measured by the flow meter 13 can be used to detect the clogging of the intercepting filter 12. The flow meter 13 outputs the flow measurement result to the control unit 14. The liquid medicine passing through the flow meter 13 is conveyed to the mixing tank 5 via the flow path P12.

[0034] The control unit 14 controls various operations of the substrate processing apparatus of this embodiment. Based on the flow rate measurement received from the flow meter 13, the control unit 14 supplies a chemical solution from the mixing tank 5 to the retention filter 12 via the flow path P13. For example, if the flow rate is greater than a threshold, the control unit 14 closes the valve (not shown) provided in the flow path P13, stopping the supply of chemical solution from the mixing tank 5 to the retention filter 12. On the other hand, if the flow rate is less than the threshold, the control unit 14 opens the valve, supplying chemical solution from the mixing tank 5 to the retention filter 12. This allows particles adhering to the retention filter 12 to be transformed into an ammonia complex. This ammonia complex, along with the chemical solution, is recovered back into the mixing tank 5. This removes particles from the retention filter 12, eliminating clogging. The chemical solution supplied from the mixing tank 5 to the retention filter 12 is recovered back into the mixing tank 5 via the flow path P12. Furthermore, the supply of chemical solution from the mixing tank 5 to the interception filter 12 can also be carried out, for example, during maintenance of the substrate processing apparatus when the substrate processing apparatus is not processing the substrate W.

[0035] The control unit 14 can also control the pH of the ammonia water in the ammonia water tank 2 based on the pH measurement results received from the pH meter 2a. This allows the aforementioned pH of the ammonia water to be achieved. The control unit 14 can also control the pH and metal concentration of the drug solution in the mixing tank 5 based on the pH and absorbance measurement results received from the pH meter 5a and the absorbance meter 5b, respectively. This allows the aforementioned pH and metal concentration of the drug solution to be achieved. The control unit 14 can also control the pH and metal concentration of the drug solution in the recovery tank 11 based on the pH and absorbance measurement results received from the pH meter 11a and the absorbance meter 11b, respectively. Furthermore, in addition to the pH measurement results of the ammonia water and the drug solution, the pH meters 2a, 5a, and 11a can also output the temperature measurement results of the ammonia water and the drug solution to the control unit 14.

[0036] In this embodiment, the control unit 14 controls the pH and metal concentration of the medicinal solution in the mixing tank 5 by controlling valve 21 provided in flow path P2 and valve 22 provided in flow path P4. For example, when the pH of the medicinal solution in the mixing tank 5 is low, the opening of valve 21 is increased, thereby increasing the flow rate of ammonia water through valve 21. This increases the pH of the medicinal solution in the mixing tank 5. On the other hand, when the metal concentration of the medicinal solution in the mixing tank 5 is low, the opening of valve 22 is increased, thereby increasing the flow rate of the medicinal solution through valve 22. This increases the metal concentration of the medicinal solution in the mixing tank 5.

[0037] Alternatively, the control unit 14 in this embodiment can also control the pH of the drug solution in the mixing tank 5 using ammonia bubbling or a buffer material. Examples of buffer materials include ammonium nitrate, ammonium sulfate, ammonium chloride, and ammonium hydroxide. Therefore, the pH of the drug solution in the mixing tank 5 can be controlled in a manner other than valves 21 and 22. In this case, a mechanism for ammonia bubbling or a mechanism for buffer material are provided in the mixing tank 5. The control unit 14 can control the pH of the drug solution in the mixing tank 5 by controlling this mechanism using ammonia bubbling or a buffer material.

[0038] As shown above, the substrate processing apparatus of this embodiment processes the substrate W by supplying a chemical solution from the mixing tank 5 to the substrate W. This allows Ni atoms from the chemical solution to be imparted to the amorphous silicon layer within the substrate W. The substrate W is then subjected to heat treatment, for example, outside the substrate processing apparatus. As a result, the amorphous silicon layer crystallizes. Furthermore, the chemical solution of this embodiment can also be used to process layers other than the amorphous silicon layer within the substrate W.

[0039] Next, continue to refer to Figure 1 The substrate processing apparatus of this embodiment will be described in more detail.

[0040] In this embodiment, the control unit 14 controls the pH of the medicinal solution in the mixing tank 5 to make the pH of the medicinal solution in the mixing tank 5 11 or higher. This control has the following advantages.

[0041] For example, suppose the solution in mixing tank 5 contains metal ions (e.g., Ni). 2+ In the case of ions and a pH value less than 7, the solution in mixing tank 5 is acidic. If this solution is supplied to the amorphous silicon layer (a-Si layer), metal atoms can be introduced onto the surface of the a-Si layer. However, in this case, the concentration of metal atoms on the surface of the a-Si layer may not reach the concentration required for the crystallization of the a-Si layer.

[0042] Furthermore, consider a scenario where a chemical solution is generated by adding an alkaline substance to an aqueous solution containing metal ions, resulting in a pH of 7 or higher but less than 10 in the mixing tank 5. In this case, the chemical solution in the mixing tank 5 is alkaline. Depending on the type of chemical solution, the pH of the solution can be controlled to generate hydroxides of the aforementioned metals. If this chemical solution is supplied to the a-Si layer, the metal hydroxides are adsorbed onto the a-Si layer. This allows the concentration of metal atoms on the surface of the a-Si layer to reach the concentration required for crystallization of the a-Si layer. In this case, the amount of metal hydroxide generated is determined by the content of metal ions in the aqueous solution and the amount of alkaline substance added. Therefore, by appropriately setting their content and addition amount, the amount of metal hydroxide generated can be increased, and the concentration of metal atoms on the surface of the a-Si layer can be increased. However, if this chemical solution is supplied to the a-Si layer, both the adsorption of metal hydroxides onto the a-Si layer and the precipitation of metal hydroxides in the chemical solution occur simultaneously. Therefore, the metal concentration in the chemical solution on the a-Si layer will be lower than the desired metal concentration. As a result, the concentration of metal atoms on the surface of the a-Si layer may not reach the desired concentration. Furthermore, the condensation of metal hydroxides deposited in the solution may adhere to the surface of the a-Si layer in a certain quantity, potentially creating localized areas of high metal concentration. This could negatively impact the crystallization of the a-Si layer.

[0043] The precipitation of metal hydroxides in the liquid also occurs in the flow path P5 between the mixing tank 5 and the nozzle 7. Therefore, similar to the interception filter 12, a filter to remove particles from the liquid is considered to be installed in the flow path P5. This allows the removal of metal hydroxides as particles from the liquid in the flow path P5, suppressing the aforementioned adhesion of condensate. However, if a filter is installed in the flow path P5, there is a problem that the metal concentration in the liquid decreases due to the presence of the filter.

[0044] Therefore, in this embodiment, the substrate processing apparatus controls the pH of the solution in the mixing tank 5 via the control unit 14, ensuring that the pH of the solution in the mixing tank 5 is 11 or higher. If the pH of the solution is 11 or higher, the precipitation of metal hydroxides in the solution is suppressed. Thus, even without a filter in the flow path P5 to remove particles from the solution, the adhesion of the aforementioned condensate can be suppressed. Therefore, in this embodiment, the substrate processing apparatus does not include the aforementioned filter in the flow path P5, and the solution is conveyed from the mixing tank 5 to the nozzle 7 without passing through the filter. This suppresses the problem of the metal concentration in the solution decreasing due to the filter.

[0045] As shown above, according to this embodiment, by using an alkaline solution, the concentration of metal atoms on the surface of the a-Si layer can be sufficiently increased. Furthermore, by controlling the pH of the solution in the mixing tank 5 to 11 or higher, the adhesion of condensate to the surface of the a-Si layer can be suppressed without using a filter. Furthermore, by using a filterless flow path P5 to deliver the solution, the problem of metal concentration in the solution decreasing due to filtration can be suppressed. Furthermore, by using the control unit 14 to suppress the metal concentration in the solution, the concentration of metal atoms on the surface of the a-Si layer can be suppressed. Therefore, according to this embodiment, metal elements can be appropriately supplied to the substrate W.

[0046] (Second Implementation)

[0047] Figure 2 This is a schematic diagram showing the configuration of the substrate processing apparatus according to the second embodiment.

[0048] Figure 2 The substrate processing device in Figure 1 In addition to the constituent elements of the substrate processing apparatus, it also includes a pre-retention filter 15, a pre-mixing tank 16, valves 23 and 24, and flow paths P1', P2', and P4'. The pre-mixing tank 16 contains a pH meter 16a, an absorbance meter 16b, and a particle counter 16c. The pre-mixing tank 16 is an example of a pre-mixing section.

[0049] Figure 2 The substrate processing apparatus also includes flow paths P11a, P11b, and P11c, which serve as flow paths P11. A pre-filter 15 is provided in flow path P11a. A pre-mixing tank 16 is provided between flow paths P11a, P11b, and P11c. Flow paths P1', P2', P4', P11a, P11b, and P11c are formed, for example, by piping.

[0050] The following is for reference Figure 2 The detailed description of the substrate processing apparatus of this embodiment is explained below.

[0051] In the first embodiment, the liquid medicine discharged from the recovery tank 11 is filtered by the retention filter 12 and supplied to the mixing tank 5, where it is mixed. In this embodiment, the liquid medicine discharged from the recovery tank 11 is pre-filtered by the pre-retention filter 15 and then supplied to the pre-mixing tank 16, where it is pre-mixed. The liquid medicine discharged from the pre-mixing tank 16 is then filtered by the retention filter 12 and supplied to the mixing tank 5, where it is mixed.

[0052] The pre-retention filter 15 recovers powder from the liquid medicine flowing from the recovery tank 11 to the premixing tank 5 via the flow path P11a. Specifically, the pre-retention filter 15 in this embodiment removes particles from the liquid medicine, similar to the retention filter 12. This allows the liquid medicine, after the particles have been removed, to be supplied to the premixing tank 16. These particles are, for example, metal hydroxides generated in the liquid medicine. The liquid medicine passing through the pre-retention filter 15 is conveyed to the premixing tank 16 via the flow path P11a.

[0053] The premixing tank 16 mixes the liquid medicine flowing from the pre-retention filter 15 and discharges the mixed liquid medicine into either flow path P11b or flow path P11c. The liquid medicine discharged into flow path P11b is conveyed to the retention filter 12. On the other hand, the liquid medicine discharged into flow path P11c is returned to the recovery tank 11.

[0054] pH meter 16a measures the pH of the drug solution in premixing tank 16 and outputs the measurement result to control unit 14. Absorbance meter 16b measures the absorbance of the drug solution in premixing tank 16 and outputs the measurement result to control unit 14. Particle counter 16c counts the number of particles detected in the drug solution in premixing tank 16 and outputs the counting result to control unit 14.

[0055] Flow paths P1', P2', and P4' extend from the metal aqueous solution tank 1, the ammonia tank 2, and the dilution tank 4, respectively, towards the recovery tank 11. However, a portion of flow path P1' is omitted in the diagram. Flow path P1' transports the metal aqueous solution in the metal aqueous solution tank 1 to the recovery tank 11. Flow path P2' transports the ammonia in the ammonia tank 2 to the recovery tank 11. Flow path P4' transports the metal aqueous solution generated in the dilution tank 4 to the recovery tank 11. Valve 23 is located in flow path P2'. Valve 24 is located in flow path P4'.

[0056] Next, continue to refer to Figure 2 The substrate processing apparatus of this embodiment will be described in more detail.

[0057] In this embodiment, the control unit 14 controls the pH of the drug solution in the mixing tank 5 to make the pH of the drug solution in the mixing tank 5 between 11 and 12. As a result, the nozzle 7 ejects the drug solution with a pH between 11 and 12 toward the substrate W. On the other hand, the recovery tank 11 recovers the drug solution whose pH is lower than that at the nozzle 7. This is because the pH of the drug solution is lowered due to the processing of the substrate W.

[0058] If the drug solution in the recovery tank 11 is directly supplied to the mixing tank 5, the pH of the drug solution in the mixing tank 5 will decrease. For example, if the pH of the drug solution in the mixing tank 5 is 11 and the pH of the drug solution in the recovery tank 11 is 10, if the drug solution in the recovery tank 11 is directly supplied to the mixing tank 5, the pH of the drug solution in the mixing tank 5 will be lower than 11. In this case, the control unit 14 needs to bring the pH of the drug solution in the mixing tank 5 back to 11.

[0059] To reduce the aforementioned wasted effort, the control unit 14 of this embodiment controls the pH of the drug solution in the recovery tank 11 so that the pH of the drug solution in the recovery tank 11 is close to the pH of the drug solution in the mixing tank 5. The control unit 14 of this embodiment can also control the metal concentration of the drug solution in the recovery tank 11 so that the metal concentration of the drug solution in the recovery tank 11 is close to the metal concentration of the drug solution in the mixing tank 5. The control unit 14 of this embodiment can control the pH and metal concentration of the drug solution in the recovery tank 11 by controlling valve 23 provided in flow path P2' and valve 24 provided in flow path P4'. For example, when the pH of the drug solution in the recovery tank 11 is low, the opening degree of valve 23 is increased, thereby increasing the flow rate of ammonia water through valve 23. This increases the pH of the drug solution in the recovery tank 11. On the other hand, when the metal concentration of the drug solution in the recovery tank 11 is low, the opening degree of valve 24 is increased, thereby increasing the flow rate of the drug solution through valve 24. This increases the metal concentration of the drug solution in the recovery tank 11. The control unit 14 can perform the above-mentioned pH control and metal concentration control by using the pH measured by the pH meter 11a and the absorbance measured by the absorbance meter 11b.

[0060] The above-mentioned control can also be implemented in the premixing tank 16. The control unit 14 can also control the pH of the drug solution in the premixing tank 16 so that the pH of the drug solution in the premixing tank 16 is close to the pH of the drug solution in the mixing tank 5. The control unit 14 can also control the metal concentration of the drug solution in the premixing tank 16 so that the metal concentration of the drug solution in the premixing tank 16 is close to the metal concentration of the drug solution in the mixing tank 5. The control unit 14 can perform the above-mentioned pH control and metal concentration control by using the pH measured by the pH meter 16a and the absorbance measured by the absorbance meter 16b.

[0061] For example, if the pH of the drug solution in the mixing tank 5 is 11, and the pH of the drug solution just recovered from the recovery tank 11 is 10, the control unit 14 can also control the pH of the drug solution in the recovery tank 11 to make the pH of the drug solution in the recovery tank 11 approximately 11. In this case, the control unit 14 adjusts the pH of the drug solution in the recovery tank 11 to approximately 11 and fine-tunes the pH of the drug solution in the premixing tank 16 to 11. As a result, since the drug solution with pH 11 is returned to the mixing tank 5, it is possible to prevent the pH of the drug solution in the mixing tank 5 from decreasing due to the drug solution from the premixing tank 16.

[0062] Figure 3 This is a flowchart illustrating the operation of the substrate processing apparatus according to the second embodiment.

[0063] First, in the dilution tank 4, the aqueous metal solution supplied from the aqueous metal solution tank 1 is diluted (step S1). Then, in the mixing tank 5, ammonia water supplied from the ammonia water tank 2 and the aqueous metal solution supplied from the dilution tank 4 are added to the existing solution in the mixing tank 5, and these liquids are mixed using a mixer 5c (step S2).

[0064] Then, using pH meter 5a and absorbance meter 5b, the pH and absorbance (metal concentration) of the drug solution in mixing tank 5 are measured (step S3). If the control unit 14 determines that the pH measured by pH meter 5a is less than 11, or the metal concentration measured by absorbance meter 5b is not the desired concentration, it returns to step S2. On the other hand, if the control unit 14 determines that the pH measured by pH meter 5a is 11 or higher, and the metal concentration measured by absorbance meter 5b is the desired concentration, it proceeds to step S4.

[0065] In step S4, nozzle 7 ejects the liquid medicine from mixing tank 5 onto substrate W. Then, the liquid medicine is recovered in recovery tank 11 (step S5). Next, pH and absorbance (metal concentration) of the liquid medicine in recovery tank 11 are measured using pH meter 11a and absorbance meter 11b (step S6). Then, ammonia water supplied from ammonia water tank 2 and a metal aqueous solution supplied from dilution tank 4 are added to the existing liquid medicine in recovery tank 11 (step S7). At this time, control unit 14 determines the amount of ammonia water and metal aqueous solution to be added to the liquid medicine in recovery tank 11 based on the pH measured by pH meter 11a and the metal concentration measured by absorbance meter 11b.

[0066] Then, the liquid medicine discharged from the recovery tank 11 is filtered by the pre-retention filter 15 (step S8). Then, the liquid medicine that has passed through the pre-retention filter 15 is supplied to the premixing tank 16 (step S9).

[0067] Then, using a pH meter 16a, an absorbance meter 16b, and a particle counter 16c, the pH, absorbance (metal concentration), and number of particles in the premixing tank 16 are measured (step S10). If the control unit 14 determines that the pH measured by the pH meter 16a is less than 11, or the metal concentration measured by the absorbance meter 16b is not the desired concentration, or the number of particles measured by the particle counter 16c is above a threshold, it returns to step S5. On the other hand, if the control unit 14 determines that the pH measured by the pH meter 16a is 11 or higher, the metal concentration measured by the absorbance meter 16b is the desired concentration, and the number of particles measured by the particle counter 16c is less than a threshold, it proceeds to step S11.

[0068] In step S11, the liquid medicine discharged from the premixing tank 16 is filtered by the retention filter 12. Then, the liquid medicine passing through the retention filter 12 is supplied to the mixing tank 5, where it is mixed again (step S12). Thus, the liquid medicine discharged to the substrate W is reused in the mixing tank 5. The processes of steps S1 to S12 continue until the processing of the substrate W is completed.

[0069] Figure 4 This is a graph illustrating the operation of the substrate processing apparatus according to the second embodiment.

[0070] Figure 4 Curves A1 and B1 show an example of the changes in Ni concentration and pH of the drug solution after it is discharged from the mixing tank 5, passing through the substrate W, the recovery tank 11, the pre-retention filter 15, the pre-mixing tank 16, and the retention filter 12, until it returns to the mixing tank 5.

[0071] on the other hand, Figure 4 Curves A2 and B2 show examples of the changes in Ni concentration and pH of the drug solution in the comparative example of this embodiment from discharge from the mixing tank 5 to return to the mixing tank 5. In the above comparative example, the drug solution discharged from the recovery tank 11 is directly returned to the mixing tank 5.

[0072] In the comparative example above, the pH of the drug solution in mixing tank 5 was 11, but the pH of the drug solution on substrate W decreased to 10 (B2). This is, for example, due to the evaporation of ammonia from the drug solution. Furthermore, in the comparative example above, the drug solution with a pH of 10 was returned to mixing tank 5.

[0073] Similarly, in this embodiment, the pH of the drug solution in the mixing tank 5 is 11, but the pH of the drug solution on the substrate W is reduced to 10 (B1). The reason is the same as in the comparative example above. However, in this embodiment, the pH of the drug solution rises to approximately 11 in the recovery tank 11, and the drug solution with a pH of 11 is returned to the mixing tank 5. This is because the pH control described above was performed in the recovery tank 11 and the premixing tank 16.

[0074] Furthermore, in the comparative example above, the Ni concentration of the solution decreased as the solution was discharged onto the substrate W, and also decreased significantly during the period when the solution returned from the recovery tank 11 to the mixing tank 5 (A2). This is, for example, because metal atoms adhere to the substrate W and metal atoms in the solution are released during the period when the solution returns from the recovery tank 11 to the mixing tank 5.

[0075] Similarly, in this embodiment, the Ni concentration of the solution decreases as the solution is discharged onto the substrate W (A1). The reason is the same as in the comparative example described above. However, during the return of the solution from the recovery tank 11 to the mixing tank 5, the Ni concentration of the solution changes only slightly. This is because the aforementioned metal concentration control is performed in the recovery tank 11 and the premixing tank 16. Furthermore, in Figure 4 In curve A1, the metal concentration of the drug solution increases by adding a metal aqueous solution to the drug solution in the recovery tank 11 and the mixing tank 5.

[0076] As shown above, the substrate processing apparatus of this embodiment further includes a pre-retention filter 15 and a pre-mixing tank 16 in addition to the constituent elements of the substrate processing apparatus of the first embodiment. Therefore, according to this embodiment, the pH and metal concentration of the chemical solution returned from the recovery tank 11 to the mixing tank 5 can be appropriately controlled.

[0077] The foregoing has described several embodiments, but these embodiments are merely illustrative and not intended to limit the scope of the invention. The new apparatus and method described herein can be implemented in various other ways. Furthermore, various omissions, substitutions, and modifications can be made to the embodiments of the new apparatus and method described herein without departing from the spirit of the invention. The scope of the appended claims and their equivalents are intended to encompass these embodiments and their variations as included in the scope and spirit of the invention.

Claims

1. A substrate processing apparatus comprising: In the mixing section, a first liquid containing a metal element and a second liquid exhibiting alkalinity are mixed to generate a third liquid containing the metal element and exhibiting alkalinity. The supply unit supplies the third liquid to the substrate containing the amorphous silicon layer; In the first flow path, the third liquid is transported from the mixing section to the supply section without passing through a filter, wherein... The filter is a filter that removes particles from the third liquid; as well as A control unit that controls at least one of the pH and metal concentration of the third liquid in the mixing unit. The control unit controls the pH of the third liquid so that the pH of the third liquid is 11 or higher.

2. The substrate processing apparatus according to claim 1, wherein, It also includes a measuring unit for measuring values ​​related to the third liquid in the mixing unit. The control unit controls at least one of the pH and metal concentration of the third liquid based on the values ​​measured by the measuring unit.

3. The substrate processing apparatus according to claim 2, wherein, The measuring unit includes a pH meter for measuring the pH of the third liquid and an absorbance meter for measuring the absorbance of the third liquid. The control unit controls the pH of the third liquid based on the pH measured by the pH meter, and controls the metal concentration of the third liquid based on the absorbance measured by the absorbance meter.

4. The substrate processing apparatus according to claim 1, wherein, The control unit uses bubbling or buffering materials to control the pH of the third liquid in the mixing unit.

5. The substrate processing apparatus according to claim 4, wherein, The buffer material contains ammonium nitrate, ammonium sulfate, ammonium chloride, or ammonium hydroxide.

6. The substrate processing apparatus according to claim 1, wherein, The mixing section includes a mixer for stirring the third liquid.

7. The substrate processing apparatus according to claim 1, wherein, The metal element is a transition metal element or a rare earth metal element.

8. The substrate processing apparatus according to claim 1, wherein, The metallic element is nickel (Ni), cobalt (Co), copper (Cu), iron (Fe), tungsten (W), aluminum (Al), palladium (Pd), rhodium (Rh), platinum (Pt), gold (Au), silver (Ag), lead (Pb), manganese (Mn), ruthenium (Ru), chromium (Cr), titanium (Ti), niobium (Nb), iridium (Ir), or tantalum (Ta).

9. The substrate processing apparatus according to claim 1, wherein, The first liquid is an aqueous solution containing ions of the metal element, the second liquid is ammonia, and the third liquid is an aqueous solution containing an ammonia complex containing the metal element.

10. The substrate processing apparatus according to claim 9, wherein, The concentration of the ions in the first liquid is 1.0 × 10⁻⁶. -4 1.0 × 10 mol / L or higher -1 Below mol / L.

11. The substrate processing apparatus according to claim 9, wherein, The second liquid has a pH of 10 or higher, and the concentration of ammonia in the second liquid is 28 wt% or higher.

12. The substrate processing apparatus according to claim 1, wherein, The supply unit includes a nozzle that dispenses the third liquid onto the substrate on the platform.

13. The substrate processing apparatus according to claim 1, wherein, have: A first liquid supply unit supplies the first liquid to the mixing unit; and The second liquid supply unit supplies the second liquid to the mixing unit. The first liquid supply unit dilutes a liquid containing a metal element with a higher concentration than that of the first liquid to generate the first liquid, and supplies the generated first liquid to the mixing unit.

14. The substrate processing apparatus according to claim 1, wherein, It also has: The recovery unit recovers the third liquid supplied to the substrate; and The second flow path delivers the third liquid from the recovery section to the mixing section.

15. The substrate processing apparatus according to claim 14, wherein, have: A filter, disposed in the second flow path, removes the particles from the third liquid; A flow meter, located downstream of the filter in the second flow path, measures the flow rate of the third liquid; as well as The third flow path supplies the third liquid from the mixing section to the filter. The control unit supplies the third liquid from the mixing unit to the filter via the third flow path based on the flow rate measured by the flow meter.

16. The substrate processing apparatus according to claim 14, wherein, It also has: A premixing section, disposed in the second flow path, mixes the third liquid from the recovery section and supplies it to the mixing section; and A particle counter is used to count the number of particles in the third liquid in the premixing section.

17. A substrate processing apparatus comprising: In the mixing section, a first liquid containing a metal element and a second liquid exhibiting alkalinity are mixed to generate a third liquid containing the metal element and exhibiting alkalinity. The supply unit supplies the third liquid to the substrate containing the amorphous silicon layer; The measuring unit measures values ​​related to the third liquid; and The control unit, based on the values ​​measured by the measuring unit, controls at least one of the pH and metal concentration of the third liquid. The control unit controls the pH of the third liquid so that the pH of the third liquid is 11 or higher.

18. A substrate processing method, comprising: A first liquid containing a metallic element and a second liquid exhibiting alkalinity are mixed in a mixing unit to generate a third liquid containing the metallic element and exhibiting alkalinity. The third liquid is conveyed from the mixing section to the supply section without passing through a filter, wherein the filter is a filter for removing particles from the third liquid. The third liquid is supplied to the substrate containing the amorphous silicon layer using the supply unit. The pH of the third liquid is controlled so that the pH of the third liquid is 11 or higher.

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