An optical proximity correction method

Abstract

The present invention provides an optical proximity correction method, which is applied to the field of semiconductor technology. In the present invention, for some special areas in the target layout, such as the situation that only one auxiliary pattern can be added between adjacent main patterns, a new auxiliary pattern adding method and an auxiliary pattern after adjusting the shape are proposed. Specifically, an initial auxiliary pattern with a width equal to the width of the main pattern can be added between adjacent main patterns of the target main pattern group, which changes the pattern density of the main pattern in the target layout, so that the sparse pattern also has the characteristics of a dense pattern. Then, the added initial auxiliary pattern is adjusted to change the initial auxiliary pattern into a target auxiliary pattern with multiple gaps inside, so as to reduce the actual width of the target auxiliary pattern by using the gaps, reduce the light intensity value of the diffraction light at the target auxiliary pattern during exposure and development, improve the normalized logarithmic slope of the main pattern, reduce the edge placement error EPE, and increase the process window.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an optical proximity correction method. Background Art

[0002] With the development of the semiconductor industry, people have increasingly stringent requirements on chip performance and energy consumption. In order to obtain chips with smaller area, higher performance and lower energy consumption, it is necessary to further reduce the size of each pattern on the chip and the spacing between each pattern. The reduction in spacing will cause the design distance between some patterns on the layout to be less than the length of the light wave. Therefore, it is necessary to correct the layout before it is engraved on the mask to prevent the optical proximity effect (OPE) from occurring during the photolithography process, and to avoid the pattern engraved on the chip from being inconsistent with the design and causing graphic distortion. The technology for correcting the layout to avoid the optical proximity effect is the optical proximity correction (OPC) technology. Sub-resolution assist feature (SRAF) is a widely used optical proximity correction method. By correcting the layout through sub-resolution assist feature technology, the graphic resolution of the photolithography process can be effectively improved, the process window can be increased, and the product yield can be improved. Summary of the invention

[0003] The object of the present invention is to provide an optical proximity correction method, so as to improve the normalized logarithmic slope NILS of the main pattern, reduce the edge placement error EPE, increase the process window, and ultimately improve the product yield by adjusting the shape and adding method of the auxiliary pattern.

[0004] In a first aspect, in order to solve the above technical problem, the present invention provides an optical proximity correction method, comprising: providing a target layout, including a plurality of main graphics.

[0005] Based on the spacing lengths between adjacent main graphics, a plurality of main graphics whose spacing lengths meet a preset range are screened out to form a target main graphic group.

[0006] An initial auxiliary graphic is respectively added between adjacent main graphics in the target main graphic group, and the width of the initial auxiliary graphic is the same as that of the main graphic.

[0007] A portion of the initial auxiliary pattern is removed to obtain a target auxiliary pattern.

[0008] Optical proximity correction is performed on the target layout after the target auxiliary pattern is added.

[0009] In some optional examples, the preset range may be between a range of spacing lengths corresponding to a range in which one initial auxiliary pattern may be added between adjacent main patterns but two initial auxiliary patterns may not be added.

[0010] In some optional examples, the target auxiliary pattern may have at least one gap, and the gap divides the initial auxiliary pattern into a plurality of sub-auxiliary patterns that are arranged at intervals from each other in a horizontal direction.

[0011] In some optional examples, widths of some of the sub-auxiliary patterns of the target auxiliary pattern may be the same.

[0012] In some of the optional examples, the step of removing part of the initial auxiliary graphic may include: obtaining an adjustment graphic, the adjustment graphic including at least one sub-adjustment graphic, and a width of the sub-adjustment graphic is smaller than a width of the initial auxiliary graphic.

[0013] The adjustment pattern is overlapped with the initial auxiliary pattern, and the initial auxiliary pattern that intersects with the adjustment pattern is removed.

[0014] In some optional examples, the gap is the same as the width of the sub-adjustment pattern.

[0015] In some of the optional examples, the step of adding an initial auxiliary graphic between adjacent main graphics in the target main graphic group may include: adding an initial auxiliary graphic having a width identical to the minimum width of the main graphics in the adjacent main graphics at a middle position between the adjacent main graphics, so that the distance between the initial auxiliary graphic and any main graphic in the adjacent main graphics is equal.

[0016] In some of the optional examples, after the optical proximity correction is performed on the target layout, the optical proximity correction method provided by the present invention may also include: performing simulated exposure on the target auxiliary pattern, and determining whether the target auxiliary pattern is exposed and developed, and if so, changing the width of the sub-adjustment pattern in the adjustment pattern, and returning to execute the step of removing part of the initial auxiliary pattern until all the target auxiliary patterns added to the target layout are not exposed and developed during the simulated exposure.

[0017] In some of the optional examples, the step of changing the width of the sub-adjustment pattern in the adjustment pattern may include: increasing or decreasing the width of the sub-adjustment pattern in the horizontal direction.

[0018] In some of the optional examples, the main graphic may include a sparse graphic, and the initial auxiliary graphic may include a sub-resolution auxiliary graphic.

[0019] In a second aspect, the present invention further provides an electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0020] Memory, used to store computer programs;

[0021] The processor is used to implement the above-mentioned method steps of optical proximity correction when executing the program stored in the memory.

[0022] In a third aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method steps of optical proximity correction as described above are implemented.

[0023] Compared with the prior art, the technical solution provided by the present invention has at least one of the following beneficial effects:

[0024] The present invention provides an optical proximity correction method, comprising: providing a target layout, comprising a plurality of main graphics, screening out a plurality of main graphics whose spacing lengths meet a preset range based on the spacing lengths between adjacent main graphics to form a target main graphic group, adding an initial auxiliary graphic between adjacent main graphics in the target main graphic group, respectively, wherein the width of the initial auxiliary graphic is the same as the width of the main graphic, removing part of the initial auxiliary graphic to obtain a target auxiliary graphic, and performing optical proximity correction on the target layout after the target auxiliary graphic is added.

[0025] In the present invention, for some special areas in the target layout, such as the situation that only one auxiliary graphic can be added between adjacent main graphics, a new auxiliary graphic adding method and an auxiliary graphic after adjusting the shape are proposed. Specifically, an initial auxiliary graphic with a width equal to the width of the main graphic can be first added between adjacent main graphics of the target main graphic group, and an unexpected effect is obtained: the graphic density of the main graphics in the target layout is changed, that is, the sparse graphics also have the characteristics of dense graphics, and then the added initial auxiliary graphics are adjusted to change the initial auxiliary graphics into a target auxiliary graphic with multiple gaps inside, and an unexpected effect is obtained: the actual width of the target auxiliary graphic is reduced by using the gaps, that is, the light intensity value of the diffraction light at the target auxiliary graphic during exposure and development is reduced, that is, while ensuring that the target auxiliary graphic is not developed, the normalized logarithmic slope of the main graphic is improved, the edge placement error EPE is reduced, the process window is increased, and ultimately the product yield is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present application but do not constitute a limitation to the present application. In the accompanying drawings:

[0027] Figure 1 The present invention is a schematic diagram of a layout after adding auxiliary graphics using a traditional auxiliary graphics adding method in the prior art.

[0028] Figure 2 To use Figure 1 The diagram shown is a comparison diagram of a pattern 1 to be corrected and a simulated pattern 1' thereof after adding auxiliary patterns using a conventional auxiliary pattern adding method.

[0029] Figure 3 To use Figure 1 The NILS curve of the normalized logarithmic slope of the corresponding main graph after the auxiliary graph is added using the traditional auxiliary graph adding method.

[0030] Figure 4 To use Figure 1 The light intensity curve diagram of the corresponding layout after adding auxiliary patterns using the traditional auxiliary pattern adding method is shown.

[0031] Figure 5 FIG. 4 is a flow chart of an optical proximity correction method in one embodiment of the present invention.

[0032] Figure 6 This is an example diagram of a layout of a target main graphic group in one embodiment of the present invention.

[0033] Figure 7 This is an example diagram of a layout of a target main graphic group after adding an initial auxiliary graphic 102 in one embodiment of the present invention.

[0034] Figure 8 This is an example diagram of a layout of a target main graphic group after the initial auxiliary graphic 102 and the adjustment image 201 are overlapped in one embodiment of the present invention.

[0035] Fig. 9 1 is an example diagram of a layout of a target auxiliary graphic 103 in an embodiment of the present invention.

[0036] Fig.10 To use Figure 5 The optical proximity correction method provided by the present invention is shown Figure 6 Add the target layout shown Fig. 9 The schematic diagram of comparison of the corresponding main graphic 101 and its simulation graphic 101 ′ behind the target auxiliary graphic 103 is shown.

[0037] Fig.11 To use Figure 5 The optical proximity correction method provided by the present invention is shown Figure 6 Add the target layout shown Fig. 9 The normalized logarithmic slope NILS curve diagram of the corresponding main pattern after the target auxiliary pattern 103 is shown.

[0038] Fig.12 To use Figure 5 The optical proximity correction method provided by the present invention is shown Figure 6 Add the target layout shown Fig. 9 The light intensity curve diagram of the corresponding target layout behind the target auxiliary pattern 103 is shown.

[0039] Wherein, the accompanying drawings are marked as follows:

[0040] 10-target layout, 101-main graphic, 102-initial auxiliary graphic, W1-width of initial auxiliary graphic, 103-target auxiliary graphic, 1031-sub-auxiliary graphic, SP-gap, 201-adjustment image, 2011-sub-adjustment image, X1-width of sub-adjustment image, 103'simulation graphic of target auxiliary graphic, 1-graphic to be corrected, 2-auxiliary graphic, 1'-simulation graphic of graphic to be corrected.

[0041] In the drawings, the same reference numerals are used for the same components, and the drawings are not drawn to scale. DETAILED DESCRIPTION

[0042] In order to make the technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. Although the exemplary implementation methods of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the implementation methods described here. On the contrary, these implementation methods are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0043] Please refer to Figure 1 As shown, Figure 1 A schematic diagram of a layout after adding auxiliary graphics using the conventional auxiliary graphics adding method in the prior art. Figure 1 As shown in the figure, the traditional methods of adding auxiliary graphics include rule-based adding methods, model-based adding methods, reverse lithography calculation-based adding methods, etc. Specifically, after determining the width of the auxiliary graphics and the distance between the auxiliary graphics and the main graphics after adding them near (around) the main graphics, for example, based on the layout data of the main graphics, multiple circles of auxiliary graphics are added outside the main graphics. Among them, Figure 1 The reference numeral 1 represents the figure to be corrected, and the reference numeral 2 represents the auxiliary figure.

[0044] Please refer to Figures 2 to 4 As shown, Figure 2To use Figure 1 The conventional auxiliary pattern adding method shown is a schematic diagram showing a comparison between a pattern 1 to be corrected and a simulated pattern 1' after adding auxiliary patterns. Figure 3 To use Figure 1 The NILS curve of the normalized logarithmic slope of the corresponding main graph after adding the auxiliary graph using the traditional auxiliary graph adding method shown in the figure. Figure 4 To use Figure 1 The light intensity curve diagram of the corresponding layout after adding auxiliary patterns using the traditional auxiliary pattern adding method is shown.

[0045] like Figures 2 to 4 As shown in the figure, although the conventional auxiliary pattern adding method has designed the width of the auxiliary pattern and the distance from the main pattern to the limit value, the normalized logarithmic slope NILS of some main patterns is still small, such as only Figure 3 The edge placement error EPE of the main figure is relatively large, as shown in Figure 2 The error between the pattern 1 to be corrected and its simulation pattern 1' in the vertical direction is about 3.5nm and 1nm respectively. The light intensity of the diffracted light of the auxiliary pattern is relatively large during exposure. Figure 4 As shown in the figure, the process window is low, which ultimately affects the product yield. Figure 4 In the figure, the green straight line is the exposure intensity value threshold of the graphic 1 to be corrected, that is, when the light intensity value of the blue light intensity value curve corresponding to the layout is greater than the exposure intensity value threshold corresponding to the green straight line, the graphic in the layout can be exposed and developed.

[0046] In order to solve the above problems, the present invention provides an optical proximity correction method, which improves the normalized logarithmic slope NILS of the main pattern, reduces the edge placement error EPE, increases the process window, and ultimately improves the product yield by adjusting the shape and adding method of the auxiliary pattern.

[0047] Please refer to Figure 5 As shown, Figure 5 FIG. 1 is a flow chart of an optical proximity correction method in one embodiment of the present invention. Figure 5 As shown, the optical proximity correction method may include at least the following steps:

[0048] Step S501, providing a target layout, wherein the target layout includes a plurality of main graphics.

[0049] Step S502 , based on the spacing lengths between adjacent main graphics, a plurality of main graphics whose spacing lengths meet a preset range are screened out to form a target main graphic group.

[0050] Step S503, adding an initial auxiliary graphic between adjacent main graphics in the target main graphic group, wherein the width of the initial auxiliary graphic is the same as the width of the main graphic.

[0051] Step S504: removing part of the initial auxiliary pattern to obtain a target auxiliary pattern.

[0052] Step S505, performing optical proximity calibration on the target layout after adding the target auxiliary pattern.

[0053] Please refer to Figure 6 As shown, Figure 6 Execute steps S501 and S502: Provide a target layout Fig.10 , the target version Fig.10 It can be a test layout, and the target layout Fig.10 The main graphics 101 may include multiple main graphics 101, and the intervals between adjacent main graphics 101 (the area corresponding to the spacing between the two) can be used as the additional area of ​​the auxiliary graphics corresponding to the main graphics. The main graphics 101 can be divided into densely distributed graphics, sparse graphics and semi-sparse graphics according to the spacing of the graphic lines.

[0054] In one embodiment, the target version Fig.10 The main pattern 101 in the embodiment is a sparse pattern, which is in the shape of a square and is arranged in a horizontal direction (row extension direction or X direction) and a vertical direction (column extension direction or Y direction) at intervals, but is not limited thereto. Fig.10 The distance between two adjacent main graphics 101 (hereinafter referred to as adjacent main graphics 101) (i.e., the length of the interval) is set as the target version. Fig.10 The main graphics 101 in the embodiment are classified into categories, for example, a plurality of main graphics whose spacing lengths between adjacent main graphics 101 are within a range in which multiple auxiliary graphics can be added (or added) according to a conventional auxiliary graphic adding method are referred to as a first main graphic group, and a plurality of main graphics 101 whose spacing lengths between adjacent main graphics 101 are within a range in which only one auxiliary graphic can be added according to a conventional auxiliary graphic adding method are referred to as a second main graphic group, but the present invention is not limited thereto.

[0055] Specifically, the spacing length between adjacent main graphics of the second main graphic group may specifically include: a range when only one auxiliary graphic can be added in the interval between adjacent main graphics 101, and a range corresponding to an auxiliary graphic can be added in the interval but two auxiliary graphics cannot be added, that is, the spacing length between adjacent main graphics 101 is greater than the spacing length required when one auxiliary graphic can be added and less than the spacing length required when two auxiliary graphics are added. It should be understood that for the first main graphic group as above, the method of adding auxiliary graphics is the same as the method of adding in the prior art, and the similarities are not repeated here. The second main graphic group is the main application scenario of the optical proximity correction method proposed in an embodiment of the present invention. Therefore, the second main graphic is renamed as the target main graphic group below, and in order to simplify the drawing, Figure 6 The schematic diagram of the layout shown in FIG. 1 only depicts a plurality of main graphics in the target main graphics group. In other embodiments, the Figure 6 The main graphics in the first main graphics group may also be included, but is not limited to this.

[0056] Please refer to Figure 7 As shown, Figure 7 1 is an example of a layout of a target main graphic group after adding an initial auxiliary graphic 102 in an embodiment of the present invention. Execute step S503: for a main graphic 101 in the target main graphic group (referred to as the first main graphic in this embodiment), an initial auxiliary graphic 102, such as a sub-resolution auxiliary graphic, may be added at the middle position of the interval between the main graphic 101 and another main graphic 101 adjacent thereto (referred to as the second main graphic in this embodiment), so that the distance between the initial auxiliary graphic 102 and any main graphic in the adjacent main graphics (i.e., the first main graphic or the second main graphic) is equal (e.g., Figure 7 In addition, the width of the initial auxiliary pattern 102 (eg Figure 7 The width of the initial auxiliary graphic 102 is the same as the width of the first main graphic or the second main graphic; specifically, the width of the initial auxiliary graphic 102 may be between the minimum value Wmin and the maximum value Wmax in the set consisting of all width values ​​of the first main graphic and the second main graphic. In one embodiment, since the target main graphic group is selected based on the spacing length between adjacent main graphics, when setting the width of the initial auxiliary graphic 102, the width of the initial auxiliary graphic 102 may be set to the minimum value Wmin of all width values ​​of two main graphics in the adjacent main graphics, but is not limited thereto.

[0057] It should be noted that when only one initial auxiliary pattern 102 can be added to the interval between two adjacent main patterns in the target main pattern group, in this embodiment, the width of the initial auxiliary pattern 102 and the distance S1 between the first main pattern and the second main pattern have reached the limit value, that is, W1=Wmin and S1=Smin. Under this setting, if the main pattern 101 is continuously subjected to optical proximity correction (hereinafter referred to as OPC correction), it is bound to cause the width of the main pattern 101 to be slightly different from the width of the auxiliary pattern, resulting in an increase in the light intensity value of the diffracted light of the auxiliary pattern during exposure and development, and then the problem of auxiliary pattern development occurs. For this reason, the optical proximity correction method proposed in the present invention does not adopt the traditional auxiliary pattern adding method to directly change the width of the auxiliary pattern or replace it with an auxiliary pattern of other shapes, but changes the shape of the initial auxiliary pattern 102 while ensuring that the distance S1 between the outermost line of the initial auxiliary pattern 102 and the main pattern 101 is still at the limit value, so as to reduce the light intensity value of the diffracted light of the auxiliary pattern during exposure and development, and ensure that the auxiliary pattern is not developed.

[0058] Please refer to Figure 8 and Fig. 9 As shown, Figure 8 is a layout example diagram of a target main graphic group after the initial auxiliary graphic 102 and the adjustment image 201 are overlapped in one embodiment of the present invention. Fig. 9 103 is a layout example diagram of the target auxiliary graphic 103 in one embodiment of the present invention. Execute step S504 and step S505: the initial auxiliary graphic 102 may be specially processed to modify the initial auxiliary graphic 102 into the target auxiliary graphic 103, that is, obtain Fig. 9 The structure of the target main pattern group with the target auxiliary pattern 103 is shown in FIG. In one embodiment, the target auxiliary pattern 103 has at least one space SP, which may include, for example, Fig. 9 The two spacing gaps SP shown in the figure divide the initial auxiliary graphic 102 in the horizontal direction to form a target auxiliary graphic 103 including a plurality of sub-auxiliary graphics 1031 arranged at intervals from each other in the horizontal direction. Among them, the widths of some of the sub-auxiliary graphics 1031 of the target auxiliary graphic 103 are the same, but not limited to this. Specifically, the process of performing special processing on the initial auxiliary graphic 102 in this embodiment may include removing part of the graphics of the initial auxiliary graphic 102. In one embodiment, the specific implementation method of removing part of the graphics of the initial auxiliary graphic 102 may include: step S504.1: obtaining the adjustment graphic 201; step S504.2: overlapping the adjustment graphic 201 with the initial auxiliary graphic 102, such as Figure 8As shown, the initial auxiliary graphics 102 that intersect with the adjustment graphics 201 are removed, but the present invention is not limited thereto.

[0059] Specifically, the adjustment pattern 201 may include M sub-adjustment patterns 2011, and M≥1, for example, M=1, 2, 3, 4, etc., but not limited thereto, and the width of each of the sub-adjustment patterns 2011 (eg Figure 8 X1) must be smaller than the width W1 of the initial auxiliary pattern 102. In one embodiment, the sub-adjustment pattern 2011 may be in the shape of a long strip extending in the vertical direction, and the adjustment pattern 201 includes two sub-adjustment patterns 2011 arranged at intervals from each other in the horizontal direction. Obviously, the width of the gap SP in the target auxiliary pattern 103 of the present invention is the same as the width of the sub-adjustment pattern 2011 in the adjustment pattern 201, so the target auxiliary pattern 103 can be obtained by removing the initial auxiliary pattern 102 that intersects with the adjustment pattern 201 in the above step S504.2 of this embodiment.

[0060] It should be understood that the target auxiliary pattern 103 described in this embodiment has the same width of some of the sub-auxiliary patterns 1031, specifically, it may include: the target auxiliary pattern 103 includes N sub-auxiliary patterns 1031, and N ≥ 2, such as N = 2, 3, 4, 5, 6, etc., and the widths of multiple or all of the sub-auxiliary patterns 1031 are the same, or the widths of multiple or all of the sub-auxiliary patterns 1031 are different, but not limited thereto. The number of the sub-auxiliary patterns 1031 specifically included in the target auxiliary pattern 103 needs to be dynamically adjusted according to the width of the gap SP, the actual exposure and development process parameters, and the width of the main pattern 101, but not limited thereto. Similarly, the widths of some of the M sub-adjustment patterns 2011 included in the adjustment pattern 201 in this embodiment may be the same or different, but not limited thereto, and the number of the sub-adjustment patterns 2011 needs to be dynamically adjusted according to the width of the gaps SP, the actual exposure and development process parameters, and the width of the main pattern 101, but not limited thereto. Similarly, the widths of the multiple gaps SP in the target auxiliary pattern 103 may be the same or different.

[0061] Continue to refer to Figure 5 As shown, the optical proximity correction method provided in the embodiment of the present invention may further include, after performing step S505 to perform optical proximity correction on the target layout:

[0062] Step S506 , performing simulated exposure on the target auxiliary pattern 103 , and determining whether the target auxiliary pattern 103 has been exposed and developed.

[0063] Step S507: if the target auxiliary pattern 103 is exposed and developed, the width X1 of the sub-adjustment pattern 2011 in the adjustment pattern 201 is changed, and the process returns to step S504 to remove part of the initial auxiliary pattern 102 until the target auxiliary pattern 103 is exposed and developed. Fig.10 All target auxiliary patterns 103 added in the simulation are not exposed and developed during the exposure simulation.

[0064] Step S508: If the target auxiliary pattern 103 is not exposed and developed, the optical proximity calibration is terminated.

[0065] In one embodiment, in the target version Fig.10 After the auxiliary graphics shown in the target auxiliary graphics 103 are added between the main graphics 101 in the target main graphics group, the target plate can be further corrected using a correction model, such as an optical proximity correction model. Fig.10 The target auxiliary pattern 103 in the target board is simulated exposed and developed, or the target board is simulated exposed and developed. Fig.10 Overall (i.e. target version Fig.10 The main graphic 101 and the target auxiliary graphic 103 in the image are subjected to simulated exposure and development, but not limited thereto, to determine whether the width of the target auxiliary graphic 103 is appropriate, that is, if the target auxiliary graphic 103 is exposed and developed, it is necessary to adjust the target auxiliary graphic 103 that is exposed and developed, for example, to increase or decrease the width X1 of the sub-adjustment graphic 2011 in the horizontal direction. Then, the adjustment image 201 with the width X1 of the sub-adjustment graphic 2011 modified is overlapped with the initial auxiliary graphic 102 again, so as to achieve the purpose of modifying the width of the gap SP in the target auxiliary graphic 103 by modifying the width X1 of the sub-adjustment image 2011 in the adjustment graphic 201, and further obtain the adjusted target auxiliary graphic, and then the target version is subjected to the target version again. Fig.10 The optical proximity correction is repeated until the target plate Fig.10 All target auxiliary patterns 103 added in the simulation are not exposed and developed during the simulation exposure, but the present invention is not limited thereto.

[0066] It should be understood that in another embodiment, in the target version Fig.10 After the auxiliary graphics shown in the target auxiliary graphics 103 are added between the main graphics 101 in the target main graphics group, the target version can be drawn by using a correction model, such as an optical proximity correction model. Fig.10 The light intensity curve is as follows: Fig.12 As shown, and based on the target version Fig.10 The light intensity value corresponding to the position of the target auxiliary pattern 103 determines whether there is an exposure risk. For example, if Fig.12If the peak of the blue light intensity curve corresponding to the target auxiliary graphic 103 in the image is lower than the graphic exposure light intensity value threshold corresponding to the green straight line, it means that the target auxiliary graphic 103 will not be exposed and developed, otherwise it will be exposed; and if there is a risk of exposure to the target auxiliary graphic 103, the target auxiliary graphic 103 that is exposed and developed needs to be adjusted, for example, the width X1 of the sub-adjustment graphic 2011 can be increased or reduced in the horizontal direction. Then, the adjustment image 201 with the width X1 of the sub-adjustment graphic 2011 modified is overlapped with the initial auxiliary graphic 102 again, so as to achieve the purpose of modifying the width of the gap SP in the target auxiliary graphic 103 by modifying the width X1 of the sub-adjustment image 2011 in the adjustment graphic 201, and further obtain the adjusted target auxiliary graphic, and then the target version is re-adjusted. Fig.10 The optical proximity correction is repeated until the target plate Fig.10 All target auxiliary patterns 103 added in the simulation are not exposed and developed during the simulation exposure, but the present invention is not limited thereto.

[0067] Please refer to Figures 10 to 12 , and combined with Figures 2 to 4 ,in Fig.10 To use Figure 5 The optical proximity correction method provided by the present invention is shown Figure 6 Add the target layout shown Fig. 9 The schematic diagram of the comparison of the main graphic 101 and the simulation graphic 101' corresponding to the target auxiliary graphic 103 shown in FIG. Fig.11 To use Figure 5 The optical proximity correction method provided by the present invention is shown Figure 6 Add the target layout shown Fig. 9 The normalized logarithmic slope NILS curve diagram of the corresponding main figure after the target auxiliary figure 103 is shown, Fig.12 To use Figure 5 The optical proximity correction method provided by the present invention is shown Figure 6 Add the target layout shown Fig. 9 The light intensity curve diagram of the corresponding target layout behind the target auxiliary pattern 103 is shown.

[0068] like Figures 10 to 12 As shown in the figure, the optical proximity correction method provided in the embodiment of the present invention is used to add Fig. 9 After the target auxiliary pattern 103 is shown, the edge placement error EPE between the main pattern 101 and its simulation pattern 103' can theoretically reach 0, and the normalized logarithmic slope NILS of the main pattern 101 increases, for example, it can reach Fig.11 0.73 as shown, and the exposure intensity value of the target auxiliary pattern 103 is less than the pattern exposure intensity value threshold value ( Fig.12 Therefore, the present invention not only ensures that the target auxiliary pattern is not developed, but also achieves the purpose of improving the normalized logarithmic slope of the main pattern, reducing the edge placement error EPE, and increasing the process window.

[0069] In summary, the present invention provides an optical proximity correction method, comprising: providing a target layout, comprising a plurality of main graphics, screening out a plurality of main graphics whose spacing lengths satisfy a preset range based on the spacing lengths between adjacent main graphics to form a target main graphic group, adding an initial auxiliary graphic between adjacent main graphics in the target main graphic group, respectively, the width of the initial auxiliary graphic being the same as the width of the main graphic, removing part of the initial auxiliary graphic to obtain a target auxiliary graphic, and performing optical proximity correction on the target layout after the target auxiliary graphic is added.

[0070] In the present invention, for some special areas in the target layout, such as the situation that only one auxiliary graphic can be added between adjacent main graphics, a new auxiliary graphic adding method and an auxiliary graphic after adjusting the shape are proposed. Specifically, an initial auxiliary graphic with a width equal to the width of the main graphic can be first added between adjacent main graphics of the target main graphic group, and an unexpected effect is obtained: the graphic density of the main graphics in the target layout is changed, that is, the sparse graphics also have the characteristics of dense graphics, and then the added initial auxiliary graphics are adjusted to change the initial auxiliary graphics into a target auxiliary graphic with multiple gaps inside, and an unexpected effect is obtained: the actual width of the target auxiliary graphic is reduced by using the gaps, that is, the light intensity value of the diffraction light at the target auxiliary graphic during exposure and development is reduced, that is, while ensuring that the target auxiliary graphic is not developed, the normalized logarithmic slope of the main graphic is improved, the edge placement error EPE is reduced, the process window is increased, and ultimately the product yield is improved.

[0071] An embodiment of the present invention further provides an electronic device, including a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus.

[0072] Memory, used to store computer programs;

[0073] The processor is used to implement an optical proximity correction method provided by an embodiment of the present invention when executing a program stored in the memory.

[0074] In addition, other implementations of the optical proximity correction method implemented by the processor executing the program stored in the memory are the same as the implementations mentioned in the aforementioned method embodiment part, and will not be repeated here.

[0075] The communication bus mentioned in the above control terminal can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0076] The communication interface is used for communication between the above electronic device and other devices.

[0077] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0078] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0079] In another embodiment of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium stores instructions. When the instructions are executed on a computer, the computer executes an optical proximity correction method described in any one of the above embodiments.

[0080] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive Solid State Disk (SSD)), etc.

[0081] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0082] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, electronic device, and computer-readable storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. An optical proximity correction method, characterized in that: include: Providing a target layout, including a plurality of main graphics; Based on the spacing lengths between adjacent main graphics, a plurality of main graphics whose spacing lengths meet a preset range are screened out to form a target main graphic group; Adding an initial auxiliary graphic between adjacent main graphics in the target main graphic group, respectively, wherein the width of the initial auxiliary graphic is the same as that of the main graphic; Removing a portion of the initial auxiliary pattern to obtain a target auxiliary pattern, wherein the target auxiliary pattern has at least one gap, and the gap divides the target auxiliary pattern into a plurality of sub-auxiliary patterns that are arranged in a horizontal direction and spaced from each other; Performing optical proximity correction on the target layout after adding the target auxiliary pattern; The step of removing part of the initial auxiliary graphics includes: Acquire an adjustment pattern, wherein the adjustment pattern includes at least one sub-adjustment pattern, and a width of the sub-adjustment pattern is smaller than a width of the initial auxiliary pattern; The adjustment pattern is overlapped with the initial auxiliary pattern, and the initial auxiliary pattern that intersects with the adjustment pattern is removed.

2. The optical proximity correction method according to claim 1, wherein: The preset range is between the interval length ranges corresponding to the addition of one initial auxiliary pattern between adjacent main patterns but the addition of two initial auxiliary patterns is not allowed.

3. The optical proximity correction method according to claim 1, wherein: Some of the sub-auxiliary patterns of the target auxiliary pattern have the same width.

4. The optical proximity correction method according to claim 1, wherein: The spacing gap is the same as the width of the sub-adjustment pattern.

5. The optical proximity correction method according to claim 4, wherein: The step of adding an initial auxiliary graphic between adjacent main graphics in the target main graphic group comprises: An initial auxiliary graphic having the same width as the minimum width of the main graphics among the adjacent main graphics is added at the middle position between the adjacent main graphics, so that the distance between the initial auxiliary graphic and any main graphics among the adjacent main graphics is equal.

6. The optical proximity correction method according to claim 5, wherein: After optical proximity correction of the target layout, it also includes: Performing simulated exposure on the target auxiliary pattern, and determining whether the target auxiliary pattern has been exposed and developed; If it exists, the width of the sub-adjustment pattern in the adjustment pattern is changed, and the step of removing part of the initial auxiliary pattern is returned to be executed until all the target auxiliary patterns added to the target layout do not have exposure and development during the simulated exposure.

7. The optical proximity correction method according to claim 6, wherein: The step of changing the width of the sub-adjustment pattern in the adjustment pattern includes: increasing or decreasing the width of the sub-adjustment pattern along the horizontal direction.

8. The optical proximity correction method according to claim 1, wherein: The main pattern comprises a sparse pattern, and the initial auxiliary pattern comprises a sub-resolution auxiliary pattern.

Images