Wafer processing device

Abstract

To provide a wafer processing device capable of processing a wafer with high uniformity.SOLUTION: A wafer processing device 1 comprises a processing tank 2, a wafer holding section 3, a bubbling section 5, and a control section 9. A process liquid is stored in the processing tank 2. The wafer holding section 3 holds a wafer W inside of the processing tank 2 in a state where the wafer W stands up. The bubbling section 5 is provided inside of the processing tank 2 and includes one or more lateral discharge bubbler pipes 51 including a plurality of first discharge ports 51a discharging air bubbles in a first discharge direction having a lateral direction component that is a component in a lateral direction D2, which is parallel with a principal surface of the wafer W and horizontal, and a flow rate regulation valve 54 which regulates a flow rate of gases flowing in the lateral discharge bubbler pipes 51. The control section 9 controls the flow rate regulation valve 54 in a state where the wafer W is immersed in the process liquid, changes a flow rate of the air bubbles discharged from the lateral discharge bubbler pipes 51 with the lapse of time and changes a passage range, in which the air bubbles pass the process liquid, in the lateral direction D2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus. [Background technology]

[0002] Batch-type substrate processing apparatuses for processing multiple substrates have been proposed in the past (see, for example, Patent Document 1). In Patent Document 1, the substrate processing apparatus includes a processing tank, a substrate holding unit, and a fluid supply unit. The processing tank stores a processing liquid. The substrate holding unit holds multiple substrates and immerses the multiple substrates in the processing liquid in the processing tank. The fluid supply unit includes multiple fluid supply pipes located below the multiple substrates. Each fluid supply pipe extends in the direction in which the substrates are arranged. Each fluid supply pipe is formed with multiple bubble outlets, and each bubble outlet ejects bubbles vertically upward. The bubbles from each fluid supply pipe rise between the substrates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-47885 Summary of the Invention [Problem to be solved by the invention]

[0004] In the passing regions where the bubbles pass, the processing liquid is agitated, thereby accelerating the processing of the main surface of the substrate. On the other hand, in the non-passing regions where the bubbles do not pass, the processing liquid is not agitated very much, thereby not accelerating the processing of the main surface of the substrate very much. Therefore, if the passing regions and non-passing regions are significantly distributed, the degree of processing of the main surface of the substrate may become non-uniform.

[0005] Therefore, an object of the present disclosure is to provide a substrate processing apparatus that can process substrates with high uniformity. [Means for solving the problem]

[0006] A first aspect is a substrate processing apparatus comprising: a processing tank for storing a processing liquid; a substrate holding section for holding the substrate in an upright position inside the processing tank; one or more lateral-discharge bubbler tubes provided inside the processing tank and having a plurality of first discharge ports for discharging bubbles in a first discharge direction having a lateral component that is parallel to and horizontal to a main surface of the substrate held by the substrate holding section; a bubbling section including a flow control valve for adjusting the flow rate of gas flowing through the lateral-discharge bubbler tube; and a control section for controlling the flow control valve while the substrate is immersed in the processing liquid to change the flow rate of the bubbles discharged by the lateral-discharge bubbler tube over time and change the range of passage of the bubbles through the processing liquid in the lateral direction.

[0007] A second aspect is the substrate processing apparatus according to the first aspect, wherein the first angle formed between the first discharge direction and a vertical direction is 45° or more.

[0008] A third aspect is a substrate processing apparatus according to the first or second aspect, wherein the bubbling section includes three or more of the horizontal discharge bubbler tubes arranged in the horizontal direction, a first bubbler tube located at an end of the horizontal discharge bubbler tubes further has a plurality of second discharge ports that discharge bubbles in a second discharge direction, the first bubbler tube is positioned vertically opposite an end portion of the substrate in the horizontal direction, and a second angle formed between the second discharge direction and the vertical direction is smaller than a first angle formed between the first discharge direction and the vertical direction.

[0009] A fourth aspect is a substrate processing apparatus according to any one of the first to third aspects, wherein the bubbling section includes three or more lateral discharge bubbler tubes arranged in the lateral direction, and a second bubbler tube located other than the end of the lateral discharge bubbler tube has a plurality of third discharge outlets, the third discharge outlets are located on the opposite side of the lateral direction from the first discharge outlets, and the third discharge direction of the third discharge outlets has a lateral component opposite to the lateral component of the first discharge direction.

[0010] A fifth aspect is a substrate processing apparatus according to any one of the first to fourth aspects, wherein the bubbling section is provided at a position vertically opposite to the end portion of the substrate in the lateral direction, and further includes a vertical discharge bubbler pipe that discharges upward.

[0011] A sixth aspect is a substrate processing apparatus according to any one of the first to fifth aspects, further comprising two liquid discharge pipes that discharge the processing liquid inside the processing tank to form an upward liquid flow inside the processing tank, the processing tank including a main tank and an upflow tank that receives the processing liquid that overflows from the main tank, the lateral discharge bubbler pipe including a first bubbler pipe located between the liquid discharge pipes and a second bubbler pipe located outside the liquid discharge pipe, and the bubbling section alternately discharges bubbles from the first bubbler pipe and the second bubbler pipe.

[0012] A seventh aspect is a substrate processing apparatus according to any one of the first to sixth aspects, wherein the bubbling section is provided at a position vertically opposite to the end portion of the substrate in the lateral direction, and further includes a constant flow rate bubbler tube that ejects bubbles at a constant flow rate.

[0013] An eighth aspect is a substrate processing apparatus according to any one of the first to seventh aspects, wherein a pattern of alternatingly stacked insulating films and sacrificial films for a 3D NAND is formed on the main surface of the substrate.

[0014] A ninth aspect is the substrate processing apparatus according to the eighth aspect, wherein the processing liquid is a liquid that etches the sacrificial film. [Effects of the Invention]

[0015] According to the first and fifth aspects, the range through which the bubbles pass changes over time, thereby improving the uniformity of processing on the main surface of the substrate.

[0016] According to the second aspect, the range through which the bubbles pass can be effectively changed in the lateral direction.

[0017] According to the third aspect, the first bubbler tube can supply bubbles from the second outlet toward the vicinity of the edge of the substrate, thereby making it possible to appropriately process the edge of the substrate.

[0018] According to the fourth aspect, the second bubbler tube discharges bubbles on both sides in the horizontal direction, so that bubbles can be supplied over a wide range in the horizontal direction.

[0019] According to the sixth aspect, the liquid flow can be changed over time by the bubbles, and therefore the uniformity of the processing on the main surface of the substrate can be improved.

[0020] According to the seventh aspect, the load on the control unit can be reduced.

[0021] According to the eighth and ninth aspects, the sacrificial film can be etched more uniformly. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a cross-sectional view schematically showing an example of the configuration of a substrate processing apparatus. [Figure 2] FIG. 1 is a plan view schematically illustrating an example of a configuration of a portion of a substrate processing apparatus. [Figure 3] FIG. 2 is a cross-sectional view schematically illustrating an example of a substrate structure. [Figure 4] FIG. 4 is a diagram for explaining the position of a discharge port in a bubbler tube. [Figure 5] FIG. 10 is a diagram schematically illustrating an example of a state in which bubbles are discharged from a discharge port of a bubbler tube. [Figure 6] FIG. 10 is a diagram schematically illustrating an example of a state in which bubbles are discharged from a discharge port of a bubbler tube. [Figure 7] 10 is a graph showing the relationship between the gas flow rate and the center position of the bubble passage range. [Figure 8] 10 is a graph showing an example of a change in gas flow rate over time. [Figure 9]FIG. 4 is a diagram schematically illustrating an example of the state of the substrate processing apparatus when the flow rate of the gas is at a first flow rate value. [Figure 10] FIG. 10 is a diagram schematically illustrating an example of the state of the substrate processing apparatus when the gas flow rate is at a second flow rate value. [Figure 11] FIG. 10 is a diagram schematically illustrating another example of the configuration of the substrate processing apparatus. [Figure 12] FIG. 10 is a diagram schematically illustrating another example of the configuration of the bubbling section. [Figure 13] FIG. 10 is a diagram schematically illustrating an example of the state of the substrate processing apparatus during a first bubbling period. [Figure 14] FIG. 10 is a diagram schematically illustrating an example of the state of the substrate processing apparatus during a first bubbling period. [Figure 15] FIG. 10 is a diagram schematically illustrating an example of the state of the substrate processing apparatus during a first bubbling period. [Figure 16] FIG. 10 is a diagram schematically illustrating an example of the state of the substrate processing apparatus during a first bubbling period. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the drawings, the dimensions and numbers of each part are exaggerated or simplified as necessary for ease of understanding. Parts having similar configurations and functions are assigned the same reference numerals, and duplicate explanations will be omitted below.

[0024] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0025] Furthermore, in the following description, even if ordinal numbers such as "first" or "second" are used, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and are not limited to the ordering that may result from these ordinal numbers.

[0026] When expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) are used, unless otherwise specified, the expressions not only strictly represent the positional relationship but also represent a state in which there is a relative displacement in terms of angle or distance within a range in which tolerance or equivalent functionality is obtained. When expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) are used, the expressions not only represent a state in which there is strict quantitative equality but also represent a state in which there is a difference in which tolerance or equivalent functionality is obtained, unless otherwise specified. When expressions indicating a shape (e.g., "rectangular shape" or "cylindrical shape," etc.) are used, the expressions not only represent a geometrically strict shape but also represent a shape with, for example, irregularities or chamfers within a range in which equivalent effects are obtained, unless otherwise specified. When the expressions "comprise," "include," "have," "includes," "includes," or "have" are used to describe one component, the expressions are not exclusive expressions that exclude the presence of other components. When the phrase "at least one of A, B, and C" is used, the phrase includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0027] <Outline of substrate processing equipment> FIG. 1 is a cross-sectional view schematically illustrating an example of the configuration of a substrate processing apparatus 1, and FIG. 2 is a plan view schematically illustrating an example of the configuration of a portion of the substrate processing apparatus 1. The substrate processing apparatus 1 is a batch-type processing apparatus that processes multiple substrates W collectively. The substrates W are, for example, semiconductor substrates, although there is no particular limitation. In the example of FIG. 1, the substrate W has a disk-like shape. A pattern may be formed on the main surface of the substrate W. The substrate W is, for example, a semiconductor substrate in the middle of manufacturing a 3D NAND semiconductor device. FIG. 3 is a cross-sectional view schematically illustrating an example of the structure of this substrate W. In the example of FIG. 3, the main surface of the substrate W has a pattern in which insulating films F1 and sacrificial films F2 are alternately stacked in the thickness direction of the substrate W. The insulating films F1 are, for example, silicon oxide films, and the sacrificial films F2 are, for example, silicon nitride films. Through holes are formed in the stack of the insulating films F1 and the sacrificial films F2 along the thickness direction of the substrate W, and posts PM are provided in the through holes. The post PM is configured, for example, by concentrically forming an aluminum oxide film, a silicon nitride film, and a silicon oxide film, with polysilicon disposed in the center. A slit SL is formed in the laminate. The slit SL penetrates the laminate in the thickness direction of the substrate W. The substrate processing apparatus 1 is, for example, an etching apparatus that removes a sacrificial film F2 of the substrate W by etching. In this case, the sacrificial film F2 is the film to be etched.

[0028] 1, the substrate processing apparatus 1 includes a processing tank 2, a substrate holding unit 3, a bubbling unit 5, and a control unit 9. Below, an overview of the substrate processing apparatus 1 will be described, and then an example of each component will be described in detail.

[0029] The processing tank 2 stores a processing liquid. The type of processing liquid is not particularly limited, but may be, for example, a liquid that etches the sacrificial film F2. As a specific example, the processing liquid may be phosphoric acid. Phosphoric acid can etch the sacrificial film F2 (here, silicon nitride).

[0030] The substrate holder 3 can hold multiple substrates W while immersed in the processing liquid in the processing bath 2. The substrate holder 3 holds multiple substrates W in a state where the multiple substrates W stand upright and are arranged at intervals along their thickness direction. Here, the state where the substrates W stand upright means that the thickness direction of the substrates W is aligned horizontally. By immersing multiple substrates W in the processing liquid, the substrate processing apparatus 1 can collectively process the multiple substrates W according to the type of processing liquid. Here, the substrate processing apparatus 1 collectively performs an etching process to remove the sacrificial film F2 on the multiple substrates W. Note that, hereinafter, the direction in which the multiple substrates W are arranged will also be referred to as the arrangement direction D1.

[0031] The bubbling unit 5 includes a side-discharge bubbler tube 51. Hereinafter, the side-discharge bubbler tube 51 will also be simply referred to as the bubbler tube 51. The bubbler tube 51 is provided inside the processing tank 2. When the processing liquid is stored in the processing tank 2, the bubbler tube 51 is immersed in the processing liquid. The bubbling unit 5 discharges bubbles from the bubbler tube 51 into the processing liquid. The bubbler tube 51 discharges bubbles, for example, at a position below the multiple substrates W. The multiple bubbles discharged from the bubbler tube 51 rise in the processing liquid. In the example of Figure 1, the movement of the bubbles is schematically shown by dashed arrows.

[0032] FIG. 2 shows part of the configuration of the bubbler tube 51 in a plan view. As shown in FIG. 2, the bubbler tube 51 extends across multiple substrates W. That is, in a plan view, the longitudinal direction of the bubbler tube 51 intersects with the substrates W. The plan view here refers to viewing an object with the line of sight aligned vertically. The bubbler tube 51 has multiple outlets 51a (corresponding to the first outlet or the third outlet) formed at intervals in the longitudinal direction. The multiple bubbles discharged from each outlet 51a pass upward between adjacent substrates W. Some of the multiple bubbles may come into contact with the main surfaces of the substrates W.

[0033] As multiple bubbles pass between adjacent substrates W, the processing liquid is locally agitated between the adjacent substrates W. This local agitation promotes the inflow and outflow of the processing liquid between the inside and outside of the pattern on the substrate W. In other words, the local agitation makes it easier for the processing liquid to enter the inside of the slit SL of the substrate W, making it easier for the processing liquid to act on the sacrificial film F2 and etch the sacrificial film F2. This etching causes the sacrificial film F2 to gradually retreat from the slit SL. The processing liquid also easily enters the spaces between the insulating films F1 created by this retreat. Furthermore, after acting on the sacrificial film F2, the processing liquid tends to quickly flow out from the inside of the pattern, and new processing liquid tends to re-enter the inside of the pattern. Therefore, the processing liquid can efficiently act on the main surface of the substrate W.

[0034] As described above, in the passage region through which the bubbles pass, the processing liquid is more likely to act on the main surface of the substrate W due to agitation, and processing progresses more easily. For this reason, variation in the progress of processing of the substrate W may occur between the passage region through which the bubbles pass and the non-passage region through which the bubbles do not pass.

[0035] Therefore, in this embodiment, the aim is to make the degree of processing on the main surface of the substrate W more uniform by making the time integral of the spatial distribution of bubbles more uniform in the lateral direction D2 parallel and horizontal to the main surface of the substrate W.

[0036] In this embodiment, the bubbler tube 51 has an outlet 51a (corresponding to the first outlet or the third outlet) that discharges bubbles in a discharge direction (corresponding to the first discharge direction or the third discharge direction) described below. This discharge direction has a component of the horizontal direction D2 (hereinafter referred to as the horizontal component). In the example of FIG. 1, the discharge direction of the outlet 51a of the bubbler tube 51 is parallel to the horizontal direction D2. As such, since the discharge direction of the outlet 51a has a horizontal component, the multiple bubbles discharged from the outlet 51a rise while moving in the horizontal direction D2.

[0037] Furthermore, in this embodiment, as will be described in detail later, the bubbling unit 5 changes the gas flow rate over time. When the gas flow rate is high, the bubbles are discharged from the bubbler tube 51 with force, and therefore rise at a position farther from the bubbler tube 51 in the horizontal direction D2 (see also FIG. 5). On the other hand, when the gas flow rate is low, the bubbles are discharged from the bubbler tube 51 with weak force, and therefore rise at a position closer to the bubbler tube 51 in the horizontal direction D2 (see also FIG. 6). This causes the passage range R1 of the multiple bubbles to vary over time in the horizontal direction D2. Therefore, the multiple bubbles can rise more uniformly relative to the main surface of the substrate W on average over time. In other words, the time integral of the volume of the bubbles rising at each position in the horizontal direction D2 can be made uniform. This allows the processing liquid to be agitated more uniformly relative to the main surface of the substrate W, and the main surface of the substrate W to be processed more uniformly.

[0038] An example of the configuration of the substrate processing apparatus 1 will be described in detail below.

[0039] <Treatment tank> The treatment tank 2 stores the treatment liquid. In the example of FIG. 1, the treatment tank 2 includes a main tank 21 and an upflow tank 22. The main tank 21 has a box-like shape that opens upward. The main tank 21 has, for example, a rectangular shape in a plan view. The main tank 21 stores the treatment liquid.

[0040] The upflow tank 22 is a tank that receives the treatment liquid that overflows from the top of the main tank 21. The upflow tank 22 includes a bottom 221 and a sidewall 222. The bottom 221 has an annular shape in a plan view, and its inner peripheral edge is connected to the sidewall of the main tank 21 along its entire circumference. The sidewall 222 extends upward from the entire outer peripheral edge of the bottom 221.

[0041] The substrate holding unit 3 can hold multiple substrates W immersed in a processing solution. In the example of FIG. 1, the substrate holding unit 3 includes a plate unit 31 and multiple holding rods 32. The plate unit 31 has a plate-like shape and is disposed so that its thickness direction is aligned with the arrangement direction D1 of the substrates W. Each of the multiple holding rods 32 has a rod-like shape extending from the plate unit 31 along the arrangement direction D1, with its base end connected to one main surface of the plate unit 31. The multiple holding rods 32 are disposed below the substrates W and are arranged at intervals in the circumferential direction of the substrates W. Each holding rod 32 supports multiple substrates W. Specifically, multiple holding grooves 321 are formed at the top of each holding rod 32 at intervals in the arrangement direction D1 (see also FIG. 2). A portion of each substrate W is inserted into the holding groove 321, thereby holding the multiple substrates W by the holding rod 32.

[0042] In the example of FIG. 1, the substrate holder 3 also includes a lifting / lowering drive unit 33. The lifting / lowering drive unit 33 raises and lowers the plate 31, the multiple holding rods 32, and the multiple substrates W as a unit between an upper position and a lower position. The lower position is a position where the multiple substrates W held by the substrate holder 3 are immersed in the processing liquid. In the example of FIG. 1, the multiple substrates W are shown positioned at the lower position. The upper position is a position where the multiple substrates W held by the substrate holder 3 are higher than the processing bath 2. In other words, the upper position is a position where the multiple substrates W are not immersed in the processing liquid. The lifting / lowering drive unit 33 includes a drive source and a power transmission unit. The drive source is, for example, a drive source such as a motor and a pump. The power transmission unit is, for example, a power transmission unit such as a ball screw mechanism, a cam mechanism, and an air cylinder. The lifting / lowering drive unit 33 (specifically, the drive source) is controlled by the control unit 9.

[0043] The substrate processing apparatus 1 also includes a processing liquid supply unit 4. The processing liquid supply unit 4 supplies the processing liquid to the processing tank 2, causing the processing liquid to be stored in the processing tank 2. In the example of FIG. 1, the processing liquid supply unit 4 includes a nozzle 41, a liquid supply pipe 42, and a supply valve 43. The nozzle 41 ejects the processing liquid toward the processing tank 2. The downstream end of the liquid supply pipe 42 is connected to the nozzle 41, and the upstream end of the liquid supply pipe 42 is connected to a processing liquid supply source. The processing liquid supply source has a tank that stores the processing liquid. The supply valve 43 is inserted in the liquid supply pipe 42 and switches between ejection and stop of the processing liquid from the nozzle 41. The supply valve 43 is controlled by the control unit 9.

[0044] The substrate processing apparatus 1 also includes a processing liquid discharge unit 6. The processing liquid discharge unit 6 discharges the processing liquid from the processing tank 2. In the example of FIG. 1, the processing liquid discharge unit 6 includes a discharge pipe 61 and a discharge valve 62. The upstream end of the discharge pipe 61 is connected to the bottom of the processing tank 2 (specifically, the main tank 21). The discharge valve 62 is inserted in the discharge pipe 61 and switches between discharging and stopping the discharge of the processing liquid from the processing tank 2. The discharge valve 62 is controlled by the control unit 9.

[0045] 1, the substrate processing apparatus 1 may be provided with a circulation unit 7. The circulation unit 7 circulates the processing liquid by returning the processing liquid from the upflow tank 22 to the main tank 21. In the example of FIG. 1, the circulation unit 7 includes a liquid discharge pipe 71, a circulation pipe 72, a circulation valve 73, a flow rate adjustment valve 74, and a liquid delivery unit 75.

[0046] The liquid discharge pipe 71 is provided inside the main tank 21 and discharges the processing liquid into the main tank 21. In the example of FIG. 1, the liquid discharge pipe 71 is provided below the plurality of substrates W and faces the plurality of substrates W in the vertical direction. In the example of FIG. 2, the liquid discharge pipe 71 extends in a direction intersecting the plurality of substrates W in a plan view. In other words, the longitudinal direction of the liquid discharge pipe 71 is a direction intersecting the plurality of substrates W. In the example of FIG. 2, the liquid discharge pipe 71 extends linearly along the arrangement direction D1. The liquid discharge pipe 71 has a plurality of discharge ports 71a. The liquid discharge pipe 71 discharges the processing liquid from the plurality of discharge ports 71a. The processing liquid discharged from the liquid discharge pipe 71 flows upward inside the main tank 21 and overflows from the top of the main tank 21. As a result, an upward liquid flow is formed in the processing liquid stored in the main tank 21.

[0047] 1 and 2, a plurality of liquid discharge pipes 71 are provided. Here, liquid discharge pipes 71A and 71B are provided as the plurality of liquid discharge pipes 71. Liquid discharge pipes 71A and 71B are aligned in the horizontal direction D2 and are provided on opposite sides of the center of the substrate W in a plan view. In the example of FIGS. 1 and 2, the discharge direction of discharge ports 71a of liquid discharge pipes 71 is inclined from vertically upward toward the center of the substrate W. For example, the cross section of liquid discharge pipe 71 has a circular shape, and discharge ports 71a are formed in an oblique position shifted toward the center of the substrate W from a position directly above the central axis of liquid discharge pipe 71. Therefore, discharge port 71a of liquid discharge pipe 71A is formed in an oblique position shifted toward liquid discharge pipe 71B from the directly above position, and discharge port 71a of liquid discharge pipe 71B is formed in an oblique position shifted toward liquid discharge pipe 71A from the directly above position.

[0048] The circulation pipe 72 connects the upflow tank 22 to the liquid discharge pipe 71. In the example of FIG. 1 , the circulation pipe 72 includes a common pipe 721, a branch pipe 722A, and a branch pipe 722B. The upstream end of the common pipe 721 is connected to the bottom 221 of the upflow tank 22, and the downstream end of the common pipe 721 is connected to the upstream ends of the branch pipes 722A and 722B. The downstream end of the branch pipe 722A is connected to the liquid discharge pipe 71A, and the downstream end of the branch pipe 722B is connected to the liquid discharge pipe 71B. The circulation valve 73 is inserted in the circulation pipe 72 (specifically, the common pipe 721) and switches between circulating and stopping the circulation of the treatment liquid. The flow rate adjustment valve 74 adjusts the flow rate of the treatment liquid flowing through the circulation pipe 72. The liquid delivery unit 75 is, for example, a pump, and delivers the treatment liquid from the upflow tank 22 to the main tank 21. The circulation valve 73 , the flow rate adjusting valve 74 and the liquid delivery unit 75 are controlled by the control unit 9 .

[0049] 1, the circulation pipe 72 may be provided with a temperature adjustment unit 76 and a filter 77. The temperature adjustment unit 76 is, for example, a heater, and heats the processing liquid flowing through the circulation pipe 72. The temperature adjustment unit 76 is controlled by the control unit 9. The filter 77 captures impurities in the processing liquid flowing through the circulation pipe 72.

[0050] The bubbling unit 5 supplies gas into the processing liquid stored in the processing tank 2 to generate bubbles in the processing liquid. As shown in Fig. 1, the bubbling unit 5 includes a bubbler pipe 51, an air supply pipe 52, a supply valve 53, and a flow rate adjustment valve 54.

[0051] The bubbler tube 51 is provided inside the processing tank 2. In the example of FIG. 1, the bubbler tube 51 is provided inside the processing tank 2 below the plurality of substrates W and faces the plurality of substrates W in the vertical direction. In a plan view, the bubbler tube 51 extends in a direction intersecting the plurality of substrates W (see also FIG. 2). In the example of FIG. 2, the bubbler tube 51 extends linearly along the arrangement direction D1. The bubbler tube 51 may have a length sufficient to cross all of the plurality of substrates W in a plan view.

[0052] The bubbler tube 51 has a plurality of outlets 51a. The bubbler tube 51 is immersed in the processing liquid and discharges bubbles into the processing liquid from the plurality of outlets 51a. The plurality of outlets 51a are arranged at intervals along the longitudinal direction of the bubbler tube 51. Each outlet 51a may be located between two adjacent substrates W in a plan view.

[0053] In the example of FIGS. 1 and 2, three or more (four in this example) bubbler tubes 51 are provided. The bubbler tubes 51 are arranged at intervals from one another in the horizontal direction D2. The bubbler tubes 51 may be arranged parallel to one another. Here, the three or more bubbler tubes 51 include bubbler tubes 51A to 51D. Bubbler tubes 51A to 51D are arranged in this order. That is, bubbler tube 51A is located at one end of the multiple bubbler tubes 51 in the horizontal direction D2, bubbler tube 51D is located at the other end of the multiple bubbler tubes 51 in the horizontal direction D2, bubbler tube 51B is located between bubbler tube 51A and bubbler tube 51C, and bubbler tube 51C is located between bubbler tube 51B and bubbler tube 51D.

[0054] Hereinafter, bubbler tube 51A and bubbler tube 51D located at the ends will also be referred to as first bubbler tubes 51. First bubbler tube 51 is provided at a position facing vertically an end portion of substrate W in lateral direction D2. Also, hereinafter, bubbler tube 51B and bubbler tube 51C located between bubbler tube 51A and bubbler tube 51D will also be referred to as second bubbler tubes 51. The second bubbler tube 51 can be said to be a bubbler tube 51 located other than at the ends.

[0055] In the example of FIG. 1, bubbler pipes 51B and 51C are provided between liquid discharge pipes 71A and 71B, and bubbler pipes 51A and 51D are provided outside liquid discharge pipes 71A and 71B.

[0056] The gas supply pipe 52 is a pipe that connects the bubbler pipe 51 to a gas supply source. In the example of FIG. 1, the gas supply pipe 52 includes a common pipe 521 and branch pipes 522A to 522D. The upstream end of the common pipe 521 is connected to a gas supply source. The gas supply source includes a storage unit (e.g., a cylinder) that stores gas. The gas may be an inert gas such as a rare gas or nitrogen gas. The downstream end of the common pipe 521 is connected to the upstream ends of branch pipes 522A to 522D. The downstream end of branch pipe 522A is connected to the bubbler pipe 51A, the downstream end of branch pipe 522B is connected to the bubbler pipe 51B, the downstream end of branch pipe 522C is connected to the bubbler pipe 51C, and the downstream end of branch pipe 522D is connected to the bubbler pipe 51D.

[0057] The supply valve 53 is inserted in the air supply pipe 52 (specifically, the common pipe 521) and switches between discharging and stopping the discharge of bubbles from the bubbler pipe 51. The flow rate adjustment valve 54 adjusts the flow rate of the gas flowing through the bubbler pipe 51. The supply valve 53 and the flow rate adjustment valve 54 are controlled by the control unit 9. The flow rate adjustment valve 54 is, for example, a needle valve driven by a motor.

[0058] When the supply valve 53 opens, a plurality of bubbles are discharged from the outlet 51a of each bubbler tube 51 at a flow rate adjusted by the flow rate adjustment valve 54. The discharge direction of the outlet 51a includes a horizontal component. FIG. 4 is a diagram illustrating the position of the outlet 51a in the bubbler tube 51. In the example of FIG. 4, the cross section of the bubbler tube 51 has a circular ring shape. Hereinafter, the center of the circular ring shape of the cross section of the bubbler tube 51 is referred to as the central axis C. The outlet 51a is formed at a position P2 shifted from a position P1 directly above the central axis C of the bubbler tube 51. The position P2 is, for example, the center position of the outlet 51a. The angle θ (corresponding to a first angle) formed by a line segment having both ends at the directly above position P1 and the central axis C and a line segment having both ends at position P2 and the central axis C is, for example, 45 degrees or more. The angle θ may be 45 degrees or more and 135 degrees or less. Furthermore, the angle θ may be 50 degrees or more, 60 degrees or more, or 70 degrees or more. The angle θ may be 120 degrees or less, 100 degrees or less, or 90 degrees or less. In the example of FIG. 4, the angle θ is 90 degrees. In this case, the discharge direction of the discharge port 51a is ideally parallel to the horizontal direction D2. The discharge direction of the discharge port 51a here may be the normal direction of a virtual line VL1, which will be described next. The virtual line VL1 is a virtual line connecting points p1 on the outside of two line segments corresponding to the formation surface (side surface) of the discharge port 51a that appears in the cross section of the bubbler tube 51. The angle θ can be said to be the angle between the discharge direction and the vertical direction.

[0059] 5 and 6 are schematic diagrams illustrating an example of how bubbles are discharged from the outlet 51a of the bubbler tube 51. For simplicity, in FIGS. 5 and 6, the bubbler tube 51 has one outlet 51a. In the example of FIG. 5, bubbles are discharged from the outlet 51a of the bubbler tube 51 at a relatively high flow rate, while in the example of FIG. 6, bubbles are discharged from the outlet 51a of the bubbler tube 51 at a relatively low flow rate. When the gas flow rate is high, the bubbles are discharged from the outlet 51a with relatively high force, and when the gas flow rate is low, the bubbles are discharged from the outlet 51a with relatively low force. Because the discharge direction of the outlet 51a has a lateral component, when the gas flow rate is high, the bubbles move upward while moving to a position farther away from the bubbler tube 51 in the lateral direction D2 (see FIG. 5). On the other hand, when the gas flow rate is low, the bubbles move upward in the horizontal direction D2 at a position closer to the bubbler tube 51 (see FIG. 6). Therefore, the passage range R1 through which the bubbles pass changes in the horizontal direction D2 depending on the gas flow rate. In FIGS. 5 and 6, the passage range R1 of the bubbles is schematically indicated by a two-dot chain line.

[0060] Fig. 7 is a graph showing the relationship between the gas flow rate and the central position of the bubble passage range R1. The central position here refers to the central position in the horizontal direction D2 of the passage range R1 at a position a predetermined distance above the bubbler tube 51. In Fig. 7, the central position is shown as a value with the central axis C of the bubbler tube 51 as the origin. In Fig. 7, the experimental results when the angle θ is 90 degrees are shown by black circles, and the experimental results when the angle θ is 45 degrees are shown by white circles.

[0061] 7, when the angle θ is the same, the greater the gas flow rate, the farther the center position in the horizontal direction D2 from the bubbler tube 51 at the discharge source. Also, when the gas flow rate is the same, the closer the angle θ is to 90 degrees, the farther the center position in the horizontal direction D2 is from the bubbler tube 51 at the discharge source. This is because the closer the angle θ is to 90 degrees, the larger the horizontal component of the discharge direction.

[0062] <Control unit> As will be described in detail later, while multiple substrates W are immersed in the processing liquid, the control unit 9 controls the flow rate adjustment valve 54 to change the flow rate of bubbles discharged from the bubbler tube 51 over time. As a result, the passage range R1 through which the bubbles pass in the processing liquid changes over time in the lateral direction D2. This allows multiple bubbles to pass more uniformly across the main surfaces of the substrates W. This allows the substrate processing apparatus 1 to process the main surfaces of the substrates W more uniformly. An example of the change in gas flow rate over time will be described in detail later.

[0063] The control unit 9 is an electronic circuit and includes, for example, a data processing unit and a memory unit. The data processing unit and the memory unit are connected to each other, for example, via a bus. The data processing unit may be, for example, an arithmetic processing device such as a CPU (Central Processor Unit). The memory unit may have a non-transitory memory unit (for example, a ROM (Read Only Memory)) and a temporary memory unit (for example, a RAM (Random Access Memory)). The non-transitory memory unit may store, for example, a program that defines the processing to be performed by the control unit 9. The data processing unit executes this program, allowing the control unit 9 to perform the processing defined in the program. Of course, some or all of the processing performed by the control unit 9 may be performed by hardware such as a dedicated logic circuit.

[0064] <Second bubbler tube> In the example shown in FIGS. 1 and 2, the second bubbler tube 51, located between the first bubbler tube 51 (bubbler tube 51A and bubbler tube 51D), has outlets 51a with different discharge directions. Hereinafter, the two types of outlets 51a with different discharge directions will be referred to as outlet 51aa (corresponding to the first outlet) and outlet 51ab (corresponding to the third outlet) (see also FIG. 4). The horizontal component of the discharge direction (corresponding to the first discharge direction) of outlet 51aa is opposite to the horizontal component of the discharge direction (corresponding to the third discharge direction) of outlet 51ab. In other words, outlet 51aa and outlet 51ab are formed on opposite sides of a reference line passing through the direct-up position P1 and the central axis C. Such outlets 51aa and outlet 51ab discharge bubbles in opposite directions in the horizontal direction D2.

[0065] In the example of Fig. 4, outlets 51aa and 51ab are formed at positions symmetrical with respect to the reference line. As a specific example, outlets 51aa and 51ab are positioned on a line perpendicular to the reference line. In other words, outlets 51aa and 51ab are formed on opposite sides of central axis C. In this case, the ejection direction of outlet 51aa is opposite to the ejection direction of outlet 51ab.

[0066] In the above example, the second bubbler pipe 51 is formed with the outlet 51aa and the outlet 51ab, so that the second bubbler pipe 51 can discharge bubbles on both sides, thereby widening the range over which the bubbles can be supplied.

[0067] <First bubbler tube> 1 and 2, the horizontal component of the discharge direction of the discharge port 51a of the first bubbler tube 51 (bubbler tube 51A and bubbler tube 51D) located at the end is a direction toward the center of the substrate W. This allows multiple bubbles to be discharged from the discharge port 51a of the first bubbler tube 51 toward the center of the substrate W. Then, the flow rate adjustment valve 54 changes the gas flow rate over time, so that the passage range R1 of the multiple bubbles can be changed between a position close to the first bubbler tube 51 and a position close to the center of the substrate W.

[0068] 1 and 2, the first bubbler tube 51 located at the end is formed with not only a plurality of outlets 51a but also a plurality of outlets 51b (corresponding to second outlets). The plurality of outlets 51b are arranged at intervals in the longitudinal direction of the first bubbler tube 51 (see FIG. 2). Each outlet 51b may be located between two adjacent ones of the plurality of substrates W in a plan view.

[0069] The discharge direction of outlet 51b (corresponding to the second discharge direction) is different from the discharge direction of outlet 51a (corresponding to the first discharge direction). In the example of FIG. 1, the discharge direction of outlet 51b is closer to the vertical direction than the discharge direction of outlet 51a. In other words, the angle θ of outlet 51b (corresponding to the second angle) may be smaller than the angle θ of outlet 51a (corresponding to the first angle). That is, the horizontal component of the discharge direction of outlet 51b may be smaller than the horizontal component of the discharge direction of outlet 51a, and the vertical component of the discharge direction of outlet 51b may be larger than the vertical component of the discharge direction of outlet 51a. The angle θ of outlet 51b may be less than 45 degrees, 10 degrees or less, 5 degrees or less, or 0 degrees. When the angle θ of outlet 51b is 0 degrees, the center position of the passage range of the bubbles discharged from outlet 51b is approximately directly above outlet 51a.

[0070] Since the first bubbler pipe 51 is provided at a position vertically facing the edge portion of the substrate W, the plurality of bubbles from the discharge port 51b pass through the region facing the edge portion of the substrate W. Therefore, the edge portion of the main surface of the substrate W can be effectively processed.

[0071] <Example of flow rate change over time> FIG. 8 is a graph showing an example of the change in gas flow rate over time. Under the control of the control unit 9, the flow rate adjustment valve 54 changes the gas flow rate between a first flow rate value and a second flow rate value while multiple substrates W are immersed in the processing liquid. The second flow rate value is greater than the first flow rate value. For example, the flow rate adjustment valve 54 may maintain the gas flow rate at the first flow rate value for a first period, increase the gas flow rate from the first flow rate value to the second flow rate value after the first period has elapsed, maintain the gas flow rate at the second flow rate value for a second period, and decrease the gas flow rate from the second flow rate value to the first flow rate after the second period has elapsed. The first and second periods may be preset to, for example, several minutes (10 minutes or less, as a specific example). The flow rate adjustment valve 54 performs a set of an increasing operation to increase the gas flow rate and a decreasing operation to decrease the gas flow rate at least once. In the example of FIG. 8, the flow rate adjustment valve 54 repeatedly performs the set of the increasing operation and the decreasing operation. That is, the flow rate adjusting valve 54 alternately increases and decreases the flow rate of the gas between a first flow rate value and a second flow rate value.

[0072] FIG. 9 is a diagram schematically illustrating an example of the state of the substrate processing apparatus 1 when the gas flow rate is a first flow rate value, and FIG. 10 is a diagram schematically illustrating an example of the state of the substrate processing apparatus 1 when the gas flow rate is a second flow rate value. In FIGS. 9 and 10, the movement of bubbles discharged from the bubbler tube 51 is schematically indicated by dashed arrows. During a first period when the gas flow rate is the first flow rate value, the bubbles rise at a position closer to the bubbler tube 51 from which the bubbles are discharged, as shown in FIG. 9. On the other hand, during a second period when the gas flow rate is the second flow rate value, the bubbles rise at a position farther from the bubbler tube 51 from which the bubbles are discharged, as shown in FIG. 10. Here, the first period and the second period are alternately repeated, and therefore the states of FIGS. 9 and 10 occur repeatedly.

[0073] As a result, the plurality of bubbles rise more uniformly toward the main surface of the substrate W, and more uniformly agitate the processing liquid facing the main surface of the substrate W. Therefore, the processing liquid acts more uniformly on the main surface of the substrate W. In other words, the uniformity of processing on the main surface of the substrate W can be improved.

[0074] Incidentally, bubbles from the bubbler tube 51 first move mainly along the discharge direction, and then move mainly vertically upward. Therefore, particularly when the gas flow rate is high (FIG. 10), bubbles from the discharge port 51a of the bubbler tube 51 first move a relatively long distance along the lateral direction D2, and then move vertically upward. Therefore, the bubbling unit 5 can also appropriately supply bubbles to a lower region R2, which will be described next. The lower region R2 is a region facing the main surface of the substrate W that is away from the bubbler tube 51 in the lateral direction D2 and is vertically downward.

[0075] In the above-described specific example, the first bubbler pipe 51 located at the end has an outlet 51b formed therein. The first bubbler pipe 51 is vertically opposed to the end portion of the substrate W in the horizontal direction D2. Therefore, bubbles from the outlet 51b of the first bubbler pipe 51 easily pass near the end portion of the substrate W in the horizontal direction D2. This allows the substrate processing apparatus 1 to process the end portion of the substrate W appropriately.

[0076] In the above-described specific example, the second bubbler tube 51 sandwiched between the first bubbler tubes 51 has outlets 51a (outlet 51aa and outlet 51ab) formed on both sides in the horizontal direction D2. This allows the second bubbler tube 51 to supply bubbles over a wider range. Furthermore, because the second bubbler tube 51 discharges bubbles on both sides, bubbles can be supplied more uniformly and with less gaps to the region between the liquid discharge tubes 71A and 71B.

[0077] In the above-described specific example, the main surface of the substrate W has a pattern in which insulating films F1 and sacrificial films F2 for 3D NAND are alternately stacked. Therefore, the processing liquid not only flows in and out of the slits SL along the thickness direction of the substrate W, but also needs to flow in and out of the spaces between the insulating films F1 along a direction parallel to the main surface of the substrate W. The substrate processing apparatus 1 supplies bubbles into the processing liquid to locally agitate the processing liquid, allowing the processing liquid to flow in and out of such complex spaces. Moreover, the bubbles rise more uniformly relative to the main surface of the substrate W, allowing the processing liquid to be more uniformly agitated relative to the main surface of the substrate W. Therefore, the substrate processing apparatus 1 is particularly useful for substrates W having such patterns.

[0078] <Position of the bubbler tube> 9 and 10, the flow of the processing liquid discharged from the liquid discharge pipe 71 is schematically indicated by dashed arrows. Here, the liquid discharge pipe 71 discharges the processing liquid toward the center of the substrate W. Therefore, bubbles discharged from the bubbler pipe 51B toward the liquid discharge pipe 71A may be pushed back toward the center of the substrate W by the liquid flow from the discharge port 71a of the liquid discharge pipe 71A. Therefore, the distance between the bubbler pipe 51B and the liquid discharge pipe 71A in the horizontal direction D2 may be narrower than the distance between the bubbler pipe 51A and the liquid discharge pipe 71A in the horizontal direction D2. In other words, of the bubbler pipe 51A and the bubbler pipe 51B adjacent to the liquid discharge pipe 71A in the horizontal direction D2, the bubbler pipe 51B closer to the center of the substrate W may be located closer to the liquid discharge pipe 71A.

[0079] Since the bubbler pipe 51B is close to the liquid discharge pipe 71A, the bubbles from the bubbler pipe 51B collide with the liquid flow with relatively high momentum, and therefore the bubbles tend to cross the liquid flow and pass through the area immediately above the liquid discharge pipe 71A.

[0080] On the other hand, because the bubbler tube 51A is located away from the liquid discharge tube 71A, the bubbles from the bubbler tube 51A are less likely to be attracted to the liquid flow caused by the liquid discharge tube 71A. Therefore, the bubbler tube 51A can more appropriately supply the bubbles to the region to the left of the liquid discharge tube 71A.

[0081] Similarly, the distance between the bubbler tube 51C and the liquid discharge tube 71B in the horizontal direction D2 may be narrower than the distance between the bubbler tube 51D and the liquid discharge tube 71B in the horizontal direction D2.

[0082] <Vertical discharge bubbler tube> FIG. 11 is a diagram schematically illustrating another example of the configuration of the substrate processing apparatus 1. In the example of FIG. 11, the bubbling unit 5 includes a vertical-discharge bubbler pipe 50. The vertical-discharge bubbler pipe 50 discharges bubbles upward. The vertical-discharge bubbler pipe 50 has a configuration similar to that of the first bubbler pipe 51, except for the presence or absence of a discharge port 51a. That is, the vertical-discharge bubbler pipe 50 has a discharge port 51b but does not have a discharge port 51a. In the example of FIG. 11, the vertical-discharge bubbler pipe 50 is provided in place of the bubbler pipes 51A and 51D. That is, the vertical-discharge bubbler pipe 50 is provided in a position aligned with the bubbler pipes 51B and 51C in the horizontal direction D2 and faces the edge portion of the substrate W in the horizontal direction D2 in the vertical direction.

[0083] According to this configuration, bubbles are discharged from the discharge port 51b of the vertical discharge bubbler pipe 50 toward the edge portion of the substrate W. Therefore, the edge portion of the substrate W can be effectively processed.

[0084] <Switch> The control unit 9 may alternately switch between discharging bubbles from the first bubbler tube 51 and discharging bubbles from the second bubbler tube 51. Fig. 12 is a diagram schematically showing another example of the configuration of the bubbling unit 5. In the example of Fig. 12, a supply valve 531 for the first bubbler tube 51 and a supply valve 532 for the second bubbler tube 51 are provided as the supply valve 53.

[0085] 12, air supply pipe 52 includes common pipe 521, branch pipes 522A to 522D, group pipe 5231, and group pipe 5232. The upstream ends of group pipes 5231 and 5232 are connected to the downstream end of common pipe 521. The downstream end of group pipe 5231 is connected to the upstream ends of branch pipes 522A and 522D, and the downstream end of group pipe 5232 is connected to the upstream ends of branch pipes 522B and 522C. Supply valve 531 is inserted in group pipe 5231, and supply valve 532 is inserted in group pipe 5232.

[0086] When the supply valve 531 opens, bubbles are discharged from the first bubbler tube 51 (bubbler tube 51A and bubbler tube 51D). When the supply valve 531 closes, the discharge of bubbles from the first bubbler tube 51 stops. When the supply valve 532 opens, bubbles are discharged from the second bubbler tube 51 (bubbler tube 51B and bubbler tube 51C). When the supply valve 532 closes, the discharge of bubbles from the second bubbler tube 51 stops.

[0087] 12, a flow rate adjustment valve 541 for the first bubbler tube 51 and a flow rate adjustment valve 542 for the second bubbler tube 51 are provided as the flow rate adjustment valves 54. The flow rate adjustment valve 541 is inserted into the group tube 5231. The flow rate adjustment valve 541 adjusts the flow rate of the gas flowing through the group tube 5231. In other words, the flow rate adjustment valve 541 adjusts the flow rate of the bubbles discharged from the first bubbler tube 51. The flow rate adjustment valve 542 is inserted into the group tube 5232. The flow rate adjustment valve 542 adjusts the flow rate of the gas flowing through the group tube 5232. In other words, the flow rate adjustment valve 542 adjusts the flow rate of the bubbles discharged from the second bubbler tube 51.

[0088] The control unit 9 may alternately open the supply valve 531 and the supply valve 532. During a first bubbling period when the supply valve 531 is open, bubbles are discharged from the first bubbler tube 51, but no bubbles are discharged from the second bubbler tube 51. FIGS. 13 and 14 are diagrams schematically illustrating an example of the state of the substrate processing apparatus 1 during the first bubbling period. During the first bubbling period, the control unit 9 controls the flow rate adjustment valve 541 to change the flow rate of bubbles discharged from the first bubbler tube 51 over time. For example, the flow rate adjustment valve 541 alternately increases and decreases the flow rate between a first flow rate value and a second flow rate value. As a result, the states illustrated in FIGS. 13 and 14 alternate during the first bubbling period. FIG. 13 illustrates the state of the substrate processing apparatus 1 when the gas flow rate is at the first flow rate value, and FIG. 14 illustrates the state of the substrate processing apparatus 1 when the gas flow rate is at the second flow rate value. The first bubbling period is set in advance to be longer than the sum of the first period and the second period, for example.

[0089] During the first bubbling period, bubbles are not discharged from the second bubbler pipe 51, but bubbles are discharged from the first bubbler pipe 51. As a result, the bubbles rise near the edge portion of the substrate W in the lateral direction D2. This can promote processing of the area near the edge portion of the substrate W. Note that during the first bubbling period, the liquid flows of the processing liquid from the liquid discharge pipes 71A and 71B are directed toward the center of the substrate W, with little effect from the bubbles.

[0090] On the other hand, during a second bubbling period in which the supply valve 531 is closed and the supply valve 532 is open, bubbles are not discharged from the first bubbler tube 51, but are discharged from the second bubbler tube 51. FIGS. 15 and 16 are diagrams schematically illustrating an example of the state of the substrate processing apparatus 1 during the second bubbling period. During the second bubbling period, the control unit 9 controls the flow rate control valve 542 to change the flow rate of bubbles discharged from the second bubbler tube 51 over time. For example, the flow rate control valve 542 alternately increases and decreases the flow rate between a first flow rate value and a second flow rate value. This results in the states of FIGS. 15 and 16 alternately occurring. FIG. 15 illustrates the state of the substrate processing apparatus 1 when the gas flow rate is the first flow rate value, and FIG. 16 illustrates the state of the substrate processing apparatus 1 when the gas flow rate is the second flow rate value. The second bubbling period is set in advance to be longer than the sum of the first and second periods, for example.

[0091] During the second bubbling period, bubbles are not discharged from the first bubbler pipe 51, but are discharged from the second bubbler pipe 51. As a result, the bubbles rise near the central portion of the substrate W in the lateral direction D2. This can promote processing of the central portion of the substrate W. Note that during the second bubbling period, the flow of the processing liquid from the liquid discharge pipes 71A and 71B may be slightly affected by the bubbles. As a result, the liquid flow moves slightly upward compared to the first bubbling period.

[0092] As described above, the liquid flow can be made slightly different between the first bubbling period and the second bubbling period, so that the uniformity of the processing on the substrate W can be further improved.

[0093] <Constant flow> In the above example, the first bubbler tube 51 discharges bubbles generally only to one side in the horizontal direction D2, while the second bubbler tube 51 discharges bubbles to both sides in the horizontal direction D2. Therefore, the range through which bubbles from the second bubbler tube 51 pass is wider than the range through which bubbles from the first bubbler tube 51 pass. Therefore, when the flow rate of bubbles is changed, the coverage range of bubbles from the second bubbler tube 51 (the total range through which bubbles pass) is wider than the coverage range of bubbles from the first bubbler tube 51. Therefore, the flow rate of bubbles from the first bubbler tube 51 may be set to a constant value while changing the flow rate of bubbles from the second bubbler tube 51 over time. For example, the flow rate adjustment valve 541 may be a non-driven needle valve that maintains a constant gas flow rate. In this case, the bubbler tubes 51A and 51D can be said to be constant flow rate bubbler tubes that discharge bubbles at a constant flow rate.

[0094] This eliminates the need for dynamic control of the flow rate adjustment valve 541, thereby reducing the load on the control unit 9. Moreover, compared to when the flow rate of the bubbles from the second bubbler tube 51 is set to a constant value, the range through which the bubbles pass can be adjusted more widely.

[0095] Although the substrate processing apparatus 1 has been described in detail above, the above description is merely an example in all respects, and this disclosure is not limited thereto. Furthermore, the various modifications described above can be combined and applied as long as they are not mutually inconsistent. It is understood that many modifications not exemplified can be envisioned without departing from the scope of this disclosure. [Explanation of symbols]

[0096] 1. Substrate processing equipment 2 Treatment tank 3 Board holding part 5 Bubbling section 50 Vertical discharge bubbler pipe 51 Side discharge bubbler pipe, first bubbler pipe, second bubbler pipe 51A, 51D Side discharge bubbler tube, first bubbler tube, constant flow rate bubbler tube 51B, 51C Side discharge bubbler pipe, second bubbler pipe 51a 1st discharge port, 3rd discharge port 51aa 1st outlet 51ab 3rd outlet 51b 2nd discharge port 54,541,542 Flow control valve 9 Control Unit F1 insulating film F2 sacrificial film W substrate

Claims

1. a processing tank for storing a processing liquid; a substrate holder that holds the substrate in an upright position within the processing tank; a bubbling unit including: one or more lateral-discharge bubbler tubes provided inside the processing tank, each having a plurality of first discharge ports for discharging bubbles in a first discharge direction having a lateral component that is parallel and horizontal to a main surface of the substrate held by the substrate holding unit; and a flow rate adjustment valve for adjusting the flow rate of gas flowing through the lateral-discharge bubbler tubes; a control unit that controls the flow rate adjustment valve while the substrate is immersed in the processing liquid to change the flow rate of the bubbles discharged from the lateral discharge bubbler tube over time and change the range of passage of the bubbles through the processing liquid in the lateral direction; A substrate processing apparatus comprising:

2. The substrate processing apparatus according to claim 1 , a first angle formed between the first discharge direction and a vertical direction is 45° or more.

3. 3. The substrate processing apparatus according to claim 1, the bubbling section includes three or more of the lateral discharge bubbler pipes arranged in the lateral direction, a first bubbler tube located at an end of the lateral discharge bubbler tubes further having a plurality of second discharge ports for discharging bubbles in a second discharge direction; the first bubbler tube is provided at a position vertically opposite to an end portion of the substrate in the lateral direction, a second angle formed between the second discharge direction and the vertical direction is smaller than a first angle formed between the first discharge direction and the vertical direction.

4. 3. The substrate processing apparatus according to claim 1, the bubbling section includes three or more of the lateral discharge bubbler pipes arranged in the lateral direction, a second bubbler tube located other than the end of the lateral discharge bubbler tube has a plurality of third discharge ports; The third discharge outlet is located on the opposite side of the first discharge outlet in the horizontal direction, and a third discharge direction of the third discharge outlet has a horizontal component that is opposite to the horizontal component of the first discharge direction.

5. 3. The substrate processing apparatus according to claim 1, the bubbling unit is provided at a position vertically opposite to an end portion of the substrate in the lateral direction, and further includes a vertical discharge bubbler pipe that discharges upward.

6. 3. The substrate processing apparatus according to claim 1, two liquid discharge pipes for discharging the treatment liquid into the treatment tank to form an upward liquid flow inside the treatment tank; The treatment tank comprises: A main tank; an upflow tank that receives the processing liquid that overflows from the main tank; Including, the lateral discharge bubbler pipe includes a first bubbler pipe located between the liquid discharge pipes and a second bubbler pipe located outside the liquid discharge pipes; The bubbling unit alternately discharges bubbles from the first bubbler tube and the second bubbler tube.

7. 3. The substrate processing apparatus according to claim 1, The bubbling unit is provided at a position vertically opposite to an end portion of the substrate in the lateral direction, and further includes a constant flow rate bubbler tube that discharges bubbles at a constant flow rate.

8. 3. The substrate processing apparatus according to claim 1, The substrate processing apparatus has a pattern formed on the main surface of the substrate, in which insulating films and sacrificial films for a three-dimensional NAND are alternately stacked.

9. 9. The substrate processing apparatus according to claim 8, The substrate processing apparatus, wherein the processing liquid etches the sacrificial film.

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