Photomask

Abstract

The utility model provides a photomask which comprises a graphic layer, the graphic layer comprises a main graphic area and a non-main graphic area, and the non-main graphic area is arranged around the main graphic area; four alignment patterns are arranged on the upper surface of the non-main pattern area at intervals, and the main pattern area is located in a rectangular area defined by the midpoints of the four alignment patterns; the alignment pattern comprises a rectangular frame, two first patterns and a second pattern are arranged in the rectangular frame, and the second pattern is arranged between the two first patterns. The alignment pattern can be attached to a photomask provided by each supplier. When the photomasks need to be aligned, the photomasks only need to be aligned according to the alignment patterns, alignment does not need to be performed according to different alignment patterns of different suppliers, and the difficulty of alignment of the photomasks is simplified. The unexpected effects are that the alignment efficiency of the photomask is improved, and the error rate of operators is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of photomasks, in particular to a photomask. Background Art

[0002] In the chip production process, a mask is needed. Figure 1 As shown, the mask 1 includes a bottom layer 101 and a pattern layer 102; the bottom layer 101 is arranged below the pattern layer 102, and the bottom layer 101 is usually made of quartz glass; the pattern layer 102 usually includes a metal layer 1021 and a silicide layer 1022, the metal layer 1021 is arranged above the silicide layer 1022, the metal layer 1021 is usually made of chromium (Cr), and the silicide layer 1022 is usually made of molybdenum silicide (MoSi). The circuit pattern on the upper surface of the pattern layer 102 can be exposed to the wafer using yellow light lithography technology.

[0003] refer to Figure 1 and Figure 2 As shown, the photomask 1 has a certain service life, and the photomask 1 needs to be replaced with a new one after being used for a period of time. When replacing the new photomask 1, it is necessary to use a photomask pattern inspection machine to perform operations such as alignment (alignment, alignment) and image calibration (image calibration) on the photomask 1. When performing mask alignment, it is necessary to place the photomask 1 on the carrier 2 of the photomask pattern inspection machine, and then find the R point (reference, R point or origin, reference) according to the alignment pattern (mark image, alignment pattern) Figure 2 The center of the circle in the lower left corner), point P (Primary, point P or starting point, reference Figure 2 The center of the circle in the lower left corner) and point S (Secondary, S point or second point, refer to Figure 2 As shown in the center of the circle in the lower right corner of the figure, usually point R and point P coincide. After finding point R and point S, the line between point R and point S is used as the X-axis, and the X-axis is parallel to the horizontal support plate 201 set along the X-axis direction of the carrier 2, and then the coordinates of point R are set to (0, 0). Figure 2 As shown, the dotted line mask 1 indicates that the mask 1 is tilted and needs to be realigned; the solid line mask 1 indicates that the mask 1 is correctly placed. At this time, the mask pattern inspection machine establishes an automated program based on the aforementioned X-axis and (0, 0) coordinates, and the mask alignment is completed, preparing for subsequent pattern calibration.

[0004] However, wafer manufacturing plants usually use masks 1 provided by multiple suppliers. The main graphics on the masks 1 provided by different suppliers are the same, but the alignment graphics are different, that is, the shape, position and size of the alignment graphics are all different. The operators of the wafer manufacturing plant need to change the mask alignment plan according to the different suppliers of the mask 1, resulting in low mask alignment efficiency and a high error rate among operators. Utility Model Content

[0005] The utility model provides a photomask to solve the technical problems of low photomask alignment efficiency and high error rate of operators.

[0006] In order to solve the above technical problems, the utility model provides a mask, including a graphic layer, the graphic layer including a main graphic area and a non-main graphic area, the non-main graphic area is arranged around the main graphic area; four alignment graphics are arranged at intervals on the upper surface of the non-main graphic area, the main graphic area is located in the rectangular area enclosed by the midpoints of the four alignment graphics; the alignment graphics include a rectangular frame, two first graphics and one second graphic are arranged in the rectangular frame, and the second graphic is arranged between the two first graphics.

[0007] Optionally, the first graphic is in the shape of a cross.

[0008] Optionally, the second graphic is in the shape of a rectangle.

[0009] Optionally, the two first graphics are distributed on diagonal positions of the rectangular frame.

[0010] Optionally, the center of the second graphic deviates from the center of the rectangular frame.

[0011] Optionally, the main graphic area is in the shape of a rectangle, the outline of the non-main graphic area is in the shape of a rectangle, and the center of the main graphic area, the center of the non-main graphic area and the center of the rectangle enclosed by the four alignment graphics coincide with each other.

[0012] Optionally, the length of the rectangular frame is 1.5 mm to 2.5 mm, and the width of the rectangular frame is 1.5 mm to 2.5 mm.

[0013] Optionally, the distance between two adjacent alignment patterns is 133 mm to 134 mm.

[0014] Optionally, a protective film frame is provided on the upper surface of the non-main graphic area, the main graphic area is provided within the protective film frame, and the distance between the alignment graphic and the protective film frame is 6.6 mm to 8 mm.

[0015] The utility model provides a photomask, including an alignment pattern, which can be attached to the photomasks provided by various suppliers. The alignment pattern is suitable for photomasks of positive photoresist or negative photoresist type. When the photomask needs to be aligned, it only needs to be aligned according to the alignment pattern, and it is no longer necessary to align according to different alignment patterns of various suppliers, which simplifies the difficulty of photomask alignment. The rectangular frame of the alignment pattern can be used to determine whether the photomask is tilted relative to the X-axis. The alignment pattern adopts a black and transparent color alternating design, which has high recognition and is convenient for operators to use the photomask pattern inspection machine to establish an automated program. The unexpected effect is to improve the efficiency of mask alignment and reduce the error rate of operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a photomask in the prior art.

[0017] Figure 2 The present invention is a structural schematic diagram of aligning a photomask by using a photomask pattern inspection machine in the prior art.

[0018] Figure 3 It is a structural schematic diagram of a photomask provided by an embodiment of the utility model.

[0019] Figure 4 yes Figure 3 A plan view of the alignment graphics in FIG.

[0020] [Description of reference numerals is as follows]:

[0021] Figure 1-2 : Mask-1; bottom layer-101, pattern layer-102; metal layer-1021, silicide layer-1022;

[0022] Load-bearing platform-2; horizontal support plate-201.

[0023] Figure 3-4 : Main graphic area-11, non-main graphic area-12, alignment graphic-13, protective film frame-14;

[0024] Rectangular border-1301, first graphic-1302, second graphic-1303. DETAILED DESCRIPTION

[0025] In order to make the purpose, advantages and features of the utility model clearer, a light mask proposed by the utility model is further described in detail below with reference to the accompanying drawings. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0026] In the description of the present invention, the terms "first", "second", etc. are added for the convenience of description and reference, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined by the terms "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0027] like Figure 3 and Figure 4 As shown, this embodiment provides a mask, including a graphic layer, the graphic layer including a main graphic area 11 and a non-main graphic area 12, the non-main graphic area 12 is arranged around the main graphic area 11; four alignment graphics 13 are arranged at intervals on the upper surface of the non-main graphic area 12, and the main graphic area 12 is located in a rectangular area enclosed by the midpoints of the four alignment graphics 13; the alignment graphics 13 include a rectangular frame 1301, two first graphics 1302 and one second graphic 1303 are arranged in the rectangular frame 1301, and the second graphic 1303 is arranged between the two first graphics 1302.

[0028] Wherein, when the light mask is actually used, Figure 4 The color of the area filled with the middle oblique line is black, and the color of the hollow area, i.e., the unfilled area, is transparent. The main graphic area 11 refers to the area where the circuit graphic is located, and the non-main graphic area 12 refers to the area used for alignment. The second graphic 1303 may be provided with text, such as NSC QRAMARK, which can be used as part of the alignment graphic 13 on the one hand, and as a product logo on the other hand.

[0029] The present embodiment provides a photomask, including an alignment pattern 13, which can be attached to the photomasks provided by various suppliers. The alignment pattern 13 is suitable for positive photoresist or negative photoresist type photomasks. When the photomask needs to be aligned, it only needs to be aligned according to the alignment pattern 13, and it is no longer necessary to align according to different alignment patterns of various suppliers, which simplifies the difficulty of photomask alignment. The rectangular frame 1301 of the alignment pattern 13 can be used to determine whether the photomask is tilted relative to the X-axis. The alignment pattern 13 adopts a black and transparent color alternating design, which has high recognition and is convenient for operators to use the mask pattern inspection machine to establish an automated program. The unexpected effect is to improve the efficiency of mask alignment and reduce the error rate of operators.

[0030] Optional, such as Figure 4 As shown, the shape of the first graphic 1302 is a cross. The cross can be used as a reference point for the alignment graphic 13, which is convenient for operators to find the reference point using a mask pattern inspection machine, and then find the coordinate position of the alignment graphic 13. In other embodiments, the shape of the first graphic 1302 can be a T-shape or an L-shape.

[0031] Optional, such as Figure 4 As shown, the shape of the second graphic 1303 is a rectangle. The rectangle and the cross can be used as a reference point for the alignment graphic 13, which is convenient for operators to find the reference point using the mask pattern inspection machine, and then find the coordinate position of the alignment graphic 13. In addition, the rectangular and cross structures are convenient for processing and forming. In other embodiments, the shape of the second graphic 1303 can be a rhombus or a parallelogram.

[0032] Optional, such as Figure 4 As shown, the two first graphics 1302 are distributed on the diagonal positions of the rectangular frame 1301. When the mask is aligned, it is sometimes necessary to rotate 180° or 270° before alignment. The two first graphics 1302 are distributed on the diagonal positions of the rectangular frame 1301, which can make it easy for operators and mask graphic inspection machines to distinguish and identify the rotated alignment graphics 13.

[0033] Optional, such as Figure 4 As shown, the center of the second graphic 1303 deviates from the center of the rectangular frame 1301. The second graphic 1303 can be used as a reference point for the alignment graphic 13. When the alignment graphic 13 rotates a certain angle, the rotation angle of the alignment graphic 13 can be distinguished according to the change in the position of the second graphic 1303.

[0034] Optional, such as Figure 3 As shown, the main graphic area 11 is in the shape of a rectangle, the outline of the non-main graphic area 12 is in the shape of a rectangle, and the center of the main graphic area 11, the center of the non-main graphic area 12, and the center of the rectangle surrounded by the four alignment graphics 13 coincide with each other, which can further improve the mask alignment efficiency.

[0035] Optional, such as Figure 4 As shown, the length of the rectangular frame 1301 is 1.5mm to 2.5mm, and the width of the rectangular frame 1301 is 1.5mm to 2.5mm. Specifically, the length (lateral outline) of the rectangular frame 1301 can be 1.65mm, and the width (longitudinal outline) of the rectangular frame 1301 is 1.65mm. The outline size of the alignment pattern 13 is relatively large, which can improve the efficiency and accuracy of coarse alignment and fine alignment. Coarse alignment refers to roughly finding the position of the alignment pattern 13, and fine alignment refers to finding the specific position of the alignment pattern 13 and finding the R point and the S point according to the alignment pattern 13, and then using the line between the R point and the S point as the X-axis. The P point of the alignment pattern 13 can be used as the coordinate position of the alignment pattern 13.

[0036] Optional, such as Figure 3As shown, the distance between two adjacent alignment patterns 13 is 133 mm to 134 mm. Specifically, the distance between two adjacent alignment patterns 13 can be 133.15 mm. The distance between two adjacent alignment patterns 13 is relatively large, which can reserve a larger space for the main pattern area 11.

[0037] Optional, such as Figure 3 As shown, a protective film frame 14 is provided on the upper surface of the non-main graphic area 12, the main graphic area 11 is provided in the protective film frame 14, and the distance between the alignment graphic 13 and the protective film frame 14 is 6.6 mm to 8 mm. The protective film frame 14 is used to attach a protective film, and the protective film frame 14 has a shadow effect. In order to prevent the shadow of the protective film frame 14 from affecting the position of the alignment graphic 13, the distance between the alignment graphic 13 and the protective film frame 14 cannot be too close, and the distance can be set to 7.5 mm.

[0038] In summary, the utility model provides a photomask, including an alignment pattern 13, which can be attached to the photomasks provided by various suppliers. The alignment pattern 13 is suitable for positive photoresist or negative photoresist type photomasks. When the photomask needs to be aligned, it only needs to be aligned according to the alignment pattern 13, and it is no longer necessary to align according to different alignment patterns of various suppliers, which simplifies the difficulty of photomask alignment. The rectangular frame 1301 of the alignment pattern 13 can be used to determine whether the photomask is tilted relative to the X-axis. The alignment pattern 13 adopts a black and transparent color alternating design, which has high recognition and is convenient for operators to use the photomask pattern inspection machine to establish an automated program. The unexpected effect is to improve the efficiency of mask alignment and reduce the error rate of operators.

[0039] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation to the scope of the utility model. Any changes and modifications made by ordinary technicians in this field based on the above disclosure are within the protection scope of the utility model.

Claims

1. A photomask, characterized in that: It includes a graphic layer, the graphic layer includes a main graphic area and a non-main graphic area, the non-main graphic area is arranged around the main graphic area; four alignment graphics are arranged at intervals on the upper surface of the non-main graphic area, and the main graphic area is located in a rectangular area enclosed by the midpoints of the four alignment graphics; the alignment graphics include a rectangular frame, two first graphics and one second graphic are arranged in the rectangular frame, and the second graphic is arranged between the two first graphics.

2. A photomask as claimed in claim 1, characterized in that: The first figure is in a cross shape.

3. A photomask as claimed in claim 2, characterized in that: The second figure is in the shape of a rectangle.

4. A photomask as claimed in claim 1, characterized in that: The two first graphics are distributed on the diagonal positions of the rectangular frame.

5. A photomask as claimed in claim 1, characterized in that: The center of the second graphic deviates from the center of the rectangular frame.

6. A photomask as claimed in claim 1, characterized in that: The main graphic area is in the shape of a rectangle, the outline of the non-main graphic area is in the shape of a rectangle, and the center of the main graphic area, the center of the non-main graphic area and the center of the rectangle surrounded by the four alignment graphics coincide with each other.

7. A photomask as claimed in claim 1, characterized in that: The length of the rectangular frame is 1.5 mm to 2.5 mm, and the width of the rectangular frame is 1.5 mm to 2.5 mm.

8. A photomask as claimed in claim 1, characterized in that: The distance between two adjacent alignment patterns is 133 mm to 134 mm.

9. A photomask as claimed in claim 1, characterized in that: A protective film frame is disposed on the upper surface of the non-main graphic area, the main graphic area is disposed within the protective film frame, and the distance between the alignment graphic and the protective film frame is 6.6 mm to 8 mm.

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