A mask correction method and system

Abstract

The present invention provides a correction method and system for a mask, the correction method comprising the following steps: inputting a plurality of initial main graphics, dividing the plurality of initial main graphics into important main graphics and secondary main graphics according to the pattern type in the initial main graphics, wherein the important main graphics and the secondary main graphics have a primary priority constant; assigning a secondary priority constant to the initial main graphics according to the size interval where the characteristic key size of the initial main graphics is located; assigning a weight coefficient and a priority coefficient to the plurality of initial main graphics in sequence, wherein the priority coefficient is the product of the primary priority constant, the secondary priority constant and the weight coefficient; sorting the priorities of the plurality of initial main graphics according to the size of the priority coefficient of the initial main graphics; and obtaining the adding rule of the auxiliary graphics, and sequentially adding the auxiliary graphics to the mask according to the priority order of the initial main graphics. The present invention provides a correction method and system for a mask, which can increase the graphic process window.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a mask correction method and system. Background Art

[0002] Sub-resolution auxiliary graphics are a widely used optical proximity correction (OPC) method. Sub-resolution auxiliary graphics cannot be imaged. After adding sub-resolution auxiliary graphics to the layout, the original line graphics can be formed on the substrate. By correcting the layout with sub-resolution auxiliary graphics, the graphic resolution of the lithography process can be effectively improved, the process window can be increased, and the product yield can be improved. However, due to cost constraints, the current auxiliary graphics addition rules still have the problem of insufficient graphic process window in complex environments. Summary of the invention

[0003] The object of the present invention is to provide a mask correction method and system, which can increase the graphic process window.

[0004] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0005] The present invention provides a method for correcting a mask, comprising the following steps:

[0006] Input a plurality of initial main graphics, and divide the plurality of initial main graphics into important main graphics and secondary main graphics according to the pattern types in the initial main graphics, wherein the important main graphics and the secondary main graphics have a first-level priority constant;

[0007] Allocating a secondary priority constant to the initial main graphic according to a size interval in which a characteristic key size of the initial main graphic is located;

[0008] sequentially assigning weight coefficients and priority coefficients to the plurality of initial main graphics, wherein the priority coefficient is the product of the first-level priority constant, the second-level priority constant and the weight coefficient;

[0009] sorting the priorities of the plurality of initial main graphics according to the priority coefficients of the initial main graphics; and

[0010] A rule for adding auxiliary patterns is obtained, and the auxiliary patterns are added to the mask in sequence according to the priority order of the initial main patterns.

[0011] In one embodiment of the present invention, the important main pattern includes a metal structure pattern and / or a through silicon via pattern.

[0012] In one embodiment of the present invention, the important main graphic has a first-level priority constant, and the secondary main graphic has a second-level priority constant, wherein the first-level priority constant is A, the second-level priority constant is B, and A<B.

[0013] In one embodiment of the present invention, the step of allocating the secondary priority constant includes:

[0014] Set the number of weight size intervals;

[0015] Obtain the critical dimension range of the pattern on the mask;

[0016] Generating a plurality of weight size intervals according to the critical size range and the number of weight size intervals;

[0017] Matching different secondary priority constants for a plurality of said weight size intervals; and

[0018] According to the characteristic key size of the initial main graphic, the initial main graphic is matched to the corresponding weight size interval, and the secondary priority constant of the weight size interval is used as the secondary priority constant of the initial main graphic.

[0019] In one embodiment of the present invention, in the step of generating a plurality of weight size intervals, as the critical size of the weight size interval decreases, the secondary priority constant of the weight size interval decreases.

[0020] In one embodiment of the present invention, in the step of generating a plurality of weight size intervals, as the critical size of the weight size interval decreases, the size span of the weight size interval increases.

[0021] In one embodiment of the present invention, in the step of allocating the weight coefficients, the weight coefficient of the initial main graphic in the Nth weight size interval is the Nth weight coefficient, and the value of the Nth weight coefficient satisfies the following formula:

[0022] a N / a1 <BQ1 / AQ N ;

[0023] Among them, a N is the Nth weight coefficient, a1 is the first weight coefficient, B is the second first-level priority constant, A is the first first-level priority constant, Q1 is the second-level priority constant of the first weight size interval, Q N is the secondary priority constant for the Nth weight size interval;

[0024] Wherein, N is a natural number greater than 1, and the plurality of weight size intervals are arranged in ascending order of critical size.

[0025] In one embodiment of the present invention, the mask correction method further comprises the following steps:

[0026] According to the optical proximity correction model, the initial main pattern with high process variation bandwidth, high mask error enhancement factor and low normalized logarithmic slope is obtained from the mask as a hot spot pattern; and

[0027] The optimal auxiliary graphic positions of the plurality of hot spot graphics are obtained, and the optimal auxiliary graphics are collected to establish a replacement database.

[0028] In one embodiment of the present invention, the mask correction method further comprises the following steps:

[0029] After adding the auxiliary graphics according to the priority order of the initial main graphics, obtaining the process window of the hot spot graphics; and

[0030] When the size of the process window is less than or equal to a preset threshold, the optimal auxiliary pattern of the hotspot pattern is queried and acquired from the replacement database, and the auxiliary pattern of the hotspot pattern is replaced with the optimal auxiliary pattern.

[0031] The present invention provides a mask correction system, comprising:

[0032] A first classification module, after inputting a plurality of initial main graphics, is used to classify the plurality of initial main graphics into feature key dimension shapes of important main graphics and secondary main graphics according to pattern types in the initial main graphics, wherein the important main graphics and the secondary main graphics have a primary priority constant;

[0033] A second classification module, used for assigning a secondary priority constant to the initial main graphic according to the size interval;

[0034] A priority coefficient calculation module, used for sequentially allocating weight coefficients and priority coefficients to the plurality of initial main graphics, wherein the priority coefficient is the product of the first-level priority constant, the second-level priority constant and the weight coefficient;

[0035] a sorting module, configured to sort the priorities of a plurality of initial main graphics according to the priority coefficients of the initial main graphics; and

[0036] The auxiliary pattern adding module is used to obtain the adding rule of the auxiliary pattern and add the auxiliary pattern to the mask in sequence according to the priority order of the initial main pattern.

[0037] As described above, the present invention provides a mask correction method and system, and its unexpected technical effect is that it can make isolated patterns and sparse patterns also have the characteristics of dense patterns, thereby improving light intensity distribution and improving imaging quality. The mask correction method and system provided by the present invention can increase the process window while complying with the auxiliary pattern addition rules, avoid insufficient process window, and thus improve the yield of illumination.

[0038] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0040] Figure 1 FIG. 4 is a flow chart of a method for correcting a mask according to an embodiment of the present invention.

[0041] Figure 2 It is a schematic diagram of adding auxiliary graphics in one embodiment of the present invention.

[0042] Figure 3 It is a schematic diagram of adding auxiliary graphics in one embodiment of the present invention.

[0043] Figure 4 FIG. 4 is a flow chart of step S600 in an embodiment of the present invention.

[0044] Figure 5 Schematic diagram of the priority distinction of initial main graphics in one embodiment of the present invention.

[0045] Figure 6 FIG. 4 is a schematic structural diagram of a mask correction system according to an embodiment of the present invention.

[0046] In the figure: 10, mask correction system; 11, first classification module; 12, second classification module; 13, priority coefficient calculation module; 14, sorting module; 15, auxiliary graphics adding module. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] In order to ensure that the edge of the designed pattern is completely etched during the production process, Optical Proximity Correction (OPC) is applied to the mask pattern before photolithography, so that the target pattern formed by the mask pattern on the wafer is highly fitted with the designed layout pattern. Taking the model-based optical proximity correction as an example, in this embodiment, an optical model and a photoresist chemical reaction model are used to simulate the mask pattern after exposure, and to simulate the target pattern formed on the wafer by etching, that is, the simulation correction pattern. By comparing the error between the simulation correction pattern and the target pattern, the edge of the mask pattern is continuously adjusted so that the error between the simulation correction pattern and the target pattern reaches a preset threshold. In the exposure pattern, the lithography process window of the dense pattern is different from the lithography process window of the sparse pattern, so the common process window of the dense pattern and the sparse pattern is small. The lighting conditions suitable for the exposure of dense patterns are not suitable for the exposure of sparse patterns. In order to reduce the process differences caused by different pattern densities in the integrated circuit layout, a method of inserting sub-resolution auxiliary patterns in the area around the sparse pattern in the mask pattern to improve the uniformity of the depth of focus and process window.

[0049] It should be noted that, according to the design content, a mask is made, and the pattern on the mask is corrected. After the correction is completed, the pattern on the mask is transferred to the semiconductor material through a photolithography process, thereby forming a mask pattern. The present invention adjusts the actual process window size in the semiconductor process by correcting the mask.

[0050] See also Figure 1 As shown, the present invention provides a method for correcting a mask, comprising steps S100 to S500.

[0051] S100, input a plurality of initial main graphics, and classify the plurality of initial main graphics into important main graphics and secondary main graphics according to the pattern types in the initial main graphics, wherein the important main graphics and the secondary main graphics have a first-level priority constant.

[0052] S200 , assigning a secondary priority constant to the initial main graphic according to a size range in which a characteristic key size of the initial main graphic is located.

[0053] S300, sequentially allocating weight coefficients and priority coefficients to a plurality of initial main graphics, wherein the priority coefficient is the product of a primary priority constant, a secondary priority constant, and the weight coefficient.

[0054] S400: Sort the priorities of a plurality of initial main graphics according to the priority coefficients of the initial main graphics.

[0055] S500, obtaining a rule for adding auxiliary patterns, and sequentially adding auxiliary patterns to the mask according to the priority order of the initial main patterns.

[0056] S600: After distinguishing the priority of the initial main graph, invert the initial main graph and establish a replacement database of hot spot graphs based on the inversion result data.

[0057] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, in step S100, the initial main pattern is a design pattern on a mask. The design pattern is obtained by integrated circuit design, and the present invention does not limit this. Figure 2 As shown, the initial main graphic can be Figure 2 PATTERN in, the auxiliary graphics are Figure 2 SB in. In step S100, there are multiple initial main graphics on the mask, and the initial main graphics can be of any shape, and the initial main graphics can also be dense graphics or sparse graphics. In this embodiment, multiple initial main graphics are identified in turn, and the initial main graphics are divided into important main graphics or secondary main graphics according to whether the current initial main graphics contain important patterns. In this embodiment, when the initial main graphics contain important patterns, the current initial main graphics are marked as important main graphics. Wherein the important patterns include metal structure patterns or through silicon via (Through Silicon Via, TSV) patterns, the current initial main graphics are marked as important main graphics. Wherein the metal structure pattern is the pattern corresponding to the metal layer, and the upper or lower layer of the metal structure pattern is designed to correspond to the pattern of the contact column (contact, CT). If there is no important pattern in the current initial main graphics, the current initial main graphics are marked as secondary main graphics.

[0058] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, in step S100, a first-level priority constant is set. It should be noted that the first-level priority constant is a type of parameter, not a certain constant. In this embodiment, the first-level priority constants of the important main graphics and the secondary main graphics are assigned values ​​respectively. For example, the first-level priority constant value of the important main graphics is A. The first-level priority constant value of the secondary main graphics is B. The values ​​of A and B are different to distinguish the important main graphics from the secondary main graphics. In this embodiment, A<B. Step S100 is the first division of the initial main graphics.

[0059] See also Figure 1 and Figure 3As shown, in one embodiment of the present invention, in step S200, a secondary priority constant is assigned to the initial main graphic according to the size interval in which the characteristic key size of the initial main graphic is located. The characteristic key size of the initial main graphic is the minimum characteristic size of the initial main graphic in the photolithography process, such as the width of the minimum photolithography groove and the minimum graphic width, etc. In this embodiment, when the initial main graphic is input, the characteristic key size of the initial main graphic can be input at the same time, or in step S100, the characteristic key size of the initial main graphic can be measured in real time according to the input initial main graphic. It should be noted that what is measured here is the size of the designed mask graphic, not the actual mask graphic after OPC correction. Step S200 includes steps S210 to S250.

[0060] Step S210: Set the number of weight size intervals.

[0061] Step S220: Obtain the critical size range of the pattern on the mask.

[0062] Step S230: Generate multiple weight size intervals according to the key size range and the number of weight size intervals.

[0063] Step S240: corresponding to the multiple weight size intervals, set the secondary priority constants.

[0064] Step S250 : matching the secondary priority constant for the initial main graphic according to the weight size interval in which the characteristic key size of the initial main graphic is located.

[0065] See also Figure 1 and Figure 3 As shown, in one embodiment of the present invention, in step S210, the number of weight size intervals can be determined based on the area of ​​the mask pattern and the number of initial main patterns. For example, the fewer the number of initial main patterns, the lower the number of weight size intervals. On the contrary, the more the number of initial main patterns, the more the number of weight size intervals can be increased. For another example, the larger the blank area of ​​the mask, the lower the number of weight size intervals. The smaller the blank area of ​​the mask, the larger the number of weight size intervals. In step S220, the maximum critical size and the minimum critical size of the pattern on the mask are obtained, and based on the difference between the maximum critical size and the minimum critical size, the critical size range of the pattern on the mask is obtained. It should be noted that the maximum critical size and the minimum critical size are obtained by comparing all the initial main patterns on the mask.

[0066] See also Figure 1 and Figure 3As shown, in one embodiment of the present invention, in step S230, when the key size range and the number of weight size intervals are determined, multiple weight size intervals are generated by adjusting the interval length. In this embodiment, the lengths of the multiple weight size intervals may be equal or unequal. It should be noted that there is at least one initial main graphic in each weight size interval, and the present invention does not limit the number of initial main graphics in each weight size interval.

[0067] See also Figure 1 and Figure 3 As shown, in another embodiment of the present invention, in step S230, the initial main figure can be allocated to multiple weighted size intervals according to the importance of the critical size in the current interval. For example, for the size interval from half of the critical size range to the maximum critical size, the weighted size interval length of this interval is reduced, thereby increasing the number of weighted size intervals to increase the fineness of the division of the initial main figure in this size interval. For example, the critical size range is 10nm~90nm, and the importance of 50nm~90nm is higher, then the number of weighted size intervals within this interval can be increased. It should be noted that the present invention does not make a clear definition of the importance of the critical size. Depending on the different designed initial main figures, the important size interval can be set to any one or more size intervals in the critical size range. In the important size interval, the size span of the weighted size interval is greater than the size span of the weighted size interval in the non-important size interval. For example, in the interval of 50nm~90nm, the size span of the weighted size interval is, for example, 5nm, and in the interval of 10nm~50nm, the size span of the weighted size interval is, for example, 10nm.

[0068] See also Figure 1 and Figure 3 As shown, in one embodiment of the present invention, in step S240, a secondary priority constant Q is set corresponding to a plurality of weight size intervals. In this embodiment, no matter how many initial main graphics there are in the weight size interval, one weight size interval corresponds to a secondary priority constant. The initial main graphics in the same weight size interval correspond to the same secondary priority constant Q. In this embodiment, the sizes of the secondary priority constants Q can be sorted according to the size order of the weight size intervals. In this embodiment, as the size of the weight size interval decreases, the secondary priority constant Q is reduced. In other embodiments of the present invention, the sizes of the secondary priority constants Q can also be sorted according to the order of importance of the weight size intervals. For example, as the importance of the weight size interval increases, the secondary priority constant Q is reduced.

[0069] See also Figure 1 and Figure 3As shown, in an embodiment of the present invention, in step S240, for example, the present invention divides the critical dimension range into N weighted dimension intervals. Specifically, the multiple weighted dimension intervals are [minCD, minCD + interval span 1), [minCD + interval span 1, min CD + interval span 1 + interval span 2), [min CD + interval span 1 + interval span 2, minCD + interval span 1 + interval span 2 + interval span 3), and so on, until the weighted dimension interval [max CD - interval span N, max CD] is defined. In step S240, corresponding to the N weighted dimension intervals, N secondary priority constants are set, specifically Q1, Q2, Q3 to Q N . In this embodiment, it can be Q1 < Q2 < Q3 < ··· < Q N . In step S250, the secondary priority constant Q is associated with the corresponding weighted dimension interval, and the secondary priority constant Q is corresponding to the initial main figure. Specifically, the characteristic critical dimensions of the initial main figure are obtained in sequence, and it is determined which weighted dimension interval the characteristic critical dimensions of the initial main figure are in. And the secondary priority constant Q corresponding to the weighted dimension interval is obtained.

[0070] Please refer to Figure 1 and Figure 3 As shown, in an embodiment of the present invention, in step S300, a weighting coefficient a is set. In this embodiment, when the initial main figure is an important main figure and the initial main figure is in the Nth weighted dimension interval, the initial main figure is set as the first type of initial main figure. When the initial main figure is a secondary main figure and the initial main figure is in the first weighted dimension interval, the initial main figure is set as the second type of initial main figure. Where the Nth dimension interval refers to the Nth weighted dimension interval [max CD - interval span N, max CD] in terms of dimension sorting. The first weighted dimension interval refers to the weighted dimension interval [minCD, minCD + interval span 1) with the smallest dimension sorting. The priority of the first type of initial main figure is higher than that of the second type of initial main figure. Specifically, AQ N a N < BQ1a1. It should be noted that the present invention does not limit the specific values of the primary priority constant, the secondary priority constant, and the weighting coefficient, but only limits the magnitude relationship of the constants between different initial main figures. For example, the primary priority constant A of the important main figure is less than the primary priority constant B of the secondary main figure. In this embodiment, the priority of the important main figure is higher than that of the secondary main figure, and the smaller the weighted dimension interval, the higher the priority. In this embodiment, when calculating the priority coefficient a, it satisfies AQ N a N < BQ1a1, that is, a N / a1 < BQ1 / AQ N .

[0071] See also Figure 1 and Figure 3 As shown, in one embodiment of the present invention, in step S300, after obtaining the weight coefficient a of all initial main graphics, the priority coefficient of the initial main graphics is obtained. In this embodiment, the priority coefficient P is the product of the first-level priority constant A or B, the second-level priority constant Q and the weight coefficient a. Specifically, the priority coefficient P of each initial main graphics is obtained. In step S400, the priority coefficients P of all initial main graphics are sorted. For example, the priority coefficient of the important main graphics in the first weight size interval is P=AQ1a1. In this embodiment, the smaller the value of the priority coefficient P, the higher the priority of the initial main graphics.

[0072] See also Figures 1 to 3 As shown, in one embodiment of the present invention, in step S500, the present invention does not limit the rules for adding auxiliary graphics. Figure 2 As shown, the auxiliary graphics SB are added to the blank area of ​​the mask pattern. Specifically, one or more auxiliary graphics SB are added between two initial main graphics and / or in an initial main graphic. The initial main graphic is a sparse graphic. Figure 2 As shown, the distance between the initial main graph and the auxiliary graph meets the threshold requirement in the auxiliary graph adding rule. After adding the auxiliary graph SB, the initial main graph changes from a sparse graph to a dense graph. Figure 2 Two auxiliary graphics are shown, such as a first auxiliary graphic SB1 and a second auxiliary graphic SB2. The width of the first auxiliary graphic SB1 is W1, and the width of the second auxiliary graphic SB2 is W2. The distance between the first auxiliary graphic SB1 and the initial main graphic is S1. The distance between the second auxiliary graphic SB2 and the first auxiliary graphic SB1 is S2. The second auxiliary graphic SB2 is arranged between adjacent first auxiliary graphics SB1. In this embodiment, for example, the auxiliary graphics adding rule is set to W1≤28μm, W2≤120μm, S1≤30μm, S2≤92μm. According to steps S100 to S500, the order of adding auxiliary graphics is determined, such as Figure 2 According to the pattern spacing of the initial main pattern and the adding rule of the auxiliary pattern, the first auxiliary pattern SB1 and / or the second auxiliary pattern SB2 are added.

[0073] See also Figure 1 and Figure 3 As shown, in one embodiment of the present invention, the priority of adding auxiliary graphics is determined through steps S100 to S500. In step S600, after distinguishing the priority of the initial main graphics, the initial main graphics are inverted, and a replacement database of hot spot graphics is established based on the inversion result data. Step S600 includes steps S610 to S630.

[0074] Step S610: According to the optical proximity correction model, an initial main pattern with high process variation bandwidth, high mask error enhancement factor and low normalized logarithmic slope is obtained from the mask as a hot spot pattern.

[0075] Step S620: Obtain optimal auxiliary graphic positions of multiple hotspot graphics, and establish a replacement database, wherein the replacement database stores the optimal auxiliary graphics of the multiple hotspot graphics.

[0076] Step S630 , after adding auxiliary patterns according to the priority order, the added auxiliary patterns are replaced with the optimal auxiliary patterns according to the size of the process window.

[0077] See also Figure 1 and Figure 4 As shown, in one embodiment of the present invention, in step S610, the present invention does not limit the optical proximity correction model. The process variation band (PV band) describes the influence of changes in the photolithography focus and photolithography dose on the initial main pattern. The larger the process variation band, the more sensitive the initial main pattern is to changes in the photolithography focus and photolithography dose, and the smaller the process window of the initial main pattern. The mask error enhancement factor (MEEF) is defined as the slope of the change of the photoresist line width (CD wafer) on the wafer with the mask pattern line width (CDmask), which can quantitatively represent the influence of the feature size error on the mask on the feature size error in the photoresist, so as to amplify the mask error. The normalized image log slope (NILS) can reflect the exposure energy margin, wherein the exposure energy margin refers to the maximum deviation allowed by the exposure energy within the allowable variation range of the line width. It should be noted that a high process variation bandwidth, a high mask error enhancement factor and a low normalized logarithmic slope can be determined by the parameter threshold in the optical proximity model. For example, a parameter higher than a parameter threshold is defined as a high parameter, and a parameter lower than a parameter threshold is defined as a low parameter. The parameter threshold is input by a designer. The initial main pattern obtained by step S610 is more likely to have a problem of insufficient process window.

[0078] See also Figure 1 , Figure 2 and Figure 4As shown, in one embodiment of the present invention, in step S620, the optimal auxiliary graphic position of the hotspot graphic is obtained by inverse lithography technology (ILT). In this embodiment, the hotspot graphic can be one or more, and the present invention does not limit this. It should be noted that the optimal auxiliary graphic position refers to the complete graphic position. The complete graphic position may include the position information of a single pattern or the position information of multiple patterns, such as Figure 2 As shown. The position information includes the pattern shape and the coordinates of the pattern. In this embodiment, a replacement database of hot spot graphics is established. The replacement database stores the optimal auxiliary graphic position of the hot spot graphics. It should be noted that step S610 and step S620 can be performed before step S100 to step S500, or after step S100 to step S500.

[0079] See also Figure 1 and Figure 2 , Figure 4 and Figure 5 As shown, in one embodiment of the present invention, auxiliary graphics are added to the initial main graphics in sequence according to the priority order determined in steps S100 to S500 and step S610. Figure 5 As shown, the initial main figure H does not have an important figure, and the priority of the initial main figure H is the lowest. However, the initial main figures E1 and the initial main figures E2 have through-silicon vias, and the initial main figure F is connected to the contact column CT. Further judgment shows that since the key dimensions of the initial main figures E1 and the initial main figures E2 are small, and the key dimensions of the initial main figures E1 and the initial main figures E2 are equal, the priorities of the initial main figures E1 and the initial main figures E2 are equal and are the highest priority. The key dimension of the initial main figure F is large, so the priority of the initial main figure F is higher than that of the initial main figure H, and the priority of the initial main figure F is lower than that of the initial main figures E1 and the initial main figure E2. Therefore, when adding auxiliary graphics, the auxiliary graphics are added to the initial main graphics E1 and the initial main graphics E2 first, and then the auxiliary graphics are added to the initial main graphics F, and then the auxiliary graphics are added to the initial main graphics H. After adding the auxiliary graphics, step S630 is implemented. In step S630 , after simulated lithography, if the process window of the initial main pattern is smaller than a preset threshold, the auxiliary pattern added in step S500 is replaced with the optimal auxiliary pattern in the replacement database.

[0080] See also Figure 1 and Figure 6As shown, the present invention provides a correction system 10 for a mask, and the correction system 10 for a mask includes a first classification module 11, a second classification module 12, a priority coefficient calculation module 13, a sorting module 14 and an auxiliary graphics adding module 15. After inputting a plurality of initial main graphics, the first classification module 11 divides the plurality of initial main graphics into important main graphics and secondary main graphics according to the pattern type in the initial main graphics, wherein the important main graphics and the secondary main graphics have a first-level priority constant. The second classification module 12 assigns a second-level priority constant to the initial main graphics according to the size interval where the characteristic key size of the initial main graphics is located. The priority coefficient calculation module 13 sequentially assigns weight coefficients and priority coefficients to the plurality of initial main graphics, wherein the priority coefficient is the product of the first-level priority constant, the second-level priority constant and the weight coefficient. The sorting module 14 sorts the priorities of the plurality of initial main graphics according to the size of the priority coefficient of the initial main graphics. The auxiliary graphics adding module 15 obtains the adding rule of the auxiliary graphics, and sequentially adds the auxiliary graphics to the mask according to the priority order of the initial main graphics. The unexpected technical effect of the present invention is that it can make isolated patterns and sparse patterns also have the characteristics of dense patterns, thereby improving the light intensity distribution and enhancing the imaging quality. The mask correction method and system provided by the present invention can increase the process window while complying with the auxiliary pattern addition rules, avoid insufficient process window, and thus improve the yield of illumination.

[0081] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for correcting a mask, characterized in that: The following steps are involved: Input a plurality of initial main graphics, and divide the plurality of initial main graphics into important main graphics and secondary main graphics according to the pattern types in the initial main graphics, wherein the important main graphics and the secondary main graphics have a first-level priority constant, the important main graphics have a first-level priority constant, and the secondary main graphics have a second-level priority constant, wherein the first-level priority constant is A, the second-level priority constant is B, and A<B, wherein the important main graphics include a metal structure pattern and / or a through silicon via pattern; Allocating a secondary priority constant to the initial main graphic according to a size interval where a key feature size of the initial main graphic is located, wherein the smaller the size interval where the key feature size is located, the smaller the secondary priority constant of the initial main graphic is; Assign weight coefficients and priority coefficients to the plurality of initial main graphics in sequence, wherein the priority coefficient is the product of the first-level priority constant, the second-level priority constant, and the weight coefficient, wherein the weight coefficient of the initial main graphics in the Nth weight size interval is the Nth weight coefficient, and the value of the Nth weight coefficient satisfies the following formula: a N / a1 <BQ1 / AQ N ; Among them, a N is the Nth weight coefficient, a1 is the first weight coefficient, B is the second first-level priority constant, A is the first first-level priority constant, Q1 is the second-level priority constant of the first weight size interval, Q N is the secondary priority constant of the Nth weight size interval; wherein N is a natural number greater than 1, and the plurality of weight size intervals are arranged in ascending order of key size; sorting the priorities of the plurality of initial main graphics according to the priority coefficients of the initial main graphics; and A rule for adding auxiliary patterns is obtained, and the auxiliary patterns are added to the mask in sequence according to the priority order of the initial main patterns.

2. A method for correcting a mask according to claim 1, characterized in that: The steps of allocating the secondary priority constants include: Set the number of weight size intervals; Obtain the critical dimension range of the pattern on the mask; Generating a plurality of weight size intervals according to the critical size range and the number of weight size intervals; Matching different secondary priority constants for a plurality of said weight size intervals; and According to the characteristic key size of the initial main graphic, the initial main graphic is matched to the corresponding weight size interval, and the secondary priority constant of the weight size interval is used as the secondary priority constant of the initial main graphic.

3. A method for correcting a mask according to claim 2, characterized in that: In the step of generating a plurality of weight size intervals, as the critical size of the weight size interval decreases, the secondary priority constant of the weight size interval decreases.

4. A method for correcting a mask according to claim 2, characterized in that: In the step of generating a plurality of weight size intervals, as the critical size of the weight size interval decreases, the size span of the weight size interval increases.

5. The method for correcting a mask according to claim 1, characterized in that: The mask correction method further comprises the following steps: According to the optical proximity correction model, the initial main pattern with high process variation bandwidth, high mask error enhancement factor and low normalized logarithmic slope is obtained from the mask as a hot spot pattern; and The optimal auxiliary graphic positions of the plurality of hot spot graphics are obtained, and the optimal auxiliary graphics are collected to establish a replacement database.

6. A method for correcting a mask according to claim 5, characterized in that: The mask correction method further comprises the following steps: After adding the auxiliary graphics according to the priority order of the initial main graphics, obtaining the process window of the hot spot graphics; and When the size of the process window is less than or equal to a preset threshold, the optimal auxiliary pattern of the hotspot pattern is queried and acquired from the replacement database, and the auxiliary pattern of the hotspot pattern is replaced with the optimal auxiliary pattern.

7. A mask correction system, characterized in that: include: a first classification module, after inputting a plurality of initial main graphics, for classifying the plurality of initial main graphics into important main graphics and secondary main graphics according to pattern types in the initial main graphics, wherein the important main graphics and the secondary main graphics have a first-level priority constant, the important main graphics have a first-level priority constant, the secondary main graphics have a second-level priority constant, wherein the first-level priority constant is A, the second-level priority constant is B, and A<B, wherein the important main graphics include metal structure patterns and / or through silicon via patterns; A second classification module is used to assign a secondary priority constant to the initial main graphic according to a size interval where a key feature size of the initial main graphic is located, wherein the smaller the size interval where the key feature size is located, the smaller the secondary priority constant of the initial main graphic is; The priority coefficient calculation module is used to sequentially assign weight coefficients and priority coefficients to the plurality of initial main graphics, wherein the priority coefficient is the product of the first-level priority constant, the second-level priority constant and the weight coefficient, wherein the weight coefficient of the initial main graphics in the Nth weight size interval is the Nth weight coefficient, and the value of the Nth weight coefficient satisfies the following formula: a N / a1 <BQ1 / AQ N ; Among them, a N is the Nth weight coefficient, a1 is the first weight coefficient, B is the second first-level priority constant, A is the first first-level priority constant, Q1 is the second-level priority constant of the first weight size interval, Q N is the secondary priority constant of the Nth weight size interval; wherein N is a natural number greater than 1, and the plurality of weight size intervals are arranged in ascending order of key size; a sorting module, configured to sort the priorities of a plurality of initial main graphics according to the priority coefficients of the initial main graphics; and The auxiliary pattern adding module is used to obtain the adding rule of the auxiliary pattern and add the auxiliary pattern to the mask in sequence according to the priority order of the initial main pattern.

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