WO2014178223A1

WO2014178223A1 - Wafer cassette having asymmetric groove shape

Info

Publication number: WO2014178223A1
Application number: PCT/JP2014/055360
Authority: WO
Inventors: 恭兵佐藤; 康弘不老地
Original assignee: ミライアル株式会社
Priority date: 2013-04-30
Filing date: 2014-03-04
Publication date: 2014-11-06
Also published as: TW201441119A; JP6104695B2; TWI628125B; JP2014216628A

Abstract

A plurality of substrate supporting board-like sections (50) extend in the direction intersecting a normal line of one inner surface (255), said substrate supporting board-like sections being provided on one side wall of a wafer cassette (1) having asymmetric groove shapes. Since the shape of substrate supporting board-like sections (60) that are provided on the other side wall and the shape of the substrate supporting board-like sections (50) that are provided on the one side wall are asymmetric to each other, the shape of grooves (256) among the substrate supporting board-shaped sections (50) on the one side wall, and the shape of grooves (266) among the substrate supporting board-shaped sections (60) on the other side wall are different from each other.

Description

Asymmetric groove-shaped wafer cassette

The present invention relates to an asymmetric groove-shaped wafer cassette, and more particularly to an asymmetric groove-shaped wafer cassette that can accommodate a plurality of substrates such as semiconductor wafers in parallel.

As a container for storing a substrate such as a semiconductor wafer, a container having a pair of side walls and a side substrate support is conventionally known. A side substrate support portion is formed on each of the pair of side walls. A substrate housing space capable of housing a plurality of substrates is formed between the pair of side walls. The side substrate support portions are arranged so as to form a pair in the substrate housing space, and the adjacent substrates of the plurality of substrates are separated from each other at a predetermined interval and arranged in parallel. The edge can be supported.

More specifically, one side wall has one inner surface facing the other side wall. Further, the other side wall has the other inner surface facing the one inner surface with a positional relationship parallel to the one inner surface. The side substrate support portion has a plurality of substrate support plate-like portions extending in parallel to the inside of the substrate housing space on each of the one inner surface and the other inner surface.

Between the plurality of substrate support plate-like portions, grooves into which the edges of the plurality of substrates can be inserted are formed. The groove between the plurality of substrate support plate-like portions on one side wall and the groove between the plurality of substrate support plate-like portions on the other side wall have an opposing positional relationship. The edge of the substrate is inserted into the groove between the plurality of substrate support plate-like portions on one side wall and the groove between the plurality of substrate support plate-like portions on the other side wall, so that the edge of the substrate becomes a side substrate. Supported by the support part.

The plurality of substrate support plate-like portions provided on one side wall extend in a direction orthogonal to one inner surface. Moreover, the several board | substrate support plate-shaped part provided in the other side wall is extended in the direction orthogonal to the other inner surface (refer patent document 1).

JP-A-8-8331

A semiconductor wafer having a flat disk shape is generally known, but in the future, a wafer having a warped disk shape as a whole may be used. When a wafer having such a warped shape is inserted into the groove as described above, it is considered that the edge of the wafer having a large amount of warp cannot be easily inserted into the groove, making it difficult to accommodate the wafer.

In addition, when a wafer is inserted into a groove by a manual operation in which an operator visually accommodates the wafer, the groove on one side wall side and the groove on the other side wall side are inserted while visually confirming each. There is a need. However, it is difficult to insert a wafer having a shape warped in the groove as described above into the groove by visual observation, and there is a risk of damaging the wafer if it is forced to insert the wafer.

It is an object of the present invention to provide an asymmetric groove-shaped wafer cassette that can easily accommodate a substrate such as a warped semiconductor wafer and can suppress the flutter of the substrate in the groove.

The present invention provides a pair of side walls and a pair of side walls formed between the pair of side walls so as to form a pair in a substrate housing space formed between the pair of side walls and capable of accommodating a plurality of substrates. A side substrate support portion capable of supporting edges of the plurality of substrates in a state where adjacent substrates are spaced apart and arranged in parallel, and one side wall is the other side One side surface facing the side wall, the other side wall having a positional relationship parallel to the one side surface and having the other side surface facing the one side surface, the side substrate support portion Each of the one inner surface and the other inner surface has a plurality of substrate support plate-like portions extending in parallel to the inside of the substrate housing space, and between the plurality of substrate support plate-like portions. Are formed with grooves into which edges of the plurality of substrates can be inserted, The grooves between the plurality of substrate support plate-like portions on one side wall and the grooves between the plurality of substrate support plate-like portions on the other side wall face each other, and the plurality of substrate support plate-like portions on the one side wall The edge of the substrate is inserted into the groove between and the groove between the plurality of substrate support plate-like portions on the other side wall, whereby the edge of the substrate is supported by the side substrate support, The plurality of substrate support plate-like portions provided on one side wall extend in a direction intersecting the normal line of the one inner surface, and the plurality of substrate support plate-like portions provided on the other side wall However, by having an asymmetric shape with the plurality of substrate support plate-like portions provided on one side wall, the shape of the groove between the substrate support plate-like portions on the one side wall and the above-mentioned on the other side wall The present invention relates to an asymmetric groove-shaped wafer cassette different from the shape of a groove between substrate support plate-like portions.

The plurality of substrate support plate-like portions provided on the other side wall extend in parallel to the normal line of the other inner surface, and grooves between the plurality of substrate support plate-like portions on the other side wall are formed. The width is preferably larger than the width of the groove between the plurality of substrate support plate-like portions on the one side wall.

Further, it is preferable that the plurality of substrate support plate-like portions provided on the one side wall extend in a direction intersecting at an angle of 5 ° or more and 15 ° or less with respect to the normal line of the one inner surface.

According to the present invention, it is possible to provide an asymmetric groove-shaped wafer cassette that can easily accommodate a substrate such as a warped semiconductor wafer and can suppress the flutter of the substrate in the groove.

It is a downward perspective view which shows the state in which the board | substrate W was accommodated in the asymmetrical groove shape wafer cassette 1 by embodiment of this invention. It is a front view which shows the state in which the board | substrate W was accommodated in the asymmetrical groove shape wafer cassette 1 by embodiment of this invention. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. It is an expanded sectional view which shows the board | substrate support plate-

shaped parts

50 and 60 of the asymmetrical groove shape wafer cassette 1 by embodiment of this invention. It is a figure which shows the board | substrate W accommodated in the asymmetrical groove shape wafer cassette 1 by embodiment of this invention, (a) is a front view, (b) is a perspective view.

Hereinafter, an asymmetric groove-shaped wafer cassette according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a lower perspective view showing a state in which a substrate W is accommodated in an asymmetric groove-shaped wafer cassette 1 according to an embodiment of the present invention. FIG. 2 is a front view showing a state in which the substrate W is accommodated in the asymmetric groove-shaped wafer cassette 1 according to the embodiment of the present invention. FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 4 is an enlarged cross-sectional view showing the substrate support plate-

like portions

50 and 60 of the asymmetric groove-shaped wafer cassette 1 according to the embodiment of the present invention. 5A and 5B are views showing the substrate W accommodated in the asymmetric groove-shaped wafer cassette 1 according to the embodiment of the present invention, wherein FIG. 5A is a front view and FIG. 5B is a perspective view.

Here, for convenience of explanation, a direction from the back side opening 22 (to be described later) toward the container body opening 21 (direction from the lower right to the upper left in FIG. 1) is defined as the front direction D11, and the opposite direction is the rear direction. These are defined as D12, and these are defined as the front-rear direction D1. Further, a direction (upward direction in FIG. 1) from the lower wall 24 to the upper wall 23, which will be described later, is defined as an upward direction D21, the opposite direction is defined as a downward direction D22, and these are defined as a vertical direction D2. . Further, a direction from the second side wall 26 to be described later to the first side wall 25 (a direction from right to left in FIG. 1) is defined as a left direction D31, and an opposite direction is defined as a right direction D32. It is defined as a left-right direction D3. In each figure, explanation is given with arrows indicating these directions.

The substrate W (see FIG. 5) accommodated in the asymmetric groove-shaped wafer cassette 1 is a disk-shaped silicon wafer, glass wafer, sapphire wafer or the like, and is a thin one used in the industry. The substrate W in the present embodiment is a substantially disk-shaped sapphire wafer having a diameter of about 4 inches and a thickness of about 0.1 mm. The substrate W is obtained by forming a semiconductor layer on sapphire. The semiconductor layer is, for example, a stack of nitride semiconductors. Although the thickness of the board | substrate W is not specifically limited, For example, what is necessary is just a thickness of 100 micrometers or more and 2 mm or less. The thickness of the semiconductor layer is 20 μm or less. The substrate W is warped so that the upper surface side is convex as a whole with respect to the lower surface side. The warpage amount WP of the substrate W varies depending on the substrate W and varies, but the maximum value is the distance from the virtual straight line X connecting the left and right ends of the substrate W shown in FIG. 5A to the center of the substrate W. Is about 12 mm. Further, a part of the periphery of the substrate W has a linear portion W1 (see FIG. 5B).

As shown in FIGS. 1 and 2, the asymmetric groove-shaped wafer cassette 1 has a container body 2 and substrate

support plate portions

50 and 60 as side substrate support portions.

As shown in FIG. 1, the container body 2 includes a wall 20 having a container body opening 21 formed at the front end and a back opening 22 formed at the rear end. The wall portion 20 includes an upper wall 23, a lower wall 24, a first side wall 25, and a second side wall 26. A substrate housing space 27 is formed in the container body 2. The substrate housing space 27 is formed so as to be surrounded by the wall portion 20. Substrate support plate-

like portions

50 and 60 are arranged in a portion of the wall portion 20 that forms the substrate accommodation space 27. As shown in FIG. 1, a plurality of substrates W can be stored in the substrate storage space 27.

The substrate support plate-

like portions

50 and 60 are provided on the wall portion 20 so as to make a pair in the left-right direction D3 within the substrate accommodation space 27. The substrate support plate-

like portions

50 and 60 can support the edge portions of the plurality of substrates W in a state where adjacent substrates W are separated from each other at a predetermined interval and are arranged in parallel. Substrate rear abutment walls 252 and 262 (see FIG. 3 and the like) are provided on the back side (the rear direction D12 side) of the substrate support plate-

like portions

50 and 60. Substrate

rear contact walls

252 and 262 abut the rear edge of the substrate W when the substrate W is accommodated in the substrate accommodating space 27.

The substrate W is supported in the substrate accommodation space 27 in such a positional relationship that the normal of the front surface W11 (see FIG. 5) coincides with the upper direction D21 and the normal of the back surface W12 coincides with the lower direction D22. Hereinafter, the main configuration of the present embodiment will be described in detail.

The upper wall 23, the lower wall 24, the first side wall 25, and the second side wall 26 constituting the wall portion 20 are made of a plastic material or the like. In the first embodiment, the upper wall 23, the lower wall 24, and the second side wall 26 are integrally formed of PEEK resin. ing.

The first side wall 25 and the second side wall 26 face each other, and the upper wall 23 and the lower wall 24 face each other. The upper end of the first side wall 25 and the upper end of the second side wall 26 are connected to the upper wall 23, and the lower end of the first side wall 25 and the lower end of the second side wall 26 are connected to the lower wall 24. Accordingly, as shown in FIG. 2, the upper wall 23, the lower wall 24, the first side wall 25, and the second side wall 26 form a substantially rectangular shape when viewed from the front.

The front end of the upper wall 23, the front end of the first side wall 25, and the front end of the second side wall 26 are located at the foremost side, and constitute an opening peripheral portion 28 that forms the container main body opening 21 at the front end of the container main body 2. . The front end of the first side wall 25 has a left opening flange portion 251 extending leftward. The front end of the second side wall 26 has a right opening flange portion 261 that extends rightward. The substrate housing space 27 is formed between the first side wall 25 and the second side wall 26.

Also, the rear part of the first side wall 25 and the rear part of the second side wall 26 have substrate rear contact walls 252 and 262 (see FIG. 3 and the like) that decrease in width in the left-right direction D3 as going backward. The rear edge of the substrate W accommodated in the substrate accommodating space 27 abuts on the substrate

rear abutting walls

252 and 262. Thereby, the movement to the back of the board | substrate W is controlled. Further, the rear part of the first side wall 25 and the rear part of the second side wall 26 are rear extension walls extending rearward from the substrate rear part contact wall 252 of the first side wall 25 and the substrate rear part contact wall 262 of the second side wall 26, respectively. 253, 263. The

rear extension walls

253 and 263 have a parallel positional relationship. As shown in FIG. 2, the rear end of the rear extension wall 253 and the rear end of the rear extension wall 263 form a rectangular rear opening 22 in a front view.

Moreover, as shown in FIG. 1, the lower wall 24 has a substantially H shape in a downward view. The lower wall 24 includes a left extension 241, a right extension 242, and a central connection part 243. The left extension 241 extends from the rear end of the first side wall 25 to the vicinity of the front end along the lower end of the first side wall 25. The right extension 242 extends from the rear end of the second side wall 26 to the vicinity of the front end along the lower end of the second side wall 26. The central connecting portion 243 is integrally formed with the left extending portion 241 and the right extending portion 242, and connects the left extending portion 241 and the right extending portion 242 so as to be bridged.

The inner surface of the wall portion 20, that is, the inner surface 231 (see FIG. 2) of the upper wall 23, the inner surface 245 of the lower wall 24, the inner surface 255 of the first side wall 25 as one inner surface, and the second side wall as the other inner surface. An inner surface 265 of 26 forms a substrate housing space 27 (see FIG. 1 and the like) surrounded by these. The inner surface 265 of the second side wall 26 has a positional relationship parallel to the inner surface 255 of the first side wall 25 and faces the first side wall 25. As shown in FIG. 2, the inner surface 255 of the first side wall 25 and the inner surface 265 of the second side wall 26 have a positional relationship parallel to the front-rear direction D1 and the up-down direction D2. A maximum of 12 substrates W can be stored in the substrate storage space 27.

The substrate

support plate portions

50 and 60 are provided in the first side wall 25 and the second side wall 26, respectively, and are arranged in the substrate housing space 27 so as to form a pair in the left-right direction D3. Specifically, as shown in FIGS. 1 and 2, 13 substrate support plate-like portions 50 are provided on the inner surface 255 of the first side wall 25. The substrate support plate-like portion 50 is integrally formed with the first side wall 25, extends from the front end of the first side wall 25 to a substantially central position in the front-rear direction D 1 of the substrate rear contact wall 252, and also includes the substrate accommodation space 27. It extends parallel to the inside.

As shown in FIG. 4, the extending direction of the substrate support plate-like portion 50 is a direction intersecting with the normal line 255A of the inner surface 255 of the first side wall 25 extending in parallel to the right direction D32, specifically, An imaginary plane 256A located at the center between the upper surface of the groove 256 and the lower surface of the groove 256 formed between the substrate support plate-like portions 50 is 5 ° upward with respect to the normal line 255A of the inner surface 255 of the first side wall 25. The direction is an angle θ of 15 ° or less. The reason why the angle θ is set to 5 ° or more is that if the angle θ is less than 5 °, the effect that the edge of the substrate W can be easily inserted into the groove 256 cannot be obtained. The reason why the angle θ is set to 15 ° or less is that, even in the case of the substrate W having the maximum warping amount WP, if it exceeds 15 °, it becomes difficult to insert the edge of the substrate W into the groove 256. is there. In the present embodiment, it is a direction that forms an angle θ of 10 ° upward with respect to the normal line 255 </ b> A of the inner surface 255 of the first side wall 25. The extension length of the substrate support plate-like portion 50 from the inner surface 255 in the left-right direction D3 is about 12.5 mm. The thickness of the board | substrate support plate-shaped part 50 in the up-down direction D2 is about 6.8 mm.

The grooves 256 formed between the substrate support plate portions 50 are formed in a total of 12 lines. The width of the groove 256 is about 2.7 mm. Further, a draining through hole 257 (see FIG. 3 and the like) is formed in a portion of the substrate rear contact wall 262 corresponding to the rear end portion of the groove 256. The draining through hole 257 communicates the inside of the substrate housing space 27 and the outside of the substrate housing space 27. Further, as shown in FIG. 3, a through hole 258 extending along the front-rear direction D <b> 1 in which the groove 256 extends is formed at the bottom of the groove 256. The through hole 258 communicates the inside of the substrate accommodation space 27 and the outside of the substrate accommodation space 27. One edge of the substrate W can be inserted into each of the grooves 256.

Similarly, 13 substrate support plate portions 60 are provided on the inner surface 265 of the second side wall 26. The substrate support plate-like portion 60 is integrally formed with the second side wall 26, and as shown in FIG. 3, reaches from the front end of the second side wall 26 to a substantially central position in the front-rear direction D1 of the substrate rear contact wall 262. And extends parallel to the inside of the substrate housing space 27. As shown in FIG. 4, the extending direction of the substrate support plate-like portion 60 is between the substrate support plate-like portions 60 with respect to the normal line 265A of the inner surface 265 of the second side wall 26 extending parallel to the left-right direction D3. A virtual plane 266A located at the center between the upper surface of the formed groove 266 and the lower surface of the groove 266 is a parallel direction (coincident direction). The extension length of the substrate support plate-like portion 60 from the inner surface 265 in the left-right direction D3 is about 12.5 mm. The thickness of the board | substrate support plate-shaped part 60 in the up-down direction D2 is about 3.2 mm.

As shown in FIG. 4, the relationship between the extension length A1 of the substrate support plate-like portion 50 and the extension length B1 of the substrate support plate-like portion 60 is such that the extension length B1 of the substrate support plate-like portion 60 is the substrate. It is preferable that the extension length A1 of the support plate-like portion 50 is longer (B1> A1). The extension length B1 of the substrate support plate-like portion 60 is preferably in the range of 12.5 mm to 15 mm. Within this range, the substrate W can be stably held in the asymmetric groove-shaped wafer cassette 1. On the other hand, by making the length A1 of the substrate support plate-like portion 50 shorter than B1, the warped substrate W hits the upper surface of the substrate support plate-like portion 50, and the force that presses the substrate W downward works. It is possible to avoid the occurrence of cracks in the substrate W as much as possible.

The grooves 266 formed between the substrate support plate portions 60 are formed in a total of 12 lines. The width of the groove 266 is about 6.3 mm, which is larger than the width of the groove 256 formed between the substrate support plate-like portions 50 of the first side wall 25. Further, a draining through hole 267 is formed in a portion of the substrate rear contact wall 262 corresponding to the rear end portion of the groove 266. The draining through-hole 267 communicates the inside of the substrate housing space 27 and the outside of the substrate housing space 27. As shown in FIG. 3, a through hole 268 extending along the front-rear direction D <b> 1 in which the groove 266 extends is formed at the bottom of the groove 266. The through hole 268 communicates the inside of the substrate housing space 27 and the outside of the substrate housing space 27. One edge of the substrate W can be inserted into each of the grooves 266.

As shown in FIG. 4, a groove formed between the opening portion 255 </ b> B of the groove 256 formed between the substrate support plate-like portions 50 of the first side wall 25 and the substrate support plate-like portion 60 of the second side wall 26. It faces the opening 265B of 266. With this configuration, the groove 256 formed between the substrate support plate-like portions 50 on the first side wall 25 and the groove 266 formed between the substrate support plate-like portions 60 on the second side wall 26 are formed on the substrate W. By inserting the edge portion, the edge portion of the substrate W is supported by the substrate support plate-

like portions

50 and 60 as the side substrate support portions.

Further, from the configuration as described above, as shown in FIG. 2, the first side wall 25 has a virtual plane C that passes through the center position of the substrate housing space 27 in the left-right direction D3 and is parallel to the front-rear direction D1 and the up-down direction D2. The substrate support plate-like portion 50 and the substrate support plate-like portion 60 of the second side wall 26 have an asymmetric shape. For this reason, the shape of the groove 256 formed between the substrate support plate-like portions 50 of the first side wall 25 and the shape of the groove 266 formed between the substrate support plate-like portions 60 of the second side wall 26 are: Is different.

In FIG. 2, the state in which the substrate W having the maximum warpage is inserted into the

grooves

256 and 266 is illustrated, but actually, the substrate W having a smaller warpage than the substrate W shown in FIG. 266 and accommodated in the substrate accommodating space 27. Therefore, actually, the virtual plane 256A located at the center between the upper surface of the groove 256 and the lower surface of the groove 256, and the upper surface (front surface W11) and the lower surface (back surface W12) of the substrate W accommodated in the groove 256 are substantially the same. Has a parallel positional relationship.

According to the asymmetric groove-shaped wafer cassette 1 according to the first embodiment having the above-described configuration, the following effects can be obtained.
As described above, the plurality of substrate support plate-like portions 50 provided on the first side wall 25 as one side wall intersect with the normal line 255A of the inner surface 255 of the first side wall 25 as one inner surface. It extends to. The plurality of substrate support plate-like portions 60 provided on the second side wall 26 as the other side wall have an asymmetric shape with the plurality of substrate support plate-like portions 50 provided on the first side wall 25. The shape of the groove 256 between the substrate support plate-like portions 50 of the first side wall 25 is different from the shape of the groove 266 between the substrate support plate-like portions 60 of the second side wall 26.

With this configuration, the edge portion of the substrate W having a warped shape as a whole and a large amount of warpage can be surely inserted into the

grooves

256 and 266. As a result, the substrate W having a warped shape can be accommodated in the substrate accommodating space 27. Further, when the container body opening 21 is positioned upward and the back opening 22 is positioned downward, the substrate W flutters in the

grooves

256 and 266 when the so-called vertical position is set. Can be suppressed.

Further, the plurality of substrate support plate-like portions 60 provided on the second side wall 26 as the other side wall extend in parallel to the normal line 265A of the inner surface 265 of the second side wall 26 as the other inner surface, and the second side wall The width of the groove 266 between the plurality of substrate support plate portions 60 of the 26 is larger than the width of the groove 256 between the plurality of substrate support plate portions 50 of the first side wall 25 as one side wall.

With this configuration, when the operator inserts the substrate W into the

grooves

256 and 266 by a manual operation of visually inserting the substrate W into the

grooves

256 and 266, the substrate support plate-like portion 50 of the first side wall 25 is visually observed. By inserting the edge of the substrate W into the groove 256 between them, the opposite end of the substrate W can be inserted into the groove 266 of the substrate support plate-like portion 60 of the second side wall 26 without visual inspection. can do. That is, considering the amount of warpage of the substrate W and the direction in which the substrate support plate portion 50 extends, the width of the groove 266 between the plurality of substrate support plate portions 60 of the second side wall 26 is appropriately increased. To do. Accordingly, the edge of the substrate W is inserted into the groove 256 between the substrate supporting plate-like portions 50 of the first side wall 25 by visual observation, so that the substrate supporting plate-like portion 60 of the second side wall 26 is not visually observed. The opposite end of the substrate W can be inserted into the groove 266. Further, it is possible to easily form the second side wall 26 provided with the substrate support plate-like portion 60 in which the groove 266 is formed.

In addition, the plurality of substrate support plate-like portions 50 provided on the first side wall 25 as one side wall are 5 ° or more and 15 ° or less with respect to the normal line 255A of the inner surface 255 of the first side wall 25 as one inner surface. It extends in the direction that intersects at the angle θ. For this reason, the insertion of the substrate W into the groove 256 between the substrate support plate-like portions 50 of the first side wall 25 can be facilitated more reliably.

The present invention is not limited to the above-described embodiment, and can be modified within the technical scope described in the claims. For example, the

grooves

256 and 266 are each formed with 12 lines, but the number is not limited to this. That is, the number of substrate support plate-like portions 50 and substrate support plate-like portions 60 is not limited to 13.

The plurality of substrate support plate-like portions 60 provided on the second side wall 26 extend parallel to the normal line 265A of the inner surface 265 of the second side wall 26, and the plurality of substrate support plate-like portions 60 on the second side wall 26. The width of the groove 266 in between is configured to be larger than the width of the groove 256 between the plurality of substrate support plate-like portions 50 of the first side wall 25, but is not limited to this configuration. The plurality of substrate support plate-like portions provided on the other side wall have an asymmetric shape with respect to the plurality of substrate support plate-like portions provided on the one side wall, so that between the substrate support plate-like portions on one side wall The shape of the groove and the shape of the groove between the substrate support plate portions on the other side wall may be different.

Moreover, although the upper wall 23, the lower wall 24, the 1st side wall 25, and the 2nd side wall 26 were integrally formed by PEEK resin, it is not limited to PEEK resin. For the upper wall 23, the lower wall 24, the first side wall 25, and the second side wall 26, for example, a general-purpose resin such as PFA (fluororesin) or PP (polypropylene) may be used.

Further, the shapes of the upper wall 23, the lower wall 24, the first side wall 25, and the second side wall 26 are not limited to the shapes of the present embodiment. Similarly, the dimension value of each part is not limited to the dimension value described in the present embodiment. The substrate W in this embodiment is a substantially disk-shaped sapphire wafer having a diameter of 4 inches and a thickness of about 0.1 mm, but is not limited to this dimension.

1 Asymmetric groove-shaped wafer cassette 25 First side wall (a pair of side walls)
26 Second side wall (a pair of side walls)
27

Substrate accommodation space

50, 60 Substrate support plate-like portion (side substrate support portion)
255 Inner surface (one inner surface)
255A,

265A Normal line

256, 266 Groove 265 Inner surface (the other inner surface)
W substrate

Claims

A pair of side walls;
In the substrate accommodation space formed between the pair of side walls and capable of accommodating a plurality of substrates, each pair of the side walls is formed to form a pair, and adjacent substrates of the plurality of substrates are defined to each other. A side substrate support portion capable of supporting the edge portions of the plurality of substrates in a state of being spaced apart and arranged in parallel,
The one side wall has one inner surface facing the other side wall, and the other side wall has the other inner surface facing the one inner surface having a positional relationship parallel to the one inner surface. Have
The side substrate support portion has a plurality of substrate support plate-like portions extending in parallel to the inside of the substrate accommodation space on each of the one inner surface and the other inner surface,
A groove is formed between the plurality of substrate support plate-like portions, into which edges of the plurality of substrates can be inserted, and the groove between the plurality of substrate support plate-like portions on the one side wall and the other side wall Grooves between the plurality of substrate support plate-like portions facing each other, grooves between the plurality of substrate support plate-like portions on the one side wall, and grooves between the plurality of substrate support plate-like portions on the other side wall The edge portion of the substrate is supported by the side substrate support portion by inserting the edge portion of the substrate into,
The plurality of substrate support plate-like portions provided on the one side wall extend in a direction intersecting with the normal line of the one inner surface,
The plurality of substrate support plate-like portions provided on the other side wall have an asymmetric shape with the plurality of substrate support plate-like portions provided on the one side wall, whereby the substrate support on the one side wall is provided. An asymmetric groove-shaped wafer cassette in which the shape of the groove between the plate-like portions is different from the shape of the groove between the substrate support plate-like portions on the other side wall.
The plurality of substrate support plate-like portions provided on the other side wall extend in parallel to the normal line of the other inner surface,
2. The asymmetric groove shape according to claim 1, wherein a width of a groove between the plurality of substrate support plate-like portions on the other side wall is larger than a width of a groove between the plurality of substrate support plate-like portions on the one side wall. Wafer cassette.
The plurality of substrate support plate-like portions provided on the one side wall extend in a direction intersecting at an angle of 5 ° or more and 15 ° or less with respect to a normal line of the one inner surface. 2. An asymmetric groove-shaped wafer cassette according to 2.