CN109188857B - Layout splitting method and splitting system - Google Patents

Abstract

The application provides a layout splitting method and a splitting system. The splitting method comprises the following steps: performing multiple pre-splitting on at least one part of the layout according to a pre-splitting rule to form multiple layout groups; simulating different layout groups to obtain the total number of dead pixels of each layout group; and extracting a splitting rule corresponding to the layout group with the least dead pixel total number so as to split the layout. The splitting method comprises the steps of firstly carrying out pre-splitting, splitting a layout into a plurality of layout groups according to a plurality of modes in the splitting process, then simulating each layout group to obtain the total number of dead pixels of each layout group, and finally comparing the total number of dead pixels of each layout group and extracting a splitting rule corresponding to the layout group with the minimum total number of dead pixels to split the layout. The final splitting scheme in the splitting method is the splitting scheme with the least total number of dead pixels, so that the imaging effect of the mask graph obtained by splitting is relatively good.

Description

Layout splitting method and splitting system

Technical Field

The application relates to the field of semiconductors, in particular to a layout splitting method and a layout splitting system.

Background

When the resolution provided by the lithography machine cannot meet the requirements of the technical nodes, a double exposure technique is required. For example, a 1.35NA 193nm immersion lithography machine can provide a half-cycle resolution of 36-40nm, and can meet the requirements of logic technology nodes below 28nm by matching with a double exposure technology.

The core of the double exposure technique is to split the original one-layer designed pattern into two masks, and one of the common methods is to use two times of photolithography and etching to realize the original one-layer designed pattern.

The key lithography layer-via layer (via/contact) pattern of the node below 28nm has only a few or even a single dimension-specific regular pattern of Critical Dimension (CD), which is generally square and rectangular. As shown in fig. 1.

The ground rule of splitting of a via layer generally simply indicates the minimum distance of two shapes that must be split. The layout is split only by using the basic splitting rule, and the problem that a part of patterns still have dead spots (also called hot spots) in the exposure imaging effect of the two mask patterns after splitting is faced, and the exposure imaging effect is the most important effect. Although the problem of bad points can be solved by modifying the layout design, the method is the most compelling means and is slightly complicated, and meanwhile, the construction period is delayed.

The above information disclosed in this background section is only for enhancement of understanding of the background of the technology described herein and, therefore, certain information may be included in the background that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Disclosure of Invention

The application mainly aims to provide a layout splitting method and a layout splitting system, so as to solve the problem that in the prior art, the imaging effect of a mask pattern obtained by splitting only according to the existing splitting mode is poor.

In order to achieve the above object, according to an aspect of the present application, there is provided a splitting method of a layout, the splitting method including: performing multiple pre-splitting on at least one part of the layout according to a pre-splitting rule to form multiple layout groups; simulating different version groups to obtain the total number of dead pixels of each version group; and extracting a splitting rule corresponding to the layout group with the least dead pixel total number so as to split the layout.

Further, the performing multiple pre-splits on at least one part of the layout according to a pre-split rule includes: selecting a part in the layout as a split layout; and carrying out various pre-splitting on the split layout.

Further, before the performing a plurality of pre-splits on at least one part of the layout according to the pre-split rule, the splitting method further includes: simulating the combination of a plurality of different adjacent two patterns in the split layout to obtain the number of bad points of the two patterns in each combination at different intervals; when the number of the bad points is larger than a preset value, determining the interval range of the two patterns in the corresponding combination as a pre-splitting range; and determining the pre-splitting rule based on the pre-splitting range.

Further, the pre-splitting rule is an exhaustive rule.

Further, the predetermined value is A, and A is more than or equal to 0 and less than or equal to 2.

Furthermore, the number of the combinations is six, namely a first combination, a second combination, a third combination, a fourth combination, a fifth combination and a sixth combination, wherein the first combination is two squares which are arranged at intervals; the second combination is a square and a rectangle which are arranged at intervals, and the interval between the short side of the rectangle and one side of the square forms the interval between the square and the rectangle; the third group is a square and a rectangle which are arranged at intervals, and the interval between the long side of the rectangle and one side of the square forms the interval between the square and the rectangle; the fourth combination is two rectangles arranged at intervals, and the interval between the long sides of the two rectangles forms the interval between the two rectangles; a fifth combination is formed by two rectangles which are arranged at intervals, and the interval between the long side of one rectangle and the short side of the other rectangle forms the interval between the two rectangles; a sixth combination is two rectangles arranged at an interval, the interval between the short sides of the two rectangles forms the interval between the two rectangles, the predetermined value is a, and a is 0, the pre-splitting range of the first combination includes an interval range smaller than 45nm and an interval range larger than 75nm and smaller than 150nm, the pre-splitting range of the second combination includes an interval range smaller than 50nm and an interval range larger than 85nm and smaller than 140nm, the pre-splitting range of the third combination includes an interval range smaller than 50nm and an interval range larger than 70nm and smaller than 135nm, and the pre-splitting range of the fourth combination includes an interval range smaller than 30nm and an interval range larger than 70nm and smaller than 110 nm; the pre-splitting range of the fifth combination comprises a spacing range smaller than 45nm and a spacing range larger than 80nm and smaller than 135nm, and the pre-splitting range of the sixth combination comprises a spacing range smaller than 35 nm.

Further, each layout group includes at least one sub-layout, and before the simulation of the different layout groups, the splitting method further includes: optimizing the sub-layouts in each layout group; the simulating of the different sets of layouts may include: and performing the simulation on the optimized layout group.

Further, the optimization process includes: and inserting the auxiliary graph with sub-resolution into the sub-layout.

Further, the splitting method further comprises: and splitting the layout according to the splitting rule.

According to another aspect of the application, a splitting system of a layout is provided, which includes: the pre-splitting unit is used for carrying out multiple pre-splitting on at least one part of the layout according to a pre-splitting rule to form multiple layout groups; the simulation unit is used for simulating different version groups to obtain the total number of dead pixels of each version group; and the splitting rule extracting unit is used for extracting the splitting rule according to the layout group with the least dead pixel total number so as to split the layout.

By applying the technical scheme of the application, in the splitting method, pre-splitting is performed, the layout is split into multiple layout groups according to multiple modes in the pre-splitting process, then, the layout groups are simulated to obtain the total number of dead pixels of the various layout groups, finally, the total number of dead pixels of the various layout groups is compared, and the splitting rule corresponding to the layout group with the minimum total number of dead pixels is extracted to split the layout. The final splitting scheme in the splitting method is the splitting scheme with the least total number of dead pixels, so that the imaging effect of the mask pattern corresponding to the sub-layout obtained by splitting is relatively good.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:

FIG. 1 shows a layout of the prior art;

fig. 2 shows a flow diagram of an embodiment of a splitting method of a layout according to the present application;

FIG. 3 is a schematic diagram of a portion of a layout;

fig. 4 to 9 respectively show structural schematic diagrams of a first combination to a sixth combination; and

fig. 10 to 15 show graphs of simulation results of the first combination to the sixth combination, respectively.

Wherein the figures include the following reference numerals:

01. a first pattern; 02. a second pattern; 03. a third pattern; 10. a square shape; 20. rectangular.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. Also, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element or "connected" to the other element through a third element.

As introduced in the background art, the mask pattern obtained by splitting in the splitting manner in the prior art has a poor imaging effect, and in order to solve the above technical problems, the present application provides a splitting method and a splitting system for a layout.

In an exemplary embodiment of the present application, a method for splitting a layout is provided, as shown in fig. 2, the method for splitting a layout includes:

and step S1, performing multiple pre-splitting on at least part of the layout according to a pre-splitting rule, namely performing multiple pre-splitting on all the layout or part of the layout to form multiple layout groups. Wherein each of the layout groups includes at least one sub-layout.

For example, in fig. 3, the layout including three patterns may be divided into four layout groups according to the pre-splitting rule, where the first layout group is: the layout group is not split, namely the layout group comprises a sub-layout, and the first pattern 01, the second pattern 02 and the third pattern 03 are all on the sub-layout; the second layout group: the method comprises the following steps of (1) including two sub-layouts, wherein one sub-layout comprises a first pattern 01 and a second pattern 02, and the other sub-layout comprises a third pattern 03; third version set: the method comprises the following steps of (1) including two sub-layouts, wherein one sub-layout comprises a second pattern 02 and a third pattern 03, and the other sub-layout only comprises a first pattern 01; fourth set of versions: two sub-layouts are included, wherein one sub-layout includes a first pattern 01 and a third pattern 03, and the other sub-layout includes only a second pattern 02.

And step S2, simulating different layout groups to obtain the total number of dead pixels of each layout group.

For example, using Ming lead corporation (Mentor)

The layout shown in fig. 3 is pre-split according to the four splitting modes, the four layout groups are simulated, and the simulation result shows that the number of bad points is the least when the second pattern 02 and the third pattern 03 are in the same sub-layout.

In step S2, a Process Variation band (PV band for short) may be selected to evaluate the quality of the points. The PVband is used for evaluating the evaluation value of imaging contour change when the focusing position deviation, the exposure dose deviation and the layout error exist, the smaller the value is, the more stable the imaging system is, and the PVband is a key parameter for measuring the manufacturability. Based on industry level, 4.5nm is generally selected as a criterion for measuring bad spots (hot spots), i.e. PVband somewhere in the pattern exceeds 4.5nm, which is considered as bad spots. The fewer the total number of dead pixels of the layout group obtained by different splitting modes, the better the splitting scheme.

And step S3, extracting the splitting rule corresponding to the layout group with the least dead pixel total number so as to split the layout.

The corresponding splitting rule can be transmitted to the splitting rule base, so that the subsequent splitting of other layouts is facilitated.

In the splitting method, pre-splitting is carried out, the layout is split into a plurality of layout groups according to a plurality of modes in the pre-splitting process, then each layout group is simulated to obtain the total number of dead pixels of each layout group, finally, the total number of dead pixels of each layout group is compared, and the splitting rule corresponding to the layout group with the least total number of dead pixels is extracted to split the layout. The final splitting scheme in the splitting method is the splitting scheme with the least total number of dead pixels, so that the imaging effect of the mask pattern corresponding to the sub-layout obtained by splitting is relatively good.

In the above step S1, the whole layout may be pre-split, or parts of the layout may be pre-split, for layouts with fewer patterns, the whole layout may be pre-split, and for layouts with more patterns and more complexity, the parts of the layout may be pre-split. Of course, those skilled in the art may also choose to pre-split part or all of the layout according to other practical situations.

Wherein, in order to simplify the pre-splitting process and improve the splitting efficiency of the present application, in an embodiment of the present application, the step S1 includes: selecting a part in the layout as a split layout; and carrying out the pre-splitting on the split layout.

Each of the layout groups includes at least one sub-layout. When the layout group comprises one sub-layout, the layout is not split. For various layout groups, only one layout group comprises one sub-layout, and the other layout groups usually comprise two sub-layouts, but of course, more than two sub-layouts can be included.

In an embodiment of the present application, when the set of plates includes two sub-plates, the splitting scheme may be applied in a double lithography and etching (LELE) process.

In order to further ensure that the imaging effect corresponding to the mask obtained by splitting the splitting scheme is better and the number of dead pixels after exposure is less, an embodiment of the present application further provides a specific form of a pre-splitting rule, and before the step S1, the splitting method further includes: simulating the combination of a plurality of different adjacent two patterns in a to-be-split layout (namely at least part of the layout or all the layout) to obtain the number of bad points of the two patterns in each combination at different intervals; when the number of the bad points is larger than a preset value, determining the interval range of the two patterns in the corresponding combination as a pre-splitting range; and determining the pre-splitting rule based on the pre-splitting range.

In this case, a combination of two different adjacent patterns is illustrated, as shown in fig. 4 to 9, the two patterns have shapes of a square 10 and a long direction 20, respectively, and the combination of two different adjacent patterns may include the forms of fig. 4 to 9, as shown in fig. 4, a combination of two adjacent squares; or as shown in figure 5, square 10 and a rectangle 20 adjacent combination, and the rectangle 20 short side and the square 10 a side between the interval form the square 10 and the rectangular 20 between the interval; and the like.

Specifically, the pre-splitting rule includes: and splitting the two patterns when the interval of the two corresponding patterns in each combination is within the pre-splitting range. For each combination, its corresponding pre-splitting range is usually determined, and may also vary depending on the splitting environment. And finally, obtaining a pre-splitting rule according to the pre-splitting ranges of the plurality of combinations.

It should be noted that, in the actual splitting process, because there are a large number of patterns in the layout, and there are other patterns closely adjacent to each other around each pattern, when the layout to be split is to be pre-split according to the pre-splitting rule, two adjacent patterns in the pre-splitting range do not necessarily need to be split, so there are multiple pre-splitting modes.

In one embodiment of the present application, the predetermined value is a, and a is greater than or equal to 0 and less than or equal to 2. Thus, the imaging effect corresponding to the mask obtained by splitting the splitting scheme is better, the number of dead spots after exposure is less,

here, the predetermined value a is not an absolutely limited value, but is a relative value obtained from a simulation result.

In a specific embodiment, the predetermined value a is 0, that is, in each of the combinations, when the number of bad points is greater than 0, an interval range of two corresponding patterns is a pre-splitting range, and when an interval between two corresponding patterns in the layout is within the pre-splitting range, the two patterns are pre-split. The total number of dead pixels in the layout group obtained by the pre-splitting scheme is less, so that the total number of the dead pixels corresponding to the exposed mask is further ensured to be less, and the imaging effect of the mask is further ensured.

Of course, the pre-splitting rule of the present application is not limited to the pre-splitting rule, and in an embodiment of the present application, an interval range of two patterns corresponding to a bad point number within a certain range may be used as the pre-splitting range, for example, an interval range of two patterns corresponding to a bad point number between 0 and 2 is used as the pre-splitting range, and when an interval of two corresponding patterns in the layout is within the pre-splitting range, the two patterns are split. Those skilled in the art can select the pre-splitting rule corresponding to the pre-splitting range according to actual situations.

Certainly, in the step S1, the layout or part of the layout may also be split according to other pre-splitting rules instead of the pre-splitting rule obtained by the method, and a person skilled in the art may split the layout or part of the layout according to other pre-splitting rules according to actual situations, for example, in fig. 3, it is omitted that whether the distances between two patterns are within the pre-splitting range, such as 0.041um (micrometer), 0.045um, and 0.065um, but the exhaustive rule of various pattern combinations is exhausted, so there are four pre-splitting modes.

In a specific embodiment, as shown in fig. 4 to 9, the above-mentioned combinations are six, namely, a first combination, a second combination, a third combination, a fourth combination, a fifth combination and a sixth combination.

As shown in fig. 4, the first combination is two squares 10 arranged at intervals; as shown in fig. 5, the second combination is a square 10 and a rectangle 20 which are arranged at intervals, and the interval between the short side of the rectangle 20 and one side of the square 10 forms the interval between the square 10 and the rectangle 20; as shown in fig. 6, the third combination is a square 10 and a rectangle 20 which are arranged at intervals, and the interval between the long side of the rectangle 20 and one side of the square 10 forms the interval between the square 10 and the rectangle 20; as shown in fig. 7, the fourth combination is two rectangles 20 arranged at an interval, and the interval between the long sides of the two rectangles 20 forms the interval between the two rectangles 20; as shown in fig. 8, a fifth combination is two rectangles 20 arranged at an interval, and an interval between a long side of one of the rectangles 20 and a short side of the other of the rectangles 20 forms an interval between the two rectangles 20; as shown in fig. 9, the sixth combination is two rectangles 20 provided at an interval, and the interval between the short sides of the two rectangles 20 forms the interval between the two rectangles 20.

The above six combinations are simulated, specifically, the distance between the two patterns is designed to be 5nm (nanometer) step length, the combination from the minimum distance to the larger distance is simulated, and the simulation result is shown in fig. 10 to fig. 15, wherein the abscissa represents the distance between the two patterns, the unit is nm, and the ordinate represents the number of dead pixels (i.e., the number of hot spots). Further, according to the simulation result, a specific pre-splitting rule can be obtained, where a is 0, and for the first combination, the pre-splitting range includes an interval range smaller than 45nm and an interval range larger than 75nm and smaller than 150 nm; for the second combination, the pre-splitting range includes a spacing range less than 50nm and a spacing range greater than 85nm and less than 140 nm; for the third combination, the pre-splitting range includes a spacing range less than 50nm and a spacing range greater than 70nm and less than 135 nm; for the fourth combination, the pre-splitting range includes a spacing range of less than 30nm and a spacing range of greater than 70nm and less than 110 nm; for the fifth combination, the pre-splitting range includes a spacing range less than 45nm and a spacing range greater than 80nm and less than 135 nm; for the sixth combination, the pre-splitting range includes a spacing range of less than 35 nm.

Of course, the number of combinations is not limited to six, and may be six or more for different cases (for example, the pattern includes a rectangle and a plurality of squares with different side lengths).

In order to make the splitting method more suitable for the layout with dense patterns, in an embodiment of the present application, before the step S2, the splitting method further includes: the sub-layouts in each of the layout groups are optimized, and the simulation is performed on the optimized layout group in step S2.

The above optimization is some conventional layout optimization methods, such as optical proximity correction, correction of main patterns, or addition of sub-resolution auxiliary patterns.

In a specific embodiment of the present application, the optimization process includes: and inserting the auxiliary graph with sub-resolution into the sub-layout. The insertion of the sub-resolution auxiliary pattern makes the independent pattern look like a dense pattern in an optical angle, and because the auxiliary pattern is generally a very fine pattern and is smaller than the resolution of a photoetching machine, the auxiliary pattern only plays a role in scattering light and does not image on a photoresist.

In an embodiment of the present application, the splitting method further includes a splitting process of the whole layout: and splitting the layout according to the splitting rule.

Specifically, the splitting rule may be that when the number of bad points is greater than a predetermined value B, an interval range of two patterns in the combination is a splitting range, that is, when an interval between two corresponding patterns in the layout is within the splitting range, the two patterns in the layout are split, where B is greater than or equal to 0 and less than or equal to 2.

In another exemplary embodiment of the present application, a splitting system of a layout is provided, where the splitting system includes: the device comprises a pre-splitting unit, a simulation unit and a splitting rule extraction unit, wherein the pre-splitting unit is used for carrying out multiple pre-splitting on at least one part of a layout according to a pre-splitting rule to form multiple layout groups, and each layout group comprises at least one sub-layout; the simulation unit is used for simulating different version groups to obtain the total number of dead pixels of each version group; and the splitting rule extracting unit is used for extracting the splitting rule according to the layout group with the least dead pixel total number so as to split the layout.

In the splitting system, the pre-splitting unit splits the layout into a plurality of layout groups in a plurality of modes in the splitting process, then the simulation unit simulates each layout group to obtain the total number of dead pixels of each layout group, and finally the splitting rule extraction unit extracts the splitting rule corresponding to the layout group with the least total number of dead pixels to split the layout. The final splitting scheme in the splitting system is the splitting scheme with the least total number of dead pixels, so that the imaging effect of the mask graph obtained by splitting is relatively good.

From the above description, it can be seen that the above-described embodiments of the present application achieve the following technical effects:

1) according to the splitting method, pre-splitting is carried out, the layout is split into multiple layout groups according to multiple modes in the splitting process, then the layout groups are simulated to obtain the total number of dead pixels of the various layout groups, finally, the total number of dead pixels of the various layout groups is compared, and the splitting rule corresponding to the layout group with the least total number of dead pixels is extracted to split the layout. The final splitting scheme in the splitting method is the splitting scheme with the least total number of dead pixels, so that the imaging effect of the mask pattern corresponding to the sub-layout obtained by splitting is relatively good.

2) In the splitting system, the pre-splitting unit is firstly used for splitting, the layout is split into multiple layout groups according to multiple modes in the splitting process, then the simulation unit simulates all the layout groups to obtain the total number of dead pixels of all the layout groups, and finally the splitting rule extraction unit extracts the splitting rule corresponding to the layout group with the minimum total number of dead pixels to split the layout. The final splitting scheme in the splitting system is the splitting scheme with the least total number of dead pixels, so that the imaging effect of the mask graph corresponding to the sub-layout obtained by splitting is relatively good.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (9)

1. A method for splitting a layout is characterized in that the method for splitting the layout comprises the following steps:

performing multiple pre-splitting on at least one part of the layout according to a pre-splitting rule to form multiple layout groups;

simulating different layout groups to obtain the total number of dead pixels of each layout group;

extracting a splitting rule corresponding to the layout group with the least dead pixel total number so as to split the layout; before the performing a plurality of pre-splits on at least one part of the layout according to the pre-split rule, the splitting method further includes:

simulating the combination of a plurality of different adjacent two patterns in the split layout to obtain the number of bad points of the two patterns in each combination at different intervals;

when the number of the bad points is larger than a preset value, determining the interval range of the two corresponding patterns in the combination as a pre-splitting range;

determining the pre-splitting rule based on the pre-splitting range.

2. The splitting method according to claim 1, wherein the performing multiple pre-splitting on at least one part of the layout according to a pre-splitting rule comprises:

selecting a part in the layout as a split layout;

and carrying out multiple pre-splitting on the split layout.

3. The splitting method according to claim 1 or 2, wherein said pre-splitting rule is an exhaustive rule.

4. The method for splitting according to claim 1, wherein the predetermined value is A, and 0 ≦ A ≦ 2.

5. The method for splitting according to claim 1, wherein there are six combinations, namely a first combination, a second combination, a third combination, a fourth combination, a fifth combination and a sixth combination, the first combination is two squares arranged at intervals; the second combination is a square and a rectangle which are arranged at intervals, and the interval between the short side of the rectangle and one side of the square forms the interval between the square and the rectangle; the third group is a square and a rectangle which are arranged at intervals, and the interval between the long side of the rectangle and one side of the square forms the interval between the square and the rectangle; the fourth combination is two rectangles arranged at intervals, and the interval between the long sides of the two rectangles forms the interval between the two rectangles; the fifth combination is two rectangles arranged at intervals, and the interval between the long side of one rectangle and the short side of the other rectangle forms the interval between the two rectangles; the sixth combination is two rectangles arranged at intervals, and the interval between the short sides of the two rectangles forms the interval between the two rectangles,

the predetermined value is a, and a is 0, the first combination pre-split range includes a spacing range less than 45nm and a spacing range greater than 75nm and less than 150nm, the second combination pre-split range includes a spacing range less than 50nm and a spacing range greater than 85nm and less than 140nm, the third combination pre-split range includes a spacing range less than 50nm and a spacing range greater than 70nm and less than 135nm, the fourth combination pre-split range includes a spacing range less than 30nm and a spacing range greater than 70nm and less than 110 nm; the fifth combined pre-split range includes a spacing range less than 45nm and a spacing range greater than 80nm and less than 135nm, and the sixth combined pre-split range includes a spacing range less than 35 nm.

6. The splitting method according to claim 1, wherein each of said set of layouts comprises at least one sub-layout,

before the simulating the different layout groups, the splitting method further includes: optimizing the sub-layouts in each layout group;

the simulating different said set of layouts comprises: and performing the simulation on the optimized layout group.

7. The splitting method according to claim 6, wherein the optimization procedure comprises:

inserting the sub-resolution auxiliary graph into the sub-layout.

8. The splitting method according to claim 1, wherein the splitting method further comprises:

and splitting the layout according to the splitting rule.

9. A splitting system of a layout, the splitting system comprising:

the pre-splitting unit is used for carrying out multiple pre-splitting on at least one part of the layout according to a pre-splitting rule to form multiple layout groups;

the simulation unit is used for simulating different layout groups to obtain the total number of dead pixels of each layout group;

a splitting rule extracting unit, configured to extract a splitting rule according to the layout group with the smallest total number of dead pixels, so as to split the layout;

before the performing a plurality of pre-splits on at least one part of the layout according to the pre-split rule, the splitting method further includes:

simulating the combination of a plurality of different adjacent two patterns in the split layout to obtain the number of bad points of the two patterns in each combination at different intervals;

when the number of the bad points is larger than a preset value, determining the interval range of the two corresponding patterns in the combination as a pre-splitting range;

determining the pre-splitting rule based on the pre-splitting range.

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