Sub-resolution auxiliary pattern and forming method thereof

Abstract

The invention provides a sub-resolution auxiliary pattern and a forming method thereof, a photoetching pattern at least comprises a first target pattern and a second target pattern which are adjacent to each other, and the key size of the second target pattern is larger than that of the first target pattern; sequentially adding a first sub-resolution auxiliary pattern and a second sub-resolution auxiliary pattern to form a forbidden area of the second sub-resolution auxiliary pattern; and judging whether the forbidden area of the second sub-resolution auxiliary graph is in contact with the second target graph or not, and if so, removing the second sub-resolution auxiliary graph. According to the method, after the second sub-resolution auxiliary graph is inserted, the forbidden area directly grows, and if the forbidden area makes contact with the second target graph, the second sub-resolution auxiliary graph is removed. By means of the method, placement of other sub-resolution auxiliary graphs cannot be affected, other needed sub-resolution auxiliary graphs cannot be deleted by mistake, and too many resources do not need to be consumed during follow-up design rule detection.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to a sub-resolution auxiliary pattern and a forming method thereof. Background Art

[0002] With the continuous miniaturization of process nodes, in order to improve the process window, OPC (optical proximity correction) is an indispensable part of today's semiconductor process.

[0003] SRAF (Sub-Resolution Assist Feature) is mainly used to improve the resolution of lithography patterns, especially to balance the optical proximity effect between dense and sparse patterns to avoid pattern deformation. It is a common practice in the industry to add SRAF to improve the depth of focus (DOF) during the OPC process, but the addition of SRAF is often accompanied by risks. If the size and distance of SRAF are not controlled well, it may cause defects on the wafer. Therefore, how to prevent wafer defects while maximizing DOF is an issue that needs to be paid attention to in the development of advanced nodes.

[0004] After setting the insertion conditions, the existing SRAF recipe (process file) will use the DRC (Design Rule Check) method to remove some SRAFs that violate the conditions from the target graphic (target) to ensure that the SRAF meets the requirements. However, the disadvantage is that it must be executed after the SRAF is added, which not only wastes a lot of time, but also may accidentally delete some necessary SRAFs. Summary of the invention

[0005] The object of the present invention is to provide a sub-resolution auxiliary pattern and a method for forming the same, so as to solve the problem that the formation process of the sub-resolution auxiliary pattern wastes time and some required sub-resolution auxiliary patterns are mistakenly deleted.

[0006] In order to solve the above technical problems, the present invention provides a method for forming a sub-resolution auxiliary pattern, comprising:

[0007] Providing a photolithography pattern, wherein the photolithography pattern includes at least a first target pattern and a second target pattern adjacent to each other, wherein a critical dimension of the second target pattern is greater than a critical dimension of the first target pattern;

[0008] Adding a first sub-resolution auxiliary graphic, wherein the first sub-resolution auxiliary graphic is located on both sides of the first target graphic, and the first sub-resolution auxiliary graphic is added between the first target graphic and the second target graphic;

[0009] adding a second sub-resolution auxiliary pattern, wherein the second sub-resolution auxiliary pattern is added between the first sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the second sub-resolution auxiliary pattern is formed;

[0010] It is determined whether the prohibited area of ​​the second sub-resolution auxiliary pattern contacts or overlaps with the second target pattern. If so, the second sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern.

[0011] Optionally, the prohibited area is an area within a predetermined distance range on both sides of the second sub-resolution auxiliary pattern.

[0012] Optionally, the second sub-resolution auxiliary pattern is located on a side of the first sub-resolution auxiliary pattern away from the first target pattern.

[0013] Optionally, determining whether the prohibited area of ​​the second sub-resolution auxiliary pattern contacts or overlaps with the second target pattern;

[0014] If not, adding a third sub-resolution auxiliary pattern, wherein the third sub-resolution auxiliary pattern is added between the second sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the third sub-resolution auxiliary pattern is formed;

[0015] It is determined whether the prohibited area of ​​the third sub-resolution auxiliary pattern contacts or overlaps with the second target pattern. If so, the third sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern.

[0016] Optionally, determining whether the prohibited area of ​​the third sub-resolution auxiliary pattern contacts or overlaps with the second target pattern;

[0017] If not, adding a fourth sub-resolution auxiliary pattern, wherein the fourth sub-resolution auxiliary pattern is added between the third sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the fourth sub-resolution auxiliary pattern is formed;

[0018] It is determined whether the prohibited area of ​​the fourth sub-resolution auxiliary pattern contacts or overlaps with the second target pattern. If so, the fourth sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern.

[0019] Optionally, the photolithography pattern includes a plurality of first target patterns and a plurality of second target patterns, and the distances between the second target patterns and adjacent first target patterns are different.

[0020] Optionally, a critical dimension of the second target graphic in the first direction is greater than a critical dimension of the first target graphic in the first direction, and a critical dimension of the second target graphic in the second direction is equal to a critical dimension of the first target graphic in the second direction, and the first direction is perpendicular to the second direction.

[0021] Optionally, the first direction is a width direction, the second direction is a length direction, a width critical dimension of the second target graphic is greater than a width critical dimension of the first target graphic, and a length critical dimension of the second target graphic is equal to a length critical dimension of the first target graphic.

[0022] Optionally, after forming the final sub-resolution auxiliary pattern, a design rule check is performed to obtain the sub-resolution auxiliary pattern that meets the design rule.

[0023] Based on the same inventive concept, the present invention further provides a sub-resolution auxiliary pattern, which is prepared by any of the above-mentioned methods for forming a sub-resolution auxiliary pattern.

[0024] In the method for forming a sub-resolution auxiliary pattern provided by the present invention, a photolithography pattern is provided, wherein the photolithography pattern includes at least one adjacent first target pattern and one second target pattern, and the critical size of the second target pattern is greater than the critical size of the first target pattern; a first sub-resolution auxiliary pattern is added, wherein the first sub-resolution auxiliary pattern is located on both sides of the first target pattern, and the first sub-resolution auxiliary pattern is added between the first target pattern and the second target pattern; a second sub-resolution auxiliary pattern is added, wherein the second sub-resolution auxiliary pattern is added between the first sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the second sub-resolution auxiliary pattern is formed; it is determined whether the prohibited area of ​​the second sub-resolution auxiliary pattern contacts or overlaps with the second target pattern, and if so, the second sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern. In the present invention, a prohibited area is directly grown after the second sub-resolution auxiliary pattern is inserted, and if the prohibited area of ​​the second sub-resolution auxiliary pattern contacts the second target pattern, the second sub-resolution auxiliary pattern itself is removed. Using this method will not only not affect the placement of other sub-resolution auxiliary patterns, but also will not mistakenly delete other required sub-resolution auxiliary patterns, and will not consume too many resources in subsequent design rule detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0026] Figure 1 to Figure 2It is a schematic diagram of the photolithography patterns of the corresponding steps of the method for forming sub-resolution auxiliary patterns in the prior art.

[0027] Figure 3 It is a flow chart of a method for forming a sub-resolution auxiliary pattern according to an embodiment of the present invention.

[0028] Figures 4 to 8 It is a schematic diagram of photolithography patterns corresponding to the steps of the method for forming a sub-resolution auxiliary pattern according to an embodiment of the present invention.

[0029] In the attached figure:

[0030] 11 - first target graphic; 12 - second target graphic; 21 - first sub-resolution auxiliary graphic; 22 - second sub-resolution auxiliary graphic. DETAILED DESCRIPTION

[0031] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0032] As used in the present invention, the singular forms "one", "an" and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" and "third" can explicitly or implicitly include one or at least two of the features. In addition, as used in the present invention, an element is arranged on another element, which usually only indicates that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, an element can be in any orientation such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Figure 1 to Figure 2Schematic diagram of the photolithography pattern of the corresponding steps of the method for forming a sub-resolution auxiliary pattern in the prior art. Figure 1 As shown, the photolithography pattern includes a plurality of first target patterns 11 and second target patterns 12, the first target patterns 11 and the second target patterns 12 are adjacent, and the distances between the second target pattern 12 and the first target patterns 11 on both sides are different. The distance between the second target pattern 12 and the first target pattern 11 on the first side is greater than the distance between the second target pattern 12 and the first target pattern 11 on the second side. Therefore, a first sub-resolution auxiliary pattern 21 and a second sub-resolution auxiliary pattern 22 are added between the second target pattern 12 and the first target pattern 11 on the first side, and only the first sub-resolution auxiliary pattern 21 is added between the second target pattern 12 and the first target pattern 11 on the second side. After setting the insertion conditions, the SRAF recipe (sub-resolution auxiliary pattern process file) will use the DRC (DesignRule Check) method to remove some SRAFs that violate the conditions from the target pattern (target) to ensure that the SRAF meets the requirements. Figure 2 As shown, in the DRC check, the sub-resolution auxiliary graphics within the predetermined distance A on both sides of the second target graphic 12 will be deleted, that is, the first sub-resolution auxiliary graphics 21 on the second side of the second target graphic 12 and the second sub-resolution auxiliary graphics 22 on the first side of the second target graphic 12 are deleted. However, the deletion of the first sub-resolution auxiliary graphics 21 between the second target graphic 12 and the first target graphic 11 on the second side will affect the first target graphic 11 on the second side. That is, the first sub-resolution auxiliary graphics 21 between the second target graphic 12 and the first target graphic 11 on the second side is mistakenly deleted. The disadvantage of the method for forming sub-resolution auxiliary graphics in the prior art is that the DRC check must be performed after the SRAF is added, which not only wastes a lot of time, but also may mistakenly delete some required SRAFs.

[0034] Based on this, the core idea of ​​the present invention is to provide a method for forming a sub-resolution auxiliary pattern, provide a photolithography pattern, the photolithography pattern includes at least one adjacent first target pattern and a second target pattern, the critical size of the second target pattern is greater than the critical size of the first target pattern; add a first sub-resolution auxiliary pattern, the first sub-resolution auxiliary pattern is located on both sides of the first target pattern, and the first sub-resolution auxiliary pattern is added between the first target pattern and the second target pattern; add a second sub-resolution auxiliary pattern, the second sub-resolution auxiliary pattern is added between the first sub-resolution auxiliary pattern and the second target pattern, and form a prohibited area of ​​the second sub-resolution auxiliary pattern; judge whether the prohibited area of ​​the second sub-resolution auxiliary pattern contacts or overlaps with the second target pattern, if so, remove the second sub-resolution auxiliary pattern to generate a final sub-resolution auxiliary pattern. The present invention directly grows a prohibited area after inserting the second sub-resolution auxiliary pattern, and removes the second sub-resolution auxiliary pattern itself if the prohibited area of ​​the second sub-resolution auxiliary pattern contacts the second target pattern. Using this method will not only not affect the placement of other sub-resolution auxiliary patterns, but also will not mistakenly delete other required sub-resolution auxiliary patterns, and will not consume too many resources in subsequent design rule detection.

[0035] The following description is given with reference to the accompanying drawings.

[0036] Figure 3 FIG. 1 is a flow chart of a method for forming a sub-resolution auxiliary pattern according to an embodiment of the present invention. Figure 3 As shown, this embodiment provides a method for forming a sub-resolution auxiliary pattern, comprising:

[0037] Step S10, providing a photolithography pattern, wherein the photolithography pattern includes at least one adjacent first target pattern and one adjacent second target pattern, wherein a critical dimension of the second target pattern is greater than a critical dimension of the first target pattern;

[0038] Step S20, adding a first sub-resolution auxiliary pattern, wherein the first sub-resolution auxiliary pattern is located on both sides of the first target pattern, and the first sub-resolution auxiliary pattern is added between the first target pattern and the second target pattern;

[0039] Step S30, adding a second sub-resolution auxiliary pattern, wherein the second sub-resolution auxiliary pattern is added between the first sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the second sub-resolution auxiliary pattern is formed;

[0040] Step S40, determining whether the prohibited area of ​​the second sub-resolution auxiliary pattern contacts or overlaps with the second target pattern, and if so, removing the second sub-resolution auxiliary pattern to generate a final sub-resolution auxiliary pattern.

[0041] Figures 4 to 8 1 is a schematic diagram of the photolithography pattern of the corresponding steps of the method for forming a sub-resolution auxiliary pattern according to an embodiment of the present invention. Figures 4 to 8 The specific embodiments of the present invention are described in detail.

[0042] like Figure 4 As shown, a photolithography pattern is provided, and the photolithography pattern includes at least one adjacent first target pattern 11 and one adjacent second target pattern 12. In some embodiments, the photolithography pattern includes multiple first target patterns 11 and multiple second target patterns 12, and some first target patterns 11 are adjacent to the first target patterns 11, some first target patterns 11 are adjacent to the second target patterns 12, and some second target patterns 12 are adjacent to the second target patterns 12.

[0043] like Figure 4 As shown, in this embodiment, the second target pattern 12 is adjacent to two of the first target patterns 11, and the distances between the second target pattern 12 and the adjacent first target patterns 11 are different. The distance between the second target pattern 12 and the first target pattern 11 on the first side is greater than the distance between the second target pattern 12 and the first target pattern 11 on the second side, wherein the first side is arranged opposite to the second side. That is, the number of sub-resolution auxiliary patterns added between the second target pattern 12 and the first target pattern 11 on the first side may be greater than the number of sub-resolution auxiliary patterns added between the second target pattern 12 and the first target pattern 11 on the second side. The critical dimension of the second target pattern 12 is greater than the critical dimension of the first target pattern 11. The critical dimension (CD) includes a critical dimension along a first direction and a dimension along a second direction, wherein the first direction is perpendicular to the second direction, the first direction is, for example, a width direction, and the second direction is, for example, a length direction, i.e., a length critical dimension and a width dimension.

[0044] Specifically, the critical dimension of the second target pattern 12 in the first direction is greater than the critical dimension of the first target pattern 11 in the first direction, and the critical dimension of the second target pattern 12 in the second direction is equal to the critical dimension of the first target pattern 11 in the second direction. In other words, the width critical dimension of the second target pattern 12 is greater than the width critical dimension of the first target pattern 11, and the length critical dimension of the second target pattern 12 is equal to the length critical dimension of the first target pattern 11.

[0045] In the photolithography process, when the width critical dimension of the target pattern is too small, the target pattern is easily deformed when transferred to the wafer. Therefore, when the width critical dimension of the target pattern is less than a preset threshold, a sub-resolution auxiliary pattern needs to be added to balance the optical proximity effect and avoid deformation of the target pattern. The preset threshold is determined by the minimum pitch and / or width of the pattern of the material layer to be etched and the light source of the photolithography process after the OPC model simulation determines the process window. In this embodiment, the first target pattern 11 needs to add a sub-resolution auxiliary pattern, and the second target pattern 12 does not need to add a sub-resolution auxiliary pattern.

[0046] like Figure 5 As shown, a first sub-resolution auxiliary pattern 21 is added, the first sub-resolution auxiliary pattern 21 is located on both sides of the first target pattern, and a first sub-resolution auxiliary pattern 21 is added between the first target pattern 11 and the second target pattern 12. That is, a first sub-resolution auxiliary pattern 21 is added between the second target pattern 12 and the first target pattern 11 on the first side, and a first sub-resolution auxiliary pattern 21 is also added between the second target pattern 12 and the first target pattern 11 on the second side.

[0047] like Figure 6 and Figure 7 As shown, a second sub-resolution auxiliary pattern 12 is added, and the second sub-resolution auxiliary pattern 22 is added between the first sub-resolution auxiliary pattern 21 and the second target pattern 12, and a prohibited area of ​​the second sub-resolution auxiliary pattern 22 is formed. The second sub-resolution auxiliary pattern 22 is located on the side of the first sub-resolution auxiliary pattern 21 away from the first target pattern 11. The distance between the second target pattern 12 and the first target pattern 11 on the first side is greater than the distance between the second target pattern 12 and the first target pattern 11 on the second side. Therefore, the second sub-resolution auxiliary pattern 22 is added between the second target pattern 12 and the first target pattern 11 on the first side, and the second sub-resolution auxiliary pattern 22 is not added between the second target pattern 12 and the first target pattern 11 on the second side. The prohibited area is within a predetermined distance A on both sides of the second sub-resolution auxiliary pattern. Since the photoresist will affect the prohibited area range of the second sub-resolution auxiliary pattern 22, the predetermined distance A value of the prohibited area of ​​the second sub-resolution auxiliary pattern 22 is obtained by OPC simulation, and then cooperated with the lithography result feedback of the wafer.

[0048] like Figure 8As shown, it is determined whether the prohibited area of ​​the second sub-resolution auxiliary pattern 22 contacts or overlaps with the second target pattern 12. If so, the second sub-resolution auxiliary pattern 22 itself is removed to generate the final sub-resolution auxiliary pattern. In this embodiment, a prohibited area is directly grown after the second sub-resolution auxiliary pattern 22 is inserted. If the prohibited area of ​​the second sub-resolution auxiliary pattern 22 contacts the second target pattern 12, the second sub-resolution auxiliary pattern 22 itself is removed. Using this method will not only not affect the placement of other sub-resolution auxiliary patterns (for example, the first sub-resolution auxiliary pattern 21 on the second side of the second target pattern 12), but also will not mistakenly delete other required sub-resolution auxiliary patterns (for example, the first sub-resolution auxiliary pattern 21 on the second side of the second target pattern 12), and will not consume too many resources in the subsequent design rule detection.

[0049] In some embodiments, when the distance between the second target pattern 12 and the first target pattern 11 is large, a third sub-resolution auxiliary pattern needs to be added between the second target pattern 12 and the first target pattern 11. Therefore, it is determined whether the prohibited area of ​​the second sub-resolution auxiliary pattern 22 is in contact with or overlaps with the second target pattern 12;

[0050] If not, add a third sub-resolution auxiliary graphic, and the third sub-resolution auxiliary graphic is located on the side of the second sub-resolution auxiliary graphic 22 away from the first target graphic 11, that is, the third sub-resolution auxiliary graphic is added between the second sub-resolution auxiliary graphic 22 and the second target graphic 12, and a prohibited area of ​​the third sub-resolution auxiliary graphic is formed; the calculation method of the range of the prohibited area of ​​the third sub-resolution auxiliary graphic is the same as the calculation method of the range of the prohibited area of ​​the second sub-resolution auxiliary graphic, and is not repeated here.

[0051] It is determined whether the prohibited area of ​​the third sub-resolution auxiliary pattern contacts or overlaps with the second target pattern 12 . If so, the third sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern.

[0052] In some embodiments, when the distance between the second target pattern 12 and the first target pattern 11 is greater, a fourth sub-resolution auxiliary pattern needs to be added between the second target pattern 12 and the first target pattern 11. Therefore, it is determined whether the prohibited area of ​​the third sub-resolution auxiliary pattern is in contact with or overlaps with the second target pattern 12;

[0053] If not, add a fourth sub-resolution auxiliary graphic, which is located on the side of the third sub-resolution auxiliary graphic away from the first target graphic 11, that is, the fourth sub-resolution auxiliary graphic is added between the third sub-resolution auxiliary graphic and the second target graphic, and forms a prohibited area of ​​the fourth sub-resolution auxiliary graphic; the calculation method of the range of the prohibited area of ​​the fourth sub-resolution auxiliary graphic is the same as the calculation method of the range of the prohibited area of ​​the second sub-resolution auxiliary graphic, which will not be repeated here.

[0054] It is determined whether the prohibited area of ​​the fourth sub-resolution auxiliary pattern contacts or overlaps with the second target pattern 12 . If so, the fourth sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern.

[0055] In other embodiments, more sub-resolution auxiliary graphics such as a fifth sub-resolution auxiliary graphic and a sixth sub-resolution auxiliary graphic may be added according to the distance between the second target graphic 12 and the first target graphic 11. The judgment method is the same as that of the second sub-resolution auxiliary graphic, the third sub-resolution auxiliary graphic, and the fourth sub-resolution auxiliary graphic, and they are not listed one by one here.

[0056] After forming the final sub-resolution auxiliary pattern, a design rule check (DRC) is performed to obtain the sub-resolution auxiliary pattern that meets the design rule.

[0057] This embodiment also provides a sub-resolution auxiliary pattern, which is prepared by using any of the above-mentioned methods for forming a sub-resolution auxiliary pattern.

[0058] In summary, in the method for forming a sub-resolution auxiliary pattern provided in an embodiment of the present invention, a photolithography pattern is provided, wherein the photolithography pattern includes at least one adjacent first target pattern and one second target pattern, and the critical dimension of the second target pattern is greater than the critical dimension of the first target pattern; a first sub-resolution auxiliary pattern is added, wherein the first sub-resolution auxiliary pattern is located on both sides of the first target pattern, and the first sub-resolution auxiliary pattern is added between the first target pattern and the second target pattern; a second sub-resolution auxiliary pattern is added, wherein the second sub-resolution auxiliary pattern is added between the first sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the second sub-resolution auxiliary pattern is formed; and it is determined whether the prohibited area of ​​the second sub-resolution auxiliary pattern contacts or overlaps with the second target pattern, and if so, the second sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern. In the present invention, a prohibited area is directly grown after the second sub-resolution auxiliary pattern is inserted, and if the prohibited area of ​​the second sub-resolution auxiliary pattern contacts the second target pattern, the second sub-resolution auxiliary pattern itself is removed. Using this method will not affect the placement of other sub-resolution auxiliary graphics, that is, other required sub-resolution auxiliary graphics will not be deleted by mistake, and too many resources will not be consumed in subsequent design rule detection.

[0059] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other. In addition, the different parts between the various embodiments can also be used in combination with each other, and the present invention is not limited to this.

[0060] In addition, it should be recognized that although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the scope of protection of the technical solution of the present invention.

Claims

1. A method for forming a sub-resolution auxiliary pattern, characterized in that: include: Providing a photolithography pattern, wherein the photolithography pattern includes at least a first target pattern and a second target pattern adjacent to each other, wherein a critical dimension of the second target pattern is greater than a critical dimension of the first target pattern; Adding a first sub-resolution auxiliary graphic, wherein the first sub-resolution auxiliary graphic is located on both sides of the first target graphic, and the first sub-resolution auxiliary graphic is added between the first target graphic and the second target graphic; adding a second sub-resolution auxiliary pattern, wherein the second sub-resolution auxiliary pattern is added between the first sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the second sub-resolution auxiliary pattern is formed; It is determined whether the prohibited area of ​​the second sub-resolution auxiliary pattern contacts or overlaps with the second target pattern. If so, the second sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern.

2. The method for forming a sub-resolution auxiliary pattern according to claim 1, characterized in that: The prohibited area is an area within a predetermined distance range on both sides of the second sub-resolution auxiliary pattern.

3. The method for forming a sub-resolution auxiliary pattern according to claim 1, characterized in that: The second sub-resolution auxiliary pattern is located on a side of the first sub-resolution auxiliary pattern far away from the first target pattern.

4. The method for forming a sub-resolution auxiliary pattern according to claim 1, characterized in that: determining whether the prohibited area of ​​the second sub-resolution auxiliary pattern contacts or overlaps with the second target pattern; If not, adding a third sub-resolution auxiliary pattern, wherein the third sub-resolution auxiliary pattern is added between the second sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the third sub-resolution auxiliary pattern is formed; It is determined whether the prohibited area of ​​the third sub-resolution auxiliary pattern contacts or overlaps with the second target pattern. If so, the third sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern.

5. The method for forming a sub-resolution auxiliary pattern according to claim 4, characterized in that: determining whether the prohibited area of ​​the third sub-resolution auxiliary pattern contacts or overlaps with the second target pattern; If not, adding a fourth sub-resolution auxiliary pattern, wherein the fourth sub-resolution auxiliary pattern is added between the third sub-resolution auxiliary pattern and the second target pattern, and a prohibited area of ​​the fourth sub-resolution auxiliary pattern is formed; It is determined whether the prohibited area of ​​the fourth sub-resolution auxiliary pattern contacts or overlaps with the second target pattern. If so, the fourth sub-resolution auxiliary pattern is removed to generate a final sub-resolution auxiliary pattern.

6. The method for forming a sub-resolution auxiliary pattern according to claim 1, characterized in that: The photolithography pattern includes a plurality of first target patterns and a plurality of second target patterns, and the distances between the second target patterns and adjacent first target patterns are different.

7. The method for forming a sub-resolution auxiliary pattern according to claim 1, characterized in that: The critical dimension of the second target pattern in the first direction is greater than the critical dimension of the first target pattern in the first direction, and the critical dimension of the second target pattern in the second direction is equal to the critical dimension of the first target pattern in the second direction, and the first direction is perpendicular to the second direction.

8. The method for forming a sub-resolution auxiliary pattern according to claim 7, characterized in that: The first direction is a width direction, the second direction is a length direction, a width critical dimension of the second target pattern is greater than a width critical dimension of the first target pattern, and a length critical dimension of the second target pattern is equal to a length critical dimension of the first target pattern.

9. The method for forming a sub-resolution auxiliary pattern according to claim 1, characterized in that: After the final sub-resolution auxiliary pattern is formed, a design rule check is performed to obtain the sub-resolution auxiliary pattern that meets the design rule.

10. A sub-resolution auxiliary graphic, characterized in that: The sub-resolution auxiliary pattern is prepared by the method for forming the sub-resolution auxiliary pattern according to any one of claims 1 to 9.

Images