Mask and design method thereof

Abstract

The embodiment of the invention provides a mask and a design method thereof. In the mask provided by the embodiment of the invention, for the pattern array comprising at least two target patterns, at least one second auxiliary pattern is arranged at the corner of each target pattern, and the included angle between the second auxiliary pattern and the straight line where the side edge is located is the acute angle or the obtuse angle; the distance between the second auxiliary pattern and the adjacent corner part is smaller than the distance between the first auxiliary pattern and the adjacent side edge, so that the arrangement density of the auxiliary patterns near the corner part can be improved, the light intensity distribution near the corner part of the target pattern can be improved in the exposure process, the fillet degree of the corner part can be reduced, and the exposure quality of the target pattern can be improved. The matching degree of a pattern formed by a photoresist layer after exposure and a target pattern can be improved. Meanwhile, the arrangement density of the auxiliary patterns on the periphery of each target pattern can be increased, the focusing depth in the exposure process can be increased, and the matching degree of the pattern formed by the photoresist layer after exposure and the target pattern can be further improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular, to a mask and a design method thereof. Background Art

[0002] In the photolithography process of manufacturing semiconductor devices, a mask is needed to transfer the target pattern of the mask to the film layer to be etched on the substrate.

[0003] As the size of semiconductor devices decreases, the diffraction effect of light becomes increasingly significant, resulting in an increasing difference between the pattern formed on the film to be etched and the target pattern. In particular, due to the Optical Proximity Effect (OPE), the pattern formed on the film to be etched has obvious problems of rounded corners and tightened ends of straight lines.

[0004] Currently, the difference between the pattern formed on the film layer to be etched and the target pattern is mainly reduced by using the OPC (Optical Proximity Correction) technology. However, the existing OPC technology still has difficulty in solving the problem of obvious corner rounding of the pattern formed on the film layer to be etched. Summary of the invention

[0005] In view of the shortcomings of the existing methods, the present application proposes a mask and a design method thereof to solve the technical problem that in the photolithography process of the prior art, the pattern formed on the film layer to be etched has obvious rounded corners.

[0006] In a first aspect, an embodiment of the present application provides a mask, including:

[0007] at least two target graphics, the target graphics comprising at least two corners and at least two sides;

[0008] At least two first auxiliary combination figures, each of which surrounds a target figure, and the first auxiliary combination figures include at least two first auxiliary figures and at least two second auxiliary figures; a first auxiliary figure is arranged outside each side, and the first auxiliary figure is parallel to the adjacent side; a second auxiliary figure is arranged outside each corner, and the angle between the straight line where the second auxiliary figure is located and the straight line where the side is located is an acute angle or an obtuse angle; the distance between the second auxiliary figure and the adjacent corner is smaller than the distance between the first auxiliary figure and the adjacent side;

[0009] At least one second auxiliary combination pattern surrounds the periphery of all the first auxiliary combination patterns.

[0010] In a second aspect, an embodiment of the present application provides a method for designing a mask as provided in the first aspect, comprising:

[0011] Determine whether the distance between any two adjacent target graphics is less than a set threshold;

[0012] If it is less than the set threshold, it is determined that each target pattern is surrounded by at least one first auxiliary combination pattern, and all first auxiliary combination patterns are surrounded by at least one second auxiliary combination pattern.

[0013] The beneficial technical effects brought about by the technical solution provided by the embodiment of the present application include:

[0014] In the mask provided in the embodiment of the present application, for a graphic array including at least two target graphics, since each target graphic is provided with at least one second auxiliary graphic whose angle with the straight line where the side is located is acute or obtuse, and the distance between the second auxiliary graphic and the adjacent corner is smaller than the distance between the first auxiliary graphic and the adjacent side, the arrangement density of the auxiliary graphics near the corner can be improved, thereby helping to improve the light intensity distribution near the corner of the target graphic during the exposure process, helping to reduce the degree of rounding of the corner, and improving the degree of matching between the graphic formed on the film layer to be etched after exposure and the target graphic.

[0015] At the same time, by surrounding at least one first auxiliary combination pattern on the periphery of each target pattern and setting a second auxiliary combination pattern surrounding all first auxiliary combination patterns, the arrangement density of the auxiliary patterns on the periphery of each target pattern can be increased, the focusing depth during the exposure process can be increased, and the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern can be further improved.

[0016] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0018] Figure 1 A schematic diagram of a graphic design scheme in a mask provided in an embodiment of the present application;

[0019] Figure 2 A schematic diagram of another graphic design scheme in a mask provided in an embodiment of the present application;

[0020] Figure 3a Provided for the embodiments of this application Figure 1 A comparison diagram of a simulated pattern formed on a photoresist layer of a target pattern located at the center of an array, a simulated pattern formed by a pattern design scheme in a related art, and the target pattern;

[0021] Figure 3b Provided for the embodiments of this application Figure 1 A comparison diagram of a simulated pattern formed on a photoresist layer of a target pattern located at an edge of an array and between two corners, a simulated pattern formed by a pattern design scheme in a related art, and the target pattern;

[0022] Figure 3c Provided for the embodiments of this application Figure 1 A comparison diagram of a simulated pattern formed in a photoresist layer of a target pattern located at a corner of an array, a simulated pattern formed by a pattern design scheme in a related art, and the target pattern;

[0023] Figure 3d Provided for the embodiments of this application Figure 1 Error comparison diagram of the simulated pattern formed by the photoresist layer of the target pattern located at the corner of the array and the simulated pattern formed by the pattern design scheme in the related art at different defocus distances;

[0024] Figure 4 A schematic diagram of a process flow of a mask design method provided in an embodiment of the present application;

[0025] Figure 5 A schematic diagram of an arrangement relationship between a single target pattern and a plurality of first auxiliary patterns after determining that the spacing between any two adjacent target patterns is greater than a set threshold value in a mask design method provided in an embodiment of the present application;

[0026] Figure 6 Provided for the embodiments of this application Figure 5 The exposure simulation schematic diagram of a single target pattern and a plurality of first auxiliary patterns is shown;

[0027] Figure 7 In a mask design method provided in an embodiment of the present application, after determining that the distance between any two adjacent target patterns is greater than a set threshold, a schematic diagram of another arrangement relationship between a single target pattern and a plurality of first auxiliary patterns is provided.

[0028] Description of reference numerals:

[0029] 10- target graphics;

[0030] 11-side; 12-corner;

[0031] 20-First auxiliary combination figure;

[0032] 21-first auxiliary graphic; 211-sub-segment; 22-second auxiliary graphic;

[0033] 30- the second auxiliary combination figure;

[0034] 31- third auxiliary figure; 32- fourth auxiliary figure;

[0035] 40- fifth auxiliary figure;

[0036] 101-simulated graphics formed by relevant graphic design schemes;

[0037] 102-a simulated pattern formed on the photoresist layer by a target pattern located at the center of the array;

[0038] 103-a simulated pattern formed in the photoresist layer by a target pattern located at the edge of the array and between two corners;

[0040] 104-a simulated pattern formed in the photoresist layer by a target pattern located at a corner of the array;

[0041] 105-A simulation pattern of a single target pattern and a plurality of first auxiliary patterns formed on a photoresist layer. DETAILED DESCRIPTION

[0043] The embodiments of the present application are described below in conjunction with the drawings in the present application. It should be understood that the implementation methods described below in conjunction with the drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.

[0044] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the implementation of other features, information, data, steps, operations, elements, components and / or combinations thereof supported by the technical field. The term "and / or" used herein refers to at least one of the items defined by the term, for example, "A and / or B" may be implemented as "A", or as "B", or as "A and B".

[0045] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0046] First, several terms involved in this application are introduced and explained:

[0047] In the field of semiconductor manufacturing, a graphic process is required to transfer the design to the surface of the film layer to be etched in the substrate. At present, the graphic process mainly includes exposure, development, etching and other steps. In the exposure step, light is irradiated to the film layer to be etched coated with photoresist through the light-transmitting area in the mask, and the photoresist undergoes a chemical reaction under the irradiation of light; in the development step, the different degrees of solubility of the photosensitive and non-photosensitive photoresists in the developer are used to form a photolithography pattern, and the pattern is transferred from the mask to the photoresist; in the etching step, the film layer to be etched is etched based on the photolithography pattern formed by the photoresist layer, so as to further transfer the pattern of the mask to the film layer to be etched.

[0048] As the size of the target pattern continues to decrease, the diffraction effect of light becomes more and more obvious, resulting in OPE problems, which causes the actual lithography pattern to be seriously distorted relative to the design pattern on the mask, ultimately resulting in the actual pattern formed by lithography on the film layer to be etched being different from the target pattern.

[0049] Currently, OPE is mainly offset by setting auxiliary patterns around the target pattern through OPC. However, the existing OPC technology still finds it difficult to solve the problem of obvious corner rounding of the pattern formed by the film layer to be etched. At the same time, the density of the mask pattern (including the target pattern and the auxiliary pattern) in the existing mask is relatively small, resulting in insufficient DOF (Depth Of Focus) of the mask pattern density, which further causes the actual pattern formed by photolithography on the film layer to be etched to be different from the target pattern.

[0050] The mask and design method thereof provided in this application are intended to solve the above technical problems of the prior art.

[0051] The following is a detailed description of the technical solution of the present application and how the technical solution of the present application solves the above technical problems with specific embodiments. It should be noted that the following implementations can refer to, draw on or combine with each other, and the same terms, similar features and similar implementation steps in different implementations will not be described repeatedly.

[0052] The present application embodiment provides a mask, and a schematic diagram of a graphic design scheme in the mask is as follows Figure 1As shown, it includes: at least two target graphics 10, the target graphics 10 includes at least two corners 12 and at least two sides 11; at least two first auxiliary combination graphics 20, each first auxiliary combination graphic 20 surrounds the periphery of a target graphic 10, and the first auxiliary combination graphic 20 includes at least two first auxiliary graphics 21 and at least two second auxiliary graphics 22; a first auxiliary graphic 21 is arranged on the outside of each side 11, and the first auxiliary graphic 21 is parallel to the adjacent side 11; a second auxiliary graphic 22 is arranged on the outside of each corner 12, and the angle between the straight line where the second auxiliary graphic 22 is located and the straight line where the side 11 is located is an acute angle or an obtuse angle; the distance between the second auxiliary graphic 22 and the adjacent corner 12 is less than the distance between the first auxiliary graphic 11 and the adjacent side 11; at least one second auxiliary combination graphic 30 surrounds the periphery of all first auxiliary combination graphics 20.

[0053] In the mask provided in the embodiment of the present application, for a pattern array including at least two target patterns 10, since the corner 12 of each target pattern 10 is provided with at least one second auxiliary pattern 22 whose angle with the straight line where the side 11 is located is acute or obtuse, and the distance between the second auxiliary pattern 22 and the adjacent corner 12 is smaller than the distance between the first auxiliary pattern 21 and the adjacent side 11, the arrangement density of the auxiliary patterns near the corner 12 can be improved, thereby helping to improve the light intensity distribution near the corner 12 of the target pattern 10 during the exposure process, helping to reduce the degree of rounding of the corner 12, and improving the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0054] At the same time, by surrounding at least one first auxiliary combination pattern 20 on the periphery of each target pattern 10 and setting a second auxiliary combination pattern 30 surrounding all the first auxiliary combination patterns 20, the arrangement density of the auxiliary patterns on the periphery of each target pattern 10 can be increased, which helps to increase the focus depth during the exposure process, is beneficial to improving the photolithography process window, and can further improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0055] In the embodiment of the present application, the mask includes at least two target patterns 10, optionally, as Figure 1 As shown, the mask includes nine target patterns 10, and the target patterns 10 are arranged in an array.

[0056] In the embodiment of the present application, each target pattern 10 includes at least two corners 12 and at least two sides 11. Optionally, as Figure 1 As shown, the target pattern 10 is in a square shape, and includes four corners 12 and four sides 11 .

[0057] In the present application embodiment, Figure 1As shown, each target pattern 10 is surrounded by a first auxiliary combination pattern 20 , that is, the number of the target patterns 10 is the same as the number of the first auxiliary combination patterns 20 .

[0058] In the present application embodiment, Figure 1 As shown, the first auxiliary combination pattern 20 includes at least two first auxiliary patterns 21 and at least two second auxiliary patterns 22, the first auxiliary patterns 21 are parallel to the adjacent side edges 11, and the angle between the straight line where the second auxiliary patterns 22 are located and the straight line where the side edges 11 are located is an acute angle or an obtuse angle.

[0059] Alternatively, if Figure 1 As shown, for the same target graphic 10, a first auxiliary graphic 21 is arranged on the outer side of each side 11, that is, the number of the first auxiliary graphics 21 is the same as the number of the side edges 11; a second auxiliary graphic 22 is arranged on the outer side of each corner 12, that is, the number of the second auxiliary graphics 22 is the same as the number of the corners 12.

[0060] In the embodiment of the present application, the distance between the second auxiliary pattern 22 and the adjacent corner 12 is smaller than the distance between the first auxiliary pattern 11 and the adjacent side 11. It should be noted that in the embodiment of the present application, unless otherwise specified, the distance between the two refers to the shortest distance between the two.

[0061] In the embodiment of the present application, by setting at least one second auxiliary pattern 22 at the corner 12 of each target pattern 10, and the distance between the second auxiliary pattern 22 and the adjacent corner 12 is smaller than the distance between the first auxiliary pattern 21 and the adjacent side 11, the arrangement density of the auxiliary patterns near the corner 12 can be improved. During the exposure process, the second auxiliary pattern 22 can offset part of the OPE, thereby helping to improve the light intensity distribution near the corner 12 of the target pattern 10, which is beneficial to reduce the degree of rounding of the corner 12, and can improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0062] In the present application embodiment, Figure 1 As shown, the periphery of the array pattern formed by all the first auxiliary combination patterns 20 is surrounded by at least one second auxiliary combination pattern 30, thereby being able to further increase the arrangement density of the auxiliary patterns around the target pattern 10, helping to increase the depth of field of the pattern in the mask, and helping to increase the focusing depth of the light of the lithography machine reaching the photoresist layer after passing through the mask, thereby helping to further improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0063] Alternatively, if Figure 1 As shown, the periphery of the array pattern formed by all the first auxiliary combination patterns 20 is surrounded by two second auxiliary combination patterns 30 .

[0064] Those skilled in the art can determine the specific number of the first auxiliary combined graphics 20 and the second auxiliary combined graphics 30 according to the parameter information of the target graphics 10 .

[0065] It should be noted that in the embodiment of the present application, the target pattern 10, the first auxiliary pattern 21 and the second auxiliary pattern 22 are all light-transmitting areas. Optionally, the target pattern 10, the first auxiliary pattern 21 and the second auxiliary pattern 22 are via holes penetrating the mask.

[0066] Alternatively, if Figure 1 As shown, in one embodiment of the present application, the first auxiliary combination graphic 20 is arranged concentrically with the target graphic 10 surrounded by it; the first auxiliary combination graphic 20 is a non-closed ring, and along the direction of the surrounding target graphic 10, the first auxiliary graphics 21 and the second auxiliary graphics 22 are alternately arranged at intervals; the length of the first auxiliary graphic 21 is less than the length of the side 11.

[0067] In the present application embodiment, Figure 1 As shown, the first auxiliary combination pattern 20 is concentrically arranged with the target pattern 10 surrounded by it, so that the distances between each side 11 of the target pattern 10 and the adjacent first auxiliary pattern 21 are the same, which helps to ensure the consistency of the arrangement density of the first auxiliary patterns 21 near each side 11 of the target pattern 10; the distances between each corner 12 of the target pattern 10 and the adjacent second auxiliary pattern 22 are the same, which helps to ensure the consistency of the arrangement density of the second auxiliary patterns 22 near each corner 12 of the target pattern 10, and helps to make the degree of reduction of the rounding of each corner 12 the same, which helps to ensure the consistency of each corner in the pattern formed on the film layer to be etched after exposure.

[0068] In the present application embodiment, Figure 1 As shown, along the direction surrounding the target pattern 10, the first auxiliary patterns 21 and the second auxiliary patterns 22 are alternately arranged at intervals to form a first auxiliary combined pattern 20 that is a non-closed ring.

[0069] Alternatively, if Figure 1 As shown, the length of the first auxiliary pattern 21 is smaller than the length of the side 11, which helps to ensure the length of the second auxiliary pattern 22, helps to ensure the density of the auxiliary pattern near the corner 12 of the target pattern 10, and thus helps to improve the light intensity distribution near the corner 12, which helps to reduce the degree of rounding of the corner 12, and can improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0070] Alternatively, if Figure 1As shown, in one embodiment of the present application, the second auxiliary combination pattern 30 includes at least two third auxiliary patterns 31 and at least two fourth auxiliary patterns 32; in the array formed by all the first auxiliary combination patterns 20, the third auxiliary pattern 31 is arranged on the outside of the outermost first auxiliary pattern 21, and the fourth auxiliary pattern 32 is arranged on the outside of the second auxiliary pattern 22 located at the corner; the third auxiliary pattern 31 is parallel to the adjacent first auxiliary pattern 21, and the fourth auxiliary pattern 32 is parallel to the adjacent second auxiliary pattern 22.

[0071] In the present application embodiment, Figure 1 As shown, the second auxiliary combination pattern 30 includes a plurality of third auxiliary patterns 31 and a plurality of fourth auxiliary patterns 32, the third auxiliary patterns 31 are parallel to the adjacent first auxiliary patterns 21, and the fourth auxiliary patterns 32 are parallel to the adjacent second auxiliary patterns 22, so that the shape of the second auxiliary combination pattern 30 is the same as that of the first auxiliary combination pattern 20.

[0072] Alternatively, if Figure 1 As shown, for the array formed by all the first auxiliary combination patterns 20, the third auxiliary patterns 31 are arranged on the outer side of each first auxiliary pattern 21 located at the outermost side, that is, the number of the third auxiliary patterns 31 is the same as the number of the first auxiliary patterns 21 located at the outermost side; the fourth auxiliary patterns 32 are arranged on the outer side of the second auxiliary patterns 22 located at the corner, that is, the number of the fourth auxiliary patterns 32 is the same as the number of the second auxiliary patterns 22 located at the corner.

[0073] Alternatively, if Figure 1 As shown, for an array formed by nine first auxiliary combination patterns 20 , the second auxiliary combination pattern 30 includes twelve third auxiliary patterns 31 and four fourth auxiliary patterns 32 .

[0074] Those skilled in the art understand that, for an array formed by a plurality of target patterns 10, the target pattern 10 located in the central portion and the first auxiliary combination patterns 20 of adjacent target patterns 10 are close to each other, thereby ensuring the arrangement density of the auxiliary patterns near the target pattern 10 located in the central portion, while the partial corners 12 and partial side edges 11 of the target pattern 10 located at the corners and the outermost portion cannot be close to the first auxiliary combination patterns 20 of the adjacent target pattern 10, thereby causing the arrangement density of the auxiliary patterns near the corners and the outermost target pattern 10 to be less than the arrangement density of the auxiliary patterns near the target pattern 10 located in the central portion.

[0075] In the embodiment of the present application, a fourth auxiliary pattern 32 is provided on the outer side of the second auxiliary pattern 22 located at the corner. Since the fourth auxiliary pattern 32 is parallel to the second auxiliary pattern 22, the arrangement density of the auxiliary patterns near the corner 12 located on the outer side of the target pattern 10 located at the corner can be further improved. During the exposure process, it helps to improve the light intensity distribution near the corner 12 of the target pattern 10, which is beneficial to reduce the degree of rounding of the corner 12, and can improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0076] In the embodiment of the present application, by providing a third auxiliary pattern 31 on the outer side of each first auxiliary pattern 21 located on the outermost side, the arrangement density of the auxiliary patterns near the outer side 11 of the outermost target pattern 10 can be further improved. During the exposure process, it helps to improve the focusing depth of the light reaching the photoresist layer after passing through the side 11, and can further improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0077] It should be noted that in the embodiment of the present application, the third auxiliary pattern 31 and the fourth auxiliary pattern 32 in the second auxiliary combined pattern 30 are both light-transmitting areas. Optionally, the third auxiliary pattern 31 and the fourth auxiliary pattern 32 are via holes penetrating the mask.

[0078] Alternatively, if Figure 1 As shown, in one embodiment of the present application, all second auxiliary combination graphics 30 are non-closed rings; the second auxiliary combination graphics 30 are concentrically arranged with the array surrounded by it; in the same second auxiliary combination graphics 30, the fourth auxiliary graphics 32 are spaced apart from the adjacent third auxiliary graphics 31, and any two adjacent fourth auxiliary graphics 32 are spaced apart; the length of the third auxiliary graphics 31 is greater than the length of the side 11.

[0079] In the present application embodiment, Figure 1 As shown, all the second auxiliary combination graphics 30 are non-closed rings. Figure 1 As shown, along the direction of the array formed by surrounding all the first auxiliary combination patterns 20, every three third auxiliary patterns 31 and one fourth auxiliary pattern 32 are alternately arranged.

[0080] In the present application embodiment, Figure 1 As shown, the second auxiliary combination pattern 30 is arranged concentrically with the array surrounded by it, that is, Figure 1As shown, the center of the second auxiliary combination pattern 30 overlaps with the center of the target pattern 10 located in the middle and the center of the first auxiliary combination pattern 10 located in the middle. The distances between each third auxiliary pattern 31 and the adjacent side 11 are equal, and the distances between each fourth auxiliary pattern 32 and the adjacent corner 12 are equal, which helps to ensure the consistency of the auxiliary pattern arrangement density near each corner 12 in the target pattern 10, helps to make the degree of rounding reduction of each corner 12 the same, and helps to ensure the consistency of each corner in the pattern formed on the film layer to be etched after exposure.

[0081] Alternatively, if Figure 1 As shown, in the same second auxiliary combination pattern 30, the fourth auxiliary pattern 32 is spaced apart from the adjacent third auxiliary pattern 31, and any two adjacent fourth auxiliary patterns 32 are spaced apart, so that the second auxiliary combination pattern 30 forms a non-closed ring.

[0082] Alternatively, if Figure 1 As shown, the length of the third auxiliary pattern 31 is greater than the length of the side 11, so that the third auxiliary pattern 31 can increase the density of the auxiliary pattern near the corner 12 of the target pattern 10 located at the outermost side and between two adjacent corners, which helps to further reduce the degree of rounding of each corner 12 to the same extent, and helps to ensure the consistency of each corner in the pattern formed on the film layer to be etched after exposure.

[0083] Optionally, in the embodiment of the present application, in any two adjacent second auxiliary combination graphics 30, the length of the third auxiliary graphic 31 of the second auxiliary combination graphic 30 located on the outside is greater than the length of the third auxiliary graphic 31 of the second auxiliary combination graphic 30 located on the inside; the length of the fourth auxiliary graphic 32 of the second auxiliary combination graphic 30 located on the outside is greater than the length of the fourth auxiliary graphic 32 of the second auxiliary combination graphic 30 located on the inside.

[0084] Alternatively, if Figure 1 As shown, in one embodiment of the present application, in the outermost second auxiliary combination graphic 30, a third auxiliary graphic 31 is arranged between any two adjacent fourth auxiliary graphics 32, and the length of the third auxiliary graphic 31 is greater than the length of the third auxiliary graphic 31 in the adjacent second auxiliary combination graphic 30.

[0085] In the present application embodiment, Figure 1 As shown, in the outermost second auxiliary combination pattern 30, a third auxiliary pattern 31 is arranged between any two adjacent fourth auxiliary patterns 32. Optionally, as Figure 1 As shown, the second auxiliary combination pattern 30 located on the outermost side includes four third auxiliary patterns 31 and four fourth auxiliary patterns 32 .

[0086] In the embodiment of the present application, the length of the third auxiliary pattern 31 of the outermost second auxiliary combination pattern 30 is greater than the length of the third auxiliary pattern 31 in the adjacent second auxiliary combination pattern 30, thereby simplifying the design of the outermost second auxiliary combination pattern 30 and helping to reduce the production cost of the mask.

[0087] Alternatively, if Figure 1 As shown, the length of the third auxiliary pattern 31 of the outermost second auxiliary combination pattern 30 is greater than the sum of the lengths of all the third auxiliary patterns 31 located on the same side in the adjacent second auxiliary combination pattern 30, which helps to ensure the arrangement density of the auxiliary patterns around the target pattern 10, helps to further reduce the degree of rounding of each corner 12 to the same extent, and helps to ensure the consistency of each corner in the pattern formed on the film layer to be etched after exposure.

[0088] Alternatively, if Figure 2 As shown, in one embodiment of the present application, the second auxiliary combination figures 30 except the outermost second auxiliary combination figures 30 are non-closed rings; the second auxiliary combination figures 30 are arranged concentrically with the array surrounded by them; in the same non-closed ring-shaped second auxiliary combination figures 30, both ends of the fourth auxiliary figure 32 are connected to a third auxiliary figure 31, and any two adjacent third auxiliary figures 31 are arranged at intervals; the length of the third auxiliary figure 31 is greater than the length of the side 11.

[0089] In the embodiment of the present application, the second auxiliary combination figures 30 except the outermost second auxiliary combination figures 30 are non-closed rings. Figure 2 As shown, two second auxiliary combination figures 30 are provided, and the second auxiliary combination figure 30 located on the inner side is a non-closed ring.

[0090] Alternatively, if Figure 2 As shown, the second auxiliary combination pattern 30 is arranged concentrically with the array surrounded by it, that is, Figure 2 As shown, the center of the second auxiliary combination pattern 30 overlaps with the center of the target pattern 10 located in the middle and the center of the first auxiliary combination pattern 10 located in the middle, which helps to ensure the consistency of the auxiliary pattern arrangement density near each corner 12 in the target pattern 10, helps to make the degree of rounding reduction of each corner 12 the same, and helps to ensure the consistency of each corner in the pattern formed on the film layer to be etched after exposure.

[0091] Alternatively, if Figure 2As shown, in the same non-closed ring-shaped second auxiliary combination pattern 30, any two adjacent third auxiliary patterns 31 are arranged at intervals, and the length of the third auxiliary pattern 31 is greater than the length of the side 11, so that the third auxiliary pattern 31 can increase the density of the auxiliary patterns near the corner 12 and the side 11 of the outermost target pattern 10, which helps to further reduce the rounding degree of the corner 12 and increase the focusing depth of the light reaching the photoresist layer after passing through the side 11, which helps to ensure the consistency of the corners in the pattern formed on the film layer to be etched after exposure.

[0092] Alternatively, if Figure 2 As shown, in the same non-closed ring-shaped second auxiliary combination pattern 30, both ends of the fourth auxiliary pattern 32 are connected to a third auxiliary pattern 31, thereby further increasing the density of the auxiliary patterns near the outermost corner 12 of the target pattern 10 located at the corner, which helps to further reduce the degree of rounding of each corner 12.

[0093] Alternatively, if Figure 2 As shown, in one embodiment of the present application, in the second auxiliary combination pattern 30 located on the outermost side, all the third auxiliary patterns 31 and the fourth auxiliary patterns 32 are connected to form a closed ring.

[0094] In the embodiment of the present application, for the outermost second auxiliary combination pattern 30, along the direction of the array formed by surrounding all the first auxiliary combination patterns 20, all the third auxiliary patterns 31 and all the fourth auxiliary patterns 32 are connected to form a closed ring, thereby simplifying the design of the outermost second auxiliary combination pattern 30 and helping to reduce the production cost of the mask.

[0095] Moreover, for the closed ring-shaped second auxiliary combination pattern 30, the arrangement density of the auxiliary patterns around the target pattern 10 can be increased, which helps to further reduce the degree of rounding of each corner 12 to the same extent, and helps to ensure the consistency of each corner in the pattern formed on the film layer to be etched after exposure.

[0096] Alternatively, if Figure 2 As shown, in one embodiment of the present application, the first auxiliary graphic 21 includes: two sub-segments 211 arranged at intervals; in the same first auxiliary combination graphic 20, one end of the second auxiliary graphic 22 is connected to one end of a sub-segment 211 of a first auxiliary graphic 21, and the other end of the second auxiliary graphic 22 is connected to one end of a sub-segment 211 of another first auxiliary graphic 21.

[0097] In the present application embodiment, Figure 2 As shown, the first auxiliary pattern 21 includes two sub-segments 211 that are spaced apart from each other. For the same first auxiliary pattern 21 , the straight lines where the two sub-segments 211 are located overlap each other.

[0098] In the present application embodiment, Figure 2 As shown, in the same first auxiliary combination pattern 20, one end of each second auxiliary pattern 22 is connected to a sub-segment 211, and optionally, one end of the second auxiliary pattern 22 is connected to one end of a sub-segment 211 of a first auxiliary pattern 21, and the other end of the second auxiliary pattern 22 is connected to one end of a sub-segment 211 of another first auxiliary pattern 21. This arrangement can further increase the density of the auxiliary patterns near the corner 12 of the target pattern 10, help to further improve the light intensity distribution near the corner 12 of the target pattern 10, help to further reduce the rounding degree of the corner 12, and can further improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0099] It should be noted that, in the embodiment of the present application, the length of the first auxiliary pattern 21 is the sum of the lengths of the two sub-segments 211 disposed at intervals.

[0100] Alternatively, if Figure 1 and Figure 2 As shown, in one embodiment of the present application, the mask further includes: at least two fifth auxiliary patterns 40 surrounded by the second auxiliary combination patterns 30; and a fifth auxiliary pattern 40 is arranged on the outer side of at least one second auxiliary pattern 22 in the first auxiliary combination pattern 20 away from the corner 12.

[0101] This application is in the embodiment, Figure 1 and Figure 2 As shown, a plurality of fifth auxiliary graphics 40 are further arranged in the space surrounded by the second auxiliary combination graphics 30 , and the fifth auxiliary graphics 40 are arranged outside the space surrounded by the first auxiliary combination graphics 20 .

[0102] In the present application embodiment, Figure 1 and Figure 2 As shown, a fifth auxiliary pattern 40 is disposed on the outer side of at least one second auxiliary pattern 22 of the first auxiliary combination pattern 20 away from the corner 12 .

[0103] Alternatively, if Figure 1 and Figure 2 As shown, for the array formed by all the first auxiliary combination patterns 20, the outer sides of the second auxiliary patterns 22 other than the outermost corners in the first auxiliary combination patterns 20 located at the corners are all provided with fifth auxiliary patterns 40, so that the arrangement density of the auxiliary patterns near the corners 12 other than the corners in the array can be increased, which helps to further improve the light intensity distribution near all the corners 12 in the target pattern 10, is conducive to further reducing the rounding degree of the corners 12, and can further improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0104] Alternatively, if Figure 1 and Figure 2 As shown, the outer sides of any two adjacent second auxiliary patterns 22 share a fifth auxiliary pattern 40, thereby helping to simplify the design difficulty of the mask.

[0105] Alternatively, if Figure 1 and Figure 2 As shown, in one embodiment of the present application, the center point between any two adjacent third auxiliary graphics 31 spaced apart in the same second auxiliary combination graphic 30 is collinear with a central axis of the fifth auxiliary graphic 40 .

[0106] In the present application embodiment, Figure 1 As shown, a dotted line is used to represent the connection line of the central axes between two adjacent third auxiliary graphics 31 arranged at intervals of the innermost second auxiliary combination graphic 30, and the center point between the two adjacent third auxiliary graphics 31 arranged at intervals is located in the dotted line; another dotted line is used to represent the central axis of the fifth auxiliary graphic 40.

[0107] Alternatively, if Figure 1 As shown, the central axis of the fifth auxiliary pattern 40 is perpendicular to the line connecting the central axes of two adjacent third auxiliary patterns 31 spaced apart, so that the fifth auxiliary pattern 40 is located on the inner side of the center point between any two adjacent third auxiliary patterns 31 spaced apart, so that the fifth auxiliary pattern 40 can fill the graphic gap between any two adjacent third auxiliary patterns 31 spaced apart, and can further increase the arrangement density of the auxiliary patterns around the target pattern 10.

[0108] In the embodiment of the present application, in order to further illustrate the effect of the mask provided by the embodiment of the present application, the applicant Figure 1 The graphic design of the mask shown in the figure was simulated, and the simulation results are shown in Figure 3a , Figure 3b , Figure 3c and Figure 3d shown.

[0109] like Figure 3a for Figure 1 A comparison diagram of a simulated pattern 102 formed on a photoresist layer of a target pattern 10 located at the center of an array, a simulated pattern 101 formed by a related pattern design scheme, and the target pattern 10; Figure 3b for Figure 1 A comparison diagram of a simulated pattern 103 formed on a photoresist layer of a target pattern 10 located at an edge of an array and between two corners, a simulated pattern 101 formed by a related pattern design scheme, and the target pattern 10; Figure 3c for Figure 1A comparison diagram of a simulated pattern 104 formed in a photoresist layer of a target pattern 10 located at a corner of an array, a simulated pattern 101 formed by a related pattern design scheme, and the target pattern 10 .

[0110] like Figure 3a , Figure 3b and Figure 3c As shown, for the target graphic 10 located at any orientation in the array, using the graphic design scheme of the mask provided in the embodiment of the present application, the degree of rounding of the corner 12 of the target graphic 10 is significantly reduced compared to the related graphic design schemes, and the degree of matching between the graphic formed by the photoresist layer after exposure and the target graphic 10 can be improved.

[0111] like Figure 3d As shown, the horizontal axis represents the defocus distance D, the vertical axis represents the error E, and the units of the horizontal axis and the vertical axis are both nm (nanometers); Curve A represents the change curve of the distance between the corner of the simulated pattern 104 formed on the photoresist layer of the target pattern 10 of the present application and the corner 12 of the target pattern 10 as the focal distance D changes, and Curve B represents the change curve of the distance between the corner of the simulated pattern 101 formed on the photoresist layer of the graphic design scheme in the related art and the corner 12 of the target pattern 10 as the focal distance D changes. Figure 3d It can be seen that for the same defocus distance D, compared with the graphic design scheme in the related art, the simulated graphic formed in the photoresist layer of the target graphic 10 in the mask provided in the embodiment of the present application has a smaller error with the target graphic 10, so that the degree of rounding of the corner 12 of the target graphic 10 is significantly reduced, which can improve the matching degree between the graphic formed by the photoresist layer after exposure and the target graphic 10.

[0112] In the embodiment of the present application, when using Figure 1 or Figure 2 In the process of manufacturing semiconductor devices using the mask shown, the degree of matching between the pattern formed on the film layer to be etched after exposure and the target pattern 10 can be improved, thereby helping to ensure the area of ​​the hole pattern formed on the film layer to be etched, helping to reduce the resistance of the wire in the hole, and thus helping to ensure the performance of the semiconductor device.

[0113] Based on the same inventive concept, an embodiment of the present application provides a mask design method, which is used to form a graphic design scheme of any mask in the above embodiments. The flow chart of the design method is as follows: Figure 4 As shown, it includes steps S401 to S402.

[0114] S401, determine whether the distance between any two adjacent target graphics 10 is less than a set threshold; if so, execute step S402; otherwise, execute step S403.

[0115] S402 , determining that each target graphic 10 is surrounded by at least one first auxiliary combined graphic 20 , and all first auxiliary combined graphics 20 are surrounded by at least one second auxiliary combined graphic 30 .

[0116] In the embodiment of the present application, the structure and arrangement of the first auxiliary combination graphic 20 and the second auxiliary combination graphic 30 refer to the above embodiments and will not be described again here.

[0117] In the mask design method provided in the embodiment of the present application, after determining that the spacing between any two adjacent target graphics 10 is less than a set threshold, it is determined that each target graphic 10 is surrounded by at least one first auxiliary combination graphic 20, and all first auxiliary combination graphics 20 are surrounded by at least one second auxiliary combination graphic 30, thereby increasing the arrangement density of the auxiliary graphics around each target graphic 10, helping to increase the depth of field of the graphics in the mask, and improving the degree of matching between the graphics formed on the film layer to be etched after exposure and the target graphic 10.

[0118] At the same time, by arranging each target pattern 10 to be surrounded by at least one first auxiliary combination pattern 20, the corners 12 of the target pattern 10 are all provided with at least one second auxiliary pattern 22 whose angle with the straight line where the side 11 is located is acute or obtuse, and the distance between the second auxiliary pattern 22 and the adjacent corner 12 is smaller than the distance between the first auxiliary pattern 21 and the adjacent side 11, which can improve the arrangement density of the auxiliary patterns near the corners 12, thereby helping to improve the light intensity distribution near the corners 12 of the target pattern 10 during the exposure process, which is beneficial to reducing the rounding degree of the corners 12, and can improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0119] Optionally, in one embodiment of the present application, the step S402 further includes: determining to set a fifth auxiliary graphic 40 on the outer side of the first auxiliary combination graphic 20 and the inner side of the second auxiliary combination graphic 30 .

[0120] Optionally, for an array formed by all first auxiliary combined patterns 20, a fifth auxiliary pattern 40 is disposed outside each of the second auxiliary patterns 22 except for the first auxiliary combined patterns 20 located at the outermost corners.

[0121] In the embodiment of the present application, the structure and arrangement of the fifth auxiliary pattern 40 refer to the above embodiments and will not be described again here.

[0122] Optionally, in one embodiment of the present application, if it is determined in step S401 that the distance between any two adjacent target graphics 10 is greater than a set threshold, step S403 is executed: determining that each target graphic 10 is surrounded by at least two first auxiliary combined graphics 20 .

[0123] Optionally, if it is determined that the distance between any two adjacent target graphics 10 is greater than a set threshold, it is determined that each target graphic 10 is surrounded by three first auxiliary combined graphics 20, such as Figure 5 As shown, among any two adjacent first auxiliary combination graphics 20, the length of the first auxiliary graphic 21 of the first auxiliary combination graphic 20 located on the outside is greater than the length of the first auxiliary graphic 21 of the first auxiliary combination graphic 20 located on the inside; the length of the second auxiliary graphic 22 of the first auxiliary combination graphic 20 located on the outside is greater than the length of the second auxiliary graphic 22 of the first auxiliary combination graphic 20 located on the inside.

[0124] like Figure 6 As shown, Figure 5 A comparison diagram of a simulated pattern 105 formed on a photoresist layer of a single target pattern 10 and a plurality of first auxiliary patterns 20, a simulated pattern 101 formed by a related pattern design scheme, and the target pattern 10 is shown. For the scheme of a single target pattern 10, using the pattern design scheme of the mask provided in the embodiment of the present application, the degree of rounding of the corner 12 of the target pattern 10 is significantly reduced compared to the related pattern design scheme, which can improve the matching degree between the pattern formed by the photoresist layer after exposure and the target pattern 10, and further improve the matching degree between the pattern formed by the film layer to be etched and the target pattern 10.

[0125] Optionally, if it is determined that the distance between any two adjacent target graphics 10 is greater than a set threshold, it is determined that each target graphic 10 is surrounded by three first auxiliary combined graphics 20, such as Figure 7 As shown, in the same first auxiliary combination pattern 20, one end of each second auxiliary pattern 22 is connected to a sub-segment 211. Optionally, one end of the second auxiliary pattern 22 is connected to one end of a sub-segment 211 of a first auxiliary pattern 21, and the other end of the second auxiliary pattern 22 is connected to one end of a sub-segment 211 of another first auxiliary pattern 21. In any two adjacent first auxiliary combination patterns 20, the length of the sub-segment 211 of the first auxiliary combination pattern 20 located on the outside is greater than the length of the sub-segment 211 of the first auxiliary combination pattern 20 located on the inside.

[0126] Optionally, in the embodiment of the present application, after executing step S402 or step S403 , the method further includes: performing optical proximity effect correction on the target graphic 10 to obtain a corrected target graphic 10 .

[0127] By applying the embodiments of the present application, at least the following beneficial effects can be achieved:

[0128] In the mask provided in the embodiment of the present application, for a pattern array including at least two target patterns 10, since the corner 12 of each target pattern 10 is provided with at least one second auxiliary pattern 22 whose angle with the straight line where the side 11 is located is acute or obtuse, and the distance between the second auxiliary pattern 22 and the adjacent corner 12 is smaller than the distance between the first auxiliary pattern 21 and the adjacent side 11, the arrangement density of the auxiliary patterns near the corner 12 can be improved, thereby helping to improve the light intensity distribution near the corner 12 of the target pattern 10 during the exposure process, helping to reduce the degree of rounding of the corner 12, and improving the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0129] At the same time, by surrounding at least one first auxiliary combination pattern 20 on the periphery of each target pattern 10 and providing a second auxiliary combination pattern 30 surrounding all first auxiliary combination patterns 20, the arrangement density of the auxiliary patterns on the periphery of each target pattern 10 can be increased, which helps to increase the depth of field of the pattern in the mask plate, and can further improve the matching degree between the pattern formed on the film layer to be etched after exposure and the target pattern 10.

[0130] Those skilled in the art will appreciate that the various operations, methods, steps, measures, and schemes in the processes discussed in this application may be alternated, altered, combined, or deleted. Further, other steps, measures, and schemes in the various operations, methods, and processes discussed in this application may also be alternated, altered, rearranged, decomposed, combined, or deleted. Further, the steps, measures, and schemes in the prior art that are similar to those disclosed in this application may also be alternated, altered, rearranged, decomposed, combined, or deleted.

[0131] In the description of the present application, the directions or positional relationships indicated by words such as "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the exemplary directions or positional relationships shown in the accompanying drawings. They are for the convenience of describing or simplifying the description of the embodiments of the present application, and do not indicate or imply that the referred device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0132] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0133] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0134] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0135] The above is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the scheme of the present application, other similar implementation methods based on the technical ideas of the present application are also within the protection scope of the embodiments of the present application.

Claims

1. A mask, characterized in that: include: at least two target graphics, the target graphics comprising at least two corners and at least two sides; At least two first auxiliary combination figures, each of which surrounds the periphery of a target figure, and the first auxiliary combination figures include at least two first auxiliary figures and at least two second auxiliary figures; one first auxiliary figure is arranged outside each side, and the first auxiliary figure is parallel to the adjacent side; one second auxiliary figure is arranged outside each corner, and the angle between the straight line where the second auxiliary figure is located and the straight line where the side is located is an acute angle or an obtuse angle; the distance between the second auxiliary figure and the adjacent corner is smaller than the distance between the first auxiliary figure and the adjacent side; At least one second auxiliary combination pattern surrounds the periphery of all the first auxiliary combination patterns.

2. The mask according to claim 1, characterized in that: The first auxiliary combined figure is arranged concentrically with the target figure surrounded by it; The first auxiliary combination pattern is a non-closed ring, and the first auxiliary pattern and the second auxiliary pattern are alternately arranged in a direction surrounding the target pattern; The length of the first auxiliary pattern is smaller than the length of the side.

3. The mask according to claim 1, characterized in that: The second auxiliary combination graphics include at least two third auxiliary graphics and at least two fourth auxiliary graphics; In the array formed by all the first auxiliary combination patterns, the third auxiliary pattern is arranged on the outer side of the first auxiliary pattern located at the outermost side, and the fourth auxiliary pattern is arranged on the outer side of the second auxiliary pattern located at the corner; the third auxiliary pattern is parallel to the adjacent first auxiliary pattern, and the fourth auxiliary pattern is parallel to the adjacent second auxiliary pattern.

4. The mask according to claim 3, characterized in that: All the second auxiliary combined figures are non-closed rings; The second auxiliary combination pattern is arranged concentrically with the array surrounded by it; in the same second auxiliary combination pattern, the fourth auxiliary pattern is arranged at intervals from the adjacent third auxiliary pattern, and any two adjacent fourth auxiliary patterns are arranged at intervals; the length of the third auxiliary pattern is greater than the length of the side.

5. The mask according to claim 4, characterized in that: In the second auxiliary combination patterns located at the outermost side, a third auxiliary pattern is arranged between any two adjacent fourth auxiliary patterns, and the length of the third auxiliary pattern is greater than the length of the third auxiliary pattern in the adjacent second auxiliary combination patterns.

6. The mask according to claim 3, characterized in that: The second auxiliary combined figures except the outermost second auxiliary combined figures are non-closed rings; The second auxiliary combination figure is arranged concentrically with the array surrounded by it; in the same non-closed ring-shaped second auxiliary combination figure, both ends of the fourth auxiliary figure are connected to a third auxiliary figure, and any two adjacent third auxiliary figures are arranged at intervals; the length of the third auxiliary figure is greater than the length of the side.

7. The mask according to claim 6, characterized in that: In the second auxiliary combination pattern located at the outermost side, all the third auxiliary patterns and the fourth auxiliary patterns are connected to form a closed ring.

8. The mask according to claim 6 or 7, characterized in that: The first auxiliary pattern comprises: two sub-segments arranged at intervals; In the same first auxiliary combination pattern, one end of the second auxiliary pattern is connected to one end of one subsegment of one of the first auxiliary patterns, and the other end of the second auxiliary pattern is connected to one end of one subsegment of another of the first auxiliary patterns.

9. The mask according to claim 1, characterized in that: Also includes: at least two fifth auxiliary graphics, surrounded by the second auxiliary combined graphics; At least one of the second auxiliary patterns in the first auxiliary combination patterns is provided with a fifth auxiliary pattern on the outer side away from the corner.

10. The mask according to claim 9, characterized in that: A center point between any two adjacent third auxiliary figures arranged at intervals in the same second auxiliary combination figure is collinear with a central axis of the fifth auxiliary figure.

11. A method for designing a mask according to any one of claims 1 to 10, characterized in that: include: Determine whether the distance between any two adjacent target graphics is less than a set threshold; If it is less than the set threshold, it is determined that each of the target graphics is surrounded by at least one of the first auxiliary combined graphics, and all of the first auxiliary combined graphics are surrounded by at least one of the second auxiliary combined graphics.

12. The method for designing a mask according to claim 11, characterized in that: If it is less than the set threshold, it is determined that each of the target graphics is surrounded by at least one of the first auxiliary combination graphics, and all of the first auxiliary combination graphics are surrounded by at least one second auxiliary combination graphics, and further includes: It is determined that a fifth auxiliary pattern is arranged outside the first auxiliary combination pattern and inside the second auxiliary combination pattern.

13. The method for designing a mask according to claim 11, characterized in that: After determining whether the distance between any two adjacent target graphics is less than the set threshold, the following steps are also included: If it is greater than the set threshold, it is determined that each of the target graphics is surrounded by at least two first auxiliary combined graphics.

Images