Optical mask pattern correction method and device, equipment and storage medium

Abstract

The invention relates to the technical field of semiconductor photoetching processing, and discloses an optical mask pattern correction method, device and equipment and a storage medium, the correction method comprises the following steps: obtaining an initial mask pattern, segmenting the contour edge line of the initial mask pattern to obtain segmented edge segments; performing corresponding EPE error operation on the evaluation points on the segmentation edge sections to obtain EPE error values corresponding to the segmentation edge sections; and comparing the EPE error value corresponding to each segmentation edge segment with an EPE threshold value, and performing optimization iteration on the edge segment number, the edge segment length and the edge segment position of the segmentation edge segment according to a comparison result until the EPE error value corresponding to each segmentation edge segment is smaller than the EPE threshold value, and determining the segmentation edge segment after the initial mask pattern is corrected. In the process of correcting the optical mask pattern, optimization iteration is carried out on three different dimensions including the number, the length and the position of the segmentation edge sections, and the exposure precision of the photoetching mask plate and the semiconductor photoetching precision are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor lithography processing, in particular to a method, device and equipment for correcting an optical mask pattern and a computer readable storage medium. BACKGROUND

[0002] A lithography mask is a tool frequently used and important in semiconductor processing technology. Due to the influence of the optical proximity effect, the mask pattern of the lithography mask is not completely the same as the final required lithography pattern. In order to ensure that the exposure pattern formed by exposure of the lithography mask can be as close as possible to the target lithography pattern, the mask pattern of the lithography mask needs to be repeatedly adjusted to minimize the error between the exposure pattern and the target lithography pattern, so as to improve the precision of the lithography mask. However, the current adjustment method of the conventional lithography mask has certain limitations, which limits the exposure precision of the lithography mask. SUMMARY

[0003] The purpose of the present application is to provide a method, device and equipment for correcting an optical mask pattern and a computer readable storage medium.

[0004] To solve the above technical problems, the present application provides a method for correcting an optical mask pattern, comprising:

[0005] obtaining an initial mask pattern and cutting the profile edge line of the initial mask pattern to obtain a cut edge segment;

[0006] selecting an evaluation point on each of the cut edge segments and performing corresponding EPE error operation on the evaluation point to obtain the EPE error value corresponding to each of the cut edge segments;

[0007] comparing the EPE error value corresponding to each of the cut edge segments with an EPE threshold value, and optimizing and iterating the number, length and position of the cut edge segments according to the comparison result until the EPE error value corresponding to each of the cut edge segments is less than the EPE threshold value, to determine the cut edge segment of the initial mask pattern after correction.

[0008] In an optional embodiment of the present application, cutting the profile edge line of the initial mask pattern to obtain a cut edge segment comprises:

[0009] identifying each inflection point on the profile edge line of the initial mask pattern, cutting the profile edge line segment between any two adjacent inflection points according to a plurality of different first set cutting lengths to obtain the cut edge segment;

[0010] and / or, identifying each inflection point on the profile edge line of the initial mask pattern, segmenting the profile edge line segment between any two adjacent inflection points into the segmentation edge segments by segmenting from both ends to the middle according to a second set segmentation length, and dividing the remaining profile edge line segment in the middle which is larger than the second set segmentation length and smaller than twice the second set segmentation length into two segmentation edge segments;

[0011] and / or, identifying a selected profile edge line segment in the profile edge line which has adjacent profile edge line endpoints, taking the vertical point of the adjacent profile edge line endpoints on the selected profile edge line segment as the segmentation starting point of the selected profile edge line, and segmenting the selected profile edge line segment from both ends to the middle according to a third set segmentation length to obtain the segmentation edge segments.

[0012] In an optional embodiment of the present application, an evaluation point is selected on each segmentation edge segment and a corresponding EPE error operation is performed on the evaluation point to obtain the corresponding EPE error value of each segmentation edge segment, including:

[0013] a plurality of evaluation points are selected on each segmentation edge segment;

[0014] an EPE error operation is performed on each evaluation point to obtain a single-point EPE error value corresponding to each evaluation point;

[0015] the single-point EPE error values corresponding to each evaluation point on the same segmentation edge segment are averaged to obtain the EPE error value corresponding to the same segmentation edge segment.

[0016] In an optional embodiment of the present application, a plurality of evaluation points are selected on each segmentation edge segment, including:

[0017] a plurality of equally divided points on the segmentation edge segment are selected as the evaluation points, wherein the distance between adjacent evaluation points is within a set distance range.

[0018] In an optional embodiment of the present application, the process of optimization iteration of the segmentation edge segment includes:

[0019] the maximum single-point EPE error value and the minimum single-point EPE error value among the single-point EPE error values corresponding to each evaluation point on the same segmentation edge segment are subjected to a difference operation to obtain an EPE difference value;

[0020] the segmentation edge segment with a corresponding EPE difference value greater than a set threshold value is segmented into at least two new segmentation edge segments;

[0021] Re-select the evaluation points on the newly divided segment to perform the operation of corresponding EPE error operation on the evaluation points.

[0022] In an alternative embodiment of the present application, the process of optimizing and iterating the segment according to the comparison result comprises:

[0023] When the EPE error value corresponding to the segment is greater than the EPE threshold value, the ratio of the EPE error value to the EPE threshold value is rounded up to obtain an integer ratio value;

[0024] The segment is uniformly divided into new segments with an integer ratio value;

[0025] Re-select the evaluation points on the newly divided segment to perform the operation of corresponding EPE error operation on the evaluation points.

[0026] In an alternative embodiment of the present application, the process of optimizing and iterating the segment according to the comparison result comprises:

[0027] When the EPE error value corresponding to the segment is greater than the EPE threshold value, the ratio of the EPE error value to the EPE threshold value is rounded up to obtain an integer ratio value;

[0028] An optical mask pattern correction device, comprising:

[0029] A segmentation processing module is configured to obtain an initial mask pattern and segment the contour edge line of the initial mask pattern to obtain a segment;

[0030] An evaluation operation module is configured to select evaluation points on each segment and perform corresponding EPE error operation on the evaluation points to obtain an EPE error value corresponding to each segment;

[0031] An optimization iteration module is configured to compare the EPE error value corresponding to each segment with an EPE threshold value, and optimize and iterate the number, length and position of the segment according to the comparison result until the EPE error value corresponding to each segment is less than the EPE threshold value, and determine the segment of the initial mask pattern after correction.

[0032] An optical mask pattern correction device, comprising:

[0033] a memory for storing the computer program;

[0034] a processor for executing the computer program to implement the steps of the method for modifying an optical mask pattern according to any one of the preceding items.

[0035] A computer readable storage medium having stored therein a computer program, the computer program being executed to implement the steps of the method for modifying an optical mask pattern according to any one of the preceding items.

[0036] The method for modifying an optical mask pattern, device, equipment and computer readable storage medium provided by the application, the method for modifying an optical mask pattern comprises obtaining an initial mask pattern, and cutting the profile edge line of the initial mask pattern to obtain a cutting edge segment; selecting an evaluation point on each cutting edge segment and performing a corresponding EPE error operation on the evaluation point to obtain an EPE error value corresponding to each cutting edge segment; comparing the EPE error value corresponding to each cutting edge segment with an EPE threshold value, and optimizing and iterating the edge segment number, edge segment length and edge segment position of the cutting edge segment according to the comparison result until the EPE error value corresponding to each cutting edge segment is less than the EPE threshold value, and determining the cutting edge segment of the initial mask pattern after modification.

[0037] In the process of modifying the optical mask pattern based on the edge position error feedback technology in the application, compared with the conventional modification method of only optimizing and iterating the edge segment position, the edge of the initial mask pattern is cut in the application to obtain a plurality of cutting edge segments, and the edge segment number, edge segment length and edge segment position of the three different dimensions are simultaneously optimized and iterated. Obviously, compared with the method of only optimizing and iterating the single-dimension parameter of the edge segment position, the accuracy of the profile edge line of the mask pattern formed by the cutting edge segments finally determined in the application is higher, that is, a mask pattern with higher exposure precision can be obtained, the exposure precision of the photolithography mask plate is improved to a certain extent, and the photolithography precision in semiconductor processing is improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0039] Figure 1 The flowchart of the method for modifying an optical mask pattern provided by the embodiment of the application;

[0040] Figure 2A schematic diagram of an exposure area pattern and a corresponding initial mask pattern provided for an embodiment of the present application;

[0041] Figure 3 A first cutting mode schematic diagram for cutting a profile edge line segment provided for an embodiment of the present application;

[0042] Figure 4 A second cutting mode schematic diagram for cutting a profile edge line segment provided for an embodiment of the present application;

[0043] Figure 5 A third cutting mode schematic diagram for cutting a profile edge line segment provided for an embodiment of the present application;

[0044] Figure 6 A schematic diagram of a comparison of edge segment distribution before and after edge segment number optimization of a cutting edge segment provided for an embodiment of the present application;

[0045] Figure 7 A schematic diagram of a comparison of edge segment distribution before and after edge segment length optimization of a cutting edge segment provided for an embodiment of the present application;

[0046] Figure 8 A structure block diagram of a correction device for an optical mask pattern provided for an embodiment of the present application. DETAILED DESCRIPTION

[0047] The core of the present application is to provide an optical mask pattern correction method, device, equipment and computer readable storage medium, which optimizes the correction technology of the optical mask pattern, can improve the exposure precision of the optical mask pattern, and is beneficial to improving the semiconductor processing precision.

[0048] In order to enable personnel in the art to better understand the present application scheme, the present application will be further described in detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0049] Before manufacturing the optical mask plate, a pattern design needs to be performed to obtain a precise and reliable optical mask pattern, and then the same optical mask plate as the optical mask pattern is processed and formed based on the optical mask pattern.

[0050] Obviously, the optical mask pattern should be initially determined based on the target photolithography pattern corresponding to the optical mask plate. After the optical mask pattern is initially determined according to the target photolithography pattern, further correction of the optical mask pattern is needed due to the influence of the optical proximity effect, and finally a precise and reliable optical mask pattern is obtained.

[0051] Based on the above discussion, as Figure 1 shown, Figure 1 The flowchart of the optical mask pattern correction method provided by the embodiment of the present application is shown.

[0052] In a specific embodiment of the present application, the optical mask pattern correction method can include:

[0053] S11: obtaining an initial mask pattern, and segmenting the profile edge line of the initial mask pattern to obtain segmented edge segments;

[0054] S12: selecting evaluation points on each segmented edge segment and performing corresponding EPE error operations on the evaluation points to obtain EPE error values corresponding to each segmented edge segment;

[0055] S13: comparing the EPE error values corresponding to each segmented edge segment with the EPE threshold value, and optimizing and iterating the number, length and position of the segmented edge segments according to the comparison result until the EPE error values corresponding to each segmented edge segment are all less than the EPE threshold value, to determine the segmented edge segments of the initial mask pattern after correction.

[0056] It can be understood that the initial mask pattern in the embodiment is a pattern designed based on a target lithography pattern; and the correction of the optical mask pattern is performed on the basis of the initial mask pattern.

[0057] As Figure 2 shown, taking a partial mask pattern that needs to expose an elliptical region as an example, the profile edge line of the initial mask pattern is not an elliptical region formed by a smooth curve, but a polygonal profile edge line. It can be understood that the profile edge line of the initial mask pattern in the embodiment not only includes the outermost edge line of the entire initial mask pattern, but also should include the contour line of the hole pattern on the initial mask pattern. On this basis, the segmentation of the profile edge line of the initial mask pattern can specifically be the segmentation of the contour straight line segments between each inflection point (also referred to as vertex) of the polygonal profile edge line to form a plurality of segmented edge segments, each of which should be a straight line segment. Obviously, each segmented edge segment is a part of the profile edge line; and whether the position of each segmented edge segment is appropriate or not determines whether the accuracy of the part of the profile edge line in the initial mask pattern meets the requirements.

[0058] In actual application, the segmentation method of the profile edge line of the initial mask pattern can include various methods. As Figure 3 shown, in an alternative embodiment of the present application, the process of segmenting the profile edge line can include:

[0059] Identifying each inflection point on the profile edge line of the initial mask pattern, cutting the profile edge line segment between any two adjacent inflection points according to a plurality of different first set cutting lengths to obtain cut edge segments.

[0060] In Figure 3 In the illustrated embodiment, the first set cutting lengths include two different cutting lengths of 0.3um and 0.4um. It should be noted that the first set cutting lengths in this embodiment are set based on the consideration of reducing the inflection corner position error of the profile edge line, so as to reduce the convergence speed of the subsequent optimization iteration of the parameters of the cut edge segments to a certain extent.

[0061] When cutting the profile edge line segment between two adjacent inflection points based on the first set cutting lengths, the inflection points at both ends of the profile edge line segment can be taken as the starting points of the cutting, and the profile edge line segment is sequentially cut from both ends to the middle according to the above two different first set cutting lengths in turn, so as to obtain a plurality of cut edge segments with edge segment lengths of 0.4um, 0.3um, 0.4um, 0.3um, 0.4um,..., 0.3um, 0.4um, 0.3um, 0.4um. Of course, in actual application, the two different first set cutting lengths do not necessarily alternate in the above manner, for example, the plurality of cut edge segments can also be cut in the manner of edge segment lengths of 0.4um, 0.3um, 0.3um, 0.4um, 0.4um,..., 0.4um, 0.3um, 0.3um, 0.4um. In addition, the length of the profile edge line segment does not necessarily equal the sum of a plurality of 0.3um and a plurality of 0.4um. If the length of the remaining line segment section of the profile edge line segment is greater than 0.3um and less than 0.4um, the remaining line segment section does not need to be cut and is taken as a cut edge segment. If the length of the remaining line segment section is greater than 0.4um and less than 0.8um, the remaining line segment section is cut into two cut edge segments with equal lengths. Taking the length of the profile edge line segment as 4.1um for example, the profile line segment can be cut into 11 cut edge segments with lengths of 0.4um, 0.3um, 0.4um, 0.3um, 0.4um, 0.5um, 0.4um, 0.3um, 0.4um, 0.3um, 0.4um. Taking the length of the profile edge line segment as 1.0um for example, the profile line segment can be cut into 3 cut edge segments with lengths of 0.3um, 0.4um, 0.3um. In summary, based on cutting from both ends of the profile edge line segment to the middle, the lengths of the cut edge segments can be as close to the first set cutting lengths as possible.

[0062] In addition, it should be noted that Figure 3 The dashed line segment in the above figure indicates that the line segment is not completely shown. In the subsequentFigures 4 to 7 The dashed segments in the profile edge line also represent the same meaning, which will not be repeated hereinafter.

[0063] As shown in FIG. 1, in another optional embodiment of the present application, the process of segmenting the profile edge line can include: Figure 4

[0064] Identifying each inflection point on the profile edge line of the initial mask pattern, segmenting the profile edge line segment between any two adjacent inflection points into segmented edge segments by segmenting from both ends to the middle according to a second set segmentation length, and dividing the remaining profile edge line segment between the middle into two segmented edge segments if the remaining profile edge line segment is greater than the second set segmentation length and less than twice the second set segmentation length.

[0065] In the embodiment shown in FIG. 2, taking 0.6um as an example of the second set segmentation length, for the profile edge line segment between two adjacent inflection points, the two inflection points can be taken as the segmentation starting points, and the profile edge line segment can be segmented from both ends to the center according to the second set segmentation length. Finally, the remaining line segment in the central section of the profile edge line segment can be less than or equal to the second set segmentation length, at which time the segmentation of the profile edge line segment ends, and the remaining line segment can be greater than the second set segmentation length and less than or equal to twice the second set segmentation length, at which time the remaining line segment is directly divided into two segmented edge segments, and the segmentation of the profile edge line is completed. The segmentation method of the profile edge line in this embodiment is a kind of approximate uniform and faster segmentation method. Figure 4 As shown in FIG. 3, in another optional embodiment of the present application, the segmentation method of the profile edge line segment can further include:

[0066] Figure 5 In the profile edge line, identifying a selected profile edge line segment having a neighboring profile edge line end point, taking the vertical point of the neighboring profile edge line end point on the selected profile edge line segment as the segmentation starting point of the selected profile edge line, and uniformly segmenting the selected profile edge line segment from both ends according to a third set segmentation length to obtain a segmented edge segment.

[0067] Referring to FIG. 4, in the embodiment shown in FIG. 4, when there are two mutually adjacent profile edge line segments, if the vertical distance from the end point of the first profile edge line segment to the second profile edge line segment is less than the set distance threshold, then the end point of the first profile edge line segment close to the second profile edge line segment is the neighboring profile edge line end point of the second profile edge line segment, and the second profile edge line segment is the selected profile edge line segment.

[0068] As shown in FIG. 5, in another optional embodiment of the present application, the segmentation method of the profile edge line segment can further include: Figure 5 When there are two mutually adjacent profile edge line segments, if the vertical distance from the end point of the first profile edge line segment to the second profile edge line segment is less than the set distance threshold, then the end point of the first profile edge line segment close to the second profile edge line segment is the neighboring profile edge line end point of the second profile edge line segment, and the second profile edge line segment is the selected profile edge line segment.

[0069] Figure 5 ​​​As shown, perpendicular lines are drawn from the endpoints of adjacent contour edges to the selected contour segment. The corresponding perpendicular points serve as the starting points for dividing the selected contour segment. The selected contour segment is then evenly divided towards both ends according to the third preset division length. Figure 5 In the embodiment shown, the third set cutting length is 0.5 μm.

[0070] In this embodiment, the method of segmenting the contour edge line segments takes into account that the exposure of each contour edge line segment will be affected by the adjacent contour edges. Therefore, the perpendicular point of the endpoint of the adjacent contour edge line is used as the segmentation starting point to uniformly segment both sides, which is more in line with the light wave characteristics formed during the light wave projection process and can ensure the accuracy and reliability of the subsequent optimization of the edge segment position.

[0071] It is understandable that all contour edge segments in the same initial mask pattern can be handled according to the above method. Figures 3 to 5 The edge segmentation shown in any of the embodiments can also be partially performed according to... Figure 3 The embodiment shown performs edge segmentation, and another part follows... Figure 4 The illustrated embodiment performs edge segmentation, and a portion is based on... Figure 5 The illustrated embodiment performs edge segmentation; or a portion is divided according to... Figure 4 The illustrated embodiment performs edge segmentation, and another part is according to... Figure 5 The embodiments shown perform edge segmentation, but no specific limitations are imposed on this in this application.

[0072] Furthermore, for the same contour edge segment, especially a relatively long contour edge segment, the above steps can be followed sequentially. Figure 3 The method shown above Figure 5 The method shown and the above Figure 4 The segments are divided sequentially in the manner shown (i.e., uniform segmentation has the lowest priority). For example, a relatively long contour edge segment can be roughly divided into two end segments near both ends of the contour edge segment, a middle segment located at the two ends of the contour edge segment, and a transition segment between each end segment and the middle segment. When segmenting the edges, the inflection points at both ends of the contour edge segment can be used as the starting point, and the two end segments can be segmented simultaneously according to the first predetermined segmentation length mentioned above. Then, according to the above... Figure 5 The middle section of the contour edge segment is segmented using this method; finally, both transition sections are segmented according to... Figure 4 The uniform segmentation shown can also achieve the segmentation in this application.

[0073] After all the profile edge lines in the initial mask pattern are completed with the segment cutting, a plurality of cutting segments are obtained, and then the EPE (Edge Placement Error) error value corresponding to each cutting segment is determined.

[0074] In the embodiment, an evaluation point is selected on each cutting segment, and the exposure effect of the current initial mask pattern is simulated to determine the exposure pattern corresponding to the current initial mask pattern, and the difference between the simulation exposure position point and the target exposure position point corresponding to each evaluation point is calculated, that is, the EPE error calculation. Based on the distance difference, the EPE error value corresponding to the cutting segment where the evaluation point is located can be determined. Obviously, when the EPE error value is too large, it means that the position of the cutting segment where the sampling point is located is unreasonable, and when the EPE error value is small, it means that the position of the cutting segment where the sampling point is located is reasonable. Therefore, an EPE threshold value can be set as a basis for judging the size of the EPE error value. In actual application, the size of the EPE threshold value can be determined by the staff based on actual experience.

[0075] Based on the above discussion, in order to further ensure the accuracy and reliability of the EPE error value corresponding to each cutting segment, in an optional embodiment of the application, the process of determining the EPE error value corresponding to the cutting segment can include:

[0076] selecting a plurality of evaluation points on each cutting segment;

[0077] performing EPE error calculation on each evaluation point to obtain a single-point EPE error value corresponding to each evaluation point;

[0078] averaging the single-point EPE error values corresponding to the evaluation points on the same cutting segment to obtain the EPE error value corresponding to the cutting segment.

[0079] In the embodiment, it is further considered that the length of each cutting segment is not necessarily reasonable, and therefore, in actual application, a plurality of evaluation points can be selected on each cutting segment or only on the cutting segments whose length exceeds a certain length threshold. The evaluation points can be equally divided points on the cutting segment, and of course, the distance between adjacent evaluation points on the same cutting segment should not be too close. In actual application, the distance between adjacent evaluation points can be within a certain distance range, such as 0.2um~0.4um. For cutting segments with a length less than 0.2um, only one evaluation point should be taken.

[0080] On this basis, when two or more evaluation points are selected on the same split edge, a single-point EPE error value can be obtained for each evaluation point, and the average of the single-point EPE error values corresponding to the evaluation points on the same split edge is taken as the EPE error value corresponding to the split edge. Of course, if only one evaluation point is selected on a split edge, the single-point EPE error value corresponding to the evaluation point is also the EPE error value corresponding to the split edge. Obviously, for a split edge with a large length, the average of the single-point EPE error values of multiple evaluation points can more accurately represent the EPE error of the entire length of the edge.

[0081] Based on the above discussion, for each evaluation point on the split edge, if the corresponding EPE error value is greater than the EPE threshold value, it indicates that the position of the split edge is inaccurate, and thus the number of edges, the length of the edges, and the position of the edges can be iteratively optimized.

[0082] It should be noted that the optimization iteration of the number of split edges in the embodiment mainly refers to further splitting part of the split edges into more shorter split edges, thereby increasing the number of split edges; the optimization iteration of the length of the split edges mainly refers to increasing the length of part of the split edges and shortening the length of another part of the split edges; and the optimization iteration of the position of the split edges refers to translating the position of the split edges along a direction perpendicular to the split edges.

[0083] It can be understood that adjusting the number and length of the split edges can also adjust the position of the split edges more accurately, so that the exposure position corresponding to the finally determined contour edge is closer to the target exposure position. Therefore, in actual application, after each optimization iteration of the number and / or length of the edges is completed, the position of each split edge should also be iteratively optimized.

[0084] For the three different dimensions of edge parameters, the optimization basis can be different. The following will be described with specific embodiments.

[0085] As described above, for the same split edge, multiple evaluation points can be selected, and based on this, in an optional embodiment of the application, the process of optimizing the number of split edges can also include:

[0086] For the same split edge, the maximum single-point EPE error value and the minimum single-point EPE error value in the single-point EPE error values corresponding to the evaluation points are subjected to difference operation to obtain an EPE difference value;

[0087] cutting the segmentation segment corresponding to the EPE difference value greater than the set threshold into at least two new segmentation segments;

[0088] reselecting the evaluation points on the newly segmented segmentation segment to perform the operation of performing the corresponding EPE error operation on the evaluation points.

[0089] It can be understood that when the single-point EPE error values corresponding to the evaluation points on the same segmentation segment differ greatly, it can be determined that the deviations of different segments of the segmentation segment relative to the reasonable position are not the same, and the segmentation segment can be further segmented so that the segment of the segmentation segment where the evaluation points with large single-point EPE error values are located can be further segmented into different segmentation segments.

[0090] As shown in FIG. 1, in another optional embodiment of the present application, the process of optimizing and iterating the segment number of the segmentation segment can further include: Figure 6 As shown in FIG. 1, in another optional embodiment of the present application, the process of optimizing and iterating the segment number of the segmentation segment can further include:

[0091] When the EPE error value corresponding to the segmentation segment is greater than the EPE threshold, the ratio of the EPE error value to the EPE threshold is rounded up to obtain an integer ratio;

[0092] The segmentation segment is uniformly segmented into integer ratio new segmentation segments;

[0093] The segmentation segment is uniformly segmented into integer ratio new segmentation segments;

[0094] In the embodiment, when the EPE error value corresponding to the segmentation segment is relatively large, the ratio between the EPE error value and the EPE threshold is used as a basis for further segmentation of the segmentation segment. For example, the EPE threshold is 3 um and the EPE error value is 10 um, the ratio between the EPE error value and the EPE threshold is 3.3, and the ratio of 3.3 is rounded up to 4. Thus, the segmentation segment can be uniformly segmented into four new segmentation segments in the manner shown in FIG. 2. Figure 6

[0095] For each newly segmented segmentation segment, an evaluation point can be reselected, and the EPE error value of the segmentation segment can be determined based on the EPE error value corresponding to the evaluation point, and then the position offset of the segmentation segment can be determined to update the position of the new segmentation segment.

[0096] As shown in FIG. 1, in another optional embodiment of the present application, the process of optimizing and iterating the segment length of the segmentation segment can further include: Figure 7 As shown in FIG. 1, in another optional embodiment of the present application, the process of optimizing and iterating the segment length of the segmentation segment can further include:

[0097] ​When the EPE error values corresponding to a continuous number of adjacent segmentation segments are all greater than the EPE threshold value, the segment lengths of the segmentation segments corresponding to the EPE error values greater than the EPE threshold value are synchronously increased or decreased to optimize the segment lengths of the segmentation segments, and / or the segment positions of the segmentation segments corresponding to the EPE error values greater than the EPE threshold value are synchronously directionally translated to optimize the segment positions of the segmentation segments.

[0098] It can be understood that, as shown in Figure 7 When the EPE error values corresponding to a continuous number of adjacent segmentation segments are all greater than the EPE threshold value, it is often caused by the interference of adjacent contours. At this time, the lengths of the segmentation segments corresponding to the EPE error values greater than the EPE threshold value can be simultaneously increased or decreased to ensure that they can better adapt to the light wave interference projected by the adjacent contour edges.

[0099] Of course, when actually determining whether the segmentation segments corresponding to a plurality of EPE error values greater than the EPE threshold value are caused by the influence of adjacent contour edges, it can be further determined whether there are other contour edges within a certain set distance range of the segmentation segments. If yes, it can be determined that the segmentation segments corresponding to the plurality of EPE error values greater than the EPE threshold value are indeed caused by the interference of adjacent contour edges.

[0100] In addition, if the segmentation segments corresponding to a plurality of EPE error values greater than the EPE threshold value are not caused by the influence of adjacent contour edges, it may be caused by the unreasonable positions of the continuous adjacent segmentation segments. The segmentation segments corresponding to the plurality of EPE error values greater than the EPE threshold value can be synchronously translated in a direction perpendicular to the segmentation segments according to the same position offset.

[0101] It should be noted that the plurality of continuous adjacent segmentation segments referred to in the embodiment refer to the segments formed by segmentation from the same contour edge segment between two adjacent inflection points. If there is an inflection point between two segmentation segments, the two segmentation segments do not belong to the adjacent segmentation segments referred to in the embodiment.

[0102] In conclusion, in the process of modifying the optical mask pattern based on the edge position error feedback technology in the present application, compared with the conventional modification method of only optimizing and iterating the edge position, after the edge property of the initial mask pattern is cut to obtain a plurality of cut edges, the edge number, edge length and edge position of the three different dimensions of edge parameters are optimized and iterated. Obviously, compared with the method of only optimizing and iterating the single dimension parameter of the edge position, the contour edge line of the mask pattern formed by the cut edges finally determined in the present application is more accurate, that is, a mask pattern with higher exposure precision can be obtained, which improves the exposure precision of the photolithography mask plate to a certain extent, thereby improving the photolithography precision in semiconductor processing.

[0103] The modification device for the optical mask pattern provided by the embodiment of the present application is described below. The modification device for the optical mask pattern described below can be referred to in correspondence with the modification method for the optical mask pattern described above.

[0104] Figure 8 The structure block diagram of the modification device for the optical mask pattern provided by the embodiment of the present application is described with reference to Figure 8 The modification device for the optical mask pattern can include:

[0105] The cutting processing module 100 is configured to obtain an initial mask pattern and cut the contour edge line of the initial mask pattern to obtain a cut edge.

[0106] The evaluation operation module 200 is configured to select an evaluation point on each cut edge and perform a corresponding EPE error operation on the evaluation point to obtain an EPE error value corresponding to each cut edge.

[0107] The optimization iteration module 300 is configured to compare the EPE error value corresponding to each cut edge with an EPE threshold value, and according to the comparison result, optimize and iterate the edge number, edge length and edge position of the cut edge until the EPE error value corresponding to each cut edge is less than the EPE threshold value, and determine the cut edge after the initial mask pattern is modified.

[0108] In an alternative embodiment of the present application, the segmentation processing module 100 is specifically configured to identify each inflection point on the contour edge line of the initial mask pattern, segment the contour edge line segment between any two adjacent inflection points according to a plurality of different first set segmentation lengths to obtain the segmentation edge segments; and / or identify each inflection point on the contour edge line of the initial mask pattern, segment the contour edge line segment between any two adjacent inflection points from both ends to the middle according to a second set segmentation length to form the segmentation edge segments, and divide the remaining contour edge line segment larger than the second set segmentation length and smaller than twice the second set segmentation length in the middle into two segmentation edge segments; and / or identify a selected contour edge line segment with adjacent contour edge line endpoints in the contour edge line, take the vertical point of the adjacent contour edge line endpoint on the selected contour edge line segment as the segmentation starting point of the selected contour edge line, and segment the selected contour edge line segment from both ends according to a third set segmentation length to obtain the segmentation edge segments.

[0109] In an alternative embodiment of the present application, the evaluation operation module 200 is specifically configured to select a plurality of evaluation points on each of the segmentation edge segments; perform EPE error operation on each of the evaluation points to obtain a single-point EPE error value corresponding to each of the evaluation points; and average the single-point EPE error values corresponding to each of the evaluation points on the same segmentation edge segment to obtain the EPE error value corresponding to the same segmentation edge segment.

[0110] In an alternative embodiment of the present application, the evaluation operation module 200 is specifically further configured to select a plurality of equally divided points on the segmentation edge segments as the evaluation points, wherein the distance between adjacent two evaluation points is within a set distance range.

[0111] In an alternative embodiment of the present application, the optimization iteration module 300 is specifically configured to perform difference operation on the maximum single-point EPE error value and the minimum single-point EPE error value in the single-point EPE error values corresponding to each of the evaluation points on the same segmentation edge segment to obtain an EPE difference value; segment the segmentation edge segment with a corresponding EPE difference value greater than a set threshold into at least two new segmentation edge segments; and reselect the evaluation points on the newly segmented segmentation edge segments to perform the operation of performing corresponding EPE error operation on the evaluation points.

[0112] In an optional embodiment of the present application, the optimization iteration module 300 is specifically configured to, when the EPE error value corresponding to the split segment is greater than the EPE threshold value, round up the ratio of the EPE error value to the EPE threshold value to obtain an integer ratio; evenly split the split segment into the integer ratio of new split segments; and reselect the evaluation points on the newly split split segments to perform the operation of performing corresponding EPE error calculation on the evaluation points.

[0113] In an optional embodiment of the present application, the optimization iteration module 300 is specifically configured to, when the EPE error value corresponding to the split segment is greater than the EPE threshold value, round up the ratio of the EPE error value to the EPE threshold value to obtain an integer ratio; evenly split the split segment into the integer ratio of new split segments; and reselect the evaluation points on the newly split split segments to perform the operation of performing corresponding EPE error calculation on the evaluation points.

[0114] The optical mask pattern correction device of the present embodiment is used to implement the optical mask pattern correction method described above, and the specific embodiments of the optical mask pattern correction device can be found in the embodiment part of the optical mask pattern correction method described above. The specific embodiments can be referred to the description of the corresponding embodiment part, and will not be described here.

[0115] The present application also provides an embodiment of an optical mask pattern correction device, which can include:

[0116] a memory for storing a computer program;

[0117] a processor for executing the computer program to implement the steps of the optical mask pattern correction method according to any one of the above.

[0118] The optical mask pattern correction method implemented by the processor executing the computer program in the present embodiment can include:

[0119] obtaining an initial mask pattern and splitting the profile edge line of the initial mask pattern to obtain split segments; selecting evaluation points on each split segment and performing corresponding EPE error calculation on the evaluation points to obtain an EPE error value corresponding to each split segment; comparing the EPE error value corresponding to each split segment with an EPE threshold value, and according to the comparison result, optimizing and iterating the number, length and position of the split segments until the EPE error value corresponding to each split segment is less than the EPE threshold value, and determining the split segments of the initial mask pattern after correction.

[0120] The application also provides a computer readable storage medium, in which a computer program is stored, and the computer program is executed to implement the steps of the method for modifying an optical mask pattern according to any one of the above.

[0121] The computer readable storage medium can include random access memory (RAM), internal memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0122] It should be noted that, in this document, the terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or sequence between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device inherently includes a series of elements. Without more limitations, the element defined by the statement "includes a" does not exclude the presence of additional identical elements in the process, method, article or device including the element. In addition, the above technical solutions provided by the embodiments of the present application have not been described in detail, so as not to be too verbose.

[0123] The principles and implementation modes of the present application are described by applying specific examples in this document, and the above description of the examples is only used to help understand the method of the present application and its core idea. It should be noted that, for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the present application.

Claims

1. A method for correcting an optical mask pattern, characterized in that, include: Obtain an initial mask pattern, and then segment the outline edge lines of the initial mask pattern to obtain segmented edge segments; Evaluation points are selected on each of the segmented edges, and corresponding EPE error calculations are performed on the evaluation points to obtain the EPE error value corresponding to each segmented edge. The EPE error value and EPE threshold corresponding to each of the segmented edges are compared, and the number of edges, length and position of the segmented edges are optimized and iterated according to the comparison results until the EPE error value corresponding to each of the segmented edges is less than the EPE threshold, and the segmented edges after the initial mask pattern is determined.

2. The method for correcting optical mask patterns as described in claim 1, characterized in that, The initial mask pattern is segmented along its contour edge lines to obtain segmented edge segments, including: Identify each inflection point on the outline edge line of the initial mask pattern, and divide the outline edge line segment between any two adjacent inflection points according to multiple different first preset division lengths to obtain the division edge segment; And / or, identify each inflection point on the outline edge line of the initial mask pattern, and divide the outline edge line segment between any two adjacent inflection points from both ends to the middle according to the second set cutting length to form the cutting edge segment, and divide the remaining outline edge line segment in the middle that is greater than the second set cutting length but less than twice the second set cutting length into two cutting edge segments. And / or, identify a selected contour edge segment in the contour edge line that is adjacent to the endpoint of the contour edge line, take the perpendicular point of the endpoint of the adjacent contour edge line on the selected contour edge segment as the starting point for dividing the selected contour edge line, and divide the selected contour edge segment into segments evenly at both ends according to the third set dividing length to obtain the divided edge segment.

3. The method for correcting optical mask patterns as described in claim 1, characterized in that, Evaluation points are selected on each of the segmented edges, and corresponding EPE error calculations are performed on the evaluation points to obtain the EPE error value for each segmented edge, including: Multiple evaluation points are selected on each of the aforementioned segmentation edges; EPE error calculation is performed on each of the evaluation points to obtain the single-point EPE error value corresponding to each evaluation point. The average of the single-point EPE error values ​​corresponding to each evaluation point on the same segment is used to obtain the EPE error value corresponding to the same segment.

4. The method for correcting optical mask patterns as described in claim 3, characterized in that, Multiple evaluation points are selected on each of the aforementioned segmentation edges, including: Multiple equally divided points on the segment are selected as evaluation points, wherein the distance between two adjacent evaluation points is within a set distance range.

5. The method for correcting optical mask patterns as described in claim 3, characterized in that, The process of optimizing and iterating the segmented edges includes: For the same segmented edge, the maximum and minimum single-point EPE error values ​​among the single-point EPE error values ​​corresponding to each evaluation point are calculated to obtain the EPE difference value. The segment whose corresponding EPE difference value is greater than a set threshold is divided into at least two new segment segments. The evaluation point is reselected on the newly segmented edge to perform the corresponding EPE error calculation on the evaluation point.

6. The method for correcting an optical mask pattern as described in any one of claims 1 to 5, characterized in that, The process of optimizing and iterating the segmented edges based on the comparison results includes: When the EPE error value corresponding to the segment is greater than the EPE threshold, the ratio of the EPE error value to the EPE threshold is rounded up to obtain the rounding ratio. The segment is uniformly divided into new segments with the rounding ratio value; The evaluation point is reselected on the newly segmented edge to perform the corresponding EPE error calculation on the evaluation point.

7. The method for correcting an optical mask pattern as described in any one of claims 1 to 5, characterized in that, The process of optimizing and iterating the segmented edges based on the comparison results includes: When the EPE error values ​​corresponding to a set number of consecutive adjacent segmented edges are all greater than the EPE threshold, the length of each segmented edge with an EPE error value greater than the EPE threshold is synchronously increased or decreased to optimize the update of the segmented edge length, and / or the position of each segmented edge with an EPE error value greater than the EPE threshold is synchronously shifted to optimize the update of the segmented edge position.

8. A device for correcting optical mask patterns, characterized in that, include: The segmentation processing module is used to obtain an initial mask pattern and segment the outline edge lines of the initial mask pattern to obtain segmented edge segments; The evaluation calculation module is used to select evaluation points on each of the segmented edges and perform corresponding EPE error calculations on the evaluation points to obtain the EPE error value corresponding to each segmented edge. The optimization iteration module is used to compare the EPE error value and EPE threshold corresponding to each of the segmented edges, and optimize and iterate the number of edges, length and position of the segmented edges according to the comparison results, until the EPE error value corresponding to each of the segmented edges is less than the EPE threshold, and determine the segmented edges after the initial mask pattern is corrected.

9. An optical mask pattern correction device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the steps of the optical mask pattern correction method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that is executed to implement the steps of the optical mask pattern correction method as described in any one of claims 1 to 7.

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