Photomask box for preventing photomask vacuum adsorption area from being polluted

Abstract

The utility model provides a photomask box capable of preventing a vacuum adsorption area of a photomask from being polluted, which comprises a base and an upper cover, wherein supporting pieces are arranged at four corners of the base, and the four supporting pieces are matched to be used for placing the photomask; the upper portion of the upper cover is provided with a handle, the upper cover can cover the base to form a cavity for containing the photomask, and the inner side of the upper cover is provided with an abutting piece used for abutting against the upper surface of the photomask. By arranging the supporting pieces of the photomask conveying box at the four corners of the base, contact between the supporting pieces and the vacuum adsorption area of the photomask can be effectively reduced, and pollution to the vacuum adsorption area is reduced.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor manufacturing, and particularly relates to a reticle box for preventing pollution of the vacuum adsorption area of a reticle. Background Art

[0002] In the lithography process, a reticle is a graphic mask template used in a semiconductor lithography machine. The lithography machine transfers the process pattern onto the photoresist layer on the chip by using the reticle. During operation, the reticle is fixed on the working platform through vacuum adsorption. If the area corresponding to the vacuum adsorption area on the reticle is contaminated, it will cause insufficient vacuum in the reticle working platform of the exposure machine, resulting in the inability to establish the vacuum value of the machine tool and causing a shutdown situation.

[0003] At present, in the field of semiconductor processes, the transportation of reticles has basically been automated, generally through a reticle transfer box (Reticle SMIF Pod, RSP), which can effectively prevent reticle contamination. However, in the prior art, the contact position between the support member of the reticle transfer box and the reticle is exactly the vacuum adsorption area of the reticle on the working platform. Due to reasons such as friction between the reticle and the support member or contamination of the support member, the vacuum adsorption area of the reticle will be contaminated.

[0004] Based on the extremely high cleanliness requirements of the working platform for the vacuum adsorption area of the reticle, and the reticle box being the main cause of reticle vacuum adsorption area pollution, it is necessary to provide a reticle box that can prevent pollution of the vacuum adsorption area of the reticle. Summary of the Utility Model

[0005] The utility model provides a reticle box for preventing pollution of the vacuum adsorption area of a reticle to solve all or part of the above-mentioned prior art problems. The reticle box includes a base and an upper cover. Support members are provided at the four corners of the base, and the four support members cooperate to place the reticle. A handle is provided on the upper part of the upper cover, and the upper cover can be closed on the base to form a cavity for accommodating the reticle. An abutting member is provided on the inner side of the upper cover for abutting against the upper surface of the reticle. By arranging the support members of the reticle transfer box at the four corners of the base, the contact between the support members and the vacuum adsorption area of the reticle can be effectively reduced, and the pollution of the vacuum adsorption area can be reduced.

[0006] The support member includes a support block and a limit block. The support block is provided on the base, and the limit block is formed on the upper surface of the support block. The support block is used to support the reticle, and the limit block is used to abut against the side surface of the reticle. The support block provides support for the reticle, and the limit block on the support block is used to limit the reticle in the front-rear direction and the left-right direction. Further, the limit device and the support device separately provided in the prior art are combined to form the support member in this application, simplifying the structure and preparation of the reticle box.

[0007] The support member is integrally formed on the base. The integrally formed structure has better dimensional stability. At the same time, it simplifies the structure and preparation of the photomask box.

[0008] The support block is a rectangular block structure, and the limiting block is L-shaped. The limiting block is formed in the outer region of the upper surface of the support block. The limiting block has a first limiting surface and a second limiting surface, and the first limiting surface and the second limiting surface are used to abut against two adjacent sides of the photomask. The rectangular block-shaped support block is easy to form and can ensure the smooth contact with the photomask. The two sides of the L-shaped limiting block can respectively abut against the adjacent sides of the photomask to realize the limitation of the photomask.

[0009] The four sides of the limiting block other than the first limiting surface and the second limiting surface are flush with the four sides of the support block respectively. The corresponding sides are arranged in the same plane, which can simplify the structure, facilitate manufacturing and reduce the possible hiding space of pollutants.

[0010] The support member is made of Teflon. Teflon has good wear-resistant and antioxidant properties. Using Teflon material for the support member can reduce the generation of pollutants and avoid the pollution of the vacuum adsorption area of the photomask.

[0011] A limiting space is formed by the four limiting blocks, and the size of the limiting space is larger than the size of the photomask. In order to facilitate the manipulator to pick and place the photomask, a surplus design is carried out for the space for accommodating the photomask, so that the limiting space for accommodating the photomask is slightly larger than the size of the photomask.

[0012] The size of the limiting space is 1-2 mm larger than the size of the photomask. When designing the size of the limiting space, the size should not be too large or too small. If the size is too large, it will affect the limiting effect, and may cause the photomask to move and collide in the photomask box during transmission, damaging the photomask. If the size is too small, it will affect the manipulator to pick and place the photomask.

[0013] The size of the photomask is 145 mm * 152 mm, the length of the limiting space is 153 mm - 154 mm, and the width of the limiting space is 146 mm - 147 mm.

[0014] Compared with the prior art, the main beneficial effects of the present utility model are as follows: The support members of the photomask are arranged at the four corners of the base, effectively reducing the contact between the support members and the vacuum adsorption area of the photomask, and reducing the pollution of the vacuum adsorption area; The limiting device and the support device are combined to form an integrally formed support member, which simplifies the structure and preparation of the photomask box while meeting the requirements of support and limitation. Description of the Drawings

[0015] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 A reticle box in the prior art provided by the present invention.

[0017] Figure 2 A top view of the lower surface of the reticle.

[0018] Figure 3 A schematic diagram of a support member provided by the present invention.

[0019] Figure 4 A schematic diagram of the relative positions of the support member and the reticle in the present invention. Detailed Description of the Specific Embodiment

[0020] Regarding the foregoing and other technical contents, features, and effects of the present invention, they will be clearly presented in the following detailed description of a preferred embodiment in conjunction with the reference drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front, or back, etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for illustration and not for limiting the present invention.

[0021] As Figure 1 shown, a reticle box in the prior art includes a base 1 and an upper cover 2. The upper cover 2 can be closed on the base 1 to form a cavity for accommodating a reticle 3; a support member 11 and a limiting member 12 are provided on the base 1; the support member 11 is used to support the reticle 3. There are four support members 11, which are symmetrically arranged on both sides of the base 1 respectively. A long strip-shaped support plate is formed on the support member 11 for contacting and providing support to the lower surface of the reticle 3. There are two limiting members 12, which are arranged on one side of the base 1 where the support member 11 is not provided. The limiting member 12 is used to abut against the side surface of the reticle; an abutting member ( Figure 1 not shown in

[0022] Figure 2 is provided on the inner side of the upper cover 2 for abutting against the upper surface of the reticle 3, and a handle 21 is provided on the upper part of the upper cover 2 for clamping by an automated device. Figure 2As shown, the photomask 3 is rectangular. The gray areas on both long sides of the photomask 3 are vacuum adsorption areas 31. That is, when the photomask 3 works on the working platform of the exposure machine, it will be fixed on the working platform through vacuum adsorption, and the working area of the vacuum adsorption is the vacuum adsorption area 31 on the photomask 3. Therefore, the cleanliness of the vacuum adsorption area 31 of the photomask 3 is crucial.

[0023] Combined with Figure 1 and Figure 2 As shown, in the prior art, the contact area between the support member 11 and the photomask 3 is within the vacuum adsorption area 31 of the photomask 3, and the contact area between the support member 11 and the photomask 3 is strip-shaped, with a relatively large length of the contact area and basically covering most of the vacuum adsorption area 31 of the photomask 3. Therefore, when the support member 11 of the photomask cassette is contaminated or there is friction between the support member 11 and the photomask 3, it is easy to cause the vacuum adsorption area 31 of the photomask 3 to be contaminated, thereby affecting the operation of the exposure machine.

[0024] To solve the above problems, in this embodiment, the structure of the base 1 is modified, mainly by improving the installation position and structure of the support member 11.

[0025] In this embodiment, based on the base 1 shown in Figure 1 , improvements are first made. First, a support structure as shown in Figure 3 is respectively provided at the four corners of the base 1. To avoid confusion, the support structure shown in Figure 3 is named the support member 10. Secondly, the limit member 12 on the base 1 shown in Figure 1 is removed. When the photomask 3 is placed in the photomask cassette, the relative position between the support member 10 and the photomask 3 is as shown in Figure 4 .

[0026] In this embodiment, the support member 10 includes at least two parts, namely a support block 101 and a limit block 102. The support block 101 is a rectangular block structure integrally formed on the base 1 (in other embodiments, it can also be other shapes), and the upper surface of the support block 101 is used to contact the lower surface of the photomask 3 and provide a supporting effect. Since the support member 10 is provided at the corner of the base 1, the contact area between the support block 101 and the lower surface of the photomask 3 is also close to the upper and lower ends of the vacuum adsorption area 31 of the photomask 3, greatly reducing the pollution of the vacuum adsorption area 31.

[0027] To meet the limiting requirements of the photomask 3, an L-shaped limit block 102 is formed in the outer region of the upper surface of the support block 101. The limit block 102 has a first limit surface 1021 and a second limit surface 1022. When the photomask 3 is placed on the support block 101, the two limit surfaces of the L-shaped limit block 102 can respectively abut against the two side surfaces of the adjacent sides of the photomask 3. As shown in Figure 3As shown, the L-shaped limiting block 102 has six sides. Among them, the four sides except the first limiting surface 1021 and the second limiting surface 1022 are flush with the four sides of the supporting block 101 below them, that is, they are in the same plane as the four sides of the supporting block 101 respectively. In this embodiment, the extension direction of the long side of the photomask 3 is the front-back direction, the extension direction of the short side is the left-right direction, and the thickness direction is the up-down direction. In this embodiment, referring to Figure 3 and Figure 4 , when the installation position of the support member 10 is different, since the support member 10 is mirror-symmetrically arranged in the left-right direction and in the up-down direction, the limiting surfaces in contact with the side surface of the photomask 3 will be different. That is, when the support member 10 is arranged at the first corner and the third corner (taking the upper left corner in Figure 4 as the first corner, and the second corner, the third corner, and the fourth corner in clockwise order), the first limiting surface 1021 abuts against the side surface of the short side of the photomask 3, and the second limiting surface 1022 abuts against the side surface of the long side of the photomask 3. When the support member 10 is arranged at the second corner and the fourth corner, due to the mirror-symmetric arrangement, actually Figure 3 shown in the figure, the first limiting surface 1021 abuts against the side surface of the long side of the photomask 3, and the second limiting surface 1022 abuts against the side surface of the short side of the photomask 3. An abutting member is arranged inside the upper cover 2. When the upper cover 2 is closed on the base 1, a cavity for accommodating the photomask 3 can be formed. At this time, the abutting member of the upper cover 2 will abut against the upper surface of the photomask 3, and through the combined action of the support block 101 on the base 1 and the abutting member inside the upper cover 2, the limiting of the photomask 3 in the up-down direction is realized. In order to avoid generating pollutants, the material of the support member 10 is wear-resistant and oxidation-resistant Teflon material.

[0028] Referring to Figure 4 , it can be seen that a support member 10 is arranged at each of the four corners on the base 1. When the photomask 3 is placed in the photomask box, the support blocks 101 of the four support members 10 will respectively support the four corners of the photomask 3, and the photomask 3 is limited and fixed by the first limiting surface 1021 and the second limiting surface 1022 which are oppositely arranged in the front-back direction and in the left-right direction. However, in order to facilitate the taking and placing of the photomask 3, it is necessary to control the size of the limiting space formed by the limiting blocks on the four support members 10 to be slightly larger than the size of the photomask 3 (the limiting space refers to the space formed by the first limiting surface 1021 and the second limiting surface 1022 of the four limiting blocks 102), that is, to ensure that the relative distance between the first limiting surface 1021 and the second limiting surface 1022 in the front-back direction is slightly larger than the length of the photomask 3, and at the same time ensure that the relative distance between the first limiting surface 1021 and the second limiting surface 1022 in the left-right direction is slightly larger than the width of the photomask 3. Usually, it is sufficient that the size of the limiting space on the base 1 is 1-2 mm larger than the size of the photomask 3 to be accommodated, that is, the length and width of the limiting space are respectively 1-2 mm larger than the length and width of the photomask 3 to be accommodated.

[0029] In this embodiment, as Figure 4 shown, the photomask 3 is rectangular, with dimensions of 145 mm * 152 mm (i.e., the length of the photomask 3 is 152 mm and the width is 145 mm), and the sizes of the vacuum adsorption areas 31 on both the left and right sides of the photomask 3 are the same, both being 16 mm * 152 mm. In this embodiment, the length of the limiting space is set to 154 mm, and the width of the limiting space is set to 147 mm. In other embodiments, the length of the limiting space is set to 153 mm - 154 mm, and the width of the limiting space is set to 146 mm - 147 mm.

Claims

1. A mask box for preventing contamination of a mask vacuum adsorption area, characterized in that: It includes a base (1) and an upper cover (2): Support members (10) are provided at the four corners of the base (1), and the four support members (10) are used to place the light shield (3); A handle (21) is provided on the upper portion of the upper cover (2); the upper cover (2) can be covered on the base (1) to form a cavity for accommodating the light shield (3); an abutment member is provided on the inner side of the upper cover (2) for abutting against the upper surface of the light shield (3).

2. A mask box for preventing contamination of a mask vacuum adsorption area according to claim 1, characterized in that: The support member (10) comprises a support block (101) and a limit block (102); the support block (101) is arranged on the base (1); the limit block (102) is formed on the upper surface of the support block (101); the support block (101) is used to receive the light shield (3); and the limit block (102) is used to abut against the side surface of the light shield (3).

3. A mask box for preventing contamination of a mask vacuum adsorption area according to claim 2, characterized in that: The support member (10) is integrally formed on the base (1).

4. A mask box for preventing contamination of a mask vacuum adsorption area according to claim 2, characterized in that: The support block (101) is a rectangular block structure, the limit block (102) is L-shaped, the limit block (102) is formed on the outer side of the upper surface of the support block (101), and the limit block (102) has a first limit surface (1021) and a second limit surface (1022), and the first limit surface (1021) and the second limit surface (1022) are used to abut against two adjacent side surfaces of the light mask (3).

5. A mask box for preventing contamination of a mask vacuum adsorption area according to claim 4, characterized in that: The four side surfaces of the limiting block (102) except the first limiting surface (1021) and the second limiting surface (1022) are respectively flush with the four side surfaces of the supporting block (101).

6. The reticle box for preventing contamination of the reticle vacuum adsorption area according to claim 1, characterized in that: The support member (10) is made of Teflon material.

7. A mask box for preventing contamination of a mask vacuum adsorption area according to claim 4, characterized in that: A limited space is formed by the four limit blocks (102), and the size of the limit space is larger than the size of the light mask (3).

8. The reticle box for preventing contamination of the reticle vacuum adsorption area according to claim 7, characterized in that: The size of the limiting space is 1-2 mm larger than the size of the light cover (3).

9. The reticle box for preventing contamination of the reticle vacuum adsorption area according to claim 7, characterized in that: The size of the light shield (3) is 145 mm*152 mm, the length of the limiting space is 153 mm-154 mm, and the width of the limiting space is 146 mm-147 mm.

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