Mask plate

Abstract

The utility model discloses a mask plate and belongs to the technical field of quantum chip preparation. The mask plate is used for photoetching of a wafer and comprises a substrate with a first surface, the first surface comprises a target area and a non-target area, a mask pattern of the mask plate is located in the target area, and the mask pattern is used for facing a to-be-photoetched area of the wafer; and the convex structure is connected with the first surface and is located in the non-target area. The mask plate comprises the first surface with the target area and the non-target area, the protruding structure is connected with the non-target area of the first surface, and the mask pattern is located in the target area and faces the to-be-photoetched area of the wafer, so that in the process of using the mask plate for photolithography, the mask pattern is not prone to being damaged. The bulge structures can generate an interval between the mask pattern in the target area and the photoresist coated on the surface of the wafer, so that the pollution of the photoresist to the mask pattern in the photoetching process can be reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of quantum chip preparation, in particular to a mask. Background Art

[0002] In the existing wafer preparation process, contact lithography is mainly used for lithography. In the contact lithography process, the mask plate needs to be in direct contact with the photoresist, so there is a risk of the photoresist contaminating the mask pattern on the mask plate. When the photoresist contaminates the mask pattern of the mask plate, the accuracy of wafer preparation will be significantly reduced.

[0003] Therefore, reducing the contamination of the mask pattern on the mask plate by the photoresist during the photolithography process is an urgent problem to be solved. Utility Model Content

[0004] The utility model aims to provide a mask plate to solve the deficiencies in the prior art and can reduce the pollution of the mask pattern on the mask plate by the photoresist during the photolithography process.

[0005] The solution of this application example is implemented through the following contents.

[0006] In a first aspect, an example of the present application provides a mask for wafer lithography, comprising:

[0007] A substrate having a first surface, wherein the first surface includes a target area and a non-target area, the mask pattern of the mask is located in the target area, and the mask pattern is used to face the area to be photolithographic of the wafer;

[0008] The protruding structure is connected to the first surface and is located in the non-target area.

[0009] According to some examples of the present application, the number of the protrusion structures is plural.

[0010] According to some examples of the present application, the protruding structure and the substrate are integrally formed.

[0011] According to some examples of the present application, the non-target area surrounds the target area.

[0012] According to some examples of the present application, the target area is square, rectangular or circular.

[0013] According to some examples of the present application, the protruding structure is a cuboid, a cube or a cylinder.

[0014] According to some examples of the present application, the protruding structure has a first fixing member and a first extension member;

[0015] The first fixing member is connected to the non-target area and the first extension member respectively;

[0016] The first extension piece is used to extend in a direction perpendicular to the first surface.

[0017] According to some examples of the present application, the mask further includes: a first control member connected to the first extension member and used to control an extension length of the first extension member.

[0018] According to some examples of the present application, the mask further includes: a second fixing member and a second extending member;

[0019] The second fixing member is connected to the non-target area;

[0020] The second extension member is connected to the second fixing member and the protruding structure respectively, and is used to extend in a direction parallel to the first surface.

[0021] According to some examples of the present application, the mask further includes:

[0022] The second control member is connected to the second extension member and is used to control the extension length of the second extension member.

[0023] In the mask template of the aforementioned example of the present application, the mask template includes a first surface having a target area and a non-target area, and a protruding structure is connected to the non-target area of ​​the first surface. Since the mask pattern is located in the target area and faces the area to be photolithographic of the wafer, during the process of photolithography using the mask template, the protruding structure can create a gap between the mask pattern located in the target area and the photoresist coated on the surface of the wafer, thereby reducing the contamination of the mask pattern by the photoresist during the photolithography process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] For a clearer explanation, the following briefly introduces the drawings required for the description.

[0025] Figure 1 A cross-sectional view of the structure of a mask in an example of the present application;

[0026] Figure 2 This is a structural cross-sectional view of a mask plate and a wafer when photolithography is performed using a mask plate in an example of the present application;

[0027] Figure 3 A structural cross-sectional view of a mask plate and a wafer when photolithography is performed using a mask plate in another example of the present application;

[0028] Figure 4 A structural cross-sectional view of a mask in another example of the present application;

[0029] Figure 5It is a cross-sectional view of the structure of a mask in another example of the present application. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limitations on the present application.

[0031] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only 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 as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] Contact lithography is a microelectronics manufacturing technology that uses a photolithography machine to project graphics onto photoresist to form a fine structure. It is one of the indispensable technologies in making chips and integrated circuits. Its basic principle is to use light to pass through the mask and irradiate the photoresist layer, so that the photoresist molecules undergo a chemical reaction to form a pattern, and then through a series of cleaning, etching and other processes, the required fine structure is transferred to the chip surface. However, in the actual process, the photolithography mask is directly in contact with the photoresist layer, which makes the photolithography mask extremely vulnerable to damage, making the life of the photolithography mask short. In addition, in the actual process, due to the certain adhesion of the photoresist, each piece will cause a part of the photoresist to remain on the photolithography plate, which affects the accuracy of the photolithography pattern. At the same time, it also needs to be wiped and cleaned frequently every time the photolithography mask is used, which reduces the work efficiency. At the same time, it will affect the accuracy of the photolithography pattern.

[0034] Based on this, Figure 1As shown, an embodiment of the utility model discloses a mask plate 100, for example, the mask plate 100 is used for photolithography of a wafer 200, including:

[0035] A substrate 110 having a first surface, the first surface including a target area and a non-target area, the mask pattern of the mask plate 100 is located in the target area, and the mask pattern is used to face the area to be photolithographic of the wafer 200;

[0036] The protruding structure 120 is connected to the first surface and is located in the non-target area.

[0037] Wherein, the substrate 110 includes a transparent substrate and a mask pattern of a target area on the first surface of the transparent substrate. The material of the substrate 110 may include quartz glass. The mask pattern includes a patterned metal layer, and the material of the metal layer may include metal chromium. The areas on the first surface other than the target area are all non-target areas. The size (length and width) of the target area is greater than or equal to the size (length and width) of the mask pattern. It should be noted that the materials of the transparent substrate 110 and the mask pattern, as well as the size of the target area can be selected according to actual needs.

[0038] In addition, the raised structure 120 has a preset height in a direction perpendicular to the first surface, and the preset height is greater than zero. The raised structure 120 includes an upper surface in contact with the non-target area in the first surface, a lower surface opposite to the upper surface, and surrounding side surfaces, wherein the upper surface and the lower surface have the same shape and size, and the surrounding side surfaces are perpendicular to the upper surface and the lower surface. The shape and size of the upper surface of the raised structure 120 are related to the shape and size of the non-target area. In one embodiment of the present application, the shape of the upper surface of the raised structure 120 is consistent with the shape and size of the non-target area; in another embodiment of the present application, the shape of the upper surface of the raised structure 120 is similar to the shape of the non-target area, but the area is smaller than the area of ​​the non-target area. It should be noted that the present application does not specifically limit the shape of the upper surface of the raised structure 120, and can be selected as needed, as long as the upper surface of the raised structure 120 is located within the area where the non-target area is located.

[0039] The present application provides a mask plate 100, including a first surface having a target area and a non-target area, and a protruding structure 120 connected to the non-target area of ​​the first surface. Since the mask pattern is located in the target area and faces the area to be photolithographically processed of the wafer 200, during the process of photolithography using the mask plate 100, the protruding structure 120 can create a gap between the mask pattern located in the target area and the photoresist 300 coated on the surface of the wafer 200, which can reduce the contamination of the mask pattern by the photoresist 300 during the photolithography process, improve the accuracy of the photolithography pattern, and also reduce the risk of the mask plate 100 being damaged during the photolithography process. Since the protruding structure 120 can make a gap between the mask pattern and the wafer 200, the risk of the photoresist 300 remaining on the mask plate 100 is reduced, and it is not necessary to wipe and clean the mask plate 100 multiple times during use, which can improve work efficiency.

[0040] In one embodiment of the present application, when the size (length and width) of the target area is smaller than the size of the wafer 200, the preset height of the protruding structure 120 of the mask 100 only needs to be greater than zero, and the preset height can be set according to actual needs. Figure 2 As shown, during photolithography using the mask 100 , the protruding structure 120 of the mask 100 is placed on the photoresist 300 coated on the wafer 200 , and the preset height of the protruding structure 120 determines the distance between the mask pattern and the photoresist 300 .

[0041] In one embodiment of the present application, when the size (length and width) of the target area is greater than or equal to the size of the wafer 200, the preset height of the protrusion structure 120 in the mask 100 must satisfy that the preset height is greater than the sum of the thickness of the wafer 200 and the thickness of the photoresist 300. Figure 3 As shown, when using the above-mentioned mask plate 100 for photolithography, the wafer 200 coated with the photoresist 300 needs to be placed on the stage, and after the mask pattern on the mask plate 100 and the wafer 200 are aligned, the mask plate 100 is placed on the stage. The difference between the sum of the thickness of the wafer 200 and the thickness of the photoresist 300 and the preset height of the protruding structure 120 determines the distance between the mask pattern and the photoresist 300.

[0042] In one embodiment of the present application, there are multiple protrusion structures 120 .

[0043] There may be multiple target areas; a corresponding mask pattern is provided in each target area, the mask patterns in each target area may be the same or different, there are non-target areas between adjacent target areas, and the non-target areas are connected with a protruding structure 120 .

[0044] Based on this, the mask 100 can be used to perform the same or different photolithography on different regions of the wafer 200 at the same time.

[0045] In one embodiment of the present application, the protrusion structure 120 and the substrate 110 are integrally formed.

[0046] The protruding structure 120 and the transparent substrate of the substrate 110 are made of the same material and are integrally formed.

[0047] Specifically, according to preset parameters, integrated processing is performed to obtain a transparent substrate connected with a protruding structure 120, wherein the preset parameters include the size of the transparent substrate 110, the position of the target area and the non-target area, the size of the protruding structure 120, and the position of the protruding structure 120 on the first surface; according to the position of the target area on the first surface, magnetron sputtering is performed to form a mask pattern in the target area. In one embodiment of the present application, a transparent substrate connected with a protruding structure 120 can be obtained by filling molten glass or quartz into a tiny mold. In one embodiment of the present application, a laser beam or a micromechanical tool can be used to directly perform high-precision processing on a glass or quartz plate to obtain a transparent substrate connected with a protruding structure 120. In one embodiment of the present application, chemical etching or photolithography technology can be used to process a glass or quartz plate to obtain a transparent substrate connected with a protruding structure 120.

[0048] In one embodiment of the present application, the non-target area surrounds the target area.

[0049] The center of the target area is the same as the center of the first surface. The target area can be a regular shape or an irregular shape, and the areas of the first surface other than the target area are all non-target areas, and the shape of the non-target area is related to the shape of the target area. In one embodiment of the present application, the target area can be a square, a rectangle or a circle.

[0050] A mask pattern is set in the target area, and the size (length and width) of the target area is greater than or equal to the size of the mask pattern. It should be noted that the shape of the target area can be set according to actual needs.

[0051] In one embodiment of the present application, the protrusion structure 120 is a cuboid, a cube or a cylinder.

[0052] The upper surface of the protruding structure 120 is only located in the non-target area and does not exceed the area where the non-target area is located. The shape of the protruding structure 120 can be set according to actual needs.

[0053] like Figure 4 As shown, in one embodiment of the present application, the protruding structure 120 has a first fixing member 410 and a first extension member 420;

[0054] A first fixing member 410 is connected to the non-target area and the first extension member 420 respectively;

[0055] The first extension member 420 is configured to extend in a direction perpendicular to the first surface.

[0056] In one embodiment of the present application, the mask 100 further includes: a first control member connected to the first extension member 420 and used to control the extension length of the first extension member 420 .

[0057] Specifically, the first control member (not shown) can be located on the side of the first fixing member 410 and connected to the first extension member 420. The first extension member 420 has a preset length extension range, and the first control member can control the extension length of the first extension member 420, thereby controlling the distance between the mask pattern located in the first surface target area and the photoresist 300 coated on the wafer 200.

[0058] like Figure 5 As shown, in one embodiment of the present application, the mask 100 further includes: a second fixing member 510 and a second extension member 520;

[0059] A second fixing member 510 connected to the non-target area;

[0060] The second extension member 520 is connected to the second fixing member 510 and the protruding structure 120 respectively, and is used to extend in a direction parallel to the first surface.

[0061] The second fixing member 510 is located on both sides of the transparent substrate, which may be the transparent substrate corresponding to the non-target area. The second extension member 520 is located on the left and right sides of the transparent substrate, connected to the second fixing member 510, and extends along the length direction of the substrate.

[0062] In one embodiment of the present application, the mask 100 further includes:

[0063] The second control member is connected to the second extension member 520 and is used to control the extension length of the second extension member 520 .

[0064] Specifically, the second control member (not shown) can be located on the upper surface or side of the second fixing member 510 and connected to the second extension member 520. The second extension member 520 has a preset length extension range, and the second control member can control the extension length of the second extension member 520, thereby controlling the spacing between the protruding structures 120.

[0065] The mask plate 100 has a first extension piece 420 extending in a direction perpendicular to the first surface and a second extension piece 520 extending in a direction parallel to the second surface, so that the mask plate 100 can be applied to the lithography of wafers 200 of different sizes, thereby effectively improving the scope of application.

[0066] In the description of this specification, the description with reference to the terms "some embodiments" or "examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0067] The above are only preferred embodiments of the present invention and do not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, may make any equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which shall be deemed as the content of the technical solution of the present invention and still fall within the protection scope of the present invention.

Claims

1. A mask for wafer lithography, characterized in that: include: A substrate having a first surface, wherein the first surface includes a target area and a non-target area, the mask pattern of the mask is located in the target area, and the mask pattern is used to face the area to be photolithographic of the wafer; The protruding structure is connected to the first surface and is located in the non-target area.

2. The mask according to claim 1, characterized in that: The number of the protrusion structures is multiple.

3. The mask according to claim 1, characterized in that: The protruding structure and the substrate are integrally formed.

4. The mask according to claim 1, characterized in that: The non-target area surrounds the target area.

5. The mask according to claim 1, characterized in that: The target area is square, rectangular or circular.

6. The mask according to claim 1, characterized in that: The protruding structure is a cuboid, a cube or a cylinder.

7. The mask according to claim 1, characterized in that: The protruding structure has a first fixing member and a first extension member; The first fixing member is connected to the non-target area and the first extension member respectively; The first extension piece is used to extend in a direction perpendicular to the first surface.

8. The mask according to claim 7, characterized in that: include: The first control member is connected to the first extension member and is used to control the extension length of the first extension member.

9. The mask according to claim 1, characterized in that: The mask plate further comprises: a second fixing member and a second extending member; The second fixing member is connected to the non-target area; The second extension member is connected to the second fixing member and the protruding structure respectively, and is used to extend in a direction parallel to the first surface.

10. The mask according to claim 9, characterized in that: The mask also includes: The second control member is connected to the second extension member and is used to control the extension length of the second extension member.

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