JP2014081472A - Optical proximity effect correction method, processing unit, program, production method of mask, and production method of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical proximity effect correction method in which optical proximity effect correction can be easily and approximately performed; a processing unit; a program; a production method of a mask; and a production method of a semiconductor device.SOLUTION: In an optical proximity effect correction method, an OPC processing object layout pattern is extracted from an OPC execution region in which a difference layout pattern is assumed an origin, rule base OPC processing is performed to an OPC processing object layout pattern to generate an after OPC layout pattern, a replacement object after OPC layout pattern and a before modification after OPC layout pattern are used, and OPC layout data of an after modification layout pattern are acquired. An OPC execution region is a region in which only a distance A is removed as that a difference layout pattern is assumed an origin, and a layout data extraction region is a region in which a distance C is removed as that a difference layout pattern is assumed an origin.

Description

  The present invention relates to an optical proximity effect correction method, a processing apparatus, a program, a mask manufacturing method, and a semiconductor device manufacturing method, for example, an optical proximity effect correction method using a rule-based OPC process, a processing apparatus, a program, and a mask manufacturing. The present invention relates to a method and a method for manufacturing a semiconductor device.

  In recent years, the layout pattern of a semiconductor integrated circuit has been miniaturized and has become finer than the wavelength of a light source used for exposure. In order to prevent the resolution at the time of exposure from decreasing, a special transfer technique such as a modified illumination technique is used. When such a special transfer technique is used, a dimensional variation or the like occurs in the transferred pattern. There is optical proximity effect correction (OPC: Optical Proximity Effect Correction: hereinafter referred to as OPC) as a technique for preventing dimensional variation and the like (Patent Document 1).

JP 2010-175898 A

  In the method of Patent Document 1, when a part of the design pattern is corrected, the area to be re-OPC-processed includes the changed part and the changed part, and more than twice the optical radius from the changed part (of the optical radius). In order to reflect the influence of the surrounding pattern on the pattern at the position). If the correction target is set to be twice or more the optical radius from the changed portion, there is a problem that the processing time of OPC increases.

  Other problems and novel features will become apparent from the description of the specification and the accompanying drawings.

  According to an embodiment, the first area where the OPC process for generating the post-OPC layout pattern is performed, the starting point of the difference pattern is a value obtained by doubling the maximum reference value to the maximum minus correction value. The second area for extracting the second layout pattern from the post-OPC layout pattern is the area separated by the first distance equal to or greater than the added value obtained by adding the absolute values. Starting from the difference pattern, this is a region separated by a second distance equal to or greater than an addition value obtained by adding the absolute value of the maximum minus correction value to the maximum reference value.

  According to the one embodiment, it is possible to provide an optical proximity effect correction method, a processing apparatus, a program, a mask manufacturing method, and a semiconductor device manufacturing method capable of performing optical proximity effect correction simply and appropriately.

It is a figure which shows typically the whole structure of the system concerning this Embodiment. It is a flowchart which shows an OPC processing method. It is the figure which showed the layout data example of a LVL process. It is a figure which shows the OPC execution area calculated | required from the difference layout pattern. It is a figure which shows the post-OPC layout pattern obtained from the OPC execution area. It is a figure which shows the layout data extraction area | region containing a layout pattern after OPC. It is a figure which shows the layout pattern after replacement | exchange OPC contained in a layout data extraction area. It is a figure which shows the layout pattern which synthesize | combined the layout pattern after OPC after replacement, and the layout pattern after OPC before correction. It is the figure which showed the example of application of a rule base OPC process. It is a table | surface which shows the correction rule table used by a rule base OPC process. It is a table | surface which shows another correction rule table used by rule-based OPC process. It is the figure which showed the example which compared the OPC process area | region of this Embodiment and the comparative example. It is the figure which showed the example which compared the OPC process area | region of this Embodiment and the comparative example.

  For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In addition, each element described in the drawing as a functional block for performing various processes can be configured by a CPU, a memory, and other circuits in hardware, and is realized by a program loaded in the memory in software. The Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof, and is not limited to any one. Note that, in each drawing, the same element is denoted by the same reference numeral, and redundant description is omitted as necessary.

  Further, the above-described program can be stored using various types of non-transitory computer readable media and supplied to a computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROM (Read Only Memory) CD-R, CD -R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  The method according to the present embodiment relates to a process for designing an OPC mask. The OPC is designed to obtain a desired layout pattern after the transfer by preliminarily deforming the design pattern in consideration of the dimensional variation during transfer. The OPC determines a correction amount (bias amount) for each edge of the layout pattern from the layout pattern attributes such as the size and shape of the layout pattern and the proximity status with the adjacent layout pattern. The amount of layout pattern data has been increasing with the progress of miniaturization, and it takes an enormous amount of time to process layout pattern data of several Gbytes. However, by using the optical proximity effect method according to the present embodiment, the processing can be simplified and the processing time can be shortened.

  A system according to the present embodiment will be described. FIG. 1 shows the overall configuration of the system. The system 1 includes a computer device 10, a server 14, and a network 16. The server 14 stores a recording medium 15. The recording medium 15 stores an execution program and is held by the server 14. The server 14 is connected to a computer apparatus 10 such as an engineering workstation via a network 16 such as the Internet. The execution program stored in the recording medium 15 is downloaded to the computer device 10 via the network 16. The computer apparatus 10 has a storage unit 66 including a hard disk or a memory. The downloaded program is stored in the local storage unit 66 of the computer device 10 and is executed. Further, the memory of the storage unit 66 stores a correction rule table described later.

  The computer apparatus 10 includes an LVL processing unit 67, an OPC execution area extraction unit 62, an OPC processing unit 63, a post-OPC layout pattern extraction unit 64, and an embedded processing unit 65. Here, although one computer apparatus 10 will be described as a processing apparatus that executes the optical proximity correction method, the processing apparatus is not limited to a physically single apparatus. For example, the following processing may be performed in cooperation of two or more computer apparatuses 10 and servers 14 connected via a network.

  The computer apparatus 10 executes arithmetic processing for designing a pattern on a mask (hereinafter referred to as a mask pattern) from a layout pattern transferred to a semiconductor device such as a wafer by photolithography. For example, when a part of an existing layout pattern is changed, the computer apparatus 10 designs a mask pattern for the changed layout pattern. Here, the computer apparatus 10 designs a mask pattern of an OPC mask that performs optical proximity effect correction. That is, the computer apparatus 10 generates a mask pattern for performing optical proximity effect correction on the layout pattern to be transferred. Hereinafter, processing of each unit provided in the computer apparatus 10 will be described.

  An optical proximity effect correction method executed in the computer apparatus 10 will be described with reference to FIGS. FIG. 2 is a flowchart showing the optical proximity correction method. 3-8 is a figure for demonstrating the pattern in each process. 3 to 8, description will be made using an XY two-dimensional orthogonal coordinate system for clarification of explanation. The X direction is the horizontal direction, and the Y direction is the vertical direction.

  First, when a part of the design data (layout pattern) is corrected, the LVL processing unit 61 of the computer apparatus 10 performs an LVL (Layout vs Layout) process in order to specify a correction location (step S1). FIG. 3 is a diagram showing step S1 as a specific layout pattern. The layout pattern before correction is shown as a layout pattern 30 before correction, and the layout pattern after correction is shown as a layout pattern 31 after correction. As shown in FIG. 3, the pre-correction layout pattern 30 and the post-correction layout pattern 31 have one pattern extending in the X direction and three patterns extending in the Y direction. In one of the patterns extending in the Y direction, the modified layout pattern 31 is shorter than the unmodified layout pattern 30. That is, the layout is modified so as to shorten one of the patterns in the Y direction.

  When the LVL processing unit 61 performs an XOR process on the pre-correction layout pattern 30 and the post-correction layout pattern 31, the differential layout pattern 32 is generated. That is, the LVL processing unit 61 can obtain the differential layout pattern 32 by taking the exclusive OR of the layout pattern 30 before correction and the layout pattern 31 after correction. The differential layout pattern 32 is arranged at a location where the modified layout pattern 31 is shortened. In this manner, the difference layout pattern 32 can be obtained by comparing the layout pattern 30 before correction and the layout pattern 31 after correction. Here, the differential layout pattern 32 is a rectangle whose longitudinal direction is the Y direction. Of course, the differential layout pattern 32 is not limited to a rectangle.

  Next, the OPC execution area extraction unit 62 of the computer apparatus 10 performs an OPC execution area extraction process (step S2). The OPC execution area extraction unit 62 extracts the modified layout pattern 31 from the area starting from the differential layout pattern 32 extracted in step S1. Specifically, as illustrated in FIG. 4, the OPC execution area extraction unit 62 sets an area separated from the differential layout pattern 32 by a distance A as an OPC execution area B. The OPC execution area B is an area that extends by ± A in the X direction and the Y direction of the differential layout pattern 32. Therefore, the size of the OPC execution area B in the X direction is a value obtained by adding 2A to the size of the differential layout pattern 32 in the X direction. Similarly, the size of the OPC execution area B in the Y direction is a value obtained by adding 2A to the size of the differential layout pattern 32 in the Y direction. Since the differential layout pattern 32 is rectangular, the OPC execution area B is also rectangular.

Then, the OPC execution area extraction unit 62 extracts the modified layout pattern 31 included in the OPC execution area B. In step S2, the differential layout pattern 32 included in the OPC execution area B is not extracted. The distance A can be obtained by the following equation (1).
Distance A = maximum reference value × 2 + absolute value of maximum minus correction amount (1)

  The maximum reference value is the maximum value of the reference value necessary for determining the correction amount for all the locations in the layout pattern. If there are a plurality of correction rules, the maximum reference value is determined by referring to all of them. The maximum negative correction amount is the same idea. The maximum reference value and the maximum minus correction amount will be described later.

  Then, the OPC processing unit 63 of the computer apparatus 10 executes the difference area OPC process on the modified layout pattern 31 extracted from the OPC execution area B (step S3). The OPC processing unit 63 refers to the correction rule table stored in the storage unit 66 and executes the difference area OPC process. The process of step S3 will be described with reference to FIG. In FIG. 5, the modified layout pattern 31 extracted from the OPC execution area B is shown as an OPC processing target layout pattern 33. Further, a pattern obtained by performing the OPC process on the OPC process target layout pattern 33 is shown as a post-OPC layout pattern 34. Here, the post-OPC layout pattern 34 is generated by making a part of the OPC processing target layout pattern 33 wider. OPC processing is executed on the extracted OPC processing target layout pattern 33. By doing so, the post-OPC layout pattern 34 can be obtained.

  Next, the post-OPC layout pattern extraction unit 64 of the computer apparatus 10 extracts the post-OPC layout pattern from the layout data extraction area starting from the differential layout pattern 32 extracted in step S1 (step S4). Specifically, as shown in FIG. 6, an area separated by a distance C from the differential layout pattern 32 is set as a layout data extraction area D. Note that the layout data extraction region D is a region that extends by ± C in the X direction and the Y direction of the differential layout pattern 32. Therefore, the size of the layout data extraction region D in the X direction is a value obtained by adding 2C to the size of the differential layout pattern 32 in the X direction. Similarly, the size of the layout data extraction region D in the Y direction is a value obtained by adding 2C to the size of the differential layout pattern 32 in the Y direction. Since the differential layout pattern 32 is rectangular, the layout data extraction area D is also rectangular.

The distance C can be obtained by the following formula (2): C = maximum reference value + maximum minus correction absolute value (2)

  Since the distance C is smaller than the distance A by the maximum reference value, the layout data extraction area D is smaller than the OPC execution area B. The layout data extraction area D is included in the OPC execution area B. Specifically, the layout data extraction area D is smaller than the OPC execution area B by 2 × maximum reference value in each of the X direction and the Y direction. Here, the layout data extraction area D is a rectangle whose four sides are shorter than the rectangle of the OPC execution area B by 2 × maximum reference value.

  Then, the post-OPC layout pattern extraction unit 64 extracts the post-OPC layout pattern 34 from the layout data extraction area D. Here, as shown in FIG. 7, the post-OPC layout pattern 34 extracted from the layout data extraction area D is used as the replacement target post-OPC layout pattern 35. By performing such processing, the post-replacement OPC layout pattern 35 can be obtained. A part of the post-OPC layout pattern 34 is a replacement target post-OPC layout pattern 35. That is, the post-OPC layout pattern 34 in the layout data extraction area D becomes the replacement target post-OPC layout pattern 35.

  Then, as shown in FIG. 8, the incorporation processing unit 65 of the computer apparatus 10 incorporates the replacement target post-OPC layout pattern 35 into the pre-correction post-OPC layout pattern 36 (step S5). The pre-correction post-OPC layout pattern 36 is a pattern after the OPC process is performed on the pre-correction layout pattern 30 shown in FIG. 3, and is obtained in advance. In FIG. 8, not only the replacement target post-OPC layout pattern 35 and the pre-correction post-OPC layout pattern 36 but also the OPC execution area B, the layout data extraction area D, the post-correction layout pattern 31, and the differential layout pattern 32 are overlapped. Show.

  Here, the post-replacement OPC layout pattern 35 included in the layout data extraction area D is replaced with a part of the pre-modification post-OPC layout pattern 36. That is, layout data 35 in which the post-OPC layout pattern 35 to be replaced is arranged in the layout data extraction area D, and layout data 36 in which the pre-correction post-OPC layout pattern 36 is arranged in areas other than the layout data extraction area D is generated. In the layout data extraction area D, a layout pattern 35 after OPC to be replaced is arranged, and in a layout data extraction area D other than the layout data extraction area D, a layout pattern 36 before OPC is arranged.

  The incorporation processing unit 65 combines the replacement target post-OPC layout pattern 35 with the pre-modification post-OPC layout pattern 36. Then, only the post-OPC layout pattern 35 to be replaced is arranged in the layout data extraction area D, and only the pre-correction post-OPC layout pattern 36 is arranged outside the layout data extraction area D. A pattern in which the replacement target post-OPC layout pattern 35 and the pre-correction post-OPC layout pattern 36 are combined becomes the post-correction post-OPC layout pattern for the post-correction layout pattern 31. In FIG. 8, the post-correction post-OPC layout pattern is indicated by a bold line. In the boundary portion of the layout data extraction region D, the replacement target post-OPC layout pattern 35 and the pre-correction post-OPC layout pattern 36 are connected. In this way, the OPC layout data of the corrected layout pattern can be obtained.

  The post-correction post-OPC layout pattern data has the same shape as the result of performing the OPC process on the entire post-correction layout pattern. When layout correction (mask revision) is performed, the OPC process is not performed on the entire layout pattern, and the processes of Step S1, Step S2, Step S3, Step S4, and Step S5 are performed, so that after the OPC after the layout correction A layout pattern can be obtained. As a result, it is only necessary to perform the OPC process in the vicinity of the corrected portion, so that the process in the computer apparatus 10 can be simplified.

  Next, the maximum reference value and the maximum minus correction amount will be described with reference to FIG. 9 and FIG. FIG. 9 is a diagram for explaining a correction rule by rule-based OPC, and FIG. 10 is a table showing a rule-based OPC correction rule table. In FIG. 9, the pre-OPC layout pattern of interest is shown as a pre-OPC layout pattern 50.

  As shown in FIG. 9, the pattern width of the pre-OPC layout pattern 50 is W, and the interval S between adjacent pre-OPC layout pattern 50 and pre-OPC layout pattern 51 is S. Here, in the rule-based OPC, a correction amount T corresponding to the pattern width W and the pattern interval S is shown. When the pattern width W of the pre-OPC layout pattern 50 is 400 and the pattern interval S is 200, a correction amount T = 20 (W ≦ 400, S ≦ 200) is applied. In the correction rule table of FIG. 9, two threshold values 200 and 400 are set for the pattern width W, and the correction amount T is divided into three stages. Similarly, two threshold values 100 and 200 are set for the pattern interval S, and the correction amount T is divided into three stages. The correction amount T is set for nine combinations of 3 × 3.

  In the rule-based OPC, correction is performed according to the pattern width W and the pattern interval S of the pre-OPC layout pattern to be subjected to the OPC process. That is, the correction amount T is obtained from the pattern width W and the pattern interval S with reference to the correction rule table. Then, the pre-OPC layout pattern 50 is corrected by the correction amount T. When the correction amount is 10, a pattern obtained by expanding the pre-OPC layout pattern 50 by 10 becomes the post-OPC layout pattern 52. In this way, the rule-based OPC process is performed with reference to the correction rule table. The correction rule table is stored in the recording medium 15 or the memory of the computer device 10.

  In the correction rule table of FIG. 10, the reference value that is referred to for determining the correction amount T is the pattern width W and the pattern interval S, but other reference values for the pattern may be used. . For example, the pattern length can be used as the reference value. At least one of the pattern width W, the pattern interval S, and the pattern length L of the pre-OPC layout pattern 50 can be used as a reference value. Thereby, an appropriate correction amount can be obtained from the reference value. The reference value preferably includes the pattern width W and the pattern interval S. By referring to the correction rule table, an appropriate correction amount T can be determined from the reference value of the pre-OPC layout pattern 50. In the difference area OPC process in step S3, the post-OPC layout pattern 34 is obtained by changing the shape of the layout pattern 33 to be processed according to the correction amount T (see FIG. 5).

  Here, the maximum reference value and the minus correction amount will be described. The maximum reference value indicates the maximum value among the reference values used for determining the OPC correction amounts for all edges. For example, in the correction rule table shown in FIG. 10, the threshold values for the pattern width W are 200 and 400, and the threshold values for the pattern interval S are 100 and 200. Accordingly, the maximum value 400 among them is the maximum reference value.

  The maximum value of the minus correction amount is a correction amount T that is a negative value among the correction amounts T set in the correction rule table and whose absolute value is the maximum in the correction rule table. In the correction rule table shown in FIG. 10, the correction amount T is 1, 5, 10, 15, or 20, and there is no negative value. In this case, the maximum negative correction amount is set to zero.

  FIG. 11 shows another correction rule table. FIG. 11 shows an example of a correction rule table in which a negative correction amount is set. In the correction rule table shown in FIG. 11, the reference value is the same as in FIG. 10, but the correction amount T is different. That is, the correction amount T is -10, -5, 5, 10, or 20. In this case, the maximum value of the minus correction amount is −10. That is, the minus correction amount is −10 and −5, and among them, −10 having the maximum absolute value is the maximum value of the minus correction amount. When the correction is made with the minus correction amount, the OPC processing target layout pattern 33 is reduced by the absolute value of the correction amount.

  In the correction rule table, when the correction amount has a negative value, the maximum absolute value of the negative correction amount is set as the maximum negative correction amount. On the other hand, when there is no negative value for the correction amount, 0 is set as the maximum negative correction amount. Thereby, an appropriate area can be set.

  Then, as shown in Expression (1) and Expression (2), the distance A and the distance C are obtained based on the maximum reference value and the maximum value of the minus correction amount. By doing so, the OPC execution area B and the layout data extraction area D can be set appropriately. By setting the OPC execution area B according to the distance A, the OPC processing target layout pattern 33 in the area D can be corrected with an appropriate correction amount.

The distance A may be a value that satisfies the following expression (3).
Distance A ≧ maximum reference value × 2 and absolute value of maximum minus correction amount (3)

  In this way, the OPC processing target layout pattern 33 in the area D can be corrected with an expected correction amount. Further, the calculation time can be shortened as the distance A is made smaller. Therefore, it is preferable to obtain the distance A by the equation (1).

The distance C is preferably smaller than the distance A by a maximum reference value. That is, the distance C may be a value that satisfies the following expressions (4) and (5).
Distance C ≦ Distance A−Maximum reference value (4)
Distance C ≧ maximum reference value + maximum negative correction amount (5)

  As described above, by using Expressions (3) to (5), it is possible to prevent a pattern shift or the like from occurring at the boundary portion of the layout data extraction region D. In addition, when the distance A is (1) Formula, it is preferable to obtain | require the distance C by (2) Formula.

Next, the method according to Patent Document 1 and the method according to the present embodiment will be compared. In the method according to Patent Document 1 (hereinafter referred to as a comparative example), a passive correction fragment is extracted from a positive correction fragment to be changed and a region twice the optical radius centered on the positive fragment. The optical radius is an optically influential radius. Then, a new OPC is applied to the positive correction fragment with the correction value for the negative correction fragment as an initial value.
A transfer simulation is performed on the mask pattern in which the positive correction fragment is subjected to the OPC process. When the amount of divergence between the result of the transfer simulation and the design pattern is verified and the amount of divergence is within a certain range, a mask pattern obtained by applying new OPC to the positive correction fragment is used as the correction result. If the amount of deviation is not within a certain range, an unresolved auxiliary pattern is arranged to adjust the light intensity. A transfer simulation is performed on the mask pattern to which the unresolved auxiliary pattern is added. It is determined whether the amount of deviation between the result and the design pattern is within a certain range. If it is within a certain range, this result is taken as a correction result. If it does not fall within a certain range, a new OPC process is performed on the passive correction fragment. Then, a region within a certain range of the region subjected to the OPC process is replaced with the original mask pattern. This certain range is within the range of the optical radius around the active fragment.

Hereinafter, the method according to the comparative example and the method according to the present embodiment will be compared in two cases. First, the case where the following equation (5) is satisfied will be described with reference to FIG.
2 times optical radius> maximum reference value x 2 + absolute value of maximum minus correction amount (5)

  In FIG. 12, the modified layout pattern is the modified layout pattern 41 or the modified layout pattern 42, and the differential layout pattern generated by the LVL process is the differential layout pattern 40. The distance G is a distance obtained from the equation (1), and the region H is a region separated from the differential layout pattern 40 by the distance G. The distance I is at least twice the optical radius of the prior art, and the area J is an area away from the differential layout pattern 40 by the distance I. Further, the area P is a layout data extraction area for extracting layout data after OPC in the present embodiment.

  In the comparative example, when the layout data is changed, the OPC processing area is set to be twice or more the optical radius from the changed position. Therefore, when Expression (5) is satisfied, in the comparative example, the OPC process is performed on the modified layout pattern 42 included in the region J. On the other hand, in the present embodiment, since the corrected layout pattern 42 is located outside the region H boundary, the OPC process for the corrected layout pattern 42 is not performed. That is, when the obtained area H is smaller than the area twice the optical radius, the OPC processing area becomes smaller than that of the comparative example. Thereby, the speed of the OPC process can be increased.

  Further, the portion of the corrected layout pattern 41 on the corrected layout pattern 42 side is affected by the corrected layout pattern 42. However, the layout data extraction area P does not reach the corrected layout pattern 42 side of the corrected layout pattern 41. Here, the boundary of the layout data extraction area P is between the differential layout pattern 40 and the corrected layout pattern 41. Therefore, appropriate optical proximity correction can be performed without performing OPC processing on the modified layout pattern 42.

Next, the case where the following formula (6) is satisfied will be described with reference to FIG.
Double optical radius <maximum reference value x 2 + absolute value of maximum minus correction amount (6)

  FIG. 13 shows the modified layout patterns 44 and 45 and the differential layout pattern 43 obtained by the LVL processing. The distance K is a distance obtained from the expression (2), and the region L is a region separated from the difference layout pattern 43 by the distance K. The distance M is twice the optical radius, and the area N is an area away from the differential layout pattern 43 by the distance M. The distance O is the distance obtained from Equation 1, and the area Q is an area away from the differential layout pattern 43 by the distance O.

  In the comparative example, the corrected layout pattern 45 is not included in the area N to be subjected to the OPC process, and the corrected layout pattern 45 cannot be referred to when the corrected layout pattern 44 is subjected to the OPC process. For this reason, an appropriate post-OPC layout pattern cannot be obtained for the post-correction layout pattern 44. On the other hand, in the optical proximity effect correction method according to the present embodiment, the corrected layout pattern 45 is included in the region Q, and the corrected layout pattern 45 can be referred to when the corrected layout pattern 44 is subjected to OPC processing. Therefore, an appropriate post-OPC layout pattern can be obtained for the post-correction layout pattern 44.

  As described above, in a layout using optical proximity correction (OPC) of a semiconductor integrated circuit, difference data is obtained by performing an LVL (Layout vs Layout) process on a layout pattern before layout correction and a layout pattern after layout correction. ing. Using the obtained difference data as a starting point, an area separated by a distance equal to or larger than the value obtained by adding the absolute value of the maximum minus correction amount to twice the maximum reference value is generated as the OPC execution area. A first layout pattern included in the OPC execution area is extracted, and a rule-based OPC process is performed on the extracted first layout pattern. At this time, the rule-based OPC process is executed with reference to the correction rule table in which the correction value is set for the reference value.

  An area separated by a distance equal to or greater than a value obtained by adding the absolute value of the maximum minus correction amount to the maximum reference value starting from the difference data is generated as a layout data extraction area. A second layout pattern included in the layout data extraction area is extracted. With respect to the corrected layout data, the minimum figure required for obtaining appropriate post-OPC layout data is selected, and the post-OPC layout data before correction is replaced as post-OPC layout data for the selected figure. In this way, the processing time can be shortened by performing the minimum necessary OPC processing to obtain the correct post-OPC layout data after correction.

  In this way, the OPC mask is designed. Then, a pattern is drawn on the mask based on the design data of the OPC mask. For example, a mask pattern of an OPC mask can be formed by electron beam drawing or the like. Thereby, a pattern based on the design data is formed. By the above manufacturing method, an OPC mask having an appropriate pattern can be manufactured with high accuracy, and productivity can be improved.

  In order to manufacture a semiconductor device such as a semiconductor wafer, a thin film is formed on a substrate. The thin film is patterned using an OPC mask. For example, a photoresist on a thin film is exposed. By undergoing development of the photoresist, etching of the thin film, and removal of the photoresist, a desired thin film pattern can be formed with high accuracy. Therefore, productivity of the OPC mask and the semiconductor device can be improved.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the embodiments already described, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

DESCRIPTION OF SYMBOLS 1 System 10 Computer apparatus 14 Server 15 Recording medium 16 Network 30 Layout pattern before correction 31 Layout pattern after correction 32 Differential layout pattern 33 Layout pattern after OPC process 34 Layout pattern after OPC 35 Layout pattern after replacement OPC Layout pattern after OPC 36 Correction Pattern 40 Differential layout pattern 41 Modified layout pattern 42 Modified layout pattern 43 Modified layout pattern 44 Modified layout pattern 45 Modified layout pattern 45 Modified layout pattern 50 Pre-OPC layout pattern 51 Pre-OPC layout pattern 52 Post-OPC layout pattern 61 LVL processing unit 62 OPC Execution area extraction unit 63 OPC processing unit 64 Post OPC layout pattern extraction Section 65 Embedded processing section 66 Storage section 67 LVL processing section A Distance B OPC execution area C Distance D Layout data extraction area G, I, K, M, O Distance H, J, L, N, Q area P Layout data extraction area

Claims (14)

Find the difference pattern between the layout pattern before modification before modification and the layout pattern after modification after modification.
Extracting the layout pattern included in the first region starting from the difference pattern as the first layout pattern from the modified layout pattern;
A post-OPC layout pattern is generated by performing a rule-based OPC process on the first layout pattern with reference to a correction rule table in which a correction amount according to a reference value is set.
Extracting a layout pattern included in a second region in the first region as a second layout pattern from the post-OPC layout pattern;
Using the OPC layout pattern of the pre-correction layout pattern and the second layout pattern, obtain OPC layout data of the post-correction layout pattern;
When the maximum reference value set in the correction rule table is the maximum reference value, and the maximum negative correction value of the correction amount is the maximum negative correction value,
The first region is a region separated from the difference pattern by a first distance equal to or greater than an addition value obtained by adding the absolute value of the maximum minus correction value to a value obtained by doubling the maximum reference value, starting from the difference pattern;
The second region is a region separated by a second distance not less than an added value obtained by adding the absolute value of the maximum minus correction value to the maximum reference value, starting from the difference pattern.
Optical proximity effect correction method.   The optical proximity effect method according to claim 1, wherein the second distance is smaller than a value obtained by subtracting the maximum reference value from the first distance.   The optical proximity correction method according to claim 1, wherein in the correction rule table, at least one of a pattern width, a pattern interval, and a pattern length is the reference value. In the correction rule table,
If there is a negative value in the correction amount, the maximum absolute value of the negative correction amount is the maximum negative correction amount,
The optical proximity effect correction method according to claim 1, wherein when the correction amount has no negative value, 0 is set as the maximum negative correction amount. A mask is designed using the optical proximity correction method according to claim 1,
A mask manufacturing method for forming a pattern on a mask using the mask design data. A mask is manufactured by the mask manufacturing method according to claim 5,
A method of manufacturing a semiconductor device, wherein a thin film is patterned using the mask. A processing device that performs optical proximity correction,
A storage unit for storing a correction rule table in which a correction amount according to the reference value is set;
An LVL processing unit for obtaining a difference pattern between a layout pattern before correction before correction and a layout pattern after correction after correction;
An OPC execution area extraction unit that extracts a layout pattern included in a first area starting from the difference pattern as a first layout pattern from the modified layout pattern;
An OPC processing unit that generates a post-OPC layout pattern by performing a rule-based OPC process on the first layout pattern with reference to the correction rule table;
A post-OPC layout pattern extraction unit that extracts a layout pattern included in a second region in the first region as a second layout pattern from the post-OPC layout pattern;
An embedded processing unit that obtains OPC layout data of the post-correction layout pattern using the OPC layout pattern of the pre-correction layout pattern and the second layout pattern;
When the maximum reference value set in the correction rule table is the maximum reference value, and the maximum negative correction value of the correction amount is the maximum negative correction value,
The first area is an area separated by a first distance equal to or greater than an addition value obtained by adding the absolute value of the maximum minus correction value to a value obtained by doubling the maximum reference value starting from the difference pattern,
The second region is a region separated by a second distance not less than an added value obtained by adding the absolute value of the maximum minus correction value to the maximum reference value, starting from the difference pattern.
Processing equipment.   The processing apparatus according to claim 7, wherein the second distance is smaller than a value obtained by subtracting the maximum reference value from the first distance.   The processing apparatus according to claim 7, wherein in the correction rule table, at least one of a pattern width, a pattern interval, and a pattern length is the reference value. In the correction rule table,
If there is a negative value in the correction amount, the maximum absolute value of the negative correction amount is the maximum negative correction amount,
The processing apparatus according to claim 7, wherein when the correction amount has no negative value, 0 is set as the maximum negative correction amount. A computer program for causing a computer to execute the optical proximity correction method,
The optical proximity effect correction method comprises:
Find the difference pattern between the layout pattern before modification before modification and the layout pattern after modification after modification.
Extracting the layout pattern included in the first region starting from the difference pattern as the first layout pattern from the modified layout pattern;
A post-OPC layout pattern is generated by performing a rule-based OPC process on the first layout pattern with reference to a correction rule table in which a correction amount according to a reference value is set.
Extracting a layout pattern included in a second region in the first region as a second layout pattern from the post-OPC layout pattern;
Using the OPC layout pattern of the pre-correction layout pattern and the second layout pattern, obtain OPC layout data of the post-correction layout pattern;
When the maximum reference value set in the correction rule table is the maximum reference value, and the maximum negative correction value of the correction amount is the maximum negative correction value,
The first region is a region separated from the difference pattern by a first distance equal to or greater than an addition value obtained by adding the absolute value of the maximum minus correction value to a value obtained by doubling the maximum reference value, starting from the difference pattern;
The second region is a region separated by a second distance not less than an added value obtained by adding the absolute value of the maximum minus correction value to the maximum reference value, starting from the difference pattern.
Computer program.   The program according to claim 11, wherein the second distance is smaller than a value obtained by subtracting the maximum reference value from the first distance.   The program according to claim 11, wherein in the correction rule table, at least one of a pattern width, a pattern interval, and a pattern length is the reference value. In the correction rule table,
If there is a negative value in the correction amount, the maximum absolute value of the negative correction amount is the maximum negative correction amount,
12. The program according to claim 11, wherein when the correction amount has no negative value, 0 is set as the maximum negative correction amount.

Images