Substrate processing apparatus and substrate processing method

Abstract

Even with increased upflow flow rates, processing inconsistencies within the substrate surface are further suppressed. [Solution] The substrate processing apparatus (100) includes a control unit that controls the first flow rate control mechanism (6) based on the flow rate of the processing liquid controlled by the second flow rate control mechanism (7), such that the flow rate of the gas supplied to the first gas supply pipes (51, 52) is greater than the flow rate of the gas supplied to the second gas supply pipes (53, 54).

Description

Technical Field

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

Background Art

[0002] Substrates used in electronic components such as semiconductor devices and liquid crystal display devices are known to be processed by a substrate processing apparatus. The substrate can be processed by immersing it in a processing liquid in a processing tank.

[0003] With the miniaturization and / or three-dimensionalization of semiconductor elements formed on semiconductor substrates in recent years, there has been an increasing demand for uniform substrate processing. For example, a NAND element having a three-dimensional structure has a stacked structure provided with a three-dimensional uneven structure. When the processing liquid stays in the concave portions of the uneven structure of the element pattern, the liquid replacement in the concave portions becomes insufficient. Therefore, in order to sufficiently promote liquid replacement for the entire substrate including the concave portions, a bubble generation tube may be arranged below the substrate immersed in the processing tank, and bubbles may be generated from a bubble generator to promote liquid replacement in the processing tank.

[0004] And in such a technique, in order to suppress processing unevenness within the substrate surface in the processing tank, for example, as shown in Patent Document 1, a technique has also been developed in which the gas flow rate supplied to a plurality of bubble generation tubes is made larger for the outer bubble generation tubes than for the inner bubble generation tubes.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Furthermore, the processing tank is equipped with multiple liquid discharge pipes that discharge the processing liquid, thereby generating an upflow that flows upward within the processing tank. In the process of diligently developing a technology to suppress processing unevenness within the substrate surface in the aforementioned processing tank, the inventors discovered that when the upflow flow rate is high, bubbles flow within the processing tank in a way that causes them to gather towards the center of the tank. When such a bias occurs, the possibility of processing unevenness within the substrate surface cannot be ruled out.

[0007] One aspect of the present invention aims to further suppress processing unevenness within the substrate surface, even when the upflow flow rate is high. [Means for solving the problem]

[0008] To solve the above problems, a substrate processing apparatus according to one aspect of the present invention includes: a substrate holding section for holding at least one substrate; a processing tank for storing a processing liquid for immersing the substrate held in the substrate holding section; an outer bubble generating pipe located below the outer peripheral region of the substrate and for generating bubbles in the processing liquid by supplying gas to the processing liquid; an inner bubble generating pipe located below the central region of the substrate and for generating bubbles in the processing liquid by supplying gas to the processing liquid; a first gas supply pipe connecting a gas supply source and the outer bubble generating pipe; a second gas supply pipe connecting the gas supply source and the inner bubble generating pipe; and a method for discharging the processing liquid into the processing tank. The processing tank comprises a plurality of liquid discharge pipes that generate an upflow flowing upward inside the processing tank, a plurality of liquid supply pipes connected to the plurality of liquid discharge pipes, a first flow rate control mechanism that controls the flow rate of gas flowing through the first gas supply pipe and the second gas supply pipe, a second flow rate control mechanism that controls the flow rate of the processing liquid supplied to the plurality of liquid supply pipes, and a control unit that controls the first flow rate control mechanism and the second flow rate control mechanism, wherein the control unit controls the first flow rate control mechanism so that the flow rate of gas supplied to the first gas supply pipe is greater than the flow rate of gas supplied to the second gas supply pipe, based on the flow rate of the processing liquid controlled by the second flow rate control mechanism.

[0009] In a substrate processing apparatus according to one aspect of the present invention, the first flow rate control mechanism may control the amount of bubbles generated from the outer bubble generation tube to be greater than the amount of bubbles generated from the inner bubble generation tube.

[0010] In a substrate processing apparatus according to one aspect of the present invention, the outer bubble generating tube may generate a larger number of bubbles than the inner bubble generating tube.

[0011] In a substrate processing apparatus according to one aspect of the present invention, the outer bubble generating tube, the inner bubble generating tube, and the plurality of liquid discharge tubes extend in the direction normal to the main surface of the substrate, and when viewed from the normal direction, the plurality of liquid discharge tubes are arranged between the outer bubble generating tube and the inner bubble generating tube, and the upflow generated by the plurality of liquid discharge tubes generates a downward flow along the side surface of the processing tank after reaching the liquid surface of the processing liquid in the processing tank, and the first flow rate control mechanism may control the flow rate of the gas supplied to the first gas supply tube so that the bubbles generated by the outer bubble generating tube rise against the downward flow.

[0012] In a substrate processing apparatus according to one aspect of the present invention, the processing solution may include a phosphoric acid solution.

[0013] A substrate processing method according to one aspect of the present invention involves immersing a substrate in a processing liquid stored in a processing tank, generating bubbles in the processing liquid by supplying gas to an outer bubble generating tube located below the outer peripheral region of the substrate and an inner bubble generating tube located below the central region of the substrate, supplying the bubbles to the substrate immersed in the processing liquid, and supplying the processing liquid to a plurality of liquid discharge tubes that discharge the processing liquid within the processing tank in order to generate an upflow flowing upward through the inside of the processing tank, wherein when supplying the bubbles, the flow rate of the gas supplied to the outer bubble generating tube is adjusted based on the flow rate of the processing liquid supplied to the plurality of liquid discharge tubes so that the flow rate of the gas supplied to the outer bubble generating tube is greater than the flow rate of the gas supplied to the inner bubble generating tube. [Effects of the Invention]

[0014] According to one aspect of the present invention, a substrate processing apparatus can further suppress processing unevenness within the substrate surface, even if the upflow flow rate increases. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view illustrating the schematic configuration of a substrate processing apparatus according to an embodiment of the present invention. [Figure 2] Figure 1 is a schematic diagram showing how bubbles are generated inside the inner chamber of the processing tank of the substrate processing apparatus shown. [Figure 3] Figure 1 is a top view of the substrate processing apparatus. [Figure 4] This is a schematic diagram illustrating the general configuration around the processing tank in the substrate processing apparatus shown in Figure 1. [Figure 5] Figure 1 is a schematic diagram illustrating the flow of the processing liquid within the inner tank of the processing chamber of the substrate processing apparatus shown in Figure 1. [Figure 6] Figure 1 is a flowchart illustrating the substrate processing method performed by the substrate processing apparatus shown. [Modes for carrying out the invention]

[0016] (Configuration of the substrate processing apparatus 100) Figure 1 is a perspective view illustrating the schematic configuration of a substrate processing apparatus 100 according to an embodiment of the present invention. In Figures 1 to 5, the direction in which the multiple outer bubble generating tubes 31 and 32 are aligned is the X-axis direction, the direction in which the multiple substrates W are arranged is the Y-axis direction, and the direction in which the lifting unit 13 raises and lowers the substrate holding part 1 is the Z-axis direction. The X-axis direction, Y-axis direction, and Z-axis direction are mutually orthogonal directions.

[0017] As shown by reference numeral 101 in FIG. 1, the substrate processing apparatus 100 includes a substrate holding unit 1 and a processing tank 2. The substrate processing apparatus 100 is a processing apparatus that processes at least one substrate W. Specifically, the substrate processing apparatus 100 processes the substrate W so as to perform at least one of etching, surface treatment, property imparting, processing film formation, removal of at least a part of the film, removal of impurities, and cleaning on the substrate W.

[0018] The impurities removed by the substrate processing apparatus 100 are, for example, fine particles, metals, residues, or organic substances such as photoresist adhering to the surface of the substrate W. Further, the film removed by the substrate processing apparatus 100 is, for example, a natural oxide film or a nitride film formed on the surface of the substrate W.

[0019] The substrate W is in the form of a thin plate, for example, a thin substantially disc-shaped. In this specification, "substantially" is not limited to the case of being exactly the same, and is a concept including at least one of an error and deformation that do not lose identity. The substrate W is, for example, a semiconductor wafer, a substrate for a liquid crystal display device, a substrate for a plasma display, or a substrate for a field emission display (FED). Further, the substrate W is, for example, a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, or a substrate for a solar cell.

[0020] The substrate processing apparatus 100 is a so-called batch-type processing apparatus that can process a lot of a plurality of substrates W collectively. However, the substrate processing apparatus 100 may process the substrates W one by one.

[0021] The substrate processing apparatus 100 processes the substrate W with the processing liquid L. The processing liquid L is a cleaning liquid for cleaning the surface of the substrate W. The processing liquid L is preferably a processing liquid containing a phosphoric acid solution. In this case, the substrate processing apparatus 100 removes the nitride film formed on the surface of the substrate W.

[0022] The treatment solution L may be, for example, a mixture of sulfuric acid and hydrogen peroxide (SPM), or a mixture of ammonium hydroxide and hydrogen peroxide (APM). Alternatively, the treatment solution L may contain a mixture of hydrochloric acid and hydrogen peroxide (HPM), or a treatment solution containing diluted hydrofluoric acid (DHF).

[0023] Furthermore, the treatment solution L may be a mixture of hydrofluoric acid and hydrogen peroxide (FPM), or a mixture of ammonium fluoride and hydrofluoric acid (BHF).

[0024] (Configuration of substrate holding section 1 and processing tank 2) The substrate holder 1 holds at least one substrate W. The normal direction of the main surface WS of the substrate W held by the substrate holder 1 is the Y-axis direction. Multiple substrates W are arranged in a line along the Y-axis direction. In other words, multiple substrates W are arranged substantially parallel to the XZ plane. Furthermore, each of the multiple substrates W extends in the X-axis direction and the Z-axis direction.

[0025] The substrate holding unit 1 is specifically a lifter and includes a back plate 11, a mounting unit 12, and a lifting unit 13. The back plate 11 is a plate extending in the XZ plane. The mounting unit 12 is, for example, a holding rod extending in the negative Y-axis direction from one surface of the back plate 11. For example, three mounting units 12 extend in the negative Y-axis direction from one surface of the back plate 11. The mounting unit 12 contacts the lower edge of each substrate W when the multiple substrates W are aligned at predetermined intervals. In this way, the mounting unit 12 holds the multiple substrates W and places the multiple substrates W on it.

[0026] The lifting unit 13 raises and lowers the substrate holder 1 in the Z-axis direction. By moving the substrate holder 1 in the negative Z-axis direction, the lifting unit 13 immerses the multiple substrates W held by the substrate holder 1 in the processing liquid L stored in the processing tank 2, as shown by reference numeral 102 in Figure 1.

[0027] The processing tank 2 stores a processing liquid L for immersing the substrates W held by the substrate holding unit 1. The processing tank 2 has a double-tank structure including an inner tank 21 and an outer tank 22. The inner tank 21 and the outer tank 22 each have an upper opening that opens upward. The inner tank 21 stores the processing liquid L and is configured to accommodate multiple substrates W. The outer tank 22 is provided outside the inner tank 21. The outer tank 22 stores the processing liquid L that overflows from the inner tank 21.

[0028] (Configuration of outer bubble generating tube, inner bubble generating tube, and liquid discharge tube) Figure 2 is a schematic diagram showing how bubbles are generated in the inner tank 21 of the processing tank 2 of the substrate processing apparatus 100 shown in Figure 1. The substrate holding section 1 is not shown in Figure 2. As shown in Figure 2, the substrate processing apparatus 100 includes a plurality of outer bubble generating tubes 31, 32, a plurality of inner bubble generating tubes 33, 34, and a plurality of liquid discharge tubes 41, 42.

[0029] The outer bubble generating tubes 31 and 32 are located below the outer peripheral region of the substrate W placed in the inner tank 21, and generate bubbles in the processing liquid L by supplying gas to the processing liquid L. The outer peripheral region of the substrate W is, when viewed from the Y-axis direction, for example, the region from a position that is 0.6 times the radius of the main surface WS of the substrate W to the edge of the substrate W, in a direction parallel to the center of the substrate W.

[0030] The inner bubble generating tubes 33 and 34 are located below the central region of the substrate W placed in the inner tank 21, and generate bubbles in the processing liquid L by supplying gas to the processing liquid L. The central region of the substrate W is the region of the substrate W other than the outer peripheral region of the substrate W when viewed from the Y-axis direction, for example, the region from the center of the substrate W to a position that is 0.6 times the radius in a direction parallel to the main surface WS of the substrate W relative to the center of the substrate W. When viewed from the Y-axis direction, the inner bubble generating tubes 33 and 34 are located closer to the center of the substrate W than the outer bubble generating tubes 31 and 32.

[0031] Bubbles generated in the processing liquid L by the outer bubble generating tubes 31, 32 and the inner bubble generating tubes 33, 34 float up within the processing liquid L and reach the liquid level LS of the processing liquid L in the inner tank 21. The liquid level LS of the processing liquid L is the interface between the processing liquid L in the inner tank 21 and a gas such as air or a predetermined atmosphere. As the bubbles float up within the processing liquid L, they come into contact with the surface of the substrate W.

[0032] The liquid discharge pipes 41 and 42 discharge the processing liquid L into the inner tank 21, generating an upflow that flows upward within the inner tank 21. The liquid discharge pipes 41 and 42 discharge the processing liquid L in the direction indicated by the arrows in Figure 2. In other words, when viewed from the Y-axis direction, the liquid discharge pipes 41 and 42 discharge the processing liquid L toward a virtual center line CL that passes through the center of the substrate W and extends in the Z-axis direction, and toward the positive Z-axis direction. However, the discharge direction of the processing liquid L by the liquid discharge pipes 41 and 42 is not limited to this.

[0033] When viewed from the Y-axis direction, the liquid discharge pipes 41 and 42 are positioned between the outer bubble generating pipes 31 and 32 and the inner bubble generating pipes 33 and 34. Specifically, when viewed from the Y-axis direction, the liquid discharge pipe 41 is positioned in the X-axis direction between the outer bubble generating pipe 31 and the inner bubble generating pipe 33, and the liquid discharge pipe 42 is positioned in the X-axis direction between the outer bubble generating pipe 32 and the inner bubble generating pipe 34.

[0034] (Configuration of the upper side of the substrate processing apparatus 100) Figure 3 is a top view of the substrate processing apparatus 100 shown in Figure 1. Figure 3 omits the substrate holding section 1 and the outer tank 22. As shown in Figure 3, multiple substrates W are arranged in a single row in the Y-axis direction and at equal intervals. For example, the spacing between adjacent substrates W is between 2 mm and 20 mm.

[0035] The outer bubble generating tubes 31, 32, the inner bubble generating tubes 33, 34, and the liquid discharge tubes 41, 42 are located on the negative Z-axis side of the substrate W held by the substrate holding part 1. For example, the outer bubble generating tubes 31, 32, the inner bubble generating tubes 33, 34, and the liquid discharge tubes 41, 42 are located near the bottom surface of the inner tank 21. The outer bubble generating tubes 31, 32, the inner bubble generating tubes 33, 34, and the liquid discharge tubes 41, 42 extend in the Y-axis direction and also extend parallel to each other.

[0036] As shown in Figures 2 and 3, the outer bubble generating tube 31 has a plurality of discharge holes 31A for discharging gas, and the plurality of discharge holes 31A are arranged in a line in the Y-axis direction and at equal intervals. The spacing between the plurality of discharge holes 31A is approximately the same as the spacing between the substrates W. When viewed from the Z-axis direction, the plurality of discharge holes 31A are located between the substrates W.

[0037] Similar to the outer bubble generating tube 31, the outer bubble generating tube 32 has multiple discharge holes 32A, the inner bubble generating tube 33 has multiple discharge holes 33A, and the inner bubble generating tube 34 has multiple discharge holes 34A. Also, similar to the outer bubble generating tube 31, the liquid discharge tube 41 has multiple discharge holes 41A, and the liquid discharge tube 42 has multiple discharge holes 42A. The diameters and spacing of the multiple discharge holes 31A to 34A and the multiple discharge holes 41A and 42A are approximately the same.

[0038] The outer bubble generating tubes 31, 32 and the inner bubble generating tubes 33, 34 are preferably made of a material containing, for example, quartz. In this case, it is possible to make it difficult for the bubbles generated from the outer bubble generating tubes 31, 32 and the inner bubble generating tubes 33, 34 to come into contact with each other, and to distribute the bubbles uniformly across the surface of the substrate W. The outer bubble generating tubes 31, 32 and the inner bubble generating tubes 33, 34 may also be made of a material containing polyether ether ketone (PEEK).

[0039] When the outer bubble generating tubes 31, 32 and the inner bubble generating tubes 33, 34 are made of a material containing quartz, the diameter of each of the multiple discharge holes 31A-34A and the multiple discharge holes 41A, 42A is, for example, 0.26 mm. Also, when the outer bubble generating tubes 31, 32 and the inner bubble generating tubes 33, 34 are made of a material containing PEEK, the diameter of each of the multiple discharge holes 31A-34A and the multiple discharge holes 41A, 42A is, for example, 0.2 mm. However, the diameters of each of the multiple discharge holes 31A-34A and the multiple discharge holes 41A, 42A are not limited to these.

[0040] The substrate processing apparatus 100 comprises a gas supply source 5, a first flow rate control mechanism 6, a second flow rate control mechanism 7, a plurality of first gas supply pipes 51, 52, a plurality of second gas supply pipes 53, 54, and a plurality of liquid supply pipes 71, 72. The first gas supply pipe 51 connects the gas supply source 5 to the outer bubble generating pipe 31, and the first gas supply pipe 52 connects the gas supply source 5 to the outer bubble generating pipe 32. The second gas supply pipe 53 connects the gas supply source 5 to the inner bubble generating pipe 33, and the second gas supply pipe 54 connects the gas supply source 5 to the inner bubble generating pipe 34.

[0041] The liquid supply pipes 71 and 72 are connected to the liquid discharge pipes 41 and 42. Specifically, the liquid supply pipe 71 connects the second flow control mechanism 7 to the liquid discharge pipe 41, and the liquid supply pipe 72 connects the second flow control mechanism 7 to the liquid discharge pipe 42.

[0042] The gas supply source 5 stores the gas and supplies it to the outer bubble generating tube 31 via the first gas supply pipe 51 and to the outer bubble generating tube 32 via the first gas supply pipe 52. The gas supply source 5 also supplies gas to the inner bubble generating tube 33 via the second gas supply pipe 53 and to the inner bubble generating tube 34 via the second gas supply pipe 54. The gas supplied by the gas supply source 5 is, for example, nitrogen.

[0043] The first flow rate control mechanism 6 includes a plurality of first flow rate control mechanisms 61, 62, 63, and 64, and controls the flow rate of gas flowing through the first gas supply pipes 51 and 52 and the second gas supply pipes 53 and 54.

[0044] The first flow rate control mechanism 61 is provided in the first gas supply pipe 51 and controls the flow rate of the gas flowing through the first gas supply pipe 51. The first flow rate control mechanism 61 includes, for example, an adjustment valve (not shown) that adjusts the flow rate of the gas flowing through the first gas supply pipe 51. The adjustment valve includes a valve body (not shown) with a valve seat inside, a valve element (not shown) that opens and closes the valve seat, and an actuator (not shown) that moves the valve element between an open position and a closed position.

[0045] The first flow rate control mechanism 62 is provided in the first gas supply pipe 52 and controls the flow rate of the gas flowing through the first gas supply pipe 52. The first flow rate control mechanism 63 is provided in the second gas supply pipe 53 and controls the flow rate of the gas flowing through the second gas supply pipe 53, and the first flow rate control mechanism 64 is provided in the second gas supply pipe 54 and controls the flow rate of the gas flowing through the second gas supply pipe 54. Each of the first flow rate control mechanisms 62 to 64 includes an adjustment valve, similar to the first flow rate control mechanism 61.

[0046] The second flow rate control mechanism 7 is located outside the treatment tank 2 and controls the flow rate of the treatment liquid L supplied to the liquid supply pipes 71 and 72. The treatment liquid L flows from the second flow rate control mechanism 7 through the liquid supply pipe 71 to the liquid discharge pipe 41, and from the second flow rate control mechanism 7 through the liquid supply pipe 72 to the liquid discharge pipe 42. The second flow rate control mechanism 7 may also recirculate the liquid that has been used once as the treatment liquid L in the treatment tank 2. The flow rate of the treatment liquid L supplied to each of the liquid supply pipes 71 and 72 is, for example, 40 L / min or less, or 100 L / min or less.

[0047] (Configuration of the area surrounding the processing tank 2) Figure 4 is a schematic diagram illustrating the general configuration around the processing tank 2 in the substrate processing apparatus 100 shown in Figure 1. The second flow rate control mechanism 7 circulates the processing liquid L stored in the processing tank 2 and supplies the processing liquid L to the liquid supply pipes 71 and 72. The second flow rate control mechanism 7 includes piping 81, a pump 82, a heater 83, a filter 84, a control valve 85, and a valve 86. The pump 82, heater 83, filter 84, control valve 85, and valve 86 are arranged in this order from upstream to downstream of piping 81.

[0048] Piping 81 guides the processed liquid L discharged from the outer tank 22 to the liquid supply pipes 71 and 72. Piping 81 connects the outer tank 22 to the liquid supply pipes 71 and 72 and also branches off to the liquid supply pipes 71 and 72. Pump 82 sends the processed liquid L from the outer tank 22 to the liquid supply pipes 71 and 72. Heater 83 adjusts the temperature of the processed liquid L by heating the processed liquid L flowing through piping 81. Filter 84 filters the processed liquid L flowing through piping 81.

[0049] The regulating valve 85 adjusts the flow rate of the processing liquid L supplied to the liquid supply pipes 71 and 72. Specifically, the regulating valve 85 includes a valve body (not shown) with a valve seat inside, a valve element (not shown) that opens and closes the valve seat, and an actuator (not shown) that moves the valve element between an open position and a closed position. Valve 86 opens and closes the flow path from piping 81 to the liquid supply pipes 71 and 72.

[0050] The substrate processing apparatus 100 includes a processing liquid supply unit 110. The processing liquid supply unit 110 supplies processing liquid L to the processing tank 2. The processing liquid supply unit 110 includes a processing liquid supply source 111, a nozzle 112, piping 113, and a valve 114.

[0051] The processing liquid supply source 111 supplies processing liquid L to the piping 113. The nozzle 112 is connected to the piping 113 and discharges the processing liquid L into the processing tank 2. The valve 114 is installed in the piping 113 and opens and closes the flow path of the piping 113. When the valve 114 is opened, the processing liquid L discharged by the nozzle 112 is supplied into the processing tank 2.

[0052] The substrate processing apparatus 100 includes a drainage section 120. The drainage section 120 discharges the processing liquid L stored in the inner tank 21. The drainage section 120 includes a drainage pipe 121 and a valve 122. The bottom wall of the inner tank 21 is connected to the drainage pipe 121. The valve 122 is provided on the drainage pipe 121. When the valve 122 opens, the processing liquid L stored in the inner tank 21 is discharged to the outside of the processing tank 2 through the drainage pipe 121. The discharged processing liquid L is sent to a drainage processing apparatus (not shown) for further processing.

[0053] The substrate processing apparatus 100 includes a control unit 9. The control unit 9 includes a CPU (Central Processing Unit) 91 and memory 92 as processors. The control unit 9 may also include, for example, a microprocessing unit (MPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), or a field-programmable gateway (FPGA) as processors. Furthermore, the control unit 9 may also include a digital signal processor (DSP), a dataflow processor (DFP), or a neural processing unit (NPU) as processors.

[0054] Memory 92 may be one or more hard disks (HDs), random access memory (RAM), read-only memory (ROM), or storage devices of a distributed computing system. Alternatively, memory 92 may be an optical disc (e.g., a compact disc (CD), digital versatile disc (DVD), or Blu-ray disc (BD, registered trademark)), a flash memory device, or a memory card.

[0055] The control unit 9 controls various operations of the substrate processing device 100. For example, the control unit 9 controls the first flow rate control mechanism 6, the second flow rate control mechanism 7, the lifting unit 13, the valve 114, and the valve 122.

[0056] Specifically, regarding the control of the first flow control mechanism 6 and the second flow control mechanism 7, the control unit 9 controls each of the first flow control mechanisms 61 to 64, as well as the pump 82, the heater 83, the adjustment valve 85, and the valve 86.

[0057] The control unit 9 controls the first flow rate control mechanism 6 based on the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7, so that the flow rate of gas supplied to the first gas supply pipes 51 and 52 is greater than the flow rate of gas supplied to the second gas supply pipes 53 and 54. This allows bubbles to be distributed uniformly across the surface of the substrate W, and even if the upflow flow rate from the liquid discharge pipes 41 and 42 increases, processing unevenness within the surface of the substrate W can be further suppressed. As a result, an improvement in yield can be expected. Furthermore, even when the upflow flow rate changes, bubbles can be distributed uniformly across the surface of the substrate W.

[0058] The control unit 9 may obtain the rotational speed of a motor (not shown) in the pump 82 and, based on the rotational speed of the motor, obtain the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7. Alternatively, the control unit 9 may obtain the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7 from a flow meter (not shown) provided in the piping 81 and measuring the flow rate of the processing liquid L flowing through the piping 81. The flow meter may be provided in the piping 81 downstream of the pump 82.

[0059] Furthermore, the control unit 9 is located near the upper opening of the inner tank 21 and obtains the water pressure of the processing liquid L stored in the inner tank 21 from a pressure sensor (not shown) that measures the water pressure of the processing liquid L stored in the inner tank 21. Based on the obtained water pressure of the processing liquid L, the control unit 9 may also obtain the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7.

[0060] The control unit 9 may control the first flow rate control mechanism 6 such that, as the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7 increases, the flow rate difference between the flow rate of the gas supplied to the first gas supply pipes 51 and 52 and the flow rate of the gas supplied to the second gas supply pipes 53 and 54 increases.

[0061] Furthermore, the control unit 9 may provide real-time feedback control to the first flow rate control mechanism 6 based on the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7. Specifically, the control unit 9 may change the flow rates of the gas supplied to the first gas supply pipes 51, 52 and the second gas supply pipes 53, 54, respectively, in real time in response to changes in the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7.

[0062] The first flow rate control mechanism 6 controls the amount of bubbles generated from the outer bubble generating tubes 31 and 32 to be greater than the amount of bubbles generated from the inner bubble generating tubes 33 and 34. Specifically, the first flow rate control mechanisms 61 and 63 control the amount of bubbles generated from the outer bubble generating tube 31 to be greater than the amount of bubbles generated from the inner bubble generating tube 33. In addition, the first flow rate control mechanisms 62 and 64 control the amount of bubbles generated from the outer bubble generating tube 32 to be greater than the amount of bubbles generated from the inner bubble generating tube 34.

[0063] Furthermore, the control unit 9 controls the first flow rate control mechanism 6 based on the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7, so that the amount of bubbles generated from the outer bubble generation tubes 31 and 32 is greater than the amount of bubbles generated from the inner bubble generation tubes 33 and 34.

[0064] In this case, each of the outer bubble generating tubes 31 and 32 generates more bubbles than each of the inner bubble generating tubes 33 and 34. Specifically, the outer bubble generating tube 31 generates more bubbles than the inner bubble generating tube 33, and the outer bubble generating tube 32 generates more bubbles than the inner bubble generating tube 34.

[0065] Furthermore, it is preferable that the control unit 9 controls the first flow rate control mechanism 6 so that the flow rate of the gas supplied to the first gas supply pipes 51 and 52 is approximately three times the flow rate of the gas supplied to the second gas supply pipes 53 and 54. For example, it is preferable that the control unit 9 controls the first flow rate control mechanism 6 so that the flow rate of the gas supplied to each of the first gas supply pipes 51 and 52 is 4.9 L / min, and the flow rate of the gas supplied to each of the second gas supply pipes 53 and 54 is 1.6 L / min.

[0066] Surface treatment of substrate W using a treatment solution L containing phosphoric acid takes longer than surface treatment of substrate W using a treatment solution containing chemicals other than phosphoric acid. Therefore, as described above, further improvement in yield can be expected by the control unit 9 controlling the first flow rate control mechanism 6.

[0067] (Flow of treatment liquid L) Figure 5 is a schematic diagram illustrating the flow of processing liquid L within the inner tank 21 of the processing tank 2 of the substrate processing apparatus 100 shown in Figure 1. In Figure 5, reference numerals 501 and 502 indicate the flow of processing liquid L F1 due to bubbles generated in the outer bubble generating pipes 31 and 32 and the inner bubble generating pipes 33 and 34, respectively, indicated by dotted arrows, and the flow of processing liquid L F2 due to the discharge of processing liquid L by the liquid discharge pipes 41 and 42 is indicated by solid arrows.

[0068] As shown by reference numeral 501 in Figure 5, let's consider the case where neither liquid discharge pipe 41 nor 42 is discharging the processing liquid L into the inner tank 21, and the outer bubble generating pipes 31, 32 and the inner bubble generating pipes 33, 34 are supplying gas to the processing liquid L. In this case, the flow F1 of the processing liquid L due to the bubbles generated in the outer bubble generating pipes 31, 32 and the inner bubble generating pipes 33, 34 will be a flow in the positive Z-axis direction. In the case of reference numerals 501 and 502 in Figure 5, the flow rate of gas supplied to the first gas supply pipes 51 and 52 is 1.6 L / min, and the flow rate of gas supplied to the second gas supply pipes 53 and 54 is 1.6 L / min.

[0069] As shown by reference numeral 502 in Figure 5, let's consider the case where liquid discharge pipes 41 and 42 discharge the processing liquid L into the inner tank 21, and the flow rates of gas supplied to the processing liquid L by the outer bubble generating pipes 31 and 32 and the inner bubble generating pipes 33 and 34 are approximately the same.

[0070] In this case, the liquid discharge pipes 41 and 42 generate an upflow along the virtual centerline CL. The flow F2 of the processed liquid L discharged by the liquid discharge pipes 41 and 42 travels in the positive Z-axis direction along the virtual centerline CL, reaches the liquid level LS of the processed liquid L in the inner tank 21, and then flows downward along the side surface 2S of the inner tank 21. The side surface 2S is the inner surface of the inner tank 21 that is approximately parallel to the YZ plane.

[0071] The flow F1 of the processing liquid L caused by bubbles generated in the inner bubble generation tubes 33 and 34 is a flow in the positive Z-axis direction. In addition, the flow F1 of the processing liquid L caused by bubbles generated in the outer bubble generation tubes 31 and 32 is a downward flow of the flow F2 that descends along the side surface 2S of the inner tank 21, and as a result, it is a flow in the positive Z-axis direction along the virtual centerline CL.

[0072] In other words, flow F1 is directed in the positive Z-axis direction along the virtual centerline CL, avoiding the downward flow of flow F2 that descends from the liquid surface LS along the side surface 2S of the inner tank 21, making it difficult for bubbles to spread to the outer peripheral region of the substrate W. Furthermore, flow F1 changes according to the flow rate of the processing liquid L discharged by the liquid discharge pipes 41 and 42.

[0073] Therefore, consider the case where, as shown by reference numeral 503 in Figure 5, liquid discharge pipes 41 and 42 discharge the processing liquid L into the inner tank 21, and the flow rate of gas supplied to the processing liquid L by the outer bubble generating pipes 31 and 32 is greater than the flow rate of gas supplied to the processing liquid L by the inner bubble generating pipes 33 and 34. In this case, the flow F3 of the processing liquid L due to the bubbles generated in the outer bubble generating pipes 31 and 32 is stronger than the flow F1 of the processing liquid L due to the bubbles generated in the inner bubble generating pipes 33 and 34. As a result, flow F3 becomes an upward flow in the positive Z-axis direction, counteracting the downward flow of flow F2 that descends along the side surface 2S of the inner tank 21.

[0074] As described above, the upflow generated by the liquid discharge pipes 41 and 42 generates a downward flow along the side surface 2S of the inner tank 21 after reaching the liquid level LS of the processed liquid L in the inner tank 21. The first flow rate control mechanism 6 controls the flow rate of the gas supplied to the first gas supply pipes 51 and 52 so that the bubbles generated by the outer bubble generating pipes 31 and 32 rise against the downward flow.

[0075] In the case of reference numeral 503 in Figure 5, the flow rate of gas supplied to the first gas supply pipes 51 and 52 is 4.9 L / min, and the flow rate of gas supplied to the second gas supply pipes 53 and 54 is 1.6 L / min.

[0076] (Substrate processing method) Figure 6 is a flowchart illustrating the processing of the substrate processing method performed by the substrate processing apparatus 100 shown in Figure 1. Here, the second flow rate control mechanism 7 supplies processing liquid L to a plurality of liquid discharge pipes 41 and 42 that discharge the processing liquid L within the inner tank 21 in order to generate an upflow that flows upward inside the inner tank 21.

[0077] While the second flow rate control mechanism 7 is supplying the processing liquid L, as shown in Figure 6, the lifting unit 13 lowers the substrate holding part 1, which is holding the substrate W, to the inner tank 21 of the processing tank 2, thereby immersing the substrate W in the processing liquid L stored in the inner tank 21 (S1).

[0078] After the lifting unit 13 lowers the substrate holding unit 1, the control unit 9 acquires the flow rate of the processing liquid L controlled by the second flow rate control mechanism 7 (S2). Based on the acquired flow rate of the processing liquid L, the control unit 9 determines the flow rate of the gas supplied to the outer bubble generation tubes 31 and 32 and the flow rate of the gas supplied to the inner bubble generation tubes 33 and 34 (S3).

[0079] The gas supply source 5 generates bubbles in the processing liquid L by supplying gas to the outer bubble generation tubes 31, 32 and the inner bubble generation tubes 33, 34 at the gas flow rate determined by the control unit 9 in step S3, and supplies bubbles to the substrate W immersed in the processing liquid L (S4). In step S4, when the gas supply source 5 supplies bubbles, the control unit 9 controls the first flow rate control mechanism 6. In steps S2 to S4, the control unit 9 adjusts the gas flow rate so that the gas flow rate supplied to the outer bubble generation tubes 31, 32 is greater than the gas flow rate supplied to the inner bubble generation tubes 33, 34, based on the flow rate of the processing liquid L supplied to the liquid discharge tubes 41, 42.

[0080] [Examples of implementation using software] The function of the substrate processing apparatus 100 (hereinafter referred to as "the apparatus") is a program that causes the apparatus to function as a computer, and can be realized by a program that causes the apparatus to function as a control block (particularly the control unit 9).

[0081] In this case, the device includes a computer having at least one control device (e.g., a processor such as a CPU 91) and at least one storage device (e.g., memory 92) as hardware for executing the program. By executing the program using this control device and storage device, each of the functions described in the above embodiment is realized.

[0082] The above program may be recorded on one or more computer-readable recording media, not temporary ones. These recording media may or may not be provided by the above device. In the latter case, the program may be supplied to the above device via any wired or wireless transmission medium.

[0083] Furthermore, some or all of the functions of the control block described above can also be realized by logic circuits. For example, an integrated circuit in which a logic circuit that functions as the control block described above is formed is also included in the scope of the present invention.

[0084] [Additional Notes] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the multiple technical means disclosed in the embodiments are also included in the technical scope of the present invention. [Explanation of Symbols]

[0085] 100 Substrate Processing Equipment 1 Board holding part 2. Treatment tank 2S side 5. Gas supply source 6. First flow control mechanism 7. Second flow control mechanism 9. Control Unit 31, 32 Outer bubble generating tube 33, 34 Inner bubble generating tube 41, 42 Liquid discharge pipe 51, 52 First gas supply pipe 53, 54 Second gas supply pipe 71, 72 Liquid supply pipe L Treatment solution LS liquid level W board WS Main surface

Claims

1. A substrate holding section that holds at least one substrate, A treatment tank for storing a treatment liquid for immersing the substrate held in the substrate holding section, An outer bubble generating tube located below the outer peripheral region of the substrate, which generates bubbles in the processing liquid by supplying gas to the processing liquid, An inner bubble generating tube located below the central region of the substrate, which generates bubbles in the processing liquid by supplying gas to the processing liquid, A first gas supply pipe connecting the gas supply source and the outer bubble generating pipe, A second gas supply pipe connecting the gas supply source and the inner bubble generating pipe, Multiple liquid discharge pipes that discharge the processing liquid into the processing tank, thereby generating an upflow that flows upward inside the processing tank, Multiple liquid supply pipes connected to the multiple liquid discharge pipes, A first flow control mechanism for controlling the flow rate of gas flowing through the first gas supply pipe and the second gas supply pipe, A second flow rate control mechanism controls the flow rate of the processing liquid supplied to the plurality of liquid supply pipes, The system comprises a control unit that controls the first flow control mechanism and the second flow control mechanism, A substrate processing apparatus comprising: a control unit that controls the first flow rate control mechanism based on the flow rate of the processing liquid controlled by the second flow rate control mechanism, such that the flow rate of gas supplied to the first gas supply pipe is greater than the flow rate of gas supplied to the second gas supply pipe.

2. The substrate processing apparatus according to claim 1, wherein the first flow rate control mechanism controls the amount of bubbles generated from the outer bubble generation tube to be greater than the amount of bubbles generated from the inner bubble generation tube.

3. The substrate processing apparatus according to claim 2, wherein the outer bubble generating tube generates a larger number of bubbles than the inner bubble generating tube.

4. The outer bubble generating tube, the inner bubble generating tube, and the plurality of liquid discharge tubes extend in the direction normal to the main surface of the substrate. In the view from the normal direction, The plurality of liquid discharge pipes are arranged between the outer bubble generating pipe and the inner bubble generating pipe. The upflow generated by the plurality of liquid discharge pipes generates a downward flow along the side of the treatment tank after reaching the liquid surface of the treatment liquid in the treatment tank. The substrate processing apparatus according to claim 1, wherein the first flow rate control mechanism controls the flow rate of gas supplied to the first gas supply pipe so that the bubbles generated in the outer bubble generating pipe rise against the downward flow.

5. The substrate processing apparatus according to claim 1, wherein the processing solution includes a phosphoric acid solution.

6. The substrate is immersed in the processing liquid stored in the processing tank. By supplying gas to an outer bubble generating tube located below the outer peripheral region of the substrate placed in the processing tank and an inner bubble generating tube located below the central region of the substrate, bubbles are generated in the processing liquid, and the bubbles are supplied to the substrate immersed in the processing liquid. A substrate processing method comprising supplying the processing liquid to a plurality of liquid discharge pipes that discharge the processing liquid within the processing tank in order to generate an upward flow within the processing tank, A substrate processing method, wherein when supplying the bubbles, the flow rate of the gas supplied to the outer bubble generating tube is adjusted based on the flow rate of the processing liquid supplied to the plurality of liquid discharge tubes, such that the flow rate of the gas supplied to the outer bubble generating tube is greater than the flow rate of the gas supplied to the inner bubble generating tube.

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