Optical proximity correction method implemented using computer program
By adjusting and simulating the pattern area size of the photomask using computer programs, and combining optical and etching models, the problem of optical proximity correction in multi-patterning processes was solved, improving the efficiency and accuracy of photomask correction and ensuring the accuracy of the photolithography process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-09
- Publication Date
- 2026-04-03
AI Technical Summary
In multi-patterning processes, optical proximity correction is difficult to effectively correct the layout, resulting in a large difference between the actual pattern and the ideal pattern, which affects circuit performance and makes mask debugging difficult.
The optical proximity correction method implemented by computer program adjusts the size of the pattern area of the mask, performs simulation and merging, uses optical and etching models to simulate the photolithography and etching process, performs DRC and LRC detection until the preset value is met, and corrects the mask.
It improves the efficiency and accuracy of mask correction, can intuitively reflect mask defects, optimizes optical proximity correction, and ensures the accuracy of photolithography process.
Smart Images
Figure CN121785039A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor technology, and in particular to an optical proximity correction method implemented using a computer program. Background Technology
[0002] Lithography is a process that transfers a mask pattern onto a wafer through a series of steps, including alignment and exposure. It is a core step in chip manufacturing, and lithography resolution is the smallest linewidth that lithography can distinguish. It is a core indicator that determines the chip manufacturing process.
[0003] As chip manufacturing processes advance to smaller nodes, traditional single-exposure methods can no longer meet the resolution requirements of photolithography, making multiple patterning techniques an inevitable choice. Multiple patterning methods include: Litho-Etch-Litho-Etch (LELE), Self-Aligned Double Patterning (SADP), and Self-Aligned Quadruple Patterning (SAQP). Due to the shrinking size of semiconductor devices, the wavelength used for exposure is larger than the ideal pattern size and spacing in 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 physical layout design. This leads to substantial changes in the shape and spacing of the actual pattern, even affecting circuit performance. Especially in multiple patterning processes, multiple photolithography and etching processes result in a significant difference between the pattern morphology and the actual physical structure. Optical Proximity Correction (OPC) is often insufficient to correct the pattern effectively. In such cases, it is often necessary to provide feedback and adjustments to the pattern based on the physical structure fabricated in the process flow.
[0004] It should be noted that the information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0005] The purpose of this invention is to provide an optical proximity correction method implemented using a computer program to solve the problem of difficult mask adjustment.
[0006] To address the aforementioned technical problems, this invention provides an optical proximity correction method implemented using a computer program, comprising:
[0007] A first mask is provided, including a first patterned area and a first unpatterned area, wherein the first patterned area contains line patterns that are separated from each other;
[0008] Adjusting the size of the first patterned area yields a second patterned area and a second non-patterned area;
[0009] The first patterned area and the second non-patterned area are simulated to obtain a first simulated pattern and a second simulated pattern.
[0010] The first simulated pattern and the second simulated pattern are combined to obtain the first composite pattern;
[0011] Detect whether the first composite pattern meets the preset value. If it does, output the first mask. If it does not, correct the first pattern area or the second pattern area.
[0012] Preferably, adjusting the size of the first pattern area includes: increasing the size of the first pattern area by the same amount along a first direction and a second direction to obtain a second pattern area, wherein the first direction and the second direction are perpendicular to each other.
[0013] Preferably, simulating the graphic outline, graphic shape, or graphic curve of the first patterned area and the second non-patterned area includes: simulating the first simulated pattern and the second simulated pattern using an optical model, an etching model, or a combination of an optical model and an etching model.
[0014] Preferably, the simulation parameters of the optical model include photoresistivity, exposure conditions, and dimensions.
[0015] Preferably, the simulation parameters of the etching model include gas, shielding layer material, size, and time.
[0016] Preferably, detecting whether the first composite pattern meets the preset value includes: performing DRC detection or LRC detection on the simulated first composite pattern.
[0017] Preferably, if the rules set in DRC detection or LRC detection are not met, the first pattern area or the second pattern area is corrected, the corresponding second non-pattern area is obtained, and the simulation continues to obtain the first simulated pattern, the second simulated pattern, and the first composite pattern until the first composite pattern meets the rules set in DRC detection or LRC detection.
[0018] The present invention also provides another optical proximity correction method implemented using a computer program, comprising:
[0019] A first mask is provided, including a first patterned area and a first unpatterned area, wherein the first patterned area contains line patterns that are separated from each other;
[0020] Adjusting the size of the first patterned area yields a second patterned area and a second non-patterned area;
[0021] The first patterned area and the second non-patterned area are simulated to obtain a first simulated pattern and a second simulated pattern.
[0022] The first simulated pattern and the second simulated pattern are combined to obtain the first composite pattern;
[0023] The first composite simulated pattern is obtained by simulating the pattern outline, pattern shape, or pattern curve of the first composite pattern.
[0024] Detect whether the first composite simulation pattern meets the preset value. If it does, output the first mask. If it does not, correct the first pattern area or the second pattern area.
[0025] Preferably, adjusting the size of the first pattern area includes: increasing the size of the first pattern area by the same amount along a first direction and a second direction to obtain a second pattern area, wherein the first direction and the second direction are perpendicular to each other.
[0026] Preferably, simulating the graphic outline, graphic shape, or graphic curve of the first patterned area, the second non-patterned area, and the first composite pattern includes: simulating the first simulated pattern, the second simulated pattern, and the first composite simulated pattern using an optical model, an etching model, or a combination of an optical model and an etching model.
[0027] Preferably, detecting whether the first composite simulation pattern meets the preset value includes: performing DRC detection or LRC detection on the simulated first composite simulation pattern.
[0028] Preferably, if the rules set in DRC detection or LRC detection are not met, the first pattern area or the second pattern area is corrected, the corresponding second non-pattern area is obtained, and the simulation continues to obtain the first simulated pattern, the second simulated pattern, and the first composite simulated pattern until the first composite simulated pattern meets the rules set in DRC detection or LRC detection.
[0029] The present invention also provides yet another optical proximity correction method implemented using a computer program, comprising:
[0030] A first mask is provided, including a first patterned area and a first unpatterned area, wherein the first patterned area contains line patterns that are separated from each other;
[0031] Adjusting the size of the first patterned area yields a second patterned area and a second non-patterned area;
[0032] Transform the second non-patterned area into the third patterned area;
[0033] The first pattern area and the third pattern area are merged to obtain a second composite pattern;
[0034] The second composite pattern is obtained by simulating the graphic outline, graphic shape, or graphic curve of the second composite pattern.
[0035] Detect whether the second composite simulation pattern meets the preset value. If it does, output the first mask. If it does not, correct the first pattern area or the second pattern area.
[0036] Preferably, adjusting the size of the first pattern area includes: increasing the size of the first pattern area by the same amount along a first direction and a second direction to obtain a second pattern area, wherein the first direction and the second direction are perpendicular to each other.
[0037] Preferably, simulating the graphic outline, graphic shape, or graphic curve of the second composite pattern includes: simulating the second composite simulated pattern using an optical model, an etching model, or a combination of an optical model and an etching model.
[0038] Preferably, detecting whether the preset value is met includes: performing DRC detection or LRC detection on the simulated second composite simulation pattern.
[0039] Preferably, if the rules set in DRC detection or LRC detection are not met, the first pattern area or the second pattern area is corrected, the corresponding second non-pattern area is obtained, and the simulation continues to obtain the second composite simulation pattern until the second composite simulation pattern meets the rules set in DRC detection or LRC detection.
[0040] In the optical proximity correction method implemented using a computer program provided by this invention, a first mask is provided, including a first patterned area and a first unpatterned area, wherein the first patterned area contains separate circuit patterns; the size of the first patterned area is adjusted to obtain a second patterned area and a second unpatterned area; the first patterned area and the second unpatterned area are simulated for graphic contours, graphic shapes, or graphic curves to obtain a first simulated pattern and a second simulated pattern; the first simulated pattern and the second simulated pattern are merged to obtain a first composite pattern; whether the first composite pattern meets a preset value is detected, and if it does, the first mask is output, otherwise the first patterned area or the second patterned area is corrected. For a multi-patterning method that uses one or more masks for photolithography and etching to obtain the final solid structure, the computer system is used to adjust the mask, and the first patterned area and the second unpatterned area obtained before and after the adjustment are simulated respectively to obtain the first simulated pattern and the second simulated pattern, which are then aligned and merged to obtain the first composite pattern. Detecting the first composite pattern can intuitively reflect the defects existing in the initial first mask, which helps to provide feedback for correcting the mask pattern. Moreover, all the above processes can be executed entirely or partially with the help of a computer system, improving correction efficiency and accuracy. Attached Figure Description
[0041] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:
[0042] Figure 1 This is an execution flowchart of Embodiment 1 of the present invention;
[0043] Figure 2 This is an execution flowchart of Embodiment 2 of the present invention;
[0044] Figure 3 This is an execution flowchart of Embodiment 3 of the present invention;
[0045] Figure 4 This is a schematic diagram of the first mask plate according to Embodiment 1 of the present invention;
[0046] Figure 5 This is a schematic diagram of adjusting the size of the first pattern area according to Embodiment 1 of the present invention;
[0047] Figure 6 This is a schematic diagram of how the second non-patterned area is transformed into a third patterned area in Embodiment 3 of the present invention;
[0048] Figure 7 This is a schematic diagram of the first simulated pattern of Embodiment 1 of the present invention;
[0049] Figure 8 This is a schematic diagram of the second simulated pattern of Embodiment 1 of the present invention;
[0050] Figure 9 This is a schematic diagram of the first composite pattern obtained in Embodiment 1 of the present invention;
[0051] Figure 10 This is a schematic diagram of a pair of detectors performing a first composite pattern according to an embodiment of the present invention;
[0052] Figure 11 yes Figure 10 Enlarged diagram of point A in the middle.
[0053] In the attached image:
[0054] 100, First mask; 101, First patterned area; 102, First non-patterned area; 103, Added area; 104, Second non-patterned area; 110, First simulated pattern; 111, Boundary of the first patterned area; 112, First simulated non-patterned area; 200, Second patterned area; 201, Third patterned area; 210, Second simulated pattern; 211, Boundary of the second non-patterned area; 212, Second simulated non-patterned area; 300, First composite pattern; 301, Added area simulation region. Detailed Implementation
[0055] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.
[0056] The invention is described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, intended only to facilitate and clarify the illustration of the embodiments of the invention. It is understood that the terms "on," "above," and "over" in this invention should be interpreted in the broadest sense, such that "on" means not only "on" something without any intervening feature or layer (i.e., directly on something), but also includes "on" something with an intervening feature or layer.
[0057] In the embodiments of the present invention, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be noted that the technical solutions described in the embodiments of the present invention can be arbitrarily combined without conflict.
[0058] For details, please refer to Figure 1 , Figure 1 A schematic flowchart of the optical proximity correction method provided in this application. It includes at least the following steps:
[0059] S01, a first mask 100 is provided, including a first patterned area 101 and a first unpatterned area 102, wherein the first patterned area 101 contains line patterns that are separate from each other.
[0060] S02, adjust the size of the first pattern area 101 to obtain the second pattern area 200 and the second non-pattern area 104.
[0061] S03, simulate the graphic outline, graphic shape, or graphic curve of the first pattern area 101 and the second non-pattern area 104 to obtain the first simulated pattern 110 and the second simulated pattern 210.
[0062] S04, merge the first simulated pattern 110 and the second simulated pattern 210 to obtain the first composite pattern 300.
[0063] S05, detect whether the first composite pattern 300 meets the preset value. If it does, output the first mask 100. If it does not meet the preset value, correct the first pattern area 101 or the second pattern area 200.
[0064] For a multi-patterning method that uses one or more photomasks for photolithography and etching to obtain the final physical structure, a computer system is used to adjust the photomasks and simulate the first patterned area 101 and the second non-patterned area 104 before and after adjustment. For example, simulation is performed according to the photolithography or etching process parameters used in patterning to obtain the first simulated pattern 110 and the second simulated pattern 210, which are then aligned and merged to obtain the first composite pattern 300 with a smaller linewidth. Detecting the first composite pattern 300 can intuitively reflect the defects existing in the initial first photomask 100, which helps to provide feedback for correcting the photomask pattern. Moreover, all of the above processes can be executed entirely or partially with the help of a computer system, improving correction efficiency and accuracy, and optimizing the optical proximity correction method.
[0065] In order to enable those skilled in the art to easily understand the optical proximity correction method in the embodiments of the present invention, the optical proximity correction method proposed in the present invention will be further described below with reference to schematic diagrams of various layouts in the correction process of the optical proximity correction method.
[0066] Example 1
[0067] Figures 4 to 5 as well as Figures 7 to 11 This is a schematic diagram of the optical proximity correction method provided in Embodiment 1 of the present invention during the correction process.
[0068] like Figure 4 As shown, step S01 is performed to provide a first mask 100, including a first patterned area 101 and a first non-patterned area 102.
[0069] In step S02, the size of the first patterned area 101 is adjusted to obtain the second patterned area 200 and the second non-patterned area 104. It is understood that in a multi-patterning process, deposition and / or etching processes are often required on the solid structure fabricated by the photomask to form an intermediate solid structure. This intermediate solid structure serves as the basis for further processes, such as a hard mask pattern. Thus, feedback correction can only be achieved by transferring the pattern on the photomask to the solid structure. In this step, the pattern on the photomask is transferred to the first mask 100 for simulation correction. By adjusting the size of the first patterned area 101 on the first mask 100, the process performed on the solid structure is simulated to obtain the corresponding second non-patterned area 104. The virtual second non-patterned area 104 corresponding to the intermediate solid structure is used to correct the first mask 100.
[0070] As an optional embodiment, adjusting the size of the first pattern area 101 includes: increasing the size of the first pattern area 101 by the same amount along a first direction and a second direction to obtain a second pattern area 200, wherein the first direction and the second direction are perpendicular to each other. For example, the first direction and the second direction are respectively... Figure 5 In the X and Y directions of the first pattern area 101, the same size is added to the edges in the X and Y directions. This added portion is called the augmentation area 103. This simulates the influence of the deposition medium on the first pattern area 101, or rather, the solid structure corresponding to the first pattern area 101. More preferably, a deposition model can be introduced to simulate the deposition conditions. The deposition model includes a series of parameters such as the deposition medium and deposition rate. (Reference) Figure 5 An additional region 103 is added to the first patterned region 101 to simulate the process of depositing a sidewall structure of predetermined thickness on the pattern of the first patterned region 101. Next, a second unpatterned region 104 and a second patterned region 200 are obtained on the first patterned region 101 after the size increase. In some embodiments, the pattern on the first patterned region 101 is reduced by a certain size to obtain the second patterned region 200. More preferably, the first patterned region 101 is reduced by the same size along the first and second directions, thereby simulating the effect of the etching process on the first patterned region 101, or the solid structure corresponding to the first patterned region 101.
[0071] like Figure 7 and Figure 8 As shown, in step S03, the first pattern area 101 and the second non-pattern area 104 are simulated to obtain a first simulated pattern 110 and a second simulated pattern 210.
[0072] The simulation of the graphic outline, shape, or curve includes: simulating a first simulated pattern 110 and a second simulated pattern 210 using an optical model, an etching model, or a combination of both. The simulation parameters of the optical model include photoresist, exposure conditions, and dimensions. The simulation parameters of the etching model include gas, masking layer material, dimensions, and time. It is important to note that during the photolithography process in semiconductor manufacturing, considering optical precision, pattern distortion, and other process requirements, the pattern size on the mask is reduced and projected by the optical system before forming a pattern of actual size on the wafer. Therefore, the actual process requires simulation of the first patterned area 101 and the second unpatterned area 104. The simulated sizes of the first simulated pattern 110 and the second simulated pattern 210 may be smaller than the original sizes of the first patterned area 101 and the second unpatterned area 104. Furthermore, the simulated unpatterned area 112 corresponds to the unpatterned area of the first patterned area 101, and the simulated unpatterned area 212 corresponds to the second patterned area 200. Figure 7 and Figure 8 The dashed lines in the diagram represent the boundaries of the first patterned area 111 and the second non-patterned area 211, respectively. Figure 7 and Figure 8 The scaled-down figures are for illustrative purposes only and do not represent the actual scale used in the manufacturing process.
[0073] Understandably, the first patterned area 101 and the second unpatterned area 104 are simulated respectively by selecting an optical model or an etching model or a combination of optical and etching models according to the process flow corresponding to the first mask 100 and the formation of the second unpatterned area 104.
[0074] Taking the conventional Self-Aligned Double Patterning (SADP) process as an example, the SADP process includes: first, using a mask for photolithography and etching to obtain a mandrel; then, depositing sidewalls (spacers) on the mandrel; next, etching away the mandrel; and finally, using the remaining sidewalls as the final desired pattern. Images with smaller linewidths can be fabricated using the sidewalls as masks. Often, the sidewall structure is directly fabricated, and the corresponding mask is corrected based on the actual morphology of the sidewall structure. In this embodiment, the mask used to fabricate the mandrel is used as the first mask 100. The first patterned area 101 on the first mask 100 is increased by the same size in the first and second directions to simulate the sidewalls deposited on the pattern. Then, the second non-patterned area 104 is simulated using an etching model to simulate the effect of etching away the mandrel on the second non-patterned area 104, forming a second simulated pattern 210. More preferably, when simulating the second non-patterned area 104 using an etching model, the effect of removing the mandrel on the sidewalls can also be simulated simultaneously.
[0075] Next, as Figure 9 As shown, in step S04, the first simulation pattern 110 and the second simulation pattern 210 are merged to obtain the first composite pattern 300. For example, the first simulation pattern 110 and the second simulation pattern 210 are aligned and the two simulation areas are merged. The blank area between the simulation areas is the added area simulation area 301, which is used to simulate the area of the sidewalls deposited on the pattern.
[0076] S05, such as Figure 10 As shown, it detects whether the first composite pattern 300 meets the preset value. If it does, the first mask 100 is output; if it does not, the first pattern area 101 or the second pattern area 200 is corrected.
[0077] In one implementation, detecting whether preset values are met includes performing DRC (design rule check) or LRC (lithography rule check) on the simulated first composite pattern 300. DRC checks the geometric dimensions (such as linewidth, spacing, and capping layer alignment) of each mask layer in the layout to ensure the design meets physical manufacturing limits and avoids short circuits, open circuits, or device failures caused by process deviations. For example, it verifies whether the minimum spacing of metal layers meets the standard and whether the overlap between polysilicon and the active region meets the requirements. LRC simulates and verifies the mask design layout by establishing a lithography imaging model. By detecting geometric anomalies such as critical dimension deformation, line end offset, and via coverage deviation, it predicts manufacturing defects such as open circuits and bridging that may occur after the lithography process is implemented. More preferably, a combined approach of LRC and DRC is used, employing dead pixel fuzzy classification and pattern decomposition techniques to improve detection efficiency and reduce repetitive correction steps in optical proximity correction (OPC).
[0078] refer to Figure 10 The weak point shown at point A in the middle, and Figure 11 The enlarged schematic diagram at point A shown shows that if the rules set in DRC detection or LRC detection are not met, steps S02 to S05 are repeated. In other words, the first pattern area 101 or the second pattern area 200 is corrected, the corresponding second non-pattern area 104 is taken, and the simulation is continued to obtain the first simulated pattern 110, the second simulated pattern 210, and the first composite pattern 300 until the first composite pattern 300 meets the rules set in DRC detection or LRC detection.
[0079] The aforementioned optical proximity correction method is applicable to layout correction used in multiple patterning, including but not limited to dual patterning, self-aligned dual patterning, and self-aligned quadruple patterning. It can even be used to simulate and correct photolithography and etching processes using one or more masks, such as in the damascus process, where two masks are used to etch contact holes that are larger at the top and smaller at the bottom, but it is not limited to this.
[0080]
Example 2
[0081] Based on the same technological concept, such as Figure 2 As shown, the present invention also provides another optical proximity correction method, comprising:
[0082] S01, a first mask 100 is provided, including a first patterned area 101 and a first unpatterned area 102, wherein the first patterned area 101 contains line patterns that are separate from each other.
[0083] S02, adjust the size of the first pattern area 101 to obtain the second pattern area 200 and the second non-pattern area 104.
[0084] S03, simulate the graphic outline, graphic shape, or graphic curve of the first pattern area 101 and the second non-pattern area 104 to obtain the first simulated pattern 110 and the second simulated pattern 210.
[0085] S04, merge the first simulated pattern 110 and the second simulated pattern 210 to obtain the first composite pattern 300.
[0086] S05, simulate the pattern outline, pattern shape, or pattern curve of the first composite pattern 300 to obtain the first composite simulated pattern.
[0087] S06, detect whether the first composite simulation pattern meets the preset value. If it does, output the first mask 100. If it does not, correct the first pattern area 101 or the second pattern area 200.
[0088] refer to Figures 4 to 5 In step S01, a first mask 100 is provided, including a first patterned area 101 and a first unpatterned area 102.
[0089] In step S02, the size of the first patterned area 101 is adjusted to obtain the second patterned area 200 and the second non-patterned area 104. It is understood that in a multi-patterning process, deposition and / or etching processes are often required on the solid structure fabricated by the photomask to form an intermediate solid structure. This intermediate solid structure serves as the basis for further processes, such as a hard mask pattern. Thus, feedback correction can only be achieved by transferring the pattern on the photomask to the solid structure. In this step, the pattern on the photomask is transferred to the first mask 100 for simulation correction. By adjusting the size of the first patterned area 101 on the first mask 100, the process performed on the solid structure is simulated to obtain the corresponding second non-patterned area 104. The virtual second non-patterned area 104 corresponding to the intermediate solid structure is used to correct the first mask 100.
[0090] As an optional embodiment, adjusting the size of the first pattern area 101 includes: increasing the size of the first pattern area 101 by the same amount along a first direction and a second direction to obtain a second pattern area 200, wherein the first direction and the second direction are perpendicular to each other. For example, the same amount is added to the edges of the first pattern area 101 graphic in the X and Y directions; the added portion is the added area 103, which can be referred to... Figure 5 The simulation demonstrates the influence of the deposition medium on the first patterned region 101, or the solid structure corresponding to the first patterned region 101. More preferably, a deposition model can be introduced to simulate the deposition process, including parameters such as the deposition medium and deposition rate. An additional region 103 is set on the first patterned region 101 to simulate the process of depositing a sidewall structure of predetermined thickness on the pattern of the first patterned region 101. Next, a second non-patterned region 104 and a second patterned region 200 are obtained on the first patterned region 101 after the size increase.
[0091] Alternatively, the pattern on the first pattern area 101 can be reduced by a certain size to obtain the second pattern area 200. More preferably, the first pattern area 101 can be reduced by the same size along the first direction and the second direction, thereby simulating the effect of the etching process on the first pattern area 101 or the solid structure corresponding to the first pattern area 101.
[0092] refer to Figures 7 to 11 In step S03, the first pattern area 101 and the second non-pattern area 104 are simulated to obtain a first simulated pattern 110 and a second simulated pattern 210.
[0093] The simulation of the graphic outline, shape, or curve includes: using an optical model, an etching model, or a combination of both to simulate and obtain a first simulated pattern 110 and a second simulated pattern 210. The simulation parameters of the optical model include photoresist, exposure conditions, and dimensions. The simulation parameters of the etching model include gas, masking layer material, dimensions, and time.
[0094] Understandably, the first patterned area 101 and the second unpatterned area 104 are simulated respectively by selecting an optical model or an etching model or a combination of optical and etching models according to the process flow corresponding to the first mask 100 and the formation of the second unpatterned area 104.
[0095] Next, in step S04, the first simulated pattern 110 and the second simulated pattern 210 are combined to obtain the first composite pattern 300.
[0096] In step S05, simulating the graphic contour, shape, or curve includes: simulating a first composite simulated pattern using an optical model, an etching model, or a combination of both. The simulation parameters of the optical model include photoresist, exposure conditions, and dimensions. The simulation parameters of the etching model include gas, masking layer material, dimensions, and time.
[0097] Next, the checks to ensure that preset values are met include performing DRC (design rule check) or LRC (lithography rule check) checks on the first composite simulation pattern obtained from the simulation. DRC checks the geometric dimensions of each mask layer in the layout (such as linewidth, spacing, and capping alignment) to ensure the design meets physical manufacturing limits and avoids short circuits, open circuits, or device failures caused by process deviations. For example, it verifies whether the minimum spacing of metal layers meets the standard and whether the overlap between polysilicon and the active area meets the requirements. LRC simulates and verifies the mask design layout by establishing a lithography imaging model. By detecting geometric anomalies such as critical dimension deformation, line end offset, and via coverage deviation, it predicts manufacturing defects such as open circuits and bridging that may occur after the lithography process is implemented. Even better, using a combined LRC and (DRC) approach, employing fuzzy classification of bad pixels and pattern decomposition techniques improves detection efficiency and reduces the repetitive correction steps of optical proximity correction (OPC).
[0098] If the rules set in DRC detection or LRC detection are not met, repeat steps S02 to S06, that is, correct the first pattern area 101 or the second pattern area 200, obtain the corresponding second non-pattern area 104, and continue to simulate to obtain the first simulated pattern 110, the second simulated pattern 210 and the first composite simulated pattern until the first composite simulated pattern meets the rules set in DRC detection or LRC detection.
[0099] It should be noted that the process of this embodiment is applicable to the simulation and correction process when the target solid structure is still not obtained after performing the photolithography and / or etching processes corresponding to the first mask 100 and the second non-patterned area 104. For example, after performing the photolithography and / or etching processes corresponding to the second non-patterned area 104, the formed solid structure is not etched to the target layer, or only a hard mask pattern is etched. Further etching is still required using the hard mask pattern as a mask. Therefore, step S05 is continued to simulate the synthesized first composite pattern 300 using an optical model, an etching model, or a combination of an optical model and an etching model to obtain a first composite simulated pattern, and the first composite simulated pattern is checked.
[0100]
Example 3
[0101] Based on the same technological concept, such as Figure 3 As shown, the present invention also provides another optical proximity correction method, comprising:
[0102] S01, a first mask 100 is provided, including a first patterned area 101 and a first unpatterned area 102, wherein the first patterned area 101 contains line patterns that are separate from each other.
[0103] S02, adjust the size of the first pattern area 101 to obtain the second pattern area 200 and the second non-pattern area 104.
[0104] S03, transform the second non-pattern area 104 into the third pattern area 201.
[0105] S04. The first pattern area 101 and the third pattern area 201 are merged to obtain the second composite pattern.
[0106] S05 simulates the graphic outline, graphic shape, or graphic curve of the second composite pattern to obtain the second composite simulation pattern.
[0107] S06, detect whether the second composite simulation pattern meets the preset value. If it does, output the first mask 100. If it does not, correct the first pattern area 101 or the second pattern area 200.
[0108] exist Figures 4 to 11In step S01, a first mask 100 is provided, including a first patterned area 101 and a first non-patterned area 102.
[0109] In step S02, the size of the first patterned area 101 is adjusted to obtain the second patterned area 200 and the second non-patterned area 104. It is understood that in a multi-patterning process, deposition and / or etching processes are often required on the solid structure fabricated by the photomask to form an intermediate solid structure. This intermediate solid structure serves as the basis for further processes, such as a hard mask pattern. Thus, feedback correction can only be achieved by transferring the pattern on the photomask to the solid structure. In this step, the pattern on the photomask is transferred to the first mask 100 for simulation correction. By adjusting the size of the first patterned area 101 on the first mask 100, the process performed on the solid structure is simulated to obtain the corresponding second non-patterned area 104. The virtual second non-patterned area 104 corresponding to the intermediate solid structure is used to correct the first mask 100.
[0110] As an optional embodiment, such as Figure 5 As shown, adjusting the size of the first patterned area 101 includes: increasing the size of the first patterned area 101 by the same amount along a first direction and a second direction to obtain a second patterned area 200, wherein the first direction and the second direction are perpendicular to each other. This is used to simulate the effect of the deposition medium on the first patterned area 101, or the solid structure corresponding to the first patterned area 101. Alternatively, the pattern on the first patterned area 101 is reduced by a certain size to obtain the second patterned area 200. More preferably, the first patterned area 101 is reduced by the same amount along the first direction and the second direction, thereby simulating the effect of the etching process on the first patterned area 101, or the solid structure corresponding to the first patterned area 101. In step S03, the second non-patterned area 104 is converted into a third patterned area 201 for photolithography or etching, which can be referred to as... Figure 6 As shown. Next, step S04 is performed, aligning and merging the third pattern area 201 and the first pattern area 101 to obtain a second composite pattern. If the third pattern area 201 is completely within the first non-pattern area 102, merging the third pattern area 201 and the first pattern area 101 yields a second composite pattern for fabricating structures with smaller linewidths. For example, this alignment and merging can be achieved by directly aligning the third pattern area 201 and the first pattern area 101, or by removing the overlapping portions of the third pattern area 201 and the first pattern area 101, as in the simulation and correction of two masks used in double patterning.
[0111] Based on this, step S05 is performed to simulate the graphic outline, graphic shape, or graphic curve of the second composite pattern to obtain the second composite simulated pattern. Similarly, the second composite pattern is simulated by selecting an optical model, an etching model, or a combination of optical and etching models according to the actual process flow.
[0112] In step S06, it is detected whether the second composite simulation pattern meets the preset value. If it does, the first mask 100 is output; otherwise, the first pattern area 101 or the second pattern area 200 is corrected. In one embodiment, detecting whether the preset value is met includes performing DRC (design rule check) or LRC (lithography rule check) on the simulated second composite simulation pattern. DRC checks the geometric dimensions (such as line width, spacing, cover layer alignment, etc.) of each mask layer in the layout to ensure that the design meets the physical manufacturing limits and avoids short circuits, open circuits, or device failures caused by process deviations. LRC simulates and verifies the mask design layout by establishing a lithography imaging model. By detecting geometric anomalies such as key dimension deformation, line end offset, and via coverage deviation, manufacturing defects such as open circuits and bridging that may occur after the lithography process is implemented can be predicted. More preferably, an LRC and (DRC) linkage method is adopted, using bad pixel fuzzy classification and pattern decomposition technology to improve detection efficiency and reduce the repeated correction steps of optical proximity correction (OPC).
[0113] If the rules set in DRC detection or LRC detection are not met, repeat steps S02 to S06, that is, correct the first pattern area 101 or the second pattern area 200, obtain the corresponding second non-pattern area 104, and continue to simulate to obtain the second composite simulation pattern until the second composite simulation pattern meets the rules set in DRC detection or LRC detection.
[0114] In summary, the optical proximity correction method implemented using a computer program provided by this invention provides a first mask, including a first patterned area and a first non-patterned area, wherein the first patterned area contains separate circuit patterns; adjusting the size of the first patterned area yields a second patterned area and a second non-patterned area; simulating the graphic contour, graphic shape, or graphic curve of the first patterned area and the second non-patterned area yields a first simulated pattern and a second simulated pattern; merging the first simulated pattern and the second simulated pattern yields a first composite pattern; detecting whether the first composite pattern meets a preset value, if it does, outputting the first mask, otherwise correcting the first patterned area or the second patterned area. By using a computer system to adjust the mask and simulating the actual process flow using optical and / or etching models, and checking the simulation results, the defects existing in the initial mask can be intuitively reflected, which helps to provide feedback for correcting the mask pattern. All of the above processes can be executed entirely or partially using a computer system, improving correction efficiency and accuracy.
[0115] It should be noted that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention shall still fall within the scope of protection of the present invention.
[0116] The above description is only a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the present invention.
Claims
1. An optical proximity correction method implemented using a computer program, characterized in that, include: A first mask is provided, including a first patterned area and a first unpatterned area, wherein the first patterned area contains line patterns that are separated from each other; Adjusting the size of the first patterned area yields a second patterned area and a second non-patterned area; The first patterned area and the second non-patterned area are simulated to obtain a first simulated pattern and a second simulated pattern. The first simulated pattern and the second simulated pattern are combined to obtain the first composite pattern; Detect whether the first composite pattern meets the preset value. If it does, output the first mask. If it does not, correct the first pattern area or the second pattern area.
2. The optical proximity correction method implemented using a computer program according to claim 1, characterized in that, Adjusting the size of the first pattern area includes: increasing the size of the first pattern area by the same amount along a first direction and a second direction to obtain a second pattern area, wherein the first direction and the second direction are perpendicular to each other.
3. The optical proximity correction method implemented using a computer program according to claim 1, characterized in that, The simulation of graphic contours, graphic shapes, or graphic curves for the first patterned area and the second non-patterned area includes: using an optical model, an etching model, or a combination of optical and etching models to simulate and obtain the first and second simulated patterns.
4. The optical proximity correction method implemented using a computer program according to claim 3, characterized in that, The simulation parameters of the optical model include photoresistivity, exposure conditions, and dimensions.
5. The optical proximity correction method implemented using a computer program according to claim 3, characterized in that, The simulation parameters of the etching model include gas, shielding layer material, size, and time.
6. The optical proximity correction method implemented using a computer program according to claim 1, characterized in that, Detecting whether the first composite pattern meets the preset value includes: performing DRC detection or LRC detection on the simulated first composite pattern.
7. The optical proximity correction method implemented using a computer program according to claim 1, characterized in that, If the rules set in DRC detection or LRC detection are not met, the first pattern area or the second pattern area is corrected, the corresponding second non-pattern area is obtained, and the simulation continues to obtain the first simulated pattern, the second simulated pattern, and the first composite pattern until the first composite pattern meets the rules set in DRC detection or LRC detection.
8. An optical proximity correction method implemented using a computer program, characterized in that, include: A first mask is provided, including a first patterned area and a first unpatterned area, wherein the first patterned area contains line patterns that are separated from each other; Adjusting the size of the first patterned area yields a second patterned area and a second non-patterned area; The first patterned area and the second non-patterned area are simulated to obtain a first simulated pattern and a second simulated pattern. The first simulated pattern and the second simulated pattern are combined to obtain the first composite pattern; The first composite simulated pattern is obtained by simulating the pattern outline, pattern shape, or pattern curve of the first composite pattern. Detect whether the first composite simulation pattern meets the preset value. If it does, output the first mask. If it does not, correct the first pattern area or the second pattern area.
9. The optical proximity correction method implemented using a computer program according to claim 8, characterized in that, Adjusting the size of the first pattern area includes: increasing the size of the first pattern area by the same amount along a first direction and a second direction to obtain a second pattern area, wherein the first direction and the second direction are perpendicular to each other.
10. The optical proximity correction method implemented using a computer program according to claim 8, characterized in that, The simulation of the graphic outline, graphic shape, or graphic curve of the first patterned area, the second non-patterned area, and the first composite pattern includes: simulating the first simulated pattern, the second simulated pattern, and the first composite simulated pattern using an optical model, an etching model, or a combination of an optical model and an etching model.
11. The optical proximity correction method implemented using a computer program according to claim 8, characterized in that, Detecting whether the first composite simulation pattern meets the preset value includes: performing DRC detection or LRC detection on the simulated first composite simulation pattern.
12. The optical proximity correction method implemented using a computer program according to claim 8, characterized in that, If the rules set in DRC detection or LRC detection are not met, the first pattern area or the second pattern area is corrected, the corresponding second non-pattern area is obtained, and the simulation continues to obtain the first simulated pattern, the second simulated pattern, and the first composite simulated pattern until the first composite simulated pattern meets the rules set in DRC detection or LRC detection.
13. An optical proximity correction method implemented using a computer program, characterized in that, include: A first mask is provided, including a first patterned area and a first unpatterned area, wherein the first patterned area contains line patterns that are separated from each other; Adjusting the size of the first patterned area yields a second patterned area and a second non-patterned area; Transform the second non-patterned area into the third patterned area; The first pattern area and the third pattern area are merged to obtain a second composite pattern; The second composite pattern is obtained by simulating the graphic outline, graphic shape, or graphic curve of the second composite pattern. Detect whether the second composite simulation pattern meets the preset value. If it does, output the first mask. If it does not, correct the first pattern area or the second pattern area.
14. The optical proximity correction method implemented using a computer program according to claim 13, characterized in that, Adjusting the size of the first pattern area includes: increasing the size of the first pattern area by the same amount along a first direction and a second direction to obtain a second pattern area, wherein the first direction and the second direction are perpendicular to each other.
15. The optical proximity correction method implemented using a computer program according to claim 13, characterized in that, The simulation of the graphic outline, graphic shape, or graphic curve of the second composite pattern includes: simulating the second composite simulated pattern using an optical model, an etching model, or a combination of an optical model and an etching model.
16. The optical proximity correction method implemented using a computer program according to claim 13, characterized in that, The detection of whether the preset value is met includes: performing DRC detection or LRC detection on the simulated second composite simulation pattern.
17. The optical proximity correction method implemented using a computer program according to claim 13, characterized in that, If the rules set in DRC detection or LRC detection are not met, the first pattern area or the second pattern area is corrected, the corresponding second non-pattern area is obtained, and the simulation continues to obtain the second composite simulation pattern until the second composite simulation pattern meets the rules set in DRC detection or LRC detection.