Photomask pattern design method, photomask and manufacturing method thereof

Abstract

The invention relates to a design method of a photomask pattern, a photomask and a manufacturing method of the photomask. The method comprises the following steps: designing a main pattern, wherein the extension direction of the main pattern is obliquely crossed with a first direction; a covering layer is formed, the covering layer covers the main pattern, and the covering layer is provided with a first edge extending in the first direction; generating an auxiliary pattern based on the first edge, wherein the auxiliary pattern is located on the outer side of the first edge and has a distance from the first edge; and outputting the main pattern and the auxiliary pattern to obtain a photomask pattern. According to the method provided by the invention, the forming precision of the photomask pattern can be effectively improved, and the preparation process steps of the photomask pattern can be simplified.

Description

Technical Field

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

[0002] Sub-resolution Assistant Feature (SRAF) is an important technical means for improving the resolution of photomasks in the photolithography process. This technical means usually includes: first setting a main pattern on the substrate, and arranging a number of auxiliary patterns around the main pattern according to certain rules to obtain a photomask pattern; then using the photomask pattern to prepare the photomask, and using the aforementioned auxiliary patterns to correct defects such as shape distortion and line loss at the edge of the main pattern, so as to ensure that the obtained photomask meets the design requirements.

[0003] However, when faced with irregular patterns such as tilted main patterns, the application of the SRAF process is prone to problems such as angular deviation errors of the photomask pattern and complication of the process steps. Summary of the invention

[0004] Based on this, it is necessary to provide a photomask pattern design method, a photomask and a method for manufacturing the same in order to address the above technical issues, which can effectively improve the formation accuracy of the photomask pattern and simplify the photomask pattern preparation process steps.

[0005] On the one hand, some embodiments of the present application provide a method for designing a photomask pattern, comprising the following steps.

[0006] Designing a main pattern, wherein an extension direction of the main pattern is oblique to the first direction;

[0007] forming a covering layer, wherein the covering layer covers the main pattern, and the covering layer has a first edge extending along a first direction;

[0008] generating an auxiliary pattern based on the first edge, wherein the auxiliary pattern is located outside the first edge and has a spacing from the first edge;

[0009] Output the main pattern and the auxiliary pattern to obtain the photomask pattern.

[0010] In the embodiment of the present application, a main pattern whose extension direction is oblique to the first direction (i.e., an inclined main pattern) is first provided; then a covering layer covering the aforementioned main pattern is formed, and the covering layer has a first edge extending along the first direction; so as to directly generate an auxiliary pattern corresponding to the regular and continuous first edge. In this way, compared with the related art, the present application does not need to perform multiple rotation operations on the related pattern, thereby reducing or even eliminating process errors such as angle offset, thereby improving the formation accuracy of the photomask pattern and effectively simplifying the preparation process steps.

[0011] In some embodiments, there are multiple main graphics, and the multiple main graphics are arranged in parallel and at intervals; the covering layer covers all the main graphics.

[0012] In some embodiments, the covering layer further has a second edge extending along a second direction, the second direction is perpendicular to the first direction, and the second edge intersects the first edge perpendicularly; and the main pattern is also oblique to the second direction.

[0013] In the above embodiment, by setting a covering layer to cover all the main graphics and making the covering layer also have a first edge and a second edge that intersect vertically, the covering layer can not only accurately characterize the morphological characteristics of each main graphics, but also has relatively continuous and regular morphological characteristics, thereby further ensuring that the auxiliary graphics formed by the corresponding covering layer can achieve better correction accuracy and correction effect for the main graphics.

[0014] In some embodiments, the generating of auxiliary graphics based on the first edge includes: generating multi-order auxiliary graphics of the 1st to Nth orders based on the first edge, each order of auxiliary graphics extending along the first direction and arranged in parallel and spaced apart along the second direction; N is an integer greater than 1.

[0015] In some embodiments, the widths of the auxiliary patterns of each order are the same; and / or the spacing between the first-order auxiliary pattern and the first edge and the spacing between any two adjacent auxiliary patterns of the order are the same.

[0016] In some embodiments, the widths of the auxiliary patterns of different levels are different; and / or the spacing between the first-level auxiliary pattern and the first edge and the spacing between any two adjacent auxiliary patterns of different levels are different.

[0017] In some embodiments, the length of each order of auxiliary patterns is the same as the size of the distribution area of ​​the main pattern along the first direction.

[0018] In some embodiments, the auxiliary pattern includes a scattering strip.

[0019] On the other hand, some embodiments of the present application provide a method for making a photomask, as a practical application of the method for designing a photomask pattern described in some of the aforementioned embodiments. The photomask making method also has the technical advantages of the method for designing a photomask pattern described in some of the aforementioned embodiments, which will not be described in detail here.

[0020] For example, the method for manufacturing the photomask includes the following steps.

[0021] Designing a photomask pattern using the photomask pattern design method described in some of the aforementioned embodiments;

[0022] Providing a light-transmitting substrate, wherein a surface of the light-transmitting substrate is covered with a light-shielding layer;

[0023] The light shielding layer is patterned based on the photomask pattern, and the photomask pattern is transferred to a transparent substrate to obtain a photomask.

[0024] On the other hand, some embodiments of the present application provide a photomask that is manufactured using the photomask manufacturing method described in some of the aforementioned embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A schematic diagram of a photomask pattern forming process;

[0027] Figure 2 A schematic diagram of a process of designing a photomask pattern provided in an embodiment of the present application;

[0028] Figure 3 A schematic diagram of a structure obtained after step S100 in a method for designing a photomask pattern provided in an embodiment of the present application;

[0029] Figure 4 A schematic diagram of a structure obtained after step S200 in a method for designing a photomask pattern provided in an embodiment of the present application;

[0030] Figure 5 A schematic structural diagram of a structure obtained after step S300 in a method for designing a photomask pattern provided in an embodiment of the present application;

[0031] Figure 6It is a schematic structural diagram of a structure obtained after step S400 of a method for designing a photomask pattern provided in an embodiment of the present application; it is also a schematic structural diagram of a photomask pattern provided in some embodiments;

[0032] Figure 7 A schematic diagram of a process for manufacturing a photomask provided in another embodiment of the present application;

[0033] Figure 8 A schematic diagram of a top view of a photomask obtained by a method for manufacturing a photomask provided in another embodiment of the present application;

[0034] Figure 9a A schematic diagram of a top view of a photomask obtained by a method for manufacturing a photomask provided in an embodiment of the present application;

[0035] Figure 9b for Figure 9a A partial enlarged view of area A.

[0036] Fig.10a A schematic diagram of a top view of a photomask obtained by a method for manufacturing a photomask provided in another embodiment of the present application;

[0037] Fig.10b for Fig.10a A partial enlarged view of area B in FIG.

[0038] Description of reference numerals:

[0039] 10-main pattern, 20-auxiliary pattern, 21-first-order auxiliary pattern, 22-second-order auxiliary pattern, 23-third-order auxiliary pattern, 24-fourth-order auxiliary pattern, 30-covering layer, 301-first edge, 302-second edge, 40-transparent substrate, P1-photomask pattern. DETAILED DESCRIPTION

[0040] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0042] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0043] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0044] Sub-resolution Assistant Feature (SRAF) is an important technical means for improving the resolution of photomasks in the photolithography process. This technical means usually includes: first setting a main pattern on the substrate, and arranging a number of auxiliary patterns around the main pattern according to certain rules to obtain a photomask pattern; then using the photomask pattern to prepare the photomask, and using the aforementioned auxiliary patterns to correct defects such as shape distortion and line loss at the edge of the main pattern, so as to ensure that the obtained photomask meets the design requirements.

[0045] However, when faced with irregular patterns such as tilted main patterns, the application of the SRAF process is prone to problems such as angular deviation errors of the photomask pattern and complication of the process steps.

[0046] See also Figure 1 , shows a process of forming a photomask pattern: first, a main pattern 10 is provided, and the extension direction of the main pattern 10 has an angle with the first direction (for example, the X direction) and the second direction (for example, the Y direction), that is, the main pattern 10 is oblique to the X direction and the Y direction, as shown in FIG. Figure 1 Then the main figure 10 is rotated for the first time so that the extension direction of the main figure 10 is parallel to a preset direction (eg, the Y direction), as shown in FIG. Figure 1 As shown in FIG. (b); an auxiliary pattern 20 is formed corresponding to the edge area of ​​the main pattern 10, such as Figure 1 As shown in FIG. (c) of FIG. 1 ; the main pattern 10 and the auxiliary pattern 20 are rotated for the second time, so that the main pattern 10 is restored to the original position, and the main pattern 10 and the auxiliary pattern 20 are outputted as a photomask pattern. Figure 1 As shown in Figure (d).

[0047] It is understandable that, in the process of forming the photomask pattern, the main pattern 10 needs to be rotated multiple times, which inevitably introduces process errors such as angle offset, and may have an adverse effect on the formation accuracy of the auxiliary pattern, thereby affecting the formation accuracy of the photomask pattern.

[0048] The inventor of the present case has measured and analyzed the accuracy of the photomask patterns obtained in multiple embodiments including the aforementioned embodiment. In order to more clearly compare the accuracy of the photomask patterns obtained in each embodiment, the relevant results will be presented in the following text.

[0049] See also Figure 2 Some embodiments of the present application provide a method for designing a photomask pattern, comprising the following steps.

[0050] S100, designing a main pattern, wherein an extension direction of the main pattern is oblique to the first direction.

[0051] S200, forming a covering layer, wherein the covering layer covers the main pattern, and the covering layer has a first edge extending along a first direction.

[0052] S300, generating an auxiliary pattern based on the first edge, wherein the auxiliary pattern is located outside the first edge and has a distance from the first edge.

[0053] S400, outputting the main pattern and the auxiliary pattern to obtain a photomask pattern.

[0054] In the embodiment of the present application, a main pattern (i.e., an inclined main pattern) whose extension direction is oblique to the first direction is first provided; then a covering layer covering the aforementioned main pattern is formed, and the covering layer has a first edge extending along the first direction; so as to directly generate an auxiliary pattern corresponding to the regular and continuous first edge. In this way, compared with the need of "rotating the inclined main pattern for the first time - generating an auxiliary pattern according to the main pattern - rotating the main pattern and the auxiliary pattern to the original direction for the second time" in the related art, the present application does not need to perform multiple rotation operations on each pattern, thereby reducing or even eliminating process errors such as angle offset, thereby improving the formation accuracy of the photomask pattern and effectively simplifying the preparation process steps.

[0055] In step S100, refer to Figure 2 S100 and Figure 3 , a main graphic 10 is designed, and an extending direction of the main graphic 10 is oblique to the first direction.

[0056] Here, the first direction may be, for example, a preset reference direction for preparing a photomask pattern. The first direction usually needs to remain unchanged during the process of preparing the photomask pattern, so as to provide a positioning reference for the formation of the photomask pattern and related process equipment.

[0057] For example, the shape of the main pattern 10 may include: a line pattern or a contact hole pattern. In some embodiments where the shape of the main pattern 10 includes a line pattern, the extension direction of the main pattern 10 is the extension direction of the bar pattern; in some embodiments where the shape of the main pattern 10 includes a contact hole pattern, the extension direction of the main pattern 10 is the arrangement direction of multiple contact hole patterns. In the following embodiments and drawings, the shape of the main pattern 10 includes a line pattern as an example for description.

[0058] For example, the extension direction of the main pattern 10 forms a certain angle with the first direction (eg, the X direction), that is, the extension direction of the main pattern 10 is oblique to the first direction (eg, the X direction).

[0059] In step S200, refer to Figure 2 S200 and Figure 4 , forming a covering layer 30, the covering layer 30 covers the main pattern 10, and the covering layer 30 has a first edge 301 extending along the first direction.

[0060] Here, the purpose of forming the covering layer 30 is that the covering layer 30 has an edge extending along the first direction, which provides a reference for correspondingly forming the auxiliary pattern in the subsequent steps. It can be understood that in order to ensure the formation accuracy of the auxiliary pattern, the covering layer 30 needs to accurately characterize the morphological features of the main pattern 10 and needs to effectively avoid the interference caused by the main pattern 10.

[0061] For example, the covering layer 30 completely covers the main pattern 10 to ensure that the auxiliary pattern is not interfered by the main pattern 10 in the subsequent step of forming the auxiliary pattern.

[0062] For example, the material of the cover layer 30 may include: a photosensitive material or an anti-reflection material. In one example, the material of the cover layer 30 may be, for example, photoresist.

[0063] In some embodiments, the cover layer 30 has at least one regular edge, such as a first edge 301. The first edge 301 extends along a first direction (eg, X direction).

[0064] In other embodiments, the covering layer 30 further has a second edge 302 extending along a second direction (e.g., the Y direction), the second direction (e.g., the Y direction) is perpendicular to the first direction (e.g., the X direction), and the second edge 302 intersects the first edge 301 perpendicularly; the main pattern 10 also intersects obliquely with the second direction (e.g., the Y direction).

[0065] Please continue reading Figure 3 In some embodiments, there are multiple main graphics 10 , and the multiple main graphics 10 are arranged in parallel and spaced apart. Correspondingly, the covering layer 30 covers all the main graphics 10 .

[0066] For example, multiple main graphics 10 are arranged in parallel and spaced apart in a direction perpendicular to their extension direction. The intervals between any adjacent main graphics 10 can be the same or different, that is, main graphics 10 of multiple specifications can be arranged at uniform intervals or non-uniform intervals, which is not limited in this application.

[0067] In the above embodiment, by setting the covering layer 30 to cover all the main graphics 10 and making the covering layer 30 also have a first edge 301 and a second edge 302 that intersect vertically, the covering layer 30 can not only accurately characterize the morphological characteristics of each main graphic 10, but also has relatively continuous and regular morphological characteristics, thereby further ensuring that the auxiliary graphics 20 formed by the corresponding covering layer 30 can achieve better correction accuracy and correction effect for the main graphic 10.

[0068] In step S300, refer to Figure 2 S300 and Figure 5 , an auxiliary pattern 20 is generated based on the first edge 301 , and the auxiliary pattern 20 is located outside the first edge 301 and has a distance from the first edge 301 .

[0069] For example, the generation method of the auxiliary pattern 20 may be determined according to the actual product and process parameters, and the generation rule of the auxiliary pattern 20 may be further determined, so that each auxiliary pattern 20 may be formed corresponding to the first edge 301 .

[0070] For example, the auxiliary pattern 20 is generated in a rule-based auxiliary pattern generation method, including: providing an empirical rule library; and determining the auxiliary pattern generation rules in the empirical rule library according to the morphology parameters and process parameters of the cover layer 30 .

[0071] For example, the experience rule base may come from the accumulated experience of personnel in the product development stage or the formal production stage, or may also come from an existing experience rule base provided by other manufacturers with the same or similar product structure and process equipment.

[0072] For example, the auxiliary graphic 20 is generated in a model-based auxiliary graphic generation method, including: providing a model library containing multiple optical models and photoresist models; determining matching optical models and photoresist models in the model library according to the morphological parameters and lithography process parameters of the covering layer 30; and determining corresponding auxiliary graphic generation rules according to the aforementioned models.

[0073] For example, the auxiliary pattern generation rule includes: the number of auxiliary patterns 20 , the line width of each auxiliary pattern 20 , the spacing distance between the auxiliary patterns 20 , and the spacing distance between the auxiliary pattern 20 and the first edge 301 .

[0074] Please continue reading Figure 5 In some embodiments, the generating of the auxiliary pattern 20 based on the first edge 301 includes: generating multiple auxiliary patterns of the 1st to Nth order based on the first edge 301, each order of the auxiliary pattern 20 extends along the first direction and is arranged in parallel and spaced apart along the second direction; N is an integer greater than 1.

[0075] For example, the following embodiments and drawings of the specification continue to explain by taking the formation of four-order auxiliary graphics 20 as an example. The auxiliary graphics 20 may include: a first-order auxiliary graphic 21, a second-order auxiliary graphic 22, a third-order auxiliary graphic 23 and a fourth-order auxiliary graphic 24.

[0076] For example, each of the step auxiliary patterns 20 extends along a first direction (eg, an X direction) and is arranged in parallel and at intervals along a second direction (eg, a Y direction).

[0077] In some embodiments, the widths of the auxiliary patterns 20 of each order are the same. For example, the width W1 of the first-order auxiliary pattern 21, the width W2 of the second-order auxiliary pattern 22, the width W3 of the third-order auxiliary pattern 23, and the width W4 of the fourth-order auxiliary pattern 24 are all in the range of 18nm to 22nm; for example, 18nm, 19nm, 20nm, 21nm, and 22nm.

[0078] In other embodiments, the widths of the auxiliary patterns 20 of different orders are different. For example, the widths of any two orders of auxiliary patterns 20 are different, or the width W1 of the first-order auxiliary pattern 21, the width W2 of the second-order auxiliary pattern 22, the width W1 of the third-order auxiliary pattern 23, and the width W4 of the fourth-order auxiliary pattern 24 are all different.

[0079] In some embodiments, the spacing between the first-order auxiliary pattern 21 and the first edge 301 and the spacing between any two adjacent auxiliary patterns 20 are the same. For example, the spacing S between the first-order auxiliary pattern 21 and the first edge 301 is 0-1 , the spacing S between the first-order auxiliary pattern 21 and the second-order auxiliary pattern 20 1-2 , the spacing S between the second-order auxiliary pattern 21 and the third-order auxiliary pattern 20 2-3 and the spacing S between the third-order auxiliary pattern 21 and the fourth-order auxiliary pattern 20 3-4 are the same.

[0080] In some other embodiments, the spacing between the first-order auxiliary pattern 21 and the first edge 301 and the spacing between any two adjacent auxiliary patterns 20 are not the same. For example, the spacing S between the first-order auxiliary pattern 21 and the first edge 301 is 0-1 , the spacing S between the first-order auxiliary pattern 21 and the second-order auxiliary pattern 20 1-2 , the spacing S between the second-order auxiliary pattern 21 and the third-order auxiliary pattern 20 2-3 and the spacing S between the third-order auxiliary pattern 21 and the fourth-order auxiliary pattern 20 3-4 Are all different.

[0081] In some embodiments, the length of each level of the auxiliary pattern 20 is the same as the size of the distribution area of ​​the main pattern 10 along the first direction (eg, the X direction).

[0082] In some embodiments, the auxiliary pattern 20 includes scattering strips. In the subsequent photolithography step, each scattering strip can ensure accurate exposure of the main pattern 10 by its own influence on the light intensity, and will not be exposed or developed itself, thereby effectively avoiding adverse effects on the final photolithography pattern.

[0083] In step S400, refer to Figure 2 S400 and Figure 6 , the main pattern 10 and the auxiliary pattern 20 are output to obtain the photomask pattern P1.

[0084] For example, the main pattern 10 and the auxiliary pattern 20 can be output as a photomask pattern P1 to a related process device, and a photomask can be obtained. The photomask can have relatively accurate morphological features of the main pattern 10 and avoid the morphological features of the auxiliary pattern 20.

[0085] See also Figure 6 Some embodiments of the present application provide a method for making a photomask, as a practical application of the method for designing a photomask pattern described in some of the aforementioned embodiments. The photomask making method also has the technical advantages of the method for designing a photomask pattern described in some of the aforementioned embodiments, and will not be described in detail here.

[0086] By way of example, the photomask manufacturing method includes steps S10 to S30.

[0087] S10, design photomask pattern.

[0088] S20, providing a light-transmitting substrate, wherein a surface of the light-transmitting substrate is covered with a light-shielding layer.

[0089] S30, patterning the light shielding layer based on the photomask pattern, and transferring the photomask pattern to the transparent substrate to obtain a photomask.

[0090] In step S10, refer to Figure 7 S10 and Figure 6 , design the photomask pattern P1.

[0091] For example, the photomask pattern P1 may be designed using the photomask pattern design method described in some of the aforementioned embodiments.

[0092] For example, the photomask pattern P1 may include a main pattern 10 and an auxiliary pattern 20; wherein, the number of the main patterns 10 may include multiple, and the multiple main patterns 10 are arranged in parallel and spaced apart; the auxiliary patterns 20, for example, include: a first-order auxiliary pattern 21, a second-order auxiliary pattern 22, a third-order auxiliary pattern 23 and a fourth-order auxiliary pattern 24.

[0093] In step S20, refer to Figure 7 S20 and Figure 8 , providing a light-transmitting substrate 40, the surface of which is covered with a light-shielding layer.

[0094] For example, the material of the light-transmitting substrate 40 includes transparent materials such as quartz glass, soda glass or borosilicate glass.

[0095] For example, the material of the light shielding layer includes: opaque materials such as metal chromium, metal aluminum or metal molybdenum.

[0096] In step S30, refer to Figure 7 S30 and Figure 8 , the light shielding layer is patterned based on the photomask pattern P1, and the photomask pattern P1 is transferred to the transparent substrate 40 to obtain a photomask.

[0097] For example, an etching process may be used to pattern the light shielding layer, so as to facilitate accurate transfer of the photomask pattern to the transparent substrate 40 .

[0098] Please continue reading Figure 8 In some embodiments, a photomask is provided, which is manufactured using the photomask manufacturing method described in some of the aforementioned embodiments.

[0099] For example, the photomask includes: a transparent substrate 40 and a light shielding layer covering the transparent substrate 40. The light shielding layer also forms photomask patterns including: a main pattern 10 and an auxiliary pattern 20.

[0100] For example, the material of the light-transmitting substrate 40 includes transparent materials such as quartz glass, soda glass or borosilicate glass.

[0101] For example, the material of the light shielding layer includes: opaque materials such as metal chromium, metal aluminum or metal molybdenum.

[0102] It is worth mentioning that the inventors of the present application also prepared photomask patterns and corresponding photomasks based on the design methods of various photomask patterns provided in some of the aforementioned embodiments, and measured and compared the precision of the obtained photomasks. The relevant results are shown in Table 1.

[0103] Table 1 Comparison of the accuracy of photomasks obtained by designing methods based on different photomask patterns

[0104]

[0105]

[0106] See Table 1 and Figure 9a , Figure 9b , Fig.10a and Fig.10b Based on the same main pattern, the applicant of this case respectively adopted the design method of the photomask pattern in the related art and the design method of the photomask pattern in this application, and prepared the photomasks under the same process conditions; set measurement points (such as B1 and B2) at the same position of the photomask, and measured the process bandwidth value (i.e., the difference between the maximum line width and the minimum line width of the photomask pattern). By statistically analyzing and comparing the measurement data, compared with the related art, the method provided by this application improves the process bandwidth value by about 33% to 41%.

[0107] It can be seen that the photomask pattern design method, photomask and its manufacturing method provided in the present application can effectively improve the formation accuracy of the photomask pattern and simplify the preparation process steps of the photomask pattern, and have better technical advantages and cost advantages.

[0108] In the above embodiments of the present application, unless otherwise specified herein, the execution of each step in the method is not strictly limited in order, and these steps may not necessarily be executed in the order described, but may be executed in other ways. Moreover, at least a part of any step may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but may be executed at different times, and the execution order of these sub-steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0109] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0110] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for designing a photomask pattern, characterized in that: include: Designing a main pattern, wherein an extending direction of the main pattern is oblique to the first direction; forming a covering layer, wherein the covering layer covers the main pattern, and the covering layer has a first edge extending along the first direction; generating an auxiliary pattern based on the first edge, wherein the auxiliary pattern is located outside the first edge and has a distance from the first edge; The main pattern and the auxiliary pattern are output to obtain a photomask pattern.

2. The method for designing a photomask pattern according to claim 1, characterized in that: There are multiple main graphics, and the multiple main graphics are arranged in parallel and at intervals; the covering layer covers all the main graphics.

3. The method for designing a photomask pattern according to claim 1, wherein: The covering layer also has a second edge extending along a second direction, the second direction is perpendicular to the first direction, and the second edge intersects the first edge perpendicularly; the main pattern also intersects obliquely with the second direction.

4. The method for designing a photomask pattern according to claim 3, wherein: The generating of an auxiliary graphic based on the first edge comprises: Multiple levels of auxiliary graphics of the 1st to Nth levels are generated based on the first edge, and the auxiliary graphics of each level extend along the first direction and are arranged in parallel and at intervals along the second direction; N is an integer greater than 1.

5. The method for designing a photomask pattern according to claim 4, wherein: The widths of the auxiliary patterns at each level are the same; and / or the spacing between the auxiliary patterns at the first level and the first edge and the spacing between any two adjacent levels of the auxiliary patterns are the same.

6. The method for designing a photomask pattern according to claim 4, wherein: The widths of the auxiliary patterns at each level are different; and / or the spacing between the auxiliary patterns at the first level and the first edge and the spacing between any two adjacent levels of the auxiliary patterns are different.

7. The method for designing a photomask pattern according to claim 4, wherein: The length of the auxiliary patterns at each stage is the same as the size of the distribution area of ​​the main pattern along the first direction.

8. The method for designing a photomask pattern according to any one of claims 1 to 7, characterized in that: The auxiliary pattern includes a scattering strip.

9. A method for making a photomask, characterized in that: include: Designing a photomask pattern using the photomask pattern design method according to any one of claims 1 to 8; Providing a light-transmitting substrate, wherein a surface of the light-transmitting substrate is covered with a light-shielding layer; The light shielding layer is patterned based on the photomask pattern, and the photomask pattern is transferred to the light-transmitting substrate to obtain a photomask.

10. A photomask, characterized in that: The photomask is manufactured by the photomask manufacturing method according to claim 9.

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