Optical proximity effect correction method, mask and readable storage medium

Abstract

The invention relates to an optical proximity effect correction method, a mask and a readable storage medium. The method comprises the following steps: step A, acquiring a mask design pattern; step B, simulating the mask design pattern according to an OPC model to obtain a simulated exposure pattern; step C, calculating edge placement errors of the simulation exposure pattern and the mask design pattern at each target point; step D, adjusting the mask design pattern according to the edge placement error to obtain a corrected pattern; e, judging whether the shape of the corrected pattern after exposure meets the requirement or not, and if yes, obtaining a mask plate making pattern according to the corrected pattern; and if not, adjusting the target point on the edge of the transition part of the design pattern of the mask plate, then returning to the step C, and repeatedly executing the step C, the step D and the step E until the plate making pattern of the mask plate is obtained. According to the invention, the OPC correction effect can be improved, and the OPC correction precision can be improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to an optical proximity effect correction method, and also to a mask and a readable storage medium. Background Art

[0002] With the rapid development of ultra-large scale integrated circuits (ULSI), integrated circuit manufacturing processes have become increasingly complex and sophisticated. Among them, photolithography is the driving force behind the development of integrated circuit manufacturing processes and is also one of the most complex technologies. Compared with other single manufacturing technologies, the improvement of photolithography is of great significance to the development of integrated circuits. Before the photolithography process begins, the pattern must first be copied to the mask through a specific device, and then the pattern structure on the mask is copied to the silicon wafer through a photolithography machine. However, due to the reduction in the size of semiconductor devices, the wavelength used for exposure is greater than the size of the ideal pattern designed in the physical layout and the spacing between the patterns. The interference and diffraction effects of light waves cause a large difference between the physical pattern produced by actual photolithography and the ideal pattern designed in the layout. The shape and spacing of the actual pattern change greatly, and even affect the performance of the circuit. In order to solve this problem, the OPC (optical proximity correction) method is usually used to correct the mask design pattern.

[0003] At an exemplary process node, the layout has Figure 1a The graph shown (hereinafter referred to as a "T"-shaped graph) has a poor correction effect after OPC correction using a traditional method, which will lead to a reduction in the process window (ProcessWindow, PW), and even cause circuit failure in severe cases. Summary of the invention

[0004] Based on this, it is necessary to provide an optical proximity effect correction method with better OPC correction effect for "T"-shaped patterns.

[0005] An optical proximity effect correction method comprises: step A, obtaining a mask design pattern; step B, simulating the mask design pattern according to an OPC model to obtain a simulated exposure pattern; step C, calculating the edge placement error between the simulated exposure pattern and the mask design pattern at each target point; step D, adjusting the mask design pattern according to the edge placement error to obtain a corrected pattern; step E, judging whether the post-exposure morphology of the corrected pattern meets the requirements, if so, obtaining a mask plate-making pattern according to the corrected pattern; if not, adjusting the mask design pattern After finding the target point on the edge of the transition part of the shape, return to step C, and repeatedly perform steps C, D and E until the mask plate making pattern is obtained; wherein the mask plate design pattern includes a first pattern, the first pattern includes an adjacent portion, a neck, a head and the transition portion, the width of the adjacent portion in the first direction is greater than the width of the neck in the first direction, the width of the head in the first direction is greater than the width of the neck in the first direction, the neck and the adjacent portion are directly connected, one end of the transition portion is directly connected to the neck, and the other end is directly connected to the head.

[0006] The above optical proximity effect correction method can improve the OPC correction effect of the first pattern by optimizing the target point on the edge of the transition portion when the morphology of the correction pattern is not good.

[0007] In one embodiment, the step of adjusting the target point on the edge of the transition portion includes at least one of the following operations: moving the position of the target point, deleting the target point, placing a new target point on the edge of the transition portion, and merging the target points on the edge of the transition portion.

[0008] In one embodiment, in step E, the target point on the edge of the neck of the mask design pattern is not adjusted.

[0009] In one embodiment, the outer side included angle of the connection point between the edge of the neck and the edge of the transition portion is an obtuse angle.

[0010] In one embodiment, the outer angle at the connection point between the edge of the neck and the edge of the transition portion is a right angle, the transition portion is a rectangle or a square, and the width of the transition portion in the first direction is greater than the width of the neck in the first direction and not greater than the width of the head in the first direction.

[0011] In one embodiment, the outer angle of the connection point between the edge of the neck and the edge of the transition portion is an acute angle, and the transition portion includes a rectangle and two triangles, the width of the rectangle in the first direction is greater than the width of the neck in the first direction, and is not greater than the width of the head in the first direction; one triangle is located on one side of the neck in the first direction, and the other triangle is located on the other side of the neck in the first direction; the transition portion is connected to the neck and the head respectively through the two ends of the rectangle, each of the two triangles has a side that is common to the rectangle, and each of the two triangles has a side connected to the edge of the neck, and the connection point is the end point of the corresponding triangle side, and is also the end point of the edge of the neck.

[0012] In one embodiment, the neck and the head are rectangular in shape, the transition portion is trapezoidal in shape, and one bottom side of the trapezoid is the boundary with the head, and the other bottom side is the boundary with the neck.

[0013] In one embodiment, the adjacent portion is in the shape of an elongated strip, and the extending direction of the elongated strip is the first direction.

[0014] In one embodiment, the step C further includes the step of placing a target point on the edge of the mask design pattern.

[0015] In one of the embodiments, before step C, the steps further include: analyzing and segmenting the outer edge of the mask design pattern into multiple segments; and placing the target point on the outer edge of the mask design pattern.

[0016] In one embodiment, the outer angle at the connection point between the edge of the neck and the edge of the transition portion is a right angle or an acute angle, the width of the transition portion in the first direction is the same as the width of the head in the first direction, and the line segment on the edge of the transition portion connecting the head is a single corrected segment obtained by the analytical segmentation.

[0017] In one embodiment, the neck portion, the transition portion and the head portion are all located in the active area.

[0018] In one embodiment, the step of adjusting the target point on the edge of the transition portion includes selecting the edge of the transition portion, and the selecting the edge of the transition portion includes screening out the edge of the transition portion according to the characteristics of the edge of the transition portion, and the characteristics include at least one of the length of the edge, the length of the adjacent edge of the edge of the transition portion, and the angle between the edge of the transition portion and the adjacent edge.

[0019] It is also necessary to provide a mask, which is made of a mask plate making pattern obtained according to the optical proximity effect correction method described in any of the above embodiments.

[0020] It is also necessary to provide a readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the optical proximity effect correction method described in any of the above embodiments.

[0021] It is also necessary to provide a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the optical proximity effect correction method described in any of the above embodiments when executing the computer program.

[0022] It is also necessary to provide a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the optical proximity effect correction method described in any of the aforementioned embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1a is a schematic diagram of an exemplary "T"-shaped graph, Figure 1b FIG. 2 is a schematic diagram of the outline of a modified simulation pattern 210 obtained after OPC correction using a conventional method. Figure 1c 2 is a schematic diagram of the outline of a corrected simulation pattern 220 corresponding to a mask plate making pattern obtained by an optical proximity effect correction method according to an embodiment of the present application, Figure 1d yes Figure 1c Schematic diagram of the corresponding hole packing process window;

[0025] Figure 2 It is a schematic diagram of the analysis and segmentation of the mask design pattern and the simulated exposure in an exemplary OPC process;

[0026] Figure 3 This is a schematic diagram of an exemplary parsing and segmentation by using the Inter-feature segmentation command;

[0027] Figure 4 is a flow chart of an optical proximity effect correction method in one embodiment of the present application;

[0028] Figure 5 is a flow chart of an optical proximity effect correction method in another embodiment of the present application;

[0029] Figure 6a is a schematic diagram of another exemplary "T"-shaped graph, Figure 6b is a schematic diagram of another exemplary “T”-shaped graph. DETAILED DESCRIPTION

[0030] 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.

[0031] 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.

[0032] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers. "Connection" in this specification should be understood as "electrical connection", "communication connection" and the like if the connected circuits, modules, units, etc. have transmission of electrical signals or data to each other. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

[0033] Spatially relative terms such as "under," "below," "below," "under," "above," "above," etc., may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0034] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be a limitation of the present invention. When used herein, the singular forms of "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It is understood that "at least one" refers to one or more, and "multiple" refers to two or more. "At least part of an element" refers to part or all of an element. It should also be understood that the terms "compose" and / or "comprise" when used in this specification determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0035] Embodiments of the invention are described herein with reference to cross-sectional views that are schematic diagrams of ideal embodiments (and intermediate structures) of the invention. Thus, variations from the shapes shown due to, for example, manufacturing techniques and / or tolerances can be expected. Therefore, embodiments of the invention should not be limited to the specific shapes of the zones shown herein, but include shape deviations due to, for example, manufacturing. For example, an implanted region shown as a rectangle typically has rounded or curved features and / or an implant concentration gradient at its edges, rather than a binary change from an implanted region to a non-implanted region. Similarly, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to show the actual shape of the region of the device and are not intended to limit the scope of the invention.

[0036] An exemplary method of using computer-aided software tools for optical proximity correction (OPC) is to first identify the edge of the mask design pattern through the OPC software, and divide the edge (edge) of the mask design pattern into many small correction segments (Segments), so that each edge (each Segment) can move freely. Then place a target point (Target Point) on each correction segment, and then use the OPC software to simulate the pattern after photolithography exposure according to the OPC model, and compare it with the mask design pattern (such as Figure 2 As shown in the figure), the difference between the simulation graphic and the design graphic at the target point is calculated. The difference between them is called edge placement error (EPE), which is an indicator used to measure the quality of correction. The OPC software moves the edge position of the mask design graphic during operation and calculates the corresponding edge placement error. This process is repeated until the calculated edge placement error reaches an acceptable value. The smaller the EPE value, the better the OPC correction result, and vice versa. The mask design graphic segmentation and corresponding results in the OPC process are shown in the figure. Figure 3 As shown, Figure 3 The left half shows the positions of the mask design pattern and the cutting points. The black dots on the edge of the original layout (i.e., the mask design pattern) represent the cutting points that divide the edge into several correction line segments of different lengths. The corrected OPC result (i.e., the corrected mask plate pattern) is shown in Figure 1. Figure 3 Shown in the right half.

[0037] See also Figure 1a The "T"-shaped figure includes an adjacent portion 110, a neck portion 120, a transition portion 130 and a head portion 140. The broken lines on the upper and lower sides of the adjacent portion 110 indicate omission. The width of the adjacent portion 110 is greater than the width of the neck portion 120, the width of the head portion 140 is greater than the width of the neck portion 120, and the transition portion 130 has different widths at different positions. Figure 1a The width in the first direction (i.e. Figure 1a The neck 120 is directly connected to the adjacent portion 110, one end of the transition portion 130 is directly connected to the neck 120, and the other end is directly connected to the head 140. As described in the background art, the correction effect of the "T"-shaped pattern after OPC correction using the traditional method is poor. Figure 1b The contour of the corrected simulation pattern 210 (i.e., the exposed pattern obtained by simulation after the OPC correction of the "T"-shaped pattern) obtained by using a conventional method is shown. It can be seen that the corrected simulation pattern 210 has a large area at the neck 120 ( Figure 1b There is a more serious "rounding" effect near the edge (not marked in the figure), and the single-side CD (critical dimension) difference a is larger. Figure 1bIn order to distinguish the corrected simulation pattern 210 from the “T”-shaped pattern, the outline of a part of the structure of the “T”-shaped pattern is shown with a dotted line.

[0038] Figure 1a The angle θ at the outer side of the connection point between the edge of the neck 120 and the edge of the transition portion 130 of the "T"-shaped figure is an obtuse angle. In addition, the angle being a right angle or an acute angle will also cause the "T"-shaped figure to have a "rounding" effect. Figure 6a and Figure 6b , Figure 6a The "T"-shaped figure shown includes an adjacent portion 110a, a neck portion 120a, a transition portion 130a and a head portion 140a. The width of the adjacent portion 110a is greater than the width of the neck portion 120a, the width of the head portion 140a is greater than the width of the neck portion 120a, the width of the transition portion 130a is greater than the width of the neck portion 120a and not greater than the width of the head portion 140a; Figure 6a In the embodiment shown, the width of the transition portion 130a is equal to the width of the head portion 140a. The neck 120 and the adjacent portion 110 are directly connected, and one end of the transition portion 130 is directly connected to the neck 120 and the other end is directly connected to the head 140. The angle θ1 of the outer side at the connection point between the edge of the neck 120a and the edge of the transition portion 130a is a right angle. The transition portion 130a can be rectangular or square. Note Figure 6a The width in the first direction (i.e. Figure 6a The vertical dimension of the Figure 6a and Figure 6b The middle transition portion 130a / 130b is filled differently from the head portion 140a / 140b to distinguish it.

[0039] Figure 6b The "T"-shaped figure shown includes an adjacent portion 110b, a neck 120b, a transition portion 130b and a head 140b. The width of the adjacent portion 110b is greater than the width of the neck 120b, and the width of the head 140b is greater than the width of the neck 120b. The neck 120b and the adjacent portion 110b are directly connected, and one end of the transition portion 130b is directly connected to the neck 120b and the other end is directly connected to the head 140b. The transition portion 130b is composed of a rectangle and two triangles. The width of the rectangle is greater than the width of the neck 120b and not greater than the width of the head 140b. A triangle is located at the neck 120b in the first direction (i.e. Figure 6bThe transition portion 130b is connected to the neck 120b and the head 140b at the two ends of the rectangle. One side of the two triangles is shared with the rectangle. One side of the two triangles is connected to the edge of the neck 120b, and the connection point is the endpoint of the triangle side, which is also the endpoint of the edge of the neck 120b. The angle between the triangle side and the edge of the neck 120b at the endpoint is θ2, which is an acute angle. Note Figure 6b The width in the first direction (i.e. Figure 6b The vertical dimension of the Figure 6b In the illustrated embodiment, the width of the rectangle is equal to the width of the head 140 b , the two triangles are right triangles, and the side that shares the same side with the rectangle is a right angle side.

[0040] In order to overcome the "rounding" effect of the "T"-shaped pattern, technicians have improved the original OPC algorithm, but the problem of insufficient hole packaging process window of the "T"-shaped pattern will occur, that is, it is difficult to solve the "rounding" effect of the "T"-shaped pattern and the insufficient hole packaging process window at the same time. The present invention provides an improved optical proximity effect correction method, which optimizes the setting of the target point on the "T"-shaped pattern, can effectively improve the "rounding" effect, improve OPC accuracy, reduce EPE value, and improve process window.

[0041] Figure 4 : is a flow chart of an optical proximity effect correction method in one embodiment of the present application, comprising:

[0042] S410, obtaining a mask design pattern.

[0043] After the integrated circuit is designed according to the actual requirements, the design graphics of each layout level that meets the requirements are obtained as the mask design graphics.

[0044] S440, simulating the mask design pattern according to the OPC model to obtain a simulated exposure pattern.

[0045] OPC software can be used to simulate exposure of the mask design pattern. These software may have preset simulation exposure rules, and those skilled in the art may modify these rules. This application does not limit the specific simulation exposure rules.

[0046] S450, calculating edge placement errors between the simulated exposure pattern and the mask design pattern at each target point.

[0047] The target point is placed at the edge of the mask design pattern before step S450. Specifically, the optical proximity effect correction method may also include steps S420 and S430, see Figure 5 . Step S420 is to analytically segment (Dissection) the outer edge of the mask design graphic into multiple segments. Analytical segmentation is to divide the edge of the mask design graphic into many small correction segments (Segments), and each segmentation point divides the edge of the graphic into a number of correction line segments of different lengths. Analytical segmentation can be performed using OPC software. Step S430 is to place target points on the outer edge of the mask design graphic. In one embodiment of the present application, the target points are placed on each correction segment obtained after analytical segmentation in step S420. The position of the target point (Target Point) on the edge of the "T"-shaped graphic can refer to Figure 1a ; Target points can also be placed at other locations on the edge of the "T" shape, such as at the endpoints of each edge (the corners of the correction segment). Figure 6a and Figure 6b In the embodiment shown, the width of the transition portion 130a / 130b is the same as that of the head portion 140a / 140b, and the line segment on the edge of the transition portion 130a / 130b connecting to the head portion 140a / 140b (i.e., the line segment between the vertex of the edge of the transition portion 130a / 130b and the head portion 140a / 140b) is a single correction segment obtained by the aforementioned analytical segmentation (Dissection). That is, the length of the line segment on the edge is the same as the corresponding correction segment. In one embodiment of the present application, the edge placement error is the position of the target point on the simulated exposure pattern minus the position of the corresponding target point on the mask design pattern, and the value of the edge placement error can be positive or negative.

[0048] S460, adjusting the mask design pattern according to the edge placement error to obtain a corrected pattern.

[0049] In one embodiment of the present application, each correction segment of the mask design pattern is moved according to the edge placement error so that the edge placement error value of each correction segment approaches zero, or the absolute value of the edge placement error of each correction segment approaches a very small value.

[0050] S470, determine whether the modified graph meets the requirements, if so, execute step S480, otherwise execute step S472.

[0051] Specifically, it is necessary to determine whether the corrected pattern meets the correction requirements, that is, whether the shape meets the accuracy requirements of the OPC correction, based on the post-exposure shape of the corrected pattern obtained in step S460. The post-exposure shape can be obtained based on the simulation of the OPC correction, and specifically, the exposure simulation result of the corrected pattern can be obtained using the OPC software. If the post-exposure shape of the corrected pattern meets the correction requirements, step S480 is executed, otherwise step S472 is executed.

[0052] S472, adjusting the target point on the edge of the transition portion of the “T”-shaped figure.

[0053] The "T"-shaped figure includes an adjacent portion 110, a neck portion 120, a transition portion 130, and a head portion 140. The broken lines on the upper and lower sides of the adjacent portion 110 indicate omission. The width of the adjacent portion 110 in the first direction is greater than the width of the neck portion 120 in the first direction, the width of the head portion 140 in the first direction is greater than the width of the neck portion 120 in the first direction, and the transition portion 130 has different widths in the first direction at different positions. Figure 1a The neck 120 is directly connected to the adjacent portion 110, one end of the transition portion 130 is directly connected to the neck 120, and the other end is directly connected to the head 140. In the mask design pattern, select the edge of the transition portion 130 (for Figure 1a In the embodiment shown, the target point on the edge of the transition portion 130 is adjusted, including at least one of moving the position of the target point, deleting the target point, placing a new target point on the edge of the transition portion 130, and merging the target points on the edge of the transition portion 130 (i.e., deleting at least two target points on the edge of the transition portion 130 and placing a new target point). The adjustment can be performed manually or by the OPC software using a preset target point adjustment rule.

[0054] After adjusting the target point on the edge of the transition portion 130, return to step S450, and execute steps S450-S460-S470 again. According to the edge placement error after the target point adjustment, the mask design pattern is adjusted again to obtain a new correction pattern. That is, step S450, step S460 and step S470 are repeatedly executed in a loop until a correction pattern with a correction accuracy that meets the requirements is obtained in step S470, then the loop is jumped out and step S480 is entered.

[0055] In one embodiment of the present application, step S472 is to adjust only the target points on the edge of the transition portion 130, but not the target points on the edge of the neck 120, that is, in the cycle of steps S450-S460-S470-S472-S450..., only the target points on the edge of the transition portion 130 are adjusted, but not the target points on the edge of the neck 120. Further, step S472 is to adjust only the target points on the edge of the transition portion 130, but not other target points on the "T"-shaped figure.

[0056] S480, obtaining a mask plate making pattern according to the correction pattern.

[0057] In one embodiment of the present application, the correction pattern finally obtained in the previous step with the correction accuracy meeting the requirements is used as the mask plate making pattern.

[0058] Figure 1c The figure shows the contour of the corrected simulation pattern 220 (i.e., the exposed pattern obtained by simulating the “T”-shaped pattern after OPC correction) corresponding to the mask plate-making pattern obtained by the optical proximity effect correction method in one embodiment of the present application, wherein Figure 1b The contour of the modified simulation graph 210 in Figure 1c It is represented by continuous points, and it can be seen that the neck 120 ( Figure 1c The "rounding" effect near the edge (not shown in FIG. 2 ) is significantly improved, compared with the single-sided CD difference a (refer to FIG. 210 ) of the modified simulation graph 210. Figure 1b ), the single-side CD difference of the modified simulation pattern 220 is significantly reduced. In one embodiment of the present application, the single-side CD difference a is reduced from +11nm to -2nm (a positive single-side CD difference indicates that the edge of the modified simulation pattern is located outside the mask design pattern, and a negative single-side CD difference indicates that it is located inside).

[0059] The above optical proximity effect correction method can improve the OPC correction effect of the "T"-shaped pattern by optimizing the target point on the edge of the transition portion 130 when the morphology of the corrected pattern is not good, effectively improve the "rounding" effect, improve the OPC accuracy, and increase the process window.

[0060] Reference Figure 1b, since the deviation of the correction simulation pattern 210 of the "T"-shaped pattern (i.e., the "rounding" effect) is mainly located near the edge of the neck 120, an exemplary improvement method is to optimize the target point on the edge of the neck 120. That is, if the correction effect of a certain part of the mask pattern is poor, it is generally easy to think of correcting and adjusting the target point on the correction segment (Segment) at that place, and not correcting and adjusting the target point on the correction segment around the correction segment at that place, because correcting and adjusting the target point on the surrounding correction segment will introduce more variable factors, making it more difficult to control the correction result and not obtain an ideal pattern. The above-mentioned optical proximity effect correction method reduces the over-correction near the edge of the neck 120 by optimizing the target point on the edge of the transition part 130, and well balances the correction contradiction between the neck 120 and the transition part 130. That is, by adjusting the target point of the pattern (i.e., the transition part 130) around the poorly corrected part (neck 120), the correction accuracy of the poorly corrected part (neck 120) is effectively improved, and the "rounding" effect at the neck 120 is improved, and an unexpected technical effect is achieved. Furthermore, the corrected simulation pattern 220 corresponding to the mask plate pattern obtained by the optical proximity effect correction method has little effect on the hole packing process window 310 of the "T"-shaped pattern. Figure 1d That is, the problem of insufficient hole packing process window will not occur while solving the "rounding" effect of the "T"-shaped pattern.

[0061] In one embodiment of the present application, the neck 120 and the head 140 of the "T"-shaped figure are rectangular, the transition portion 130 is trapezoidal, and one bottom side of the trapezoid is the boundary with the head 140, and the other bottom side is the boundary with the neck 120. Figure 1a In other embodiments of the present application, the shape of the head 140 may also be other polygonal shapes.

[0062] Reference Figure 1a In one embodiment of the present application, the adjacent portion 110 of the "T"-shaped figure is in the shape of a long strip, and the extending direction of the long strip is the first direction, that is, Figure 1a The vertical direction in .

[0063] In one embodiment of the present application, the neck 120, transition portion 130 and head portion 140 of the “T”-shaped pattern are all located in the active region of the device, that is, the “T”-shaped pattern is a part of the active region pattern of the device layout.

[0064] In one embodiment of the present application, step S472 selects the edge of the transition portion 130 by screening out the edge of the transition portion 130 based on the characteristics of the edge of the transition portion 130, wherein the characteristics include at least one of the length of the edge, the length of the adjacent edge of the edge of the transition portion, and the angle between the edge of the transition portion and the adjacent edge.

[0065] The present application accordingly provides a mask made from a mask plate making pattern obtained by the optical proximity effect correction method described in any of the above embodiments.

[0066] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0067] The present application also provides a readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the optical proximity effect correction method described in any of the above embodiments are implemented.

[0068] The present application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the optical proximity effect correction method described in any of the above embodiments when executing the computer program.

[0069] The present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of the optical proximity effect correction method described in any of the aforementioned embodiments.

[0070] It should be understood that, although the various steps in the flowchart of the present application are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the present application may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0071] 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.

[0072] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features of the above-described 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.

[0073] 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 construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations 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 application shall be subject to the attached claims.

Claims

1. A method for correcting an optical proximity effect, comprising: Step A, obtaining a mask design pattern; Step B, simulating the mask design pattern according to the OPC model to obtain a simulated exposure pattern; Step C, calculating the edge placement error between the simulated exposure pattern and the mask design pattern at each target point; Step D, adjusting the mask design pattern according to the edge placement error to obtain a corrected pattern; Step E, judging whether the post-exposure morphology of the correction pattern meets the requirements, and if so, obtaining a mask plate-making pattern according to the correction pattern; If not, adjust the target point on the edge of the transition portion of the mask design pattern and return to step C, and repeatedly perform steps C, D and E until the mask plate making pattern is obtained; Among them, the mask design pattern includes a first pattern, the first pattern includes an adjacent portion, a neck, a head and the transition portion, the width of the adjacent portion in the first direction is greater than the width of the neck in the first direction, the width of the head in the first direction is greater than the width of the neck in the first direction, the neck and the adjacent portion are directly connected, and one end of the transition portion is directly connected to the neck, and the other end is directly connected to the head.

2. The optical proximity effect correction method according to claim 1, characterized in that: The step of adjusting the target point on the edge of the transition portion includes at least one of the following operations: moving the position of the target point, deleting the target point, placing a new target point on the edge of the transition portion, and merging the target points on the edge of the transition portion.

3. The optical proximity effect correction method according to claim 1, characterized in that: In the step E, the target point on the edge of the neck of the mask design pattern is not adjusted.

4. The optical proximity effect correction method according to claim 1, characterized in that: The outer side included angle of the connection point between the edge of the neck and the edge of the transition portion is an obtuse angle.

5. The optical proximity effect correction method according to claim 4, characterized in that: The shape of the neck and the head is a rectangle, the shape of the transition portion is a trapezoid, one bottom side of the trapezoid is the boundary with the head, and the other bottom side is the boundary with the neck; and / or The adjacent portion is in an elongated strip shape, and the extending direction of the elongated strip is the first direction.

6. The optical proximity effect correction method according to claim 1, characterized in that: Before step C, the following steps are also included: Analytically dividing the outer edge of the mask design pattern into multiple segments; The target point is placed on the outer edge of the mask design pattern.

7. The optical proximity effect correction method according to claim 1, characterized in that: The neck portion, transition portion and head portion are all located in the active area.

8. The optical proximity effect correction method according to claim 1, characterized in that: The step of adjusting the target point on the edge of the transition portion includes selecting the edge of the transition portion, and the step of selecting the edge of the transition portion includes screening out the edge of the transition portion according to the characteristics of the edge of the transition portion, and the characteristics include at least one of the length of the edge, the length of the adjacent edge of the edge of the transition portion, and the angle between the edge of the transition portion and the adjacent edge.

9. A mask, characterized in that: The mask plate is made of a mask plate making pattern obtained by the optical proximity effect correction method according to any one of claims 1-8.

10. A readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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