Substrate cassette and substrate processing apparatus

Abstract

To provide a substrate cassette that reduces unevenness in substrate processing in a wet process.SOLUTION: A substrate cassette 1 is a substrate cassette for arranging multiple substrates W with their main surfaces facing each other and for simultaneously immersing the multiple substrates W in a processing solution. The substrate cassette 1 includes at least one pair of side supports 30 extending in the arrangement direction of the multiple substrates W and supporting both side edges of each of the multiple substrates W, a lower support 20 extending in the arrangement direction of the multiple substrates W and supporting the lower edges of each of the multiple substrates W, multiple claws 32 arranged on the sides of each of the at least one pair of side supports 30 in the arrangement direction, protruding from the sides of the side supports 30 and supporting each of the multiple substrates W such that the multiple substrates W are spaced apart, and a protrusion 22 arranged on the lower support 20 on the side of the multiple substrates W that extends in the arrangement direction and protrudes from the lower support 20 toward the multiple substrates W, the width of the protrusion 22 being smaller than the width of the lower support 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate cassette and a substrate processing apparatus. [Background technology]

[0002] For example, wet processes are used in the manufacturing process of solar cells, including patterning of thin films such as semiconductor layers or electrode layers formed on semiconductor substrates (wafers), peeling of resists or lift-off layers (sacrificial layers) used in such patterning, anisotropic etching of the surface of the semiconductor substrate (forming a textured structure), and cleaning of the surface of the semiconductor substrate.

[0003] In such wet processes, a substrate processing apparatus is used. The substrate processing apparatus includes a processing tank that stores a processing liquid such as a chemical solution (e.g., an etching solution) or water (e.g., a rinse solution). A substrate cassette is used to simultaneously immerse multiple semiconductor substrates in the processing liquid. Patent Document 1 describes such a substrate cassette.

[0004] Such a substrate cassette accommodates a plurality of semiconductor substrates arranged with their main surfaces facing each other, and in a wet process, the substrate cassette is immersed in a processing liquid so that the plurality of semiconductor substrates are perpendicular to the surface of the processing liquid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-130831 Summary of the Invention [Problem to be solved by the invention]

[0006] In such substrate processing apparatuses, the processing liquid in the processing tank may be circulated to keep it clean, and in this case, the processing liquid convects from bottom to top or from one side to the other in the processing tank.

[0007] In addition, in such a substrate cassette, semiconductor substrates are supported by supports, and in this case, turbulence in the flow of processing liquid (e.g., Karman vortices) may occur near the supports on the upstream side of the processing liquid flow, especially on the downstream side of the supports, which may cause uneven processing (non-uniform processing) at the edge of the semiconductor substrate near the supports.

[0008] An object of the present invention is to provide a substrate cassette and a substrate processing apparatus that reduce unevenness in substrate processing in a wet process. [Means for solving the problem]

[0009] A substrate cassette according to the present invention is a substrate cassette for arranging a plurality of substrates with their main surfaces facing each other and for simultaneously immersing the plurality of substrates in a processing solution, the substrate cassette comprising: at least one pair of side supports extending in an arrangement direction of the plurality of substrates and supporting both side edges of each of the plurality of substrates; a lower support extending in the arrangement direction of the plurality of substrates and supporting a lower edge of each of the plurality of substrates; a plurality of claws arranged on the sides of each of the at least one pair of side supports in the arrangement direction and protruding from the sides of the side supports to support each of the plurality of substrates so as to keep the plurality of substrates spaced apart; and a protrusion arranged on the lower support on the side of the plurality of substrates, extending in the arrangement direction, and protruding from the lower support toward the plurality of substrates, the width of the protrusion being smaller than the width of the lower support.

[0010] A substrate processing apparatus according to the present invention includes the substrate cassette described above and a processing tank for immersing the substrate cassette in the processing liquid, wherein the processing liquid flows from below to above or from one side to the other of the processing tank, and the substrate cassette is placed in the processing tank so that the protrusion is located downstream of the flow of the processing liquid with respect to the support. [Effects of the Invention]

[0011] According to the present invention, it is possible to reduce unevenness in substrate processing in a wet process using a substrate cassette. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a perspective view showing a substrate cassette according to the embodiment. [Figure 2] FIG. 2 is a side view of the substrate cassette shown in FIG. [Figure 3] 3 is a cross-sectional view of the substrate cassette shown in FIG. 2 taken along line III-III. [Figure 4] 4 is an enlarged cross-sectional view of an example of a protrusion of a support column in the substrate cassette shown in FIG. 3. FIG. [Figure 5] 4 is an enlarged cross-sectional view of another example of a protrusion of a support column in the substrate cassette shown in FIG. 3. FIG. [Figure 6] 1 is a schematic cross-sectional view showing an example of a substrate processing apparatus according to an embodiment of the present invention. [Figure 7] FIG. 10 is a schematic cross-sectional view showing another example of the substrate processing apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] An example of an embodiment of the present invention will be described below with reference to the accompanying drawings. The same or equivalent parts in each drawing are designated by the same reference numerals. For convenience, hatching and reference numerals may be omitted. In such cases, reference should be made to other drawings.

[0014] (Substrate cassette) Fig. 1 is a perspective view showing a substrate cassette according to this embodiment, Fig. 2 is a side view of the substrate cassette shown in Fig. 1, and Fig. 3 is a cross-sectional view of the substrate cassette shown in Fig. 2 taken along line III-III.

[0015] 1 to 3 is used in wet processes in the manufacturing process of solar cells, for example. Examples of such wet processes include patterning of thin films such as semiconductor layers (e.g., amorphous silicon thin films) or electrode layers formed on semiconductor substrates (wafers: thin plates) (e.g., crystalline silicon substrates) W, peeling off resists or lift-off layers (sacrificial layers) used in such patterning, anisotropic etching of the surface of the semiconductor substrate W (forming a textured structure), and cleaning of the surface of the semiconductor substrate W.

[0016] In a wet process, the substrate cassette 1 simultaneously immerses multiple semiconductor substrates W in a processing liquid such as a chemical solution (e.g., an etching solution) or water (e.g., a rinse solution). The substrate cassette 1 accommodates multiple semiconductor substrates W arranged with their main surfaces facing each other. In the wet process, the substrate cassette 1 is immersed in the processing liquid so that the multiple semiconductor substrates W are perpendicular to the liquid surface of the processing liquid.

[0017] The substrate cassette 1 includes a front panel 11, a rear panel 12, a lower support 20, an upper support (not shown), side support 30, a claw portion 32, and a protrusion 22.

[0018] Various materials resistant to the processing solution are used as the materials for the components of the substrate cassette 1. For example, when the processing solution is an acidic solution, resin materials such as PTFE (Poly Tetra Fluoro Etylene), PVDF (Poly Vinylidene DiFluoride), or PP (polypropylene) may be used as the materials for the components of the substrate cassette 1. To reduce mechanical damage to the substrate, a metal material such as SUS (Steel Use Stainless Steel) or a titanium alloy may be used as the mandrel, and the outer periphery may be covered with a resin material. When the processing solution is an alkaline solution, metal materials such as SUS or a titanium alloy, and resin materials such as PTFE, PVDF, or PP may be used as the materials for the components of the substrate cassette 1. As described above, to increase mechanical strength, a metal material such as SUS or a titanium alloy may be used as the mandrel, and the outer periphery may be covered with a resin material.

[0019] The front plate 11 is disposed on the front side of the substrate cassette 1, and the rear plate 12 is disposed on the rear side of the substrate cassette 1. The front plate 11 and the rear plate 12 face each other so as to sandwich a plurality of semiconductor substrates W therebetween.

[0020] The lower support columns 20 are disposed at the bottom of the substrate cassette 1 and support the bottom ends of the plurality of semiconductor substrates W. There are no particular limitations on the type of lower support columns 20, and examples thereof include columnar members that extend from the front panel 11 to the rear panel 12, i.e., in the arrangement direction of the semiconductor substrates W, in consideration of not interfering with the convection of the processing liquid and of draining the processing liquid. There are no particular limitations on the number of lower support columns 20, and for example, two lower support columns 20 may be disposed at the bottom, spaced apart on the left and right. The lower support columns 20 include protrusions 22, which will be described later.

[0021] The upper support pillars (not shown) are disposed at the top of the substrate cassette 1 and support the upper ends of the plurality of semiconductor substrates W, for example, when the substrate cassette 1 is immersed in a processing liquid. The upper support pillars are not particularly limited, and may be, for example, columnar members extending from the front plate 11 to the rear plate 12, i.e., in the arrangement direction of the semiconductor substrates W, in consideration of not interfering with the convection of the processing liquid. The upper support pillars may also be detachable or openable / closable in order to set and reset the plurality of semiconductor substrates W in the substrate cassette 1.

[0022] The side supports 30 are disposed on the sides of the substrate cassette 1 and support the side edges of the plurality of semiconductor substrates W. The side supports 30 are not particularly limited, and examples thereof include columnar members extending from the front panel 11 toward the rear panel 12, i.e., in the arrangement direction of the semiconductor substrates W, in consideration of not interfering with the convection of the processing liquid, the drainage of the processing liquid, and the drying air for drying the substrates. The number of side supports 30 is not particularly limited, and for example, two side supports 30 may be disposed vertically spaced apart on each of two pairs of sides. The side supports 30 have a plurality of claws 32, which will be described later.

[0023] The plurality of claws 32 are arranged at equal intervals on the inner side of the side support 30 in the extension direction of the side support 30 (the arrangement direction of the semiconductor substrates W). As a result, the plurality of claws 32 support each of the plurality of semiconductor substrates W so that the plurality of semiconductor substrates W are spaced apart. There are no particular limitations on the type of claw 32, and it is preferable that the claws protrude from the inner side of the side support 30 and have a small contact area with the semiconductor substrate W, for example.

[0024] The protrusions 22 are disposed on the upper portions of the lower columns 20, i.e., on the semiconductor substrate W side, and extend in the extension direction of the lower columns 20 (the arrangement direction of the semiconductor substrates W). The protrusions 22 protrude from the upper portions of the lower columns 20, i.e., on the semiconductor substrate W side.

[0025] If the directions intersecting the extension direction of the lower support 20 (arrangement direction of the semiconductor substrates W) are defined as the width direction and the up-down direction, the width of the protrusion 22 in the width direction is smaller than the width of the lower support 20. In other words, the cross-sectional areas of the protrusion 22 in the width direction and the up-down direction are smaller than the cross-sectional areas of the lower support 20 in the width direction and the up-down direction.

[0026] The protrusions 22 may contain an elastic material, such as a fiber structure or resin foam that extends in the extending direction of the lower support 20 (the arrangement direction of the semiconductor substrates W).

[0027] The fiber structure may be a single fiber thread. Alternatively, the fiber structure may be a twisted yarn made by twisting multiple fiber strands, a braided yarn made by braiding multiple fiber strands, or a woven yarn made by weaving multiple fiber strands. Materials for the fiber threads and fiber strands include nylon, polyester, polypropylene, polyethylene, vinylon, etc.

[0028] Fig. 4 is an enlarged cross-sectional view of an example of a protrusion of a support column in the substrate cassette shown in Fig. 3. As shown in Fig. 4, when the protrusion 22 includes a fiber structure 24, the protrusion 22 may include an adhesive film-like resin member 25 that covers the fiber structure 24 and fixes the fiber structure 24 to the lower support column 20. The resin material is not particularly limited, but examples thereof include fluororesins such as PTFE (Poly Tetra Fluoro Etylene), PFA, and PVDF (Poly Vinylidene DiFluoride).

[0029] Fig. 5 is an enlarged cross-sectional view of another example of the protrusion of the support column in the substrate cassette shown in Fig. 3. As shown in Fig. 5, when the protrusion 22 includes the fiber structure 24, the protrusion 22 may include an adhesive resin member 26 that fixes the fiber structure 24 to the lower support column 20. The resin material is not particularly limited, but examples thereof include fluororesins such as PTFE, PFA, and PVDF.

[0030] The resin foam is not particularly limited, but from the viewpoint of chemical resistance, it is preferable that the resin foam be a fluororesin foam such as PTFE, PFA or PVDF.

[0031] (Substrate processing equipment) Fig. 6 is a schematic cross-sectional view showing an example of a substrate processing apparatus according to this embodiment. The substrate processing apparatus 100 shown in Fig. 6 includes a processing tank 101 containing a processing liquid such as a chemical solution (e.g., an etching solution) or water (e.g., a rinse solution), a circulation pump (not shown), and a filter (not shown). The processing liquid in the processing tank 101 is circulated by the circulation pump and filtered by the filter. As a result, the processing liquid convects from bottom to top in the processing tank 101 (see arrows).

[0032] In this case, the substrate cassette 1 is immersed in the processing liquid in the processing tank 101 so that the lower support 20 is located upstream of the convection of the processing liquid. As a result, the substrate cassette 1 is placed in the processing liquid in the processing tank 101 so that the protrusion 22 is located downstream of the convection of the processing liquid with respect to the lower support 20.

[0033] 7 is a schematic cross-sectional view showing another example of a substrate processing apparatus according to this embodiment. The substrate processing apparatus 100 shown in FIG. 7 includes a processing tank 101 containing a processing liquid such as a chemical solution (e.g., an etching solution) or water (e.g., a rinse solution), a circulation pump (not shown), and a filter (not shown). The processing liquid in the processing tank 101 is circulated by the circulation pump and filtered by the filter. As a result, in the processing tank 101, the processing liquid convects from one side to the other (see arrows).

[0034] Even in this case, the substrate cassette 1 is immersed in the processing liquid in the processing tank 101 so that the lower support 20 is located upstream of the convection of the processing liquid. As a result, the substrate cassette 1 is placed in the processing liquid in the processing tank 101 so that the protrusion 22 is located downstream of the convection of the processing liquid with respect to the lower support 20.

[0035] Here, near the support pillar on the upstream side of the processing liquid flow, particularly downstream of the support pillar, turbulence in the processing liquid flow (e.g., Karman vortex) may occur, which may cause processing irregularities (uneven processing) at the edge of the semiconductor substrate near this support pillar.

[0036] For example, in the case of anisotropic etching (forming a textured structure) of the surface of a semiconductor substrate W, etching may be specifically accelerated near the support columns on the upstream side of the flow of the processing liquid, resulting in flattening of the textured structure. In this case, the reflectance of a portion of the edge of the light-receiving surface of the solar cell may deteriorate.

[0037] In this regard, according to the substrate cassette 1 of this embodiment, the protrusions 22 are arranged on the semiconductor substrate W side of the lower support columns 20, and the width of the protrusions 22 is smaller than the width of the lower support columns 20. As a result, the lower support columns 20 are spaced apart from the lower ends of the semiconductor substrates W, and the contact width (contact area) between the protrusions 22 and the lower ends of the semiconductor substrates W becomes smaller.

[0038] Therefore, as in the substrate processing apparatus 100 of this embodiment, when the substrate cassette 1 is immersed in the processing liquid so that the lower support 20 is upstream of the flow of the processing liquid, i.e., so that the protrusion 22 is located downstream of the flow of the processing liquid relative to the lower support 20, it is possible to reduce turbulence in the flow of the processing liquid downstream of the lower support 20, i.e., on the protrusion 22 side of the lower support 20 (in other words, it is possible to straighten the flow of the processing liquid), thereby reducing uneven processing of the semiconductor substrate W.

[0039] Furthermore, when the thin semiconductor substrates W are loaded into the substrate cassette 1, the semiconductor substrates W may collide with the supports of the substrate cassette 1, causing the semiconductor substrates W to crack or chip.

[0040] In this regard, according to the substrate cassette 1 of this embodiment, the protrusions 22 have elasticity. For example, the protrusions 22 are a fiber structure that is a twisted yarn made by twisting a plurality of fiber wires, a braided yarn made by knitting a plurality of fiber wires, or a woven yarn made by weaving a plurality of fiber wires. Alternatively, the protrusions 22 are a resin foam. This allows the protrusions 22 to function as a buffer material, reducing the occurrence of cracks and chips in the semiconductor substrate W.

[0041] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and various modifications and variations are possible. For example, the above-described embodiments illustrate a substrate cassette and a substrate processing apparatus for simultaneously immersing a plurality of semiconductor substrates (wafers) in a processing liquid. However, the substrate cassette and substrate processing apparatus of the present invention are not limited to this and can also be used for simultaneously immersing various thin substrates (wafers) in a processing liquid. [Explanation of symbols]

[0042] 1 PCB cassette 11 Front plate 12 Back plate 20 Lower strut 22 protrusions 24 Fiber structure (resin foam) 25 Resin material (film type) 26 Adhesive resin parts 30 Lateral struts 32 Claw 100 Substrate processing apparatus 101 Treatment tank W semiconductor substrate (substrate)

Claims

1. A substrate cassette for arranging a plurality of substrates with their main surfaces facing each other and immersing the plurality of substrates simultaneously in a processing solution, comprising: At least one pair of side supports extending in the arrangement direction of the plurality of substrates and supporting both side edges of each of the plurality of substrates; a lower support extending in the arrangement direction of the plurality of substrates and supporting a lower end portion of each of the plurality of substrates; a plurality of claws arranged in the arrangement direction on the sides of each of the at least one pair of side supports, protruding from the sides of the side supports, and supporting each of the plurality of substrates so that the plurality of substrates are spaced apart; a protrusion disposed on the lower support column on the side of the plurality of substrates, the protrusion extending in the arrangement direction and protruding from the lower support column toward the plurality of substrates; Equipped with The width of the protrusion is smaller than the width of the lower support. Board cassette.

2. The substrate cassette according to claim 1 , wherein the protrusion has elasticity.

3. The substrate cassette according to claim 2 , wherein the protrusions include a fibrous structure extending in the arrangement direction.

4. 4. The substrate cassette according to claim 3, wherein the fiber structure is a twisted yarn made by twisting a plurality of fiber wires, a braided yarn made by braiding a plurality of fiber wires, or a woven yarn made by weaving a plurality of fiber wires.

5. The substrate cassette according to claim 3 or 4, wherein the protrusion includes a film-like resin member that covers the fiber structure and fixes the fiber structure to the lower support.

6. The substrate cassette according to claim 3 or 4, wherein the protrusion includes an adhesive resin member that fixes the fiber structure to the lower support.

7. The substrate cassette according to claim 2 , wherein the protrusions include a resin foam extending in the arrangement direction.

8. The substrate cassette according to claim 1; a processing tank in which a processing liquid is stored and in which the substrate cassette is immersed in the processing liquid; Equipped with the processing solution flows from below to above the processing tank or from one side to the other side of the processing tank; the substrate cassette is placed in the processing bath so that the protrusion is located downstream of the support column in a flow of the processing liquid. Substrate processing equipment.

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