Substrate processing apparatus

Abstract

To provide a substrate processing apparatus capable of improving uniformity of processing across multiple substrates.SOLUTION: A substrate processing apparatus comprises: a processing tank 2 that stores a processing liquid for processing multiple substrates W; a lifter that holds the substrates W and immerses them in the processing liquid; and a heater 8 that heats the processing tank 2. The processing tank 2 includes a first end wall 51, a second end wall 52, a first side wall 61, a second side wall 62, and a bottom wall 53. The lifter includes a holding portion that holds the substrates W arranged in an arrangement direction and a back portion connected to the holding portion, the substrates W immersed in the processing liquid while the back portion being interposed between the substrates W and the first end wall 51. The heater 8 includes an end-wall heater 84 disposed at the first end wall 51, and multiple zone heaters 85 disposed at the pair of side walls 61, 62 and the bottom wall 53 in regions divided with respect to the substrate arrangement direction R1, and does not include a heater disposed at the second end wall 52. The outputs of the multiple zone heaters 85 are individually controlled.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a substrate processing apparatus for processing substrates with a processing liquid, examples of which include semiconductor wafers, substrates for FPDs (Flat Panel Displays) such as liquid crystal displays and organic electroluminescence (EL) displays, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells. [Background technology]

[0002] Substrate processing apparatuses that process multiple substrates by immersing them in a processing solution stored in a processing tank have been used for some time, and one example is disclosed in Patent Document 1. The substrate processing apparatus of Patent Document 1 includes a processing tank having an overflow tank formed around the upper periphery of the open-top storage tank, a processing solution circulator, and a substrate transport means. A processing solution is stored in the storage tank, and multiple substrates are immersed in the processing solution. A processing solution inlet / outlet is formed at the bottom of the storage tank, and a processing solution outlet is formed at the bottom of the overflow tank. The processing solution circulator sucks the processing solution from the processing solution outlet of the overflow tank and supplies it to the processing solution inlet / outlet of the storage tank, thereby circulating the processing solution. The substrate transport means is configured with four substrate holders horizontally attached to the lower end of a transport arm that can be raised and lowered, and holds multiple substrates vertically and parallel to each other with a predetermined spacing between them. The transfer arm can lower the substrate holder to immerse multiple substrates in the processing liquid stored in the storage tank, and the transfer arm can raise the substrate holder to remove the multiple substrates from the processing liquid. A rubber heater is attached to the wall of the storage tank. The rubber heater heats the wall of the storage tank, thereby heating the processing liquid inside the storage tank to a predetermined temperature. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-103297 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the prior art of Patent Document 1, the processing liquid stored in the storage tank may not necessarily have a uniform temperature distribution, which may make it impossible to process a plurality of substrates uniformly.

[0005] Therefore, one embodiment of the present invention provides a substrate processing apparatus that can improve the uniformity of processing for a plurality of substrates. [Means for solving the problem]

[0006] One embodiment of the present invention provides a substrate processing apparatus having the following exemplary features.

[0007] 1. A processing tank having a pair of end walls facing each other in an arrangement direction, which is a predetermined horizontal direction, a pair of side walls facing each other in an intersecting direction, which is a horizontal direction intersecting (typically perpendicular to) the arrangement direction, and connected to the pair of end walls, and a bottom wall connected to the pair of end walls and the pair of side walls, and which stores a processing liquid for processing substrates in an internal space; a lifter having a holding section that holds a plurality of substrates in an upright position and arranged in the arrangement direction, and a back section connected to the holding section, and that immerses the plurality of substrates in the processing solution in the processing tank with the back section interposed between the plurality of substrates and a first end wall that is one of the pair of end walls; a heater including an end wall heater disposed on the first end wall, a plurality of zone heaters disposed on at least one of the pair of side walls and the bottom wall in each of a plurality of regions divided in the arrangement direction, and no heater disposed on the second end wall, which is the other of the pair of end walls; a heater control unit that individually controls outputs of the plurality of zone heaters.

[0008] According to this configuration, the processing tank has a pair of end walls, a pair of side walls, and a bottom wall, and a processing liquid is stored in an internal space defined by these walls. Then, by immersing multiple substrates held by the lifter in the processing liquid stored in the processing tank, the multiple substrates can be processed simultaneously with the processing liquid. When the multiple substrates are immersed in the processing liquid, the back of the lifter is interposed between the multiple substrates and the first end wall. More specifically, the back of the lifter is interposed between the first end wall and a substrate of the multiple substrates closest to the first end wall.

[0009] The processing tank is provided with a heater for heating the walls of the processing tank to heat the processing liquid stored therein. Specifically, an end wall heater is provided on a first end wall, which is one of the end walls facing each other in the arrangement direction, and this end wall heater heats the first end wall. Furthermore, multiple zone heaters are arranged in multiple regions divided in the arrangement direction, and each zone heater heats at least one of the walls in which it is located, i.e., the pair of side walls and the bottom wall. While the end wall heater is arranged on the first end wall, no heater is arranged on the second end wall. Therefore, the second end wall is not directly heated by the heater. As a result, the processing liquid stored in the processing tank may have a temperature distribution with a gradient in the arrangement direction.

[0010] Therefore, the zone heater heats at least one of a pair of side walls and a bottom wall in each of the multiple regions divided in the arrangement direction, and these are individually controlled by a heater control unit. This allows for individual control of heating for the multiple regions divided in the arrangement direction, thereby appropriately heating the processing liquid in the processing tank in the region close to the first end wall and the region close to the second end wall. Specifically, a uniform temperature distribution with a small gradient in the arrangement direction can be achieved. This improves the uniformity of processing for multiple substrates.

[0011] The upright position is typically a vertical position in which the main surfaces of the substrates are aligned vertically. The holding portion of the lifter typically holds the substrates in parallel so that the main surfaces of adjacent substrates face each other. Typically, the normal direction of the main surfaces of the substrates is aligned with the arrangement direction.

[0012] The heater control unit may also individually control the end wall heaters. The end wall heaters are typically disposed on the outer surface of the first end wall. Similarly, the zone heaters are typically disposed on the outer surface of at least one of the pair of side walls and the bottom wall. No heater is disposed on the outer surface of the second end wall.

[0013] The number of regions in the arrangement direction is at least two, and preferably three or more. By disposing zone heaters in three or more divided regions and individually controlling them, the temperature distribution of the processing liquid in the arrangement direction can be made more uniform. That is, the walls of the processing tank can be appropriately and individually heated in the region near the first end wall, which is heated by the end wall heater and has a lifter interposed between it and the substrate, the region near the second end wall, which is not heated by the heater, and the intermediate region therebetween.

[0014] 2. The plurality of zone heaters includes a first zone heater disposed in a region of the plurality of regions closest to the first end wall, and a second zone heater disposed in a region of the plurality of regions closest to the second end wall, Item 1, the substrate processing apparatus, wherein the heater control unit controls the outputs of the plurality of zone heaters so that the second zone heater generates a larger amount of heat (more specifically, a larger amount of heat per unit length in the arrangement direction) than the first zone heater.

[0015] With this configuration, a larger amount of heat can be supplied to the processing liquid in the processing tank in the region near the second end wall where no end wall heater is disposed than in the region near the first end wall where the end wall heater is disposed, thereby making the temperature distribution of the processing liquid in the arrangement direction more uniform.

[0016] 3. A substrate processing apparatus according to item 1 or 2, further comprising an outer tank having a storage space for receiving processing liquid overflowing from the processing tank, the storage space having an end space in an area facing the outer surface of the second end wall that is deeper than the depth of the internal space of the processing tank.

[0017] According to this configuration, by overflowing the processing liquid from the processing tank to the outer tank, the processing liquid can be supplied to the processing tank, and the processing liquid in the processing tank can be circulated and replaced while processing multiple substrates. The storage space of the outer tank has an end space in the area facing the outer surface of the second end wall that is substantially equal to or deeper than the depth of the internal space of the processing tank. This end space may, for example, overlap the entire second end wall when viewed in the arrangement direction. Such a deep end space has the advantage of allowing a larger circulation flow rate, for example, when pumping processing liquid from the outer tank and circulating it to the processing tank via a circulation path.

[0018] The circulation path is typically equipped with a pump. By locating the inlet end of the circulation path deep within the storage space of the outer tank, i.e., near the bottom of the end space, it is possible to avoid the inlet end of the circulation path being exposed to the air and resulting in a liquid shortage, even when a high-performance pump is used to increase the circulation flow rate.

[0019] 4. The substrate processing apparatus according to any one of items 1 to 3, wherein each zone heater is continuous across the outer surfaces of the pair of side walls and the outer surface of the bottom wall.

[0020] With this configuration, a single zone heater can heat both the pair of side walls and the bottom wall, making it possible to achieve a simple and low-cost configuration that not only uniforms the temperature distribution of the processing liquid in the arrangement direction, but also uniforms the temperature distribution of the processing liquid within the main surface of each substrate.

[0021] Alternatively, the processing liquid distribution in the arrangement direction can be made uniform by disposing individual zone heaters on each of the pair of side walls and the bottom wall and controlling them collectively or individually using a heater controller, but this would incur additional costs for wiring and mounting the multiple zone heaters.

[0022] 5. The treatment tank further includes a lid for opening and closing the opening of the treatment tank. 5. The substrate processing apparatus according to any one of items 1 to 4, wherein the heater further includes a lid heater disposed on the lid.

[0023] The opening of the processing tank is typically defined by the pair of end walls and the upper edges of the pair of side walls, and the plurality of substrates are loaded and unloaded into and from the internal space of the processing tank by the lifter through this opening. According to the above configuration, the lid of the processing tank is heated by a lid heater disposed on the lid, so that the processing liquid can also be heated from above. This makes it possible to suppress cooling of the processing liquid and further uniformize the temperature distribution of the processing liquid.

[0024] 6. A substrate processing apparatus described in any one of items 1 to 5, wherein at least one of the plurality of zone heaters has a plurality of heater sections divided in the vertical direction, and the heater control unit controls the plurality of heater sections individually.

[0025] This configuration allows the heat generation of the multiple heater sections divided vertically into the zone heater to be individually controlled, thereby achieving uniform temperature distribution of the processing liquid in the vertical direction and achieving uniform processing across the main surface of each substrate. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a conceptual diagram for explaining an example of the configuration of a substrate processing apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view illustrating an example of the configuration of the lifter. [Figure 3] FIG. 3 is a perspective view illustrating an example of the configuration of the treatment tank. [Figure 4] FIG. 4 is a block diagram for explaining the control system for the end wall heaters and the zone heaters. [Figure 5] FIG. 5 is a diagram for explaining a second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram for explaining a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0028] 1 is a conceptual diagram illustrating an example of the configuration of a substrate processing apparatus according to one embodiment of the present invention. The substrate processing apparatus 1 is a batch-type apparatus that can process a plurality of substrates W (for example, a lot of 25 or 50 substrates) all at once with a processing liquid. In this embodiment, the substrates W are substantially circular substrates. A typical example of a substantially circular substrate W is a semiconductor wafer.

[0029] The substrate processing apparatus 1 includes a processing tank 2 having a processing liquid stored in its internal space for immersing multiple substrates W therein, a lifter 3 that supports the multiple substrates W arranged in a predetermined arrangement direction R1 within the processing tank 2, multiple processing liquid nozzles 4 that supply (more specifically, eject) the processing liquid into the processing tank 2, and a processing liquid supply mechanism 5 that supplies the processing liquid to the multiple processing liquid nozzles 4. The substrate processing apparatus 1 also includes an outer tank 7 (overflow tank) that receives the processing liquid that overflows from the processing tank 2. The substrate processing apparatus 1 also includes a lifter drive mechanism 6 that moves the lifter 3 up and down to immerse the multiple substrates W supported by the lifter 3 in the processing liquid stored in the processing tank 2 or lift the multiple substrates W out of the processing liquid. The substrate processing apparatus 1 also includes a controller 10 for controlling the processing liquid supply mechanism 5, the lifter drive mechanism 6, and the like. The controller 10 includes a processor (CPU) and a storage device, and is configured to perform various control processes described below by the processor executing programs stored in the storage device.

[0030] The processing liquid supply mechanism 5 includes a new liquid supply pipe 12 that supplies unused processing liquid from a processing liquid supply source 11 to the processing tank 2, and a circulation pipe 13 that forms a circulation path that passes through the processing tank 2. An on-off valve 18 is installed in the new liquid supply pipe 12, and the on-off valve 18 is controlled to open and close by a controller 10. One end of the circulation pipe 13 is connected to the bottom of the outer tank 7, and the circulation pipe 13 branches into a plurality of branch pipes 14 that correspond to the plurality of processing liquid nozzles 4, respectively, and the branch pipes 14 are connected to the plurality of processing liquid nozzles 4, respectively.

[0031] A pump 15, an in-line heater 16, and a filter 17 are installed in the circulation pipe 13 between the outer bath 7 and the branching position to the branch pipe section 14, and in this embodiment, they are arranged in this order from the outer bath 7 toward the processing liquid nozzle 4. The pump 15 and the in-line heater 16 are controlled by a controller 10. The pump 15 sends out the processing liquid from the outer bath 7 toward the processing liquid nozzle 4. The in-line heater 16 is an example of a temperature regulator that adjusts the processing liquid passing through the circulation pipe 13 to an appropriate temperature. The filter 17 removes foreign matter from the processing liquid passing through the circulation pipe 13.

[0032] A flow rate adjustment unit 20 is provided in each of the branch pipes 14 connected to the processing liquid nozzles 4, respectively. Each flow rate adjustment unit 20 includes at least an on-off valve and, as necessary, further includes a flow meter, a flow rate adjustment valve, etc. The controller 10 controls the on-off control of the on-off valve of the flow rate adjustment unit 20, thereby controlling whether or not the processing liquid is discharged from the processing liquid nozzle 4. The controller 10 may also control the opening degree of the flow rate adjustment valve provided in the flow rate adjustment unit 20 in accordance with the flow rate measured by the flow meter provided in the flow rate adjustment unit 20, thereby controlling the flow rate of the processing liquid supplied to the processing liquid nozzle 4.

[0033] The processing liquid stored in the processing tank 2 is a chemical liquid or a rinse liquid, typically an etching liquid or other chemical liquid. Examples of chemical liquids include dilute hydrofluoric acid (DHF), hydrofluoric acid (HF), hydrofluoric nitric acid (a mixture of hydrofluoric acid and nitric acid (HNO3)), buffered hydrofluoric acid (BHF), ammonium fluoride, HFEG (a mixture of hydrofluoric acid and ethylene glycol), phosphoric acid (H3PO4), sulfuric acid, acetic acid, nitric acid, hydrochloric acid, ammonia water, hydrogen peroxide water, organic acids (e.g., citric acid, oxalic acid), organic alkalis (e.g., tetramethylammonium hydroxide (TMAH)), sulfuric acid-hydrogen peroxide water mixture (SPM), ammonia-hydrogen peroxide water mixture (SC1), hydrochloric acid-hydrogen peroxide water mixture (SC2), isopropyl alcohol (IPA), surfactants, corrosion inhibitors, and hydrophobizing agents. The substrate processing using the chemical liquid may be an etching process or a cleaning process. As an example, the substrate processing apparatus 1 may perform a process of etching a nitride film (silicon nitride film) formed on the main surface of the substrate W with phosphoric acid.

[0034] 2 is a perspective view illustrating an example of the configuration of the lifter 3. The lifter 3 is raised and lowered by a lifter drive mechanism 6 between the processing position shown in FIGS. 1 and 2 and a standby position above the processing tank 2. At the processing position, the plurality of substrates W supported by the lifter 3 are located in the internal space of the processing tank 2 and are therefore immersed in the processing liquid stored in the processing tank 2. At the standby position, the plurality of substrates W supported by the lifter 3 are located outside the processing tank 2 and are therefore pulled up above the processing liquid stored in the processing tank 2.

[0035] In this embodiment, the lifter 3 has a back plate 31 (back portion), a central holding portion 32, and a pair of side holding portions 33. The back plate 31 is a plate-like member extending in the depth direction of the processing tank 2, and in this embodiment, extends vertically along the inner surface of one wall (end wall 51) that constitutes the rectangular parallelepiped processing tank 2. The central holding portion 32 and the pair of side holding portions 33 are an example of a support portion that supports multiple substrates W.

[0036] The central holding unit 32 and the pair of side holding units 33 are connected to the back plate 31 and extend horizontally from the lower part of the back plate 31, extending parallel to each other. The central holding unit 32 and the pair of side holding units 33 are configured to support multiple substrates W aligned in a predetermined arrangement direction R1 so that the main surfaces of adjacent substrates W face each other with a gap between them. In this embodiment, the arrangement direction R1 is the horizontal direction in which the central holding unit 32 and the pair of side holding units 33 extend. In this embodiment, the central holding unit 32 and the pair of side holding units 33 are configured to support multiple substrates W at equal intervals along the arrangement direction R1. When viewed in the arrangement direction R1, the pair of side holding units 33 are arranged on both sides of the central holding unit 32. The central holding unit 32 supports the central lower edge of the substrate W, and the pair of side holding units 33 support the lower edges on the left and right sides of the substrate W. As a result, each substrate W is supported in an upright position (more specifically, an upright position with its main surface aligned vertically). The multiple substrates W are supported by the lifter 3 in an upright position with their main surfaces parallel to one another. In this embodiment, each main surface of the substrates W is substantially perpendicular to the arrangement direction R1. Therefore, the multiple substrates W are supported in a parallel upright position, and the normal direction of the main surface of each substrate W is aligned with the arrangement direction R1.

[0037] As also shown in FIG. 2 , six processing liquid nozzles 4 are provided in this embodiment. Specifically, the multiple processing liquid nozzles 4 include two processing liquid nozzles extending in the arrangement direction R1 along the bottom surface of the processing tank 2, i.e., a first bottom wall nozzle B1 and a second bottom wall nozzle B2. The first bottom wall nozzle B1 and the second bottom wall nozzle B2 are arranged parallel to each other and spaced apart in a horizontal direction perpendicular to the arrangement direction R1. The multiple processing liquid nozzles 4 also include two processing liquid nozzles 4 extending in the arrangement direction R1 along one side wall 61 of the processing tank 2, i.e., a first upper side wall nozzle T1 and a first lower side wall nozzle M1. The first upper side wall nozzle T1 and the first lower side wall nozzle M1 are arranged parallel to each other and spaced apart in the vertical direction. The multiple processing liquid nozzles 4 also include two processing liquid nozzles 4 extending in the arrangement direction R1 along the other side wall 62 of the processing tank 2, i.e., a second upper side wall nozzle T2 and a second lower side wall nozzle M2. The second sidewall upper nozzle T2 and the second sidewall lower nozzle M2 are arranged in parallel with each other and spaced apart in the vertical direction.

[0038] Each processing liquid nozzle 4 is composed of a discharge pipe extending parallel to the arrangement direction R1, with its tip end closed and its base end connected to the tip of a branch pipe section 14 of the circulation pipe 13. In this embodiment, the closed tip end of the processing liquid nozzle 4 is arranged on the side of the back plate 31 of the lifter 3, and the base end connected to the branch pipe section 14 is arranged on the opposite side of the back plate 31.

[0039] The processing liquid nozzle 4 has a plurality of outlets 41 that open at intervals in the arrangement direction R1. The plurality of outlets 41 are aligned along the arrangement direction R1. In this embodiment, the main direction of the processing liquid from each outlet 41 is toward the substrate W, i.e., toward the inside of the internal space of the processing tank 2. The main direction of the processing liquid from each outlet 41 is typically parallel to the main surface of the substrate W, i.e., a direction that intersects (more specifically, is perpendicular to) the arrangement direction R1.

[0040] FIG. 3 is a perspective view illustrating an exemplary configuration of the treatment tank 2. The treatment tank 2 includes a pair of end walls 51, 52 facing each other in the arrangement direction R1, a pair of side walls 61, 62 facing each other in a horizontal direction intersecting the arrangement direction R1 (perpendicular to the arrangement direction in this embodiment) and joined to both side edges of the pair of end walls 51, 52, respectively, and a bottom wall 53 joined to the lower edges of the pair of end walls 51, 52 and the pair of side walls 61, 62. Thus, the treatment tank 2 forms, for example, a rectangular parallelepiped container with an upwardly opening 54, defining an internal space for storing the treatment liquid therein. An outer tank 7 is provided around the treatment tank 2 to receive the treatment liquid overflowing from the treatment tank 2. In this embodiment, the treatment tank 2 and the outer tank 7 are integrally formed and made of, for example, quartz.

[0041] Of the pair of end walls 51, 52, one end wall closer to the back plate 31 (see FIG. 2) of the lifter 3 is referred to as the first end wall 51, and the other end wall is referred to as the second end wall 52. Furthermore, one of the pair of side walls 61, 62 is referred to as the first side wall 61, and the other is referred to as the second side wall 62. An upwardly opening 54 is defined by the first end wall 51, the second end wall 52, and the upper edges of the first side wall 61 and the second side wall 62. The lifter 3 transfers a plurality of substrates W into and out of the processing bath 2 through this opening 54, thereby immersing the substrates W in the processing liquid in the processing bath 2 and lifting the substrates W out of the processing liquid.

[0042] In a plan view, the outer tank 7 defines an annular storage space 70 outside the treatment tank 2 that surrounds the entire periphery of the treatment tank 2. This storage space 70 has a first end space 71, a second end space 72, a first side space 73, and a second side space 74 that face the first end wall 51, the second end wall 52, the first side wall 61, and the second side wall 62, respectively.

[0043] When viewed in the arrangement direction R1, the first end space 71 overlaps with the upper part of the internal space of the treatment tank 2, but does not overlap with the lower part of the internal space of the treatment tank 2. Similarly, when viewed in a horizontal direction perpendicular to the arrangement direction R1, the first side space 73 and the second side space 74 overlap with the upper part of the internal space of the treatment tank 2, but do not overlap with the lower part of the internal space of the treatment tank 2. In other words, the bottom wall 7a of the outer tank 7 is located higher than the bottom wall 53 of the treatment tank 2 in the portion that partitions the first end space 71, the first side space 73, and the second side space 74, and the first end space 71, the first side space 73, and the second side space 74 are shallower than the internal space of the treatment tank 2.

[0044] On the other hand, the second end space 72 overlaps the entire interior space of the treatment tank 2 when viewed in the arrangement direction R1. That is, the bottom wall 7a of the outer tank 7, in the portion defining the second end space 72, is located at the same height as or lower than the bottom wall 53 of the treatment tank 2, and the depth of the second end space 72 is substantially equal to or greater than the depth of the interior space of the treatment tank 2. This allows the storage space 70 of the outer tank 7 to have a large volume in the second end space 72. Accordingly, the widths of the first end space 71, the first side space 73, and the second side space 74 can be reduced, thereby reducing the footprint of the outer tank 7. In this embodiment, the first end space 71, the first side space 73, and the second side space 74 have substantially equal widths, and the second end space 72 has a larger width. This allows the treatment liquid overflowing from the entire periphery of the treatment tank 2 to be collected and guided to the second end space 72, which has a larger volume, for storage.

[0045] The inlet end 13a of the circulation pipe 13 is disposed near the bottom of the second end space 72, and is therefore disposed at a position sufficiently deep below the liquid surface in the outer bath 7. This allows the processing liquid to be discharged from the processing liquid nozzle 4 at a sufficient flow rate while preventing air from flowing into the circulation pipe 13, thereby increasing the processing efficiency (e.g., etching rate) using the processing liquid.

[0046] A heater 8 is provided to heat the processing liquid stored in the processing tank 2. The heater 8 includes an end wall heater 84 and multiple zone heaters 85. The end wall heater 84 is disposed on the outer surface of the first end wall 51 of the processing tank 2 at a position lower than the bottom wall 7a of the outer tank 7. The end wall heater 84 heats the first end wall 51, thereby heating the processing liquid in contact with the inner surface of the first end wall 51. Because the outer tank 7 faces the second end wall 52 entirely, no heater is provided to directly heat the second end wall 52.

[0047] The zone heater 85 includes a first sidewall zone heater 81, a second sidewall zone heater 82, and a bottom wall zone heater 83. A plurality of first sidewall zone heaters 81 are disposed on the outer surface of the first sidewall 61 at positions lower than the bottom wall 7a of the outer tank 7. The plurality of first sidewall zone heaters 81 heat the first sidewall 61 in each of a plurality of regions divided in the arrangement direction R1, thereby heating the processing liquid in contact with the inner surface of the first sidewall 61. Similarly, a plurality of second sidewall zone heaters 82 are disposed on the outer surface of the second sidewall 62 at positions lower than the bottom wall 7a of the outer tank 7. The plurality of second sidewall zone heaters 82 heat the second sidewall 62 in each of a plurality of regions divided in the arrangement direction R1, thereby heating the processing liquid in contact with the inner surface of the second sidewall 62. Similarly, a plurality of bottom wall zone heaters 83 are disposed on the outer surface (lower surface) of the bottom wall 53 of the processing tank 2. The bottom wall zone heaters 83 heat the bottom wall 53 in each of the multiple regions divided in the arrangement direction R1, thereby heating the processing liquid in contact with the inner surface (upper surface) of the bottom wall 53.

[0048] In this embodiment, the arrangement regions of the multiple first sidewall zone heaters 81, the multiple second sidewall zone heaters 82, and the multiple bottom wall zone heaters 83 are divided at the same positions in the arrangement direction R1. The first sidewall zone heater 81, the second sidewall zone heater 82, and the bottom wall zone heater 83 at the same positions in the arrangement direction R1 form an integrated strip-shaped zone heater 85. Therefore, multiple zone heaters 85 that heat the pair of side walls 61, 62 and the bottom wall 53 are provided in each of the multiple regions divided in the arrangement direction R1. In this embodiment, multiple zone heaters 85 (three in the illustrated example) are arranged in multiple regions (three regions in the illustrated example) that are equally divided in the arrangement direction R1. Therefore, the widths of the multiple zone heaters 85 in the arrangement direction R1 are substantially equal.

[0049] As shown in FIG. 1, a lid 55 is provided for opening and closing an opening 54 of the treatment tank 2. The lid 55 includes a first lid member 56 and a second lid member 57. The first lid member 56 is rotatable about a first rotation axis 56a extending horizontally outside the outer tank 7 near the first side wall 61. The second lid member 57 is rotatable about a second rotation axis 57a extending horizontally outside the outer tank 7 near the second side wall 62. In this embodiment, the rotation axes 56a, 57a are parallel to the arrangement direction R1. The first lid member 56 and the second lid member 57 form an automatic cover that opens and closes the opening 54 by rotating about the rotation axes 56a, 57a, respectively, in conjunction with the up and down movement of the lifter 3. That is, when the lifter 3 is in an upper position above the processing tank 2 to hold the substrate W, the first lid member 56 and the second lid member 57 are in an open position to open the opening 54 upward. On the other hand, when the lifter 3 is in a lower position to hold the substrate W in the processing tank 2, the first lid member 56 and the second lid member 57 are in a closed position to close the opening 54 of the processing tank 2. This suppresses temperature changes in the processing liquid in the processing tank 2, allowing stable and efficient substrate processing.

[0050] FIG. 4 is a block diagram for explaining the control system for the end wall heaters 84 and the zone heaters 85. As shown in FIG.

[0051] The end wall heater 84 and the zone heater 85 are typically rubber heaters. The rubber heater includes, for example, a metal heater wire and a silicone cover covering it. Temperature sensors 94, 95 (typically thermocouples) are disposed in the end wall heater 84 and the zone heater 85. The temperature sensors 94, 95 detect the temperatures of the end wall heater 84 and the zone heater 85, respectively. As a result, the temperature sensor 94 indirectly detects the temperature of the first end wall 51 with which the end wall heater 84 contacts. Similarly, the temperature sensor 95 indirectly detects the temperatures of the side walls 61, 62 and the bottom wall 53 with which the zone heater 85 contacts.

[0052] The power supply to the end wall heater 84 and the zone heaters 85 is controlled by a controller 10. Temperature sensors 94, 95 are connected to the controller 10. The controller 10 controls the output (power supply) of the end wall heater 84 and the multiple zone heaters 85 based on a predetermined set temperature and the temperatures detected by the temperature sensors 94, 95.

[0053] The set temperatures for the end wall heater 84 and the multiple zone heaters 85 may be equal to or different from each other. Typically, it is preferable to determine the set temperatures for the end wall heater 84 and the multiple zone heaters 85 based on a previous experiment or simulation so that the temperature distribution of the processing liquid in the processing tank 2 in the arrangement direction R1 is uniform (so that variations can be minimized).

[0054] To uniformize the temperature of the processing liquid in the processing tank 2 in the arrangement direction R1, the controller 10 controls the multiple zone heaters 85 so that the zone heater 85 (second zone heater) closest to the second end wall 52 generates a larger amount of heat (more specifically, the amount of heat generated per unit length in the arrangement direction R1) than the zone heater 85 (first zone heater) closest to the first end wall 51. This is because the first end wall 51 is heated by the end wall heater 84, whereas no heater is provided on the second end wall 52. Therefore, the zone heater 85 closer to the second end wall 52 should supply a larger amount of heat to the processing liquid than the zone heater 85 closer to the first end wall 51. For example, the set temperature of the zone heater 85 (first zone heater) closest to the first end wall 51 may be set to a first temperature, and the set temperature of the zone heater 85 (second zone heater) closest to the second end wall 52 may be set to a second temperature higher than the first temperature. By appropriately setting the first temperature and the second temperature, the temperatures of the treatment liquid in the regions near the first end wall 51 and the second end wall 52 in the treatment tank 2 can be made approximately equal.

[0055] As described above, according to this embodiment, by immersing the substrates W held by the lifter 3 in the processing liquid stored in the processing tank 2, the substrates W can be collectively processed with the processing liquid. With the substrates W immersed in the processing liquid, the back plate 31 (rear portion) of the lifter 3 is interposed between the substrates W and the first end wall 51. The processing tank 2 is provided with heaters 8 (end wall heaters 84 and zone heaters 85) for heating the walls that constitute the processing tank 2, thereby heating the processing liquid stored therein. Specifically, the end wall heater 84 is provided for heating the first end wall 51, which is one of the end walls facing each other in the arrangement direction R1. In addition, the processing tank 2 is provided with a plurality of zone heaters 85 for heating at least one of the pair of side walls 61, 62 and the bottom wall 53.

[0056] While an end wall heater 84 is provided to heat the first end wall 51, no heater is provided to the second end wall 52. Therefore, the processing liquid stored in the processing tank 2 may have a temperature distribution with a gradient in the arrangement direction R1. Therefore, the zone heater 85 heats at least one of the pair of side walls 61, 62 and the bottom wall 53 in each of the multiple regions divided in the arrangement direction R1, and these are individually controlled by the controller 10 (heater control unit). This allows for individual adjustment of heating for the multiple regions divided in the arrangement direction R1, thereby appropriately heating the processing liquid in the processing tank 2 in the region close to the first end wall 51 and the region close to the second end wall 52. Specifically, a uniform temperature distribution with a small gradient in the arrangement direction R1 can be achieved. This improves the uniformity of processing for multiple substrates W.

[0057] More specifically, in this embodiment, the controller 10 controls the outputs of the multiple zone heaters 85 so that the zone heater 85 (second zone heater) closest to the second end wall 52 generates a larger amount of heat than the zone heater 85 (first zone heater) closest to the first end wall 51. This allows a larger amount of heat to be supplied to the processing liquid in the processing tank 2 in the region close to the second end wall 52 where no heater is located, than in the region close to the first end wall 51 where the end wall heater 84 is located. Therefore, the temperature distribution of the processing liquid in the arrangement direction R1 can be made uniform.

[0058] In this embodiment, the processing tank 2 is divided into three regions in the arrangement direction R1, and each region is individually controlled by a zone heater 85. Therefore, the walls of the processing tank 2 can be appropriately and individually heated in the region near the first end wall 51, which is heated by the end wall heater 84 and where the back plate 31 of the lifter 3 is interposed between the first end wall 51 and the substrate W, the region near the second end wall 52 where no heater is disposed, and the intermediate region therebetween. This allows for a uniform temperature distribution in the arrangement direction R1. Of course, the number of regions divided in the arrangement direction R1 may be two, four, or more. The more divisions there are, the easier it is to achieve a uniform temperature distribution; however, this increases the complexity of the configuration and control of the controller 10 and the wiring process. Therefore, it is preferable to select a necessary and sufficient number of divisions.

[0059] In this embodiment, the controller 10 also individually controls the end wall heaters 84. This makes it possible to make the temperature distribution of the processing liquid in the arrangement direction R1 more uniform.

[0060] In this embodiment, an outer tank 7 is provided to receive processing liquid overflowing from the processing tank 2. This allows the processing liquid to overflow from the processing tank 2 into the outer tank 7, supplying the processing liquid to the processing tank 2 and circulating and replacing the processing liquid therein, thereby processing multiple substrates W. The storage space 70 of the outer tank 7 has a second end space 72 facing the outer surface of the second end wall 52 and having a depth equal to or greater than the depth of the internal space of the processing tank 2. That is, the depth of the second end space 72 is substantially equal to or greater than the depth of the internal space of the processing tank 2. In this embodiment, the second end space 72 overlaps the entire second end wall 52 when viewed in the arrangement direction R1. Providing such a deep second end space 72 has the advantage of increasing the circulation flow rate when the processing liquid is sucked out of the outer tank 7 and circulated to the processing tank 2 via the circulation pipe 13. Specifically, when a high-capacity pump 15 is used to increase the circulation flow rate, by positioning the inlet end 13a of the circulation pipe 13 at the bottom of the deep second end space 72, it is possible to avoid the inlet end 13a of the circulation pipe 13 being exposed to the air and running out of liquid.

[0061] On the other hand, because the second end space 72 facing the second end wall 52 is provided, a heater cannot be disposed on the outer surface of the second end wall 52. As a result, a gradient in the temperature distribution of the processing liquid in the processing tank 2 in the arrangement direction R1 may occur. Therefore, in this embodiment, multiple zone heaters 85 are disposed in multiple regions divided in the arrangement direction R1, and the multiple zone heaters 85 are controlled individually. This suppresses the temperature gradient in the arrangement direction R1, thereby achieving a uniform temperature distribution of the processing liquid in the processing tank 2.

[0062] In this embodiment, each zone heater 85 is continuous across the outer surfaces of the pair of side walls 61, 62 and the outer surface of the bottom wall 53, forming an integrated heater that is substantially U-shaped when viewed in the arrangement direction R1. With this configuration, the pair of side walls 61, 62 and the bottom wall 53 are all heated by a single zone heater 85, making it possible to homogenize the temperature distribution of the processing liquid across the main surface of each substrate W with a low-cost configuration. As a result, it is possible to homogenize not only the temperature distribution of the processing liquid in the arrangement direction R1 but also the temperature distribution of the processing liquid across the main surface of each substrate W with a simple and low-cost configuration.

[0063] The present invention is not limited to this configuration, and individual zone heaters may be disposed on the pair of side walls 61, 62 and the bottom wall 53. In other words, the first side wall zone heater 81, the second side wall zone heater 82, and the bottom wall zone heater 83 may be separate. These individual zone heaters 81, 82, and 83 may be controlled collectively or individually by the controller 10. However, in this case, additional costs are incurred for wiring and installation of the multiple zone heaters.

[0064] FIG. 5 is a diagram illustrating a second embodiment of the present invention. In this embodiment, a first lid heater 86 and a second lid heater 87 are disposed on the first lid member 56 and the second lid member 57, respectively. The first lid heater 86 and the second lid heater 87 are individually controlled by the controller 10, independently of the end wall heater 84 and the multiple zone heaters 85. The first lid heater 86 and the second lid heater 87 heat the processing liquid in the processing tank 2 from above, thereby achieving a more uniform temperature distribution in the processing liquid. In particular, since no heater is disposed in the outer tank 7, the temperature in the upper region of the processing tank 2 is likely to drop. Therefore, heating from above by the first lid heater 86 and the second lid heater 87 effectively contributes to a more uniform temperature distribution. In this way, by heating the lid 55 of the processing tank 2, the processing liquid can be heated from above, thereby suppressing cooling of the processing liquid and further uniforming the temperature distribution of the processing liquid.

[0065] FIG. 6 is a diagram illustrating a third embodiment of the present invention, showing a modified example of a zone heater 85. In this embodiment, each zone heater 85 has multiple heater sections divided vertically. More specifically, the first sidewall zone heater 81 has multiple heater sections 81a, 81b, and 81c divided vertically. Similarly, the second sidewall zone heater 82 has multiple heater sections 82a, 82b, and 82c divided vertically. The controller 10 individually controls the multiple heater sections 81a, 81b, and 81c; 82a, 82b, and 82c. This allows for uniform temperature distribution in the processing liquid not only in the arrangement direction R1 but also in the vertical direction. This not only allows for uniform processing of multiple substrates W, but also allows for uniform processing across the main surface of each substrate W.

[0066] 6, the number of divisions in the vertical direction is 3, but this number may be 2, or 4 or more. In addition, in the example shown in FIG. 6, the lowest heater portion 81c of the first side wall zone heater 81 and the lowest heater portion 82c of the second side wall zone heater 82 are integrated with the bottom wall zone heater 83, but these may be configured separately from the bottom wall zone heater 83 and controlled separately from the bottom wall zone heater 83.

[0067] In addition, in the example shown in FIG. 6, all of the zone heaters 85 are divided in the vertical direction, but only some of the zone heaters 85 (for example, the zone heaters 85 in the central region in the arrangement direction R1) may be divided in the vertical direction.

[0068] Although the embodiment of the present invention has been described above, the present invention can also be embodied in other forms.

[0069] For example, as described above, the first sidewall zone heater 81, the second sidewall zone heater 82, and the bottom wall zone heater 83 may be separate, individual heaters. In this case, the first sidewall zone heater 81, the second sidewall zone heater 82, and the bottom wall zone heater 83 at the same position in the arrangement direction R1 may be wired to different control systems of the controller 10, respectively, or may be wired and connected in common to the same control system of the controller 10. In other words, the first sidewall zone heater 81, the second sidewall zone heater 82, and the bottom wall zone heater 83 at the same position in the arrangement direction R1 may be controlled individually or in common. Similarly, in the configuration of FIG. 6, the multiple heater sections 81a, 81b, 81c; 82a, 82b, 82c divided in the vertical direction may be wired and connected in common to different control systems of the controller 10, respectively, or may be wired and connected in common to the same control system of the controller 10.

[0070] In the above embodiment, the zone heater 85 has the first side wall zone heater 81, the second side wall zone heater 82, and the bottom wall zone heater 83, but one or two of these may be omitted.

[0071] In addition, in the above-described embodiment, an example was shown in which the end wall heater 84 was controlled separately from the zone heater 85, but for example, the end wall heater 84 and the zone heater 85 closest to the first end wall 51 may be commonly wired and connected to the same control system of the controller 10, and they may be commonly controlled.

[0072] The number and arrangement of the processing liquid nozzles 4 in the above-described embodiment are merely examples. For example, the nozzles T1, M1, T2, and M2 arranged on the side walls 61 and 62 may be omitted, and only the bottom wall nozzles B1 and B2 may be provided. Furthermore, the main ejection direction of the processing liquid from the processing liquid nozzles 4 does not necessarily have to be directed toward the substrate W. For example, the main ejection direction of the bottom wall nozzles B1 and B2 may be directed toward the center of the bottom wall 53 along a direction parallel to the main surface of the substrate W, thereby forming an upward flow of the processing liquid (upflow) from the bottom wall 53 within the processing tank 2.

[0073] In addition, various design modifications can be made within the scope of the claims. [Explanation of symbols]

[0074] 1: Substrate processing equipment 2: Treatment tank 3: Lifter 7: Outer tank 8: Heater 10: Controller 31: Back plate 32: Central holding part 33: Side holding part 51: First end wall 52: Second end wall 53: Bottom wall 55: Lid 61: First side wall 62: Second side wall 70: Storage space 71: First end space 72: Second end space 73: First side space 74: Second side space 81: First side wall zone heater 81a, 81b, 81c: heater part 82: Second sidewall zone heater 82a, 82b, 82c: heater part 83: Bottom wall zone heater 84: End wall heater 85: Zone heater 86: First lid heater 87: Second lid heater 94,95:Temperature sensor R1: Array direction W: Substrate

Claims

1. a processing tank having a pair of end walls opposing each other in an arrangement direction which is a predetermined horizontal direction, a pair of side walls opposing each other in an intersecting direction which is a horizontal direction intersecting the arrangement direction and connected to the pair of end walls, and a bottom wall connected to the pair of end walls and the pair of side walls, and storing a processing liquid for processing a substrate in an internal space; a lifter having a holding section that holds a plurality of substrates in an upright position and arranged in the arrangement direction, and a back section that is connected to the holding section, and that immerses the plurality of substrates in the processing solution in the processing tank with the back section interposed between the plurality of substrates and a first end wall that is one of the pair of end walls; a heater including an end wall heater disposed on the first end wall, a plurality of zone heaters disposed on at least one of the pair of side walls and the bottom wall in each of a plurality of regions divided in the arrangement direction, and no heater disposed on the second end wall, which is the other of the pair of end walls; a heater control unit that individually controls outputs of the plurality of zone heaters.

2. the plurality of zone heaters include a first zone heater disposed in a region of the plurality of regions closest to the first end wall, and a second zone heater disposed in a region of the plurality of regions closest to the second end wall, The substrate processing apparatus according to claim 1 , wherein the heater control unit controls outputs of the plurality of zone heaters so that the second zone heater generates a larger amount of heat than the first zone heater.

3. 3. The substrate processing apparatus of claim 1, further comprising an outer tank having a storage space for receiving processing liquid overflowing from the processing tank, the storage space having an end space in an area facing the outer surface of the second end wall that is deeper than the depth of the internal space of the processing tank.

4. 3. The substrate processing apparatus according to claim 1, wherein each zone heater is continuous across the outer surfaces of the pair of side walls and the outer surface of the bottom wall.

5. Further comprising a lid for opening and closing the opening of the treatment tank; The substrate processing apparatus according to claim 1 , wherein the heater further comprises a lid heater disposed on the lid.

6. 3. The substrate processing apparatus according to claim 1, wherein at least one of the plurality of zone heaters has a plurality of heater sections divided in a vertical direction, and the heater control unit controls the plurality of heater sections individually.

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