Optical proximity correction method, mask, and readable storage medium

Abstract

The application relates to an optical proximity correction method, a mask and a readable storage medium, and 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 simulated exposure pattern and the mask design pattern at each target point; step D, adjusting the mask design pattern according to the edge placement errors to obtain a corrected pattern; step E, judging whether the appearance after exposure of the corrected pattern meets the requirements, if yes, obtaining a mask making pattern according to the corrected pattern, and if not, adjusting the target points on the edges of the transition part of the mask design pattern and returning to step C, and repeatedly executing steps C, D and E until the mask making pattern is obtained. The application can improve the OPC correction effect and improve the OPC correction precision.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to an optical proximity effect correction method, as well as a photomask and a readable storage medium. Background Technology

[0002] With the rapid development of Ultra Large Scale Integration (ULSI), integrated circuit manufacturing processes have become increasingly complex and sophisticated. Photolithography is a driving force behind the development of integrated circuit manufacturing processes and is one of the most complex technologies. Compared to other individual manufacturing technologies, improvements in photolithography are of great significance to the development of integrated circuits. Before the photolithography process begins, a pattern must first be copied onto a photomask using specific equipment. Then, a photolithography machine copies the pattern structure from the photomask onto a silicon wafer. However, due to the shrinking size of semiconductor devices, the wavelength used for exposure is larger than the ideal size and spacing of the physical layout design. The interference and diffraction effects of the light waves cause a significant difference between the actual physical pattern produced by photolithography and the ideal pattern in the layout design. The shape and spacing of the actual pattern change considerably, even affecting circuit performance. To solve this problem, the OPC (Optical Proximity Correction) method is typically used to correct the photomask design pattern.

[0003] At an exemplary process node, the layout contains, for example, the following: Figure 1a The graphic shown (hereinafter referred to as the "T" graphic) shows poor correction effect after using traditional methods for OPC correction, which will lead to a reduction in the process window (PW) and may even cause circuit failure in severe cases. Summary of the Invention

[0004] Therefore, it is necessary to provide an optical proximity effect correction method that has a better OPC correction effect for "T" shaped patterns.

[0005] An optical proximity effect correction method includes: 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, determining whether the post-exposure morphology of the corrected pattern meets the requirements; if it does, obtaining a mask fabrication pattern based on the corrected pattern; if it does not, adjusting the mask design pattern. After identifying the target point on the edge of the transition portion of the shape, return to step C and repeat steps C, D, and E until the mask pattern is obtained; wherein, the mask design pattern includes a first pattern, the first pattern including an adjacent portion, a neck, a head, and the transition portion, the width of the adjacent portion in a 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 aforementioned optical proximity effect correction method can improve the OPC correction effect of the first pattern by optimizing the target points on the edge of the transition section when the shape of the corrected pattern is not good.

[0007] In one embodiment, the step of adjusting the target point on the edge of the transition section 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 section, and merging the target points on the edge of the transition section.

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

[0009] In one embodiment, the included angle at the junction of the edge of the neck and the edge of the transition portion is an obtuse angle.

[0010] In one embodiment, the angle between the outer sides of 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 but not greater than the width of the head in the first direction.

[0011] In one embodiment, the included angle at the connection point between the edge of the neck and the edge of the transition portion is an acute angle. 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 but 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 through the two ends of the rectangle, respectively. Each of the two triangles has one side that shares a side with the rectangle, and each of the two triangles has one side that connects to the edge of the neck. The connection point is the endpoint of the corresponding triangle side and is also the endpoint of the edge of the neck.

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

[0013] In one embodiment, the adjacent portion is elongated, and the extension direction of the elongated portion is the first direction.

[0014] In one embodiment, step C is preceded by a step of placing target points on the edge of the mask design pattern.

[0015] In one embodiment, step C is preceded by: parsing 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 included 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 that connects to the head is a single corrected segment obtained by the analytical segmentation.

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

[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, which includes filtering the edge of the transition portion based on features of the edge of the transition portion, the features including at least one of the length of the edge, the length of the adjacent side of the edge of the transition portion, and the angle between the edge of the transition portion and the adjacent side.

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

[0020] It is also necessary to provide a readable storage medium on which a computer program is stored, which, 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 executes the computer program to implement the steps of the optical proximity effect correction method described in any of the above embodiments.

[0022] It is also necessary to provide a computer program product, including a computer program that, when executed by a processor, implements the steps of the optical proximity effect correction method described in any of the foregoing embodiments. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1a This is a schematic diagram of an exemplary "T"-shaped graphic. Figure 1b This is a schematic diagram of the outline of the corrected simulation graphic 210 obtained after OPC correction using a traditional method. Figure 1c This is a schematic diagram of the outline of the corrected simulation pattern 220 corresponding to the mask pattern obtained according to the optical proximity effect correction method in one embodiment of this application. Figure 1d yes Figure 1c A schematic diagram of the corresponding pore-filling process window;

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

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

[0027] Figure 4 This is a flowchart of an optical proximity effect correction method in one embodiment of this application;

[0028] Figure 5 This is a flowchart of an optical proximity effect correction method in another embodiment of this application;

[0029] Figure 6a This is a schematic diagram of another exemplary "T"-shaped graphic. Figure 6b This is yet another exemplary schematic diagram of a "T" shaped graphic. Detailed Implementation

[0030] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0032] It should be understood that when a component or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other components or layers, it may be directly on, adjacent to, connected to, or coupled to other components or layers, or there may be intervening components or layers. Conversely, when a component is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other components or layers, there are no intervening components or layers. The term "connection" in this specification, if the connected circuits, modules, units, etc., involve the transmission of electrical signals or data, should be understood as "electrical connection," "communication connection," etc. It should be understood that although the terms first, second, third, etc., may be used to describe various components, parts, areas, layers, and / or portions, these components, parts, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one component, part, area, layer, or portion from another component, part, area, layer, or portion. Therefore, without departing from the teachings of this invention, the first element, component, region, layer or portion discussed below may be represented as a second element, component, region, layer or portion.

[0033] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0034] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will be understood that “at least one” means one or more, and “a plurality” means two or more. “At least a portion of an element” means part or all of an element. It should also be understood that the terms “compose” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0035] Embodiments of the invention are described herein with reference to cross-sectional views that serve as schematic diagrams of ideal embodiments (and intermediate structures). Thus, variations in the shape shown can be anticipated due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of the invention should not be limited to the specific shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing processes. For example, implantation regions shown as rectangular typically have rounded or curved features at their edges and / or implantation concentration gradients, rather than a binary change from implantation regions to non-implantation regions. Similarly, the buried regions formed by implantation can result in some implantation in the region between the buried region and the surface traversed during implantation. Therefore, the regions shown in the figures are substantially schematic, and their shapes are not intended to show the actual shapes of the regions of the device and are not intended to limit the scope of the invention.

[0036] An exemplary computer-aided software tool method for optical proximity correction (OPC) involves first identifying the edges of a photomask design pattern using OPC software, and then dividing these edges into numerous small correction segments, allowing each segment to move freely. Target points are then placed on each correction segment. The OPC software then simulates the image after photolithography exposure based on an OPC model and compares it with the photomask design pattern (e.g., ...). Figure 2 As shown in the image, the difference between the simulated graphic and the design graphic at the target point is calculated. This difference is called the Edge Placement Error (EPE), which is used to measure the quality of the correction. During runtime, the OPC software moves the edge position of the mask design graphic 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 during the OPC process are shown in the image. Figure 3 As shown, Figure 3 The left half represents the mask design and the position of the dividing points. The black dots on the edge of the original pattern (i.e., the mask design) indicate the dividing points, which divide the edge into several correction line segments of varying lengths. The corrected OPC result (i.e., the corrected mask pattern) is as follows: Figure 3 As shown in the right half.

[0037] See Figure 1a The "T"-shaped figure includes an adjacent portion 110, a neck 120, a transition portion 130, and a head 140. The break lines on the upper and lower sides of the adjacent portion 110 are omitted. The width of the adjacent portion 110 is greater than the width of the neck 120, the width of the head 140 is greater than the width of the neck 120, and the transition portion 130 has different widths at different locations. Figure 1a The width in the text specifically refers to the width in the first direction (i.e.) Figure 1a The vertical dimension (in the image). 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. As described in the background art, the correction effect of OPC correction using conventional methods for the "T" shaped pattern is poor. Figure 1b The outline of the corrected simulation pattern 210 (i.e., the post-exposure pattern obtained by simulating the OPC correction of the "T"-shaped pattern) is shown after OPC correction using a conventional method. It can be seen that the corrected simulation pattern 210 is located at the neck 120 ( Figure 1b A significant "rounding" effect occurs near the edges (not marked in the text), resulting in a large difference in the CD (critical dimension) value 'a' on one side. Note Figure 1bIn order to make it easier to distinguish the modified simulation graphic 210 from the "T" shaped graphic, the outline of part of the structure of the "T" shaped graphic is shown with dashed lines.

[0038] Figure 1a The angle θ between the outer edges of the neck 120 and the transition portion 130 of the "T"-shaped figure is obtuse. Furthermore, a right angle or an acute angle would also cause a "rounding" effect in the "T"-shaped figure. (See reference...) Figure 6a and Figure 6b , Figure 6a The "T"-shaped pattern shown includes an adjacent portion 110a, a neck 120a, a transition portion 130a, and a head 140a. The width of the adjacent portion 110a is greater than the width of the neck 120a, the width of the head 140a is greater than the width of the neck 120a, and the width of the transition portion 130a is greater than the width of the neck 120a but not greater than the width of the head 140a; Figure 6a In the illustrated embodiment, the width of the transition portion 130a is equal to the width of the head 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, while the other end is directly connected to the head 140. The angle θ1 between the outer sides of 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 text specifically refers to the width in the first direction (i.e.) Figure 6a The vertical dimension. Figure 6a and Figure 6b The intermediate transition sections 130a / 130b are filled differently from the head sections 140a / 140b to distinguish them.

[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 consists of a rectangle and two triangles. The width of the rectangle is greater than the width of the neck 120b but not greater than the width of the head 140b. One triangle is located in the neck 120b in the first direction (i.e.,...). Figure 6bOne triangle is located on one side of the vertical axis (in the middle), and the other triangle is located on the opposite side of the neck 120b in the first direction. The transition section 130b is connected to the neck 120b and the head 140b respectively through the two ends of the rectangle. Each of the two triangles has one side shared with the rectangle. Each of the two triangles has one side connected to the edge of the neck 120b, and the connection point is the endpoint of the side of the triangle, which is also the endpoint of the edge of the neck 120b. The angle θ2 between the side of the triangle and the edge of the neck 120b at that endpoint is an acute angle. Note Figure 6b The width in the text specifically refers to the width in the first direction (i.e.) Figure 6b The vertical dimension (in the text). Figure 6b In the embodiment shown, the width of the rectangle is equal to the width of the head 140b, and the two triangles are right triangles, with the side sharing the rectangle being a right-angled side.

[0040] To overcome the "rounding" effect of the "T"-shaped pattern, engineers improved the original OPC algorithm. However, this resulted in insufficient process windows for the "T"-shaped pattern's aperture enclosure, making it difficult to simultaneously address both the "rounding" effect and the insufficient aperture enclosure window. This invention provides an improved optical proximity effect correction method that optimizes the target points on the "T"-shaped pattern, effectively improving the "rounding" effect, increasing OPC accuracy, reducing EPE values, and expanding the process window.

[0041] Figure 4 This is a flowchart of an optical proximity effect correction method in one embodiment of this application, including:

[0042] S410, obtain the mask design graphic.

[0043] After designing an integrated circuit according to actual needs, design patterns at various layout levels that match the needs are obtained, which serve as mask design patterns.

[0044] S440 simulates the mask design pattern based on the OPC model to obtain the simulated exposure pattern.

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

[0046] S450 calculates the edge placement error 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 correction method may also include steps S420 and S430, see [link to relevant documentation]. Figure 5 Step S420 involves dissectioning the outer edge of the mask design pattern into multiple segments. Dissection involves dividing the edge of the mask design pattern into many small correction segments, with each segmentation point dividing the edge into several correction line segments of varying lengths. Dissection can be performed using OPC software. Step S430 involves placing target points on the outer edge of the mask design pattern. In one embodiment of this application, the target points are placed on the correction segments obtained after dissection in step S420. The position of the target points on the edge of the "T"-shaped pattern can be referenced... Figure 1a Target points can also be placed at other locations along the edges of the "T"-shaped graphic, such as at the endpoints of each edge (corners of the correction segment). For Figure 6a and Figure 6b In the embodiment shown, where the width of the transition portion 130a / 130b is the same as that of the head 140a / 140b, the line segment connecting the edge of the transition portion 130a / 130b to the head 140a / 140b (i.e., the line segment between the vertex of the edge of the transition portion 130a / 130b and the head 140a / 140b) is a single correction segment obtained from the aforementioned analytical dissection. That is, the length of this line segment on the edge is the same as the corresponding correction segment. In one embodiment of this application, the edge placement error is the target point position on the simulated exposure pattern minus the position of the corresponding target point on the mask design pattern. The value of the edge placement error can be positive or negative.

[0048] S460 adjusts the mask design based on edge placement error to obtain a corrected design.

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

[0050] S470, determine whether the corrected graphic meets the requirements. If yes, proceed to step S480; otherwise, proceed to step S472.

[0051] Specifically, based on the post-exposure morphology of the corrected pattern obtained in step S460, it is necessary to determine whether the corrected pattern meets the correction requirements, i.e., whether the morphology meets the accuracy requirements of OPC correction. The post-exposure morphology can be obtained from OPC correction simulation, specifically by using OPC software to obtain the exposure simulation results of the corrected pattern. If the post-exposure morphology of the corrected pattern meets the correction requirements, then step S480 is executed; otherwise, step S472 is executed.

[0052] S472, Adjust the target point on the edge of the transition section of the "T" shaped graphic.

[0053] The "T"-shaped figure includes an adjacent portion 110, a neck 120, a transition portion 130, and a head 140. Break lines on the upper and lower sides of the adjacent portion 110 are omitted. The width of the adjacent portion 110 in the first direction is greater than the width of the neck 120 in the first direction, the width of the head 140 in the first direction is greater than the width of the neck 120 in the first direction, and the width of the transition portion 130 in the first direction varies at different positions. The first direction is... Figure 1a The vertical direction is shown in the image. The neck 120 and adjacent portion 110 are directly connected. 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. Select the edge of the transition portion 130 in the mask design drawing (for...). Figure 1a The illustrated embodiment (i.e., the waist of the trapezoidal transition section 130) involves adjusting target points on the edge of the transition section 130. This includes at least one of the following: moving the position of the target points, deleting target points, placing new target points on the edge of the transition section 130, or merging target points on the edge of the transition section 130 (i.e., deleting at least two target points on the edge of the transition section 130 and placing new target points). The adjustment can be performed manually or by OPC software using preset target point adjustment rules.

[0054] After adjusting the target points on the edge of the transition section 130, return to step S450 and execute steps S450-S460-S470 again. Based on the edge placement error after the target point adjustment, adjust the mask design pattern again to obtain a new corrected pattern. That is, repeatedly execute steps S450, S460, and S470 until step S470 obtains a corrected pattern with the required correction accuracy, then exit the loop and proceed to step S480.

[0055] In one embodiment of this application, step S472 adjusts only the target points on the edge of the transition portion 130, and 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, and the target points on the edge of the neck 120 are not adjusted. Further, step S472 adjusts only the target points on the edge of the transition portion 130, and not the other target points on the “T”-shaped pattern.

[0056] S480, obtain the mask pattern based on the corrected pattern.

[0057] In one embodiment of this application, the correction pattern obtained from the preceding steps that meets the required accuracy is used as the pattern for mask making.

[0058] Figure 1c The outline of the corrected simulation pattern 220 (i.e., the post-exposure pattern obtained by simulating the "T"-shaped pattern after OPC correction) corresponding to the mask pattern obtained by the optical proximity correction method according to an embodiment of this application is shown, wherein Figure 1b The outline of the corrected simulation graphic 210 in Figure 1c The middle section uses continuous dots to represent the neck area, which can be seen at 120 degrees. Figure 1c The "rounding" effect near the edges (not shown in the figure) was significantly improved compared to the single-sided CD difference a (refer to the figure) of the corrected simulation graph 210. Figure 1b The single-sided CD difference of the corrected simulation pattern 220 is significantly reduced. In one embodiment of this application, the single-sided CD difference a is reduced from +11nm to -2nm (a positive single-sided CD difference indicates that the edge of the corrected simulation pattern is located outside the mask design pattern, while a negative value indicates that it is located inside).

[0059] The aforementioned optical proximity effect correction method can improve the OPC correction effect of the "T" shaped pattern by optimizing the target points on the edge of the transition portion 130 when the shape of the correction pattern is not good. This effectively improves the "rounding" effect, increases OPC accuracy, and enlarges the process window.

[0060] Reference Figure 1bSince the deviation (i.e., the "rounding" effect) of the corrected simulation pattern 210 of the "T"-shaped pattern is mainly located near the edge of the neck 120, an exemplary improvement method is to optimize the target points on the edge of the neck 120. That is, if the correction effect is poor at a certain point in the mask pattern, it is generally easy to think of correcting and adjusting the target points on the correction segment at that point, rather than correcting and adjusting the target points on the correction segments surrounding that point. This is because correcting and adjusting the target points on the surrounding correction segments would introduce more variable factors, making it more difficult to control the correction result and thus not obtaining an ideal pattern. However, the aforementioned optical proximity effect correction method, by optimizing the target points on the edge of the transition portion 130, reduces the over-correction near the edge of the neck 120, effectively balancing the correction contradiction between the neck 120 and the transition portion 130. In other words, by adjusting the target points of the pattern surrounding the poorly corrected area (neck 120) (i.e., the transition portion 130), the correction accuracy of the poorly corrected area (neck 120) is effectively improved, the "rounding" effect at the neck 120 is reduced, and unexpected technical effects are achieved. Furthermore, the corrected simulation pattern 220 corresponding to the mask pattern obtained by the aforementioned optical proximity effect correction method has virtually no impact on the perforation process window 310 of the "T"-shaped pattern. (Refer to...) Figure 1d This means that while solving the "rounding" effect of the "T"-shaped pattern, the problem of insufficient window space in the perforation process will not occur.

[0061] In one embodiment of this application, the neck 120 and head 140 of the "T"-shaped graphic are rectangular, and the transition portion 130 is trapezoidal, with one base of the trapezoid intersecting with the head 140 and the other base intersecting with the neck 120, as shown in the reference. Figure 1a In other embodiments of this application, the shape of the head 140 may also be other polygons.

[0062] Reference Figure 1a In one embodiment of this application, the adjacent portion 110 of the "T"-shaped pattern is elongated, and the extension direction of the elongated shape is a first direction, i.e. Figure 1a The vertical direction in the middle.

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

[0064] In one embodiment of this application, step S472 selects the edge of the transition portion 130 by filtering the edge of the transition portion 130 according to the features of the edge of the transition portion 130, the features including at least one of the length of the edge, the length of the adjacent side of the edge of the transition portion, and the included angle between the edge of the transition portion and the adjacent side.

[0065] This application provides a mask made from a mask pattern obtained by the optical proximity effect correction method according to any of the above embodiments.

[0066] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, 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 storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0067] This application also provides a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the optical proximity effect correction method described in any of the above embodiments.

[0068] This application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the optical proximity effect correction method described in any of the above embodiments.

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

[0070] It should be understood that although the steps in the flowchart of this application are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart of this application may include multiple steps or multiple stages, which are not necessarily completed at the same time, but may be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but may be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0071] In the description of this specification, references to terms such as "some embodiments," "other embodiments," and "ideal embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for correcting the optical proximity effect, comprising: Step A: Obtain the mask design graphic; Step B: Simulate the mask design pattern according to the OPC model to obtain the simulated exposure pattern; Step C: Calculate the edge placement error between the simulated exposure pattern and the mask design pattern at each target point; Step D: Adjust the mask design pattern according to the edge placement error to obtain the corrected pattern; Step E: Determine whether the morphology of the corrected pattern after exposure meets the requirements. If it does, obtain the mask pattern based on the corrected pattern. If the conditions are not met, adjust the target point on the edge of the transition part of the mask design pattern and return to step C. Repeat steps C, D and E until the mask pattern is obtained. The mask design pattern includes a first pattern, which includes an adjacent portion, a neck, a head, and a transition portion. The width of the adjacent portion in a first direction is greater than the width of the neck in the first direction, and 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. In step E, the target point on the edge of the neck of the mask design pattern is not adjusted.

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 section 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 section, and merging the target points on the edge of the transition section.

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

4. The optical proximity effect correction method according to claim 3, characterized in that, The neck and head are rectangular in shape, and the transition portion is trapezoidal in shape, with one base of the trapezoid intersecting with the head and the other base intersecting with the neck; and / or The adjacent portion is elongated, and the extension direction of the elongated portion is the first direction.

5. The optical proximity effect correction method according to claim 1, characterized in that, The procedure preceding step C also includes: The outer edge of the mask design graphic is analytically segmented into multiple segments; The target point is placed on the outer edge of the mask design pattern.

6. The optical proximity effect correction method according to claim 1, characterized in that, The neck, transition section, and head are all located in the active region.

7. 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. Selecting the edge of the transition portion includes filtering the edge of the transition portion according to the characteristics of the edge of the transition portion. The characteristics include at least one of the following: the length of the edge, the length of the adjacent side of the edge of the transition portion, and the angle between the edge of the transition portion and the adjacent side.

8. A photomask, characterized in that, The mask is made from the mask pattern obtained by the optical proximity effect correction method according to any one of claims 1-7.

9. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1-7.

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