CN117850154A - OPC correction method and OPC correction system - Google Patents

Abstract

The invention provides an OPC correction method and an OPC correction system. Specifically, after layout data of an original layout including a metal layer layout or a through hole layer layout is determined, based on line edge lengths of line end point graphs with corners contained in the layout data, a plurality of line edges of the line end point graphs are divided into two line edge sets according to different lengths, and then the two line edge sets are respectively provided with cutting points of the line edges by different cutting point cutting intervals.

Description

OPC correction method and OPC correction system

Technical Field

The present invention relates to the field of semiconductor manufacturing technologies, and in particular, to an OPC correction method and an OPC correction system.

Background

The connection of the rear metal layer and the through hole layer plays a critical role in the performance of the device in the integrated circuit manufacturing process, and if the coverage rate of the metal layer and the through hole layer does not reach the standard, poor conduction performance and even failure among different metal layers can be caused, so that the yield of the product is finally reduced.

However, due to the existence of the optical proximity effect, there is a certain difference between the circuit layout design and the pattern actually formed on the wafer, and the optical proximity effect correction technology (Optical Proximity Correct, OPC) is applied in the context of the continuous rising technology node. In optical proximity correction, corner rounding (corner rounding) is a common optical effect, especially in applications of post metal layer layout and via layer layout in integrated circuit manufacturing processes.

At present, the coverage rate of a convex angle position of a metal layer layout design line end and a through hole layer is reduced due to the influence of a corner rounding effect, and a traditional correction method is that the line edge of a line endpoint graph is subjected to segmentation point setting according to a preset segmentation point length set value, and then the line edge is subjected to edge expansion or edge contraction operation based on a plurality of line segments segmented by the segmentation points.

However, since the length of the line edge where the lobe of the line endpoint graph is located is smaller than the length set value of the splitting point, the splitting point is not set on the line edge where the lobe is located, so that in the existing OPC correction process, the corner rounding effect of the area caused by that the splitting point is not set in the lobe area and the OPC correction is not performed is serious, and the coverage rate of the metal layer and the through hole layer formed subsequently based on the layout is not up to standard or the problems of area reduction and product yield reduction due to up-down lamination are caused.

Disclosure of Invention

The invention aims to provide an OPC correction method and an OPC correction system, which are used for improving a line edge cutting strategy of a line endpoint graph on a metal layer graph and/or a through hole layer graph, so that a novel method for setting a cutting point on a line edge of the line endpoint graph is provided, at least one cutting point is set on the line edge corresponding to a corner of the line endpoint graph, the line edge corresponding to the corner is subjected to OPC correction at least once, the probability of corner rounding effect of a corner area of the line endpoint graph is reduced, and the OPC correction precision and correction efficiency are improved.

In order to solve the above technical problems, the present invention provides an OPC correction method, which may include the following steps:

Determining layout data of an original layout, wherein the original layout is a metal layer layout or a through hole layer layout, the original layout comprises line endpoint graphs with corners, and the layout data comprises side lengths of all line edges of the line endpoint graphs.

And dividing the line edges of the line endpoint graph into a first line edge, a second line edge, a first line edge set containing a plurality of the first line edges and a second line edge set containing a plurality of the second line edges based on the edge lengths of the line edges, wherein the edge length of the first line edge is larger than the edge length of the second line edge.

And adopting different segmentation points to segment the distances, and respectively carrying out segmentation point setting on the first line edge in the first line edge set and the second line edge in the second line edge set to obtain a plurality of line segments, wherein each line segment comprises line edge segments which are obtained after the line edges surrounding the corners are provided with segmentation points.

And carrying out OPC correction on each segment, calculating the edge position error after the OPC correction is carried out, and if the edge position error is not smaller than a preset error threshold value, carrying out OPC correction on the segment again until the total number of preset OPC iterations is reached or the edge position error is smaller than the preset error threshold value.

Further, the corner may specifically be a lobe corner, where the lobe corner is an angle located between two adjacent line edges in the line endpoint graph and is smaller than a preset angle, and the preset angle is less than or equal to 90 °.

Further, the step of dividing the first line edge set and the second line edge set may specifically include:

comparing the side length of each line side on the line endpoint graph with 2 times of a first set length A, forming a first line side set by line sides with the side length not smaller than 2 times of the first set length A, and forming a second line side set by line sides with the side length smaller than 2 times of the first set length A.

Further, the step of dividing the first line edge in the first line edge set and the second line edge in the second line edge set by using different dividing pitches may specifically include:

starting from two line edge end points of each first line edge in the first line edge set, taking the first set length A as a distance, pre-marking two virtual cutting points on the first set length A, and determining whether the line edge length between the two virtual cutting points is larger than A.

If not greater than A, a dividing point is arranged at the midpoint of the line edge.

If the length is larger than the first set length A, setting a cutting point at the position of the two virtual cutting points, taking the cutting point as a line edge end point corresponding to the rest line edge segments of the line edge, and returning to execute the step of pre-marking the two virtual cutting points on the first set length A serving as a distance to determine whether the line edge length between the two virtual cutting points is larger than the length A.

Further, the step of dividing the first line edge in the first line edge set and the second line edge in the second line edge set by using different dividing pitches may further include:

starting from two line edge end points of each second line edge in the second line edge set, taking a second set length B as a distance, pre-marking two virtual cutting points on the second line edge end points, and determining whether the line edge length between the two virtual cutting points is larger than B.

If not greater than B, a dividing point is arranged at the midpoint of the line edge.

If the length is larger than B, respectively setting a cutting point at the positions of the two virtual cutting points, taking the cutting point as a line edge endpoint corresponding to the rest line edge segments of the line edge, returning to execute the step of taking the second set length B as a distance, pre-marking the two virtual cutting points on the second set length B, and determining whether the line edge length between the two virtual cutting points is larger than B; wherein, B is less than A.

Further, the step of performing OPC correction on each segment may include performing edge-expansion processing or edge-contraction processing along a normal direction of each segment.

Further, after determining layout data of the original layout and before forming the first line edge set and the second line edge set, adding auxiliary graphics on the periphery of the line endpoint graphics according to a preset auxiliary graphics adding rule.

In a second aspect, based on the same inventive concept as the OPC correction method described above, an embodiment of the present invention further provides an OPC correction system, which may specifically include:

the line edge length determining module is used for determining layout data of an original layout, wherein the original layout is a metal layer layout or a through hole layer layout, the original layout comprises line endpoint figures with corners, and the layout data comprises edge lengths of all line edges of the line endpoint figures.

And the line edge set classification module is used for dividing the line edges of the line endpoint graph into a first line edge set, a second line edge set and a second line edge set, wherein the first line edge set comprises a plurality of first line edges and the second line edge set comprises a plurality of second line edges, and the edge length of the first line edge is larger than the edge length of the second line edge.

The cutting point setting module is used for adopting different cutting point cutting intervals to respectively set cutting points on a first line edge in the first line edge set and a second line edge in the second line edge set so as to obtain a plurality of line segments, wherein the line segments comprise line edge segments which are obtained after the cutting points are set on the line edges surrounding the corners.

And the OPC correction module is used for carrying out OPC correction on each segment of the line segment, calculating the edge position error after the OPC correction is carried out, and carrying out OPC correction on the line segment again if the edge position error is not smaller than a preset error threshold value until the total number of preset OPC iterations is reached or the edge position error is smaller than the preset error threshold value.

Further, the corner may be a lobe corner, where the lobe corner is an angle located between two adjacent line edges in the line endpoint graph and is smaller than a preset angle, and the preset angle may be equal to or smaller than 90 °.

Further, the line edge set classification module may be specifically configured to:

comparing the side length of each line side on the line endpoint graph with 2 times of a first set length A, forming a first line side set by line sides with the side length not smaller than 2 times of the first set length A, and forming a second line side set by line sides with the side length smaller than 2 times of the first set length A.

Further, the segmentation point setting module may specifically include:

and the first virtual cutting point setting unit is used for starting from two line edge end points of each first line edge in the first line edge set, taking the first set length A as a distance, pre-marking two virtual cutting points on the first set length A, and determining whether the line edge length between the two virtual cutting points is larger than A.

And the second cutting point setting unit is used for setting a cutting point at the midpoint position of the line edge if the length of the line edge between the two virtual cutting points is not more than A, setting a cutting point at the positions of the two virtual cutting points respectively if the length of the line edge between the two virtual cutting points is more than A, taking the cutting point as the line edge end point corresponding to the rest line edge segment of the line edge, and returning to execute the steps of taking the first set length A as a distance, pre-marking the two virtual cutting points on the first set length A, and determining whether the length of the line edge between the two virtual cutting points is more than A.

Further, the segmentation point setting module may further include:

and a second virtual cutting point setting unit, configured to, starting from two line edge end points of each second line edge in the second line edge set, pre-mark two virtual cutting points on the second line edge end points with a second set length B as a distance, and determine whether the line edge length between the two virtual cutting points is greater than B.

A second dividing point setting unit, configured to set a dividing point at a midpoint position of the line edge if it is determined that the length of the line edge between the two virtual dividing points is not greater than B, set a dividing point at the positions of the two virtual dividing points if it is determined that the length of the line edge between the two virtual dividing points is greater than B, set the dividing point as a line edge endpoint corresponding to a remaining line edge segment of the line edge, and return to perform the step of pre-marking the two virtual dividing points on the line edge endpoint with the second set length B as a distance, and determine whether the length of the line edge between the two virtual dividing points is greater than B; wherein, B is less than A.

In a third aspect, based on the OPC correction method as described above, the present invention further provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, where the processor, the communication interface, and the memory complete communication with each other through the communication bus.

And a memory for storing a computer program.

And a processor for implementing the steps of the OPC correction method as described above when executing the program stored in the memory.

Compared with the prior art, the technical scheme provided by the invention has at least one of the following beneficial effects:

After layout data of an original layout including a metal layer layout or a through hole layer layout is determined, dividing a plurality of line edges of a line endpoint graph with corners into two line edge sets according to different lengths based on line edge lengths of the line endpoint graph with corners contained in the layout data, and then dividing the two line edge sets into line edge dividing points by different dividing point dividing intervals according to the two line edge sets, wherein unexpected effects are as follows: aiming at improving the line edge cutting strategy of the line endpoint graph on the metal layer graph and/or the through hole layer graph, a novel method (cutting algorithm of the cutting point) for setting the cutting point on the line edge of the line endpoint graph is provided, and when the cutting point is set for the line edge corresponding to the corner of the line endpoint graph on the metal layer graph and/or the through hole layer graph based on the cutting algorithm of the cutting point, different cutting point cutting intervals can be set for different line edge lengths, namely, the problem that the line edge corresponding to the corner can be at least provided with a cutting point and OPC correction is carried out at least once is solved, so that the problem that in the prior art, the cutting point cutting is carried out for a plurality of line edges of the line endpoint graph with different edge lengths by adopting the same cutting point cutting interval, the length of the line edge where the lobe of the line endpoint graph is located is not provided with the cutting point due to the fact that the cutting point is smaller than the preset length setting value of the cutting point, and the corner of the area is seriously corrected due to the fact that the corner effect of the corner of the area is seriously corrected is seriously OPC.

In addition, due to the OPC correction method provided by the invention, the probability of corner rounding effect of line endpoint patterns with lobe corners on the metal layer layout and/or the through hole layer layout is reduced, namely, the metal line structure or the through hole structure formed on an actual silicon wafer by utilizing the corrected mask is ensured to meet the design requirement, and meanwhile, the overlapping area of the formed metal layer structure and through hole layer structure on the upper layer and the lower layer is increased, and finally, the purpose of improving the product yield of a semiconductor device is realized.

Drawings

Fig. 1 is a schematic structural diagram of a corner rounding effect (oval circled part) of a lobe corner obtained by performing segmentation point setting, OPC correction and lithography simulation on a line end point graph with the lobe corner on a metal line layer layout or a through hole layer layout by using a segmentation point segmentation algorithm in the prior art.

FIG. 2 is a flowchart of an OPC correction method according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a line endpoint graph with a lobe corner according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of a partial layout of a line endpoint graph after OPC correction using the prior art.

FIG. 5 is a schematic diagram of a partial layout of the line end point graph of FIG. 3 after OPC correction using the OPC correction method of FIG. 2 in accordance with an embodiment of the present invention.

FIG. 6 is a comparison chart of a simulation graph of a partial OPC model after photo-etching simulation, which is provided in an embodiment of the present invention, by performing OPC correction on the line end point graph shown in FIG. 3 by using the prior art shown in FIG. 1 and the OPC correction method provided in the present invention shown in FIG. 2, respectively.

Detailed Description

In order to make the technical scheme and advantages of the embodiments of the present invention more clear, the technical scheme of the present invention will be further described in detail below with reference to the accompanying drawings and the embodiments. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The invention is more particularly described by way of example in the following paragraphs with reference to the drawings. Advantages and features of the invention will become more apparent from the following description and from the claims. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention. It is to be understood that the meanings of "on … …", "over … …" and "over … …" in the present invention are to be interpreted in the broadest sense so that "on … …" means not only that it is "on" something with no intervening features or layers therebetween (i.e., directly on something), but also that it is "on" something with intervening features or layers therebetween.

Further, spatially relative terms such as "on … …," "above … …," "above … …," "upper" and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated for ease of description. In addition to the orientations depicted in the drawings, the spatially relative terms are intended to encompass different orientations of the device in use or operation. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In embodiments of the present invention, the terms "first," "second," and the like are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. The technical schemes described in the embodiments of the present invention may be arbitrarily combined without any collision.

According to the related art, in the optical proximity correction field, for line endpoint patterns with corners, a common OPC correction method is model-based OPC correction, specifically, the edges of the mask design pattern can be first identified by OPC software, and then the edges of the mask design pattern are cut into a plurality of small correction line segments, so that the edges of each line segment can move freely. The OPC software then simulates the pattern after the lithographic exposure, and compares it with the design target pattern of the reticle, the difference between them being called edge placement error (EPE, edge Placement Error), which is an indicator for measuring the quality of the correction. The OPC software moves the edge position of the mask design graph when running, calculates the corresponding edge placement error, and repeatedly processes until the calculated edge placement error reaches an acceptable value.

However, since the length of the line edge where the lobe (which may also be referred to as a lobe corner) of the line end pattern on the metal layer layout and/or the via layer layout is located is smaller than the preset length set value of the splitting point, the splitting point is not set on the line edge where the lobe end pattern is located, which may result in a serious problem (as shown in fig. 1) of the corner rounding effect of the area caused by that the splitting point is not set in the multiple lobe areas and OPC correction is not performed in the existing OPC correction process, that is, the existing technology of adopting the same splitting point to split the pitch is not suitable for OPC correction of the layout corresponding to the metal layer structure with high coverage rate or the via layer structure with large area. Fig. 1 is a schematic structural diagram of a graph of a line end point with a lobe corner on a metal line layer layout or a through hole layer layout by using a segmentation point segmentation algorithm in the prior art, wherein the graph is obtained by performing segmentation point setting, OPC correction and photoetching simulation on the graph of the line end point with the lobe corner, and the lobe corner has a corner rounding effect (a part marked by an elliptical circle in fig. 1).

Therefore, the invention provides an OPC correction method and an OPC correction system, which are used for improving a line edge cutting strategy of line end point patterns on a metal layer layout and/or a through hole layer layout, so that a novel method for setting cutting points on the line edges of the line end point patterns is provided, at least one cutting point is set on the line edges corresponding to the corners of the line end point patterns, the line edges corresponding to the corners are subjected to OPC correction at least once, the probability of corner rounding effect of the corner areas of the line end point patterns is reduced, and the OPC correction precision and correction efficiency are improved.

An OPC correction method provided in the embodiment of the present invention will be specifically described with reference to fig. 2 to 6.

Referring to fig. 2, fig. 2 is a flowchart of an OPC correction method according to an embodiment of the present invention, the method includes the following steps:

step S201, determining layout data of an original layout, wherein the original layout is a metal layer layout or a through hole layer layout, the original layout comprises line endpoint figures with corners, and the layout data comprises side lengths of all line edges of the line endpoint figures.

As an example, the line endpoint graph with corners provided in the embodiment of the present invention is a line endpoint graph with lobe corners, such as the line endpoint graph shown in fig. 3. The original layout shown in fig. 3 is a schematic diagram of a layout including a line endpoint graph with a lobe corner.

It can be understood that the line end point graph on the layout is a closed graph formed by connecting a plurality of line edges in a tail-end manner, so that the line end point graph has both a convex corner and a concave corner, wherein the convex corner is specifically an angle that an included angle between two adjacent line edges in the line end point graph is smaller than or equal to 90 degrees, and the concave corner is an angle that an included angle between two adjacent line edges in the line end point graph is smaller than >90 degrees.

Step S202, dividing the line edges of the line endpoint graph into a first line edge set including a plurality of first line edges and a second line edge set including a plurality of second line edges based on the edge lengths of the line edges.

Wherein the side length of the first line edge in the first line edge set is larger than the side length of the second line edge in the second line edge set.

In this embodiment, since the main innovation point of the embodiment of the present invention is to perform the split point setting policy of different split point splitting pitches based on line edges with different lengths of the line endpoint graph with the lobe corner, before OPC correction is performed on each line endpoint graph on the original layout, the line edges of the line endpoint graph need to be classified.

As a preferred example, the embodiment of the present invention provides a specific implementation method for classifying line edges of the line endpoint graph according to different edge lengths, which may include the following steps:

step S202.1, comparing the side length of each line side on the line endpoint graph with 2 times of a first set length A, forming a first line side set by line sides with the side length not smaller than 2 times of the first set length A, and forming a second line side set by line sides with the side length smaller than 2 times of the first set length A.

In this embodiment, after the layout data or the layout file of the original layout is obtained in the step S201, when the conventional OPC is performed on the line endpoint graph with the lobe corner in the original layout by using the OPC model, the segmentation pitch of the corresponding segmentation point, that is, the first set length a described in the embodiment of the present invention, and then the first set length a (abbreviated as 2A) 2 times is used as a criterion for the segmentation pitch of the new segmentation point provided in the embodiment of the present invention, so as to classify the multiple line edges of the line endpoint graph on the original layout, that is, the metal layer layout and/or the through hole layer layout.

It should be noted that, the first set length a obtained based on the OPC model is usually an empirical value of the segmentation pitch of the segmentation points for different shapes and for both line edges and corners (not only the lobe corners but also the concave corners) obtained through training of the sample library, and since the line edges with different lengths and the lobe corners and the concave corners of the line end point graph have different requirements for the segmentation point setting, when the segmentation point setting of the line end point graph is performed by using the first set length a obtained by using the OPC model, the length of the first set length a is often greater than the length of the line edge where the lobe corners of the line end point graph are located, so that any segmentation point is not set on the line edges corresponding to the lobe corners at the two line end points, and the OPC correction on the line edges of the OPC model takes the line segments corresponding to the segmentation point as units.

Step 203, dividing the first line edge in the first line edge set and the second line edge in the second line edge set by adopting different dividing points to divide the distance, so as to obtain a plurality of line segments, wherein the line segments comprise line edge segments which are obtained after dividing points are arranged on the line edges surrounding the corners.

As a preferred example, the step of setting a segmentation point for a first line edge in the first line edge set in the embodiment of the present invention may include:

step S203.1, starting from two line edge end points of each first line edge in the first line edge set, taking the first set length a as a distance, pre-marking two virtual cutting points on the first line edge end points, and determining whether the line edge length between the two virtual cutting points is greater than a, wherein the unit of the first set length a is nm.

Step 203.2, if the length of the line edge between the two virtual dividing points is not greater than a, setting a dividing point at the midpoint position of the line edge; if the length of the line edge between the two virtual cutting points is greater than A, setting a cutting point at the positions of the two virtual cutting points respectively, taking the cutting point as the line edge end point corresponding to the rest line edge segments of the line edge, returning to execute the step of taking the first set length A as a distance, pre-marking the two virtual cutting points on the first set length A, and determining whether the length of the line edge between the two virtual cutting points is greater than A.

In this embodiment, the line edge lengths of the first line edges in the first line edge set are all greater than 2A, so that there is no need to set a cutting point due to the lobe corner enclosed by the line edges (the first line edges), so that, for the line edges of the line end point graph, the method for setting the cutting point in the embodiment of the present invention begins with moving the distance of the length a inward along two line edge end points of the line edges, at this time, two virtual cutting points (the assumed positions before the cutting point is to be set) are corresponding to the line edges, and then the relationship between the distance between the two virtual cutting points and the a is calculated, so as to determine whether to set the cutting point at the midpoint position on the line edges or set the cutting point on the virtual cutting point.

For example, assuming that the line end point graph to be subjected to the split point setting is an "L" type graph as shown in fig. 3, where a, b, and c represent line edge end points, respectively, so that the lobe angle corresponding to the line end point graph shown in fig. 3 is an angle surrounded by a first line edge ab and a first line edge ac, and the edge length of the first line edge ab is 100nm, the edge length of the first line edge ac is 60nm, assuming that the first set length a is 45nm, and for the first line edge ab with the edge length of 100, the process of setting the split point by using the method provided in the embodiment of the present invention is: comparing 2 a=90 nm with 100nm of the first line side ab, finding that the first line side ab has a side length greater than 2A, moving the two line side end points a and b of the first line side ab in fig. 3 in opposite directions, respectively moving the distance 45nm to obtain two virtual cut point positions, comparing the relationship between the line side segment with the remaining side length of 10 and the a, and if 10 is smaller than a (45 nm), the virtual cut point is not the target cut point setting position of the first line side ab with the side length of 100, but the midpoint position (the position corresponding to the side length of 50 nm) of the first line side ab is taken as the target cut point position of the first line side ab, setting a cut point at the position, and in the same way, since the first line side ac with the side length of 60 is smaller than 2A, directly taking the midpoint position (the position corresponding to the side length of 30) as the target cut point of the first line side, setting a virtual cut point at the position of the first line side ac, and setting a virtual cut point a subsequent to the virtual cut point a with the remaining side length of the first line side ac is set at the position, and if the virtual cut point a is set at the position of the first line ac is set as described above, and the virtual cut point a is set between the virtual cut point a subsequent cut point is set as the virtual cut point a line a and a subsequent step is set.

Further, the step of setting the segmentation point for the second line edge set in the embodiment of the present invention may include:

step S203.3, starting from two line edge end points of each second line edge in the second line edge set, taking a second set length B as a distance, pre-marking two virtual cutting points on the second set length B, and determining whether the line edge length between the two virtual cutting points is greater than B.

Step 203.4, if the length of the line edge between the two virtual dividing points is not greater than B, setting a dividing point at the midpoint position of the line edge; if the length of the line edge between the two virtual cutting points is greater than B, setting a cutting point at the positions of the two virtual cutting points respectively, taking the cutting point as a line edge end point corresponding to the rest line edge segments of the line edge, and returning to execute the step of taking the second set length B as a distance, pre-marking the two virtual cutting points on the second set length B, and determining whether the length of the line edge between the two virtual cutting points is greater than B; wherein, B is less than A.

In this embodiment, the method for setting the dividing point is unchanged for the second line edge in the second line edge set (the same method as the method for setting the first line edge in the first line edge set), but the distance between the dividing points is different from the distance between the dividing points of the first line edge set and is specifically smaller than the distance a adopted by the first line edge set, so that when the dividing point is set by using the distance a, line edges with a length smaller than the length of the line edge a, which cannot be set by the dividing point, can be selected, and according to the actual verification, the second line edge in the second line edge set selected by the match is the adjacent line edge surrounding the corner of the lobe, so that the corner region can be determined by using step S203.3 and step S203.4 provided in the embodiment of the present invention.

However, in the setting strategy of the specific dividing points provided in the embodiment of the present invention, at least one dividing point may be set on the line edge corresponding to the corner of the convex angle with the second set length B smaller than a set length a as a distance, so that the line edge corresponding to the corner of the convex angle may perform subsequent OPC correction, thereby reducing the probability of occurrence of corner rounding effect and improving the correction accuracy of OPC.

Step S204, OPC correction is carried out on each segment of the line segment, and edge position errors after the OPC correction is carried out are calculated, if the edge position errors are not smaller than a preset error threshold, OPC correction is carried out on the line segment again until the preset total OPC iteration times are reached or the edge position errors are smaller than the preset error threshold.

The preset error threshold is an ideal design value of edge position error or an experience value for enabling an OPC correction effect to achieve a design purpose in an OPC correction process of line endpoint graphics with lobe corners on a metal line layer layout or a through hole layer layout.

In this embodiment, in the step of obtaining the line segments divided from the first line edge in the first line edge set or the second line edge in the second line edge set by using the above steps, the outward expansion process or the inward contraction process is performed along the normal direction of each line segment according to the model-based OPC correction method. The normal direction of the line segment is the direction perpendicular to the length direction of the line segment.

Referring to fig. 4 to 6, fig. 4 is a schematic diagram of a partial layout after OPC correction of a line endpoint pattern by using the prior art, fig. 5 is a schematic diagram of a partial layout after OPC correction of a line endpoint pattern shown in fig. 3 by using the OPC correction method shown in fig. 2 provided in an embodiment of the present invention, and fig. 6 is a comparative diagram of a partial OPC model simulation pattern after lithography simulation after OPC correction of a line endpoint pattern shown in fig. 3 by using the prior art shown in fig. 1 and the OPC correction method provided in the present invention shown in fig. 2 provided in an embodiment of the present invention.

Obviously, after the line endpoint graph with the lobe corner on the metal line layer layout or the through hole layer layout is corrected by using the OPC method provided by the embodiment of the present invention, the corresponding simulation graph S2 is closer to the target design graph S1, and after the line endpoint graph with the lobe corner on the metal line layer layout or the through hole layer layout is corrected by using the OPC method provided by the prior art, the corresponding simulation graph S3 is significantly different from the target design graph S1 in the lobe corner region compared with the graph S2.

It can be understood that after determining layout data of the original layout and before forming the first line edge set and the second line edge set, auxiliary graphics are added to the periphery of the line endpoint graphics according to a preset auxiliary graphics adding rule.

Based on the OPC correction method as described above, there is also provided an OPC correction system in this embodiment, which may include:

the line edge length determining module is used for determining layout data of an original layout, wherein the original layout is a metal layer layout or a through hole layer layout, the original layout comprises line endpoint figures with corners, and the layout data comprises edge lengths of all line edges of the line endpoint figures.

And the line edge set classification module is used for dividing the line edges of the line endpoint graph into a first line edge set, a second line edge set and a second line edge set, wherein the first line edge set comprises a plurality of first line edges, and the second line edge set comprises a plurality of second line edges, and the edge length of the first line edge is larger than the edge length of the second line edge.

The cutting point setting module is used for adopting different cutting point cutting intervals to respectively set cutting points on a first line edge in the first line edge set and a second line edge in the second line edge set so as to obtain a plurality of line segments, wherein the line segments comprise line edge segments which are obtained after the cutting points are set on the line edges surrounding the corners.

And the OPC correction module is used for carrying out OPC correction on each segment of the line segment, calculating the edge position error after the OPC correction is carried out, and carrying out OPC correction on the line segment again if the edge position error is not smaller than a preset error threshold value until the total number of preset OPC iterations is reached or the edge position error is smaller than the preset error threshold value.

The corner is a convex corner, the convex corner is an angle smaller than a preset angle between two adjacent line edges in the line endpoint graph, and the preset angle is smaller than or equal to 90 degrees.

Further, the line edge set classification module may be specifically configured to:

comparing the side length of each line side on the line endpoint graph with 2 times of a first set length A, forming a first line side set by line sides with the side length not smaller than 2 times of the first set length A, and forming a second line side set by line sides with the side length smaller than 2 times of the first set length A.

Further, the segmentation point setting module may include:

and the first virtual cutting point setting unit is used for starting from two line edge end points of each first line edge in the first line edge set, taking the first set length A as a distance, pre-marking two virtual cutting points on the first set length A, and determining whether the line edge length between the two virtual cutting points is larger than A.

And the second cutting point setting unit is used for setting a cutting point at the midpoint position of the line edge if the length of the line edge between the two virtual cutting points is not more than A, setting a cutting point at the positions of the two virtual cutting points respectively if the length of the line edge between the two virtual cutting points is more than A, taking the cutting point as the line edge end point corresponding to the rest line edge segment of the line edge, and returning to execute the steps of taking the first set length A as a distance, pre-marking the two virtual cutting points on the first set length A, and determining whether the length of the line edge between the two virtual cutting points is more than A.

Further, the segmentation point setting module may further include:

and a second virtual cutting point setting unit, configured to, starting from two line edge end points of each second line edge in the second line edge set, pre-mark two virtual cutting points on the second line edge end points with a second set length B as a distance, and determine whether the line edge length between the two virtual cutting points is greater than B.

A second dividing point setting unit, configured to set a dividing point at a midpoint position of the line edge if it is determined that the length of the line edge between the two virtual dividing points is not greater than B, set a dividing point at the positions of the two virtual dividing points if it is determined that the length of the line edge between the two virtual dividing points is greater than B, set the dividing point as a line edge endpoint corresponding to a remaining line edge segment of the line edge, and return to perform the step of pre-marking the two virtual dividing points on the line edge endpoint with the second set length B as a distance, and determine whether the length of the line edge between the two virtual dividing points is greater than B; wherein, B is less than A.

In summary, in the OPC correction method provided by the present invention, after determining layout data of an original layout including a metal layer layout or a via layer layout, dividing a plurality of line edges of a line endpoint graph with corners into two line edge sets according to different lengths based on line edge lengths of the line endpoint graph with corners included in the layout data, and then performing line edge segmentation point setting by respectively adopting different segmentation point segmentation pitches for the two line edge sets, unexpected effects in the present application are that: aiming at improving the line edge cutting strategy of the line endpoint graph on the metal layer graph and/or the through hole layer graph, a novel method (cutting algorithm of the cutting point) for setting the cutting point on the line edge of the line endpoint graph is provided, and when the cutting point is set for the line edge corresponding to the corner of the line endpoint graph on the metal layer graph and/or the through hole layer graph based on the cutting algorithm of the cutting point, different cutting point cutting intervals can be set for different line edge lengths, namely, the problem that the line edge corresponding to the corner can be at least provided with a cutting point and OPC correction is carried out at least once is solved, so that the problem that in the prior art, the cutting point cutting is carried out for a plurality of line edges of the line endpoint graph with different edge lengths by adopting the same cutting point cutting interval, the length of the line edge where the lobe of the line endpoint graph is located is not provided with the cutting point due to the fact that the cutting point is smaller than the preset length setting value of the cutting point, and the corner of the area is seriously corrected due to the fact that the corner effect of the corner of the area is seriously corrected is seriously OPC.

In addition, due to the OPC correction method provided by the invention, the probability of corner rounding effect of line endpoint patterns with lobe corners on the metal layer layout and/or the through hole layer layout is reduced, namely, the metal line structure or the through hole structure formed on an actual silicon wafer by utilizing the corrected mask is ensured to meet the design requirement, and meanwhile, the overlapping area of the formed metal layer structure and through hole layer structure on the upper layer and the lower layer is increased, and finally, the purpose of improving the product yield of a semiconductor device is realized.

The embodiment of the invention also provides an electronic device, which comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus,

a memory for storing a computer program;

and the processor is used for realizing the OPC correction method provided by the embodiment of the invention when executing the program stored in the memory.

In addition, other implementations of the OPC correction method implemented by the processor executing the program stored in the memory are the same as those mentioned in the foregoing method embodiment, and will not be described herein again.

The communication bus mentioned by the control terminal may be a peripheral component interconnect standard (Peripheral Component Interconnect, PCI) bus or an extended industry standard architecture (Extended Industry Standard Architecture, EISA) bus, etc. The communication bus may be classified as an address bus, a data bus, a control bus, or the like. For ease of illustration, the figures are shown with only one bold line, but not with only one bus or one type of bus.

The communication interface is used for communication between the electronic device and other devices.

The Memory may include random access Memory (Random Access Memory, RAM) or may include Non-Volatile Memory (NVM), such as at least one disk Memory. Optionally, the memory may also be at least one memory device located remotely from the aforementioned processor.

The processor may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but also digital signal processors (Digital Signal Processing, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

In yet another embodiment of the present invention, a computer readable storage medium is provided, in which instructions are stored, which when run on a computer, cause the computer to perform the OPC correction method of any of the above embodiments.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may 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 loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present invention, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, optical fiber, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD)), etc.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In this specification, each embodiment is described in a related manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for apparatus, electronic devices, and computer-readable storage medium embodiments, the description is relatively simple, as it is substantially similar to method embodiments, with reference to portions of the description of method embodiments being relevant.

The foregoing description is only of the preferred embodiments of the present invention and is not intended to limit the 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 (10)

1. An OPC correction method, comprising:

determining layout data of an original layout, wherein the original layout is a metal layer layout or a through hole layer layout, the original layout comprises line endpoint figures with corners, and the layout data comprises side lengths of all line edges of the line endpoint figures;

dividing the line edges of the line endpoint graph into a first line edge, a second line edge, a first line edge set comprising a plurality of the first line edges and a second line edge set comprising a plurality of the second line edges based on the edge lengths of the line edges, wherein the edge length of the first line edge is greater than the edge length of the second line edge;

dividing the first line edge in the first line edge set and the second line edge in the second line edge set by adopting different dividing point dividing intervals to respectively perform dividing point setting so as to obtain a plurality of line segments, wherein each line segment comprises line edge fragments, which are obtained after dividing points are arranged on the line edges surrounding the corners;

And carrying out OPC correction on each segment, calculating the edge position error after the OPC correction is carried out, and if the edge position error is not smaller than a preset error threshold value, carrying out OPC correction on the segment again until the total number of preset OPC iterations is reached or the edge position error is smaller than the preset error threshold value.

2. The OPC correction method of claim 1 wherein the corners are lobe corners, the lobe corners being angles between two adjacent line edges in the line end pattern less than a predetermined angle, the predetermined angle being equal to or less than 90 °.

3. The OPC correction method of claim 2 wherein the step of dividing the first line side set and the second line side set comprises:

comparing the side length of each line side on the line endpoint graph with 2 times of a first set length A, forming a first line side set by line sides with the side length not smaller than 2 times of the first set length A, and forming a second line side set by line sides with the side length smaller than 2 times of the first set length A.

4. The OPC correction method of claim 3 wherein the step of performing split point setting for the first line edge in the first line edge set and the second line edge in the second line edge set, respectively, using different split point split pitches, comprises:

Starting from two line edge end points of each first line edge in the first line edge set, taking the first set length A as a distance, pre-marking two virtual cutting points on the first set length A, and determining whether the line edge length between the two virtual cutting points is larger than A;

if the value is not greater than A, setting a cutting point at the midpoint of the line edge;

if the length is larger than the first set length A, setting a cutting point at the position of the two virtual cutting points, taking the cutting point as a line edge end point corresponding to the rest line edge segments of the line edge, and returning to execute the step of pre-marking the two virtual cutting points on the first set length A serving as a distance to determine whether the line edge length between the two virtual cutting points is larger than the length A.

5. The OPC correction method of claim 4 wherein the step of performing split point setting for the first line edge in the first line edge set and the second line edge in the second line edge set with different split point split pitches, respectively, further comprises:

starting from two line edge end points of each second line edge in the second line edge set, taking a second set length B as a distance, pre-marking two virtual cutting points on the second set length B, and determining whether the line edge length between the two virtual cutting points is larger than B;

If not more than B, setting a cutting point at the midpoint of the line edge;

if the length is larger than B, respectively setting a cutting point at the positions of the two virtual cutting points, taking the cutting point as a line edge endpoint corresponding to the rest line edge segments of the line edge, returning to execute the step of taking the second set length B as a distance, pre-marking the two virtual cutting points on the second set length B, and determining whether the line edge length between the two virtual cutting points is larger than B; wherein, B is less than A.

6. An OPC correction system comprising:

the line edge length determining module is used for determining layout data of an original layout, wherein the original layout is a metal layer layout or a through hole layer layout, the original layout comprises line endpoint figures with corners, and the layout data comprises edge lengths of all line edges of the line endpoint figures;

the line edge set classification module is used for dividing the line edges of the line endpoint graph into a first line edge, a second line edge, a first line edge set containing a plurality of the first line edges and a second line edge set containing a plurality of the second line edges based on the edge lengths of the line edges, wherein the edge length of the first line edge is larger than the edge length of the second line edge;

The cutting point setting module is used for adopting different cutting point cutting intervals to respectively set cutting points on a first line edge in the first line edge set and a second line edge in the second line edge set so as to obtain a plurality of line segments, wherein the line segments comprise line edge segments which are obtained after the cutting points are set on the line edges surrounding the corners;

and the OPC correction module is used for carrying out OPC correction on each segment of the line segment, calculating the edge position error after the OPC correction is carried out, and carrying out OPC correction on the line segment again if the edge position error is not smaller than a preset error threshold value until the total number of preset OPC iterations is reached or the edge position error is smaller than the preset error threshold value.

7. The OPC correction system of claim 6 wherein the corners are lobe corners, the lobe corners being angles between two adjacent line edges in the line end pattern less than a predetermined angle, the predetermined angle being less than or equal to 90 °.

8. The OPC correction system of claim 7 wherein the line-side set classification module is specifically configured to:

comparing the side length of each line side on the line endpoint graph with 2 times of a first set length A, forming a first line side set by line sides with the side length not smaller than 2 times of the first set length A, and forming a second line side set by line sides with the side length smaller than 2 times of the first set length A.

9. The OPC correction system of claim 8 wherein the split point setting module comprises:

a first virtual cutting point setting unit, configured to, starting from two line edge end points of each first line edge in the first line edge set, pre-mark two virtual cutting points on the first line edge set with the first set length a as a distance, and determine whether the line edge length between the two virtual cutting points is greater than a;

and the second cutting point setting unit is used for setting a cutting point at the midpoint position of the line edge if the length of the line edge between the two virtual cutting points is not more than A, setting a cutting point at the positions of the two virtual cutting points respectively if the length of the line edge between the two virtual cutting points is more than A, taking the cutting point as the line edge end point corresponding to the rest line edge segment of the line edge, and returning to execute the steps of taking the first set length A as a distance, pre-marking the two virtual cutting points on the first set length A, and determining whether the length of the line edge between the two virtual cutting points is more than A.

10. The OPC correction system of claim 9 wherein the split point setting module further comprises:

a second virtual cutting point setting unit, configured to, starting from two line edge end points of each second line edge in the second line edge set, pre-mark two virtual cutting points on a second set length B as a distance, and determine whether a line edge length between the two virtual cutting points is greater than B;

A second dividing point setting unit, configured to set a dividing point at a midpoint position of the line edge if it is determined that the length of the line edge between the two virtual dividing points is not greater than B, set a dividing point at the positions of the two virtual dividing points if it is determined that the length of the line edge between the two virtual dividing points is greater than B, set the dividing point as a line edge endpoint corresponding to a remaining line edge segment of the line edge, and return to perform the step of pre-marking the two virtual dividing points on the line edge endpoint with the second set length B as a distance, and determine whether the length of the line edge between the two virtual dividing points is greater than B; wherein, B is less than A.