JP2002183238A - Method for deciding crowdedness recording medium with computer program for verifying crowdedness recorded thereon and verifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely decide the crowdedness. SOLUTION: This method for deciding whether or not the pattern of a plurality of contact holes of an integrated circuit forms a one-dimensional crowdedness consists of a step for acquiring pattern data defining the layout pattern of the plurality of contact holes and interval data defining respective intervals of the plurality of contact holes; a step for generating a crowdedness decision flag obtained by enlarging the individual intervals of the plurality of contact holes by a prescribed amount on the basis of the acquired pattern data and interval data, and a step for deciding whether the pattern of the plurality of contact holes form one-dimensional crowdedness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to the determination of the position of a contact hole using layout pattern data of a semiconductor integrated circuit.

[0002]

2. Description of the Related Art After a layout design of a semiconductor integrated circuit is completed, verification is performed to confirm whether the layout is performed according to a predetermined standard, that is, whether the layout is correctly designed. One of them is CAD
This is a design rule check in which a minimum distance such as a wiring width, a wiring interval, and a margin of pattern data is measured to confirm a design reference value.

[0003]

As the process becomes finer in recent years, it has become necessary to verify the density of layout pattern data in a process that uses a large number of rectangular patterns with high accuracy. For example, a contact hole forming a two-dimensional congestion has a poor finish shape due to (1) the influence of light interference at the time of photolithography, and (2) the influence of resist residue in a wafer process. Is stricter than one-dimensional density. Therefore, there is a need for a method for verifying the density with high accuracy.

However, the conventional verification based on the wiring width, the wiring interval, and the margin cannot verify the density. Specifically, a dangerous part was confirmed visually by the designer, so that the circuit scale that could be handled was limited, and there was also a problem in verification accuracy.

[0005] It is an object of the present invention to facilitate compactness and
It is to be able to make a reliable determination.

[0006]

According to the present invention, there is provided a method for judging density, which is for judging whether or not a pattern of a plurality of contact holes of an integrated circuit forms one-dimensional density. Acquiring pattern data defining a layout pattern of a plurality of contact holes, and interval data defining an interval between each of the plurality of contact holes, and a plurality of pattern data based on the acquired pattern data and the interval data. Generating a density determination flag in which the intervals between the contact holes are enlarged by a predetermined amount; and determining whether the pattern of the plurality of contact holes is one-dimensional density based on whether or not the shape of the density determination flag is rectangular. And a step of determining whether or not to form, thereby achieving the above object.

In the determining step, when the shape of the density determination flag is rectangular, it is determined that the pattern of the plurality of contact holes forms one-dimensional density, and when the shape is not rectangular, it is determined that the pattern is not one-dimensional density. Step.

[0008] The step of generating the density determination flag includes the step of comparing each interval of the plurality of contact holes with a predetermined verification value based on the acquired interval data to verify the interval. Generating an interval determination flag for each of the plurality of contact holes based on the pattern data and the interval data, and increasing the generated interval determination flag by a predetermined amount to determine the density. Generating a flag.

The predetermined amount is smaller than half the size of the contact hole.

[0010] A determination method according to the present invention is a determination method for determining the position of each contact hole in a two-dimensional congestion when a plurality of contact holes of an integrated circuit form a two-dimensional congestion. Pattern data defining a hole layout pattern, and a step of acquiring interval data defining an interval between each of the plurality of contact holes; and, based on the acquired pattern data, for all edges of the plurality of contact holes. Generating an edge flag, generating a dense contact hole flag that defines a two-dimensional dense area based on the acquired pattern data and the interval data, and removing a logical contact difference from the edge flag excluding the dense contact hole flag. Performing a calculation to generate a position determination flag; Based on the number of position determination flag, a determination method comprising the step of determining the position of each contact hole in the two-dimensional dense, whereby the above-mentioned object can be achieved.

In the step of determining, when the number of the position determination flags is 0, it is determined that the contact hole exists inside the two-dimensional dense area, and when the number of the position determination flags is 1, Determines that the contact hole exists in the outer peripheral portion of the two-dimensional dense area, and when the number of the position determination flags is two, determines that the contact hole exists in the outer peripheral corner portion of the two-dimensional dense area. Good.

The recording medium of the present invention is a recording medium on which a computer program for verifying the density by determining whether or not the pattern of a plurality of contact holes of an integrated circuit forms a one-dimensional density is recorded. Acquiring pattern data defining a layout pattern of a plurality of contact holes, and interval data defining an interval between each of the plurality of contact holes; and, based on the acquired pattern data and the interval data, Generating a denseness determination flag in which the distance between each of the contact holes is enlarged by a predetermined amount; and determining whether the pattern of the plurality of contact holes is one-dimensionally dense based on whether the shape of the denseness determination flag is rectangular. Determining whether or not to form a computer A recorded recording medium, thereby the objective described above being achieved.

A recording medium according to the present invention is a computer for verifying the density by determining the position of each contact hole in a two-dimensional density when a plurality of contact holes of an integrated circuit form a two-dimensional density. A recording medium on which a program is recorded, wherein pattern data defining a layout pattern of a plurality of contact holes, and
Acquiring interval data defining intervals of the plurality of contact holes; generating edge flags for all edges of the plurality of contact holes based on the acquired pattern data; and Generating a dense contact hole flag that defines a two-dimensional dense area based on the data and the interval data, performing a logical difference operation excluding the dense contact hole flag from the edge flag, and generating a position determination flag. And a step of determining the position of each contact hole in the two-dimensional density based on the number of the position determination flags. You.

A verification apparatus according to the present invention is a verification apparatus for verifying the density by determining whether or not patterns of a plurality of contact holes of an integrated circuit form one-dimensional density. Based on the pattern data defining the layout pattern of the holes, and the storage unit storing the interval data defining the intervals of the plurality of contact holes, based on the pattern data and the interval data acquired from the storage unit, a plurality of A density determination flag generation unit that generates a density determination flag in which the intervals between contact holes are enlarged by a predetermined amount, and whether the shape of the density determination flag generated by the density determination flag generation unit is rectangular or not. A flag shape determining unit that determines whether or not the pattern of the plurality of contact holes forms a one-dimensional density based on the A verification device, thereby the objective described above being achieved.

According to the present invention, there is provided a verification apparatus for verifying a layout by judging the position of each contact hole in a two-dimensional density when a plurality of contact holes of an integrated circuit form a two-dimensional density. Based on pattern data that defines a layout pattern of the plurality of contact holes, and a storage unit that stores interval data that defines the interval between each of the plurality of contact holes, based on the pattern data acquired from the storage unit. A contact hole edge generation unit that generates an edge flag for all edges of the plurality of contact holes, and a dense contact hole that defines a two-dimensional dense area based on the pattern data and the interval data obtained from the storage unit A flag is generated, and the edge flag is generated by the contact hole edge generation unit. A position determination flag generator that generates a position determination flag by performing a logical difference operation excluding the dense contact hole flag, and a two-dimensional cluster based on the number of the position determination flags generated by the position determination flag generator. And a position judging unit for judging the position of each individual contact hole in the verification device, thereby achieving the above object.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(Embodiment 1) In this specification, a method for verifying the density of contact holes in layout pattern data of a semiconductor integrated circuit will be described. Verification of the density of contact holes here means whether the contact holes are arranged linearly (one-dimensionally),
Or, verification of whether they are arranged two-dimensionally (two-dimensionally). Note that the contact hole is merely an example, and can be applied to any component as long as the layout pattern is a rectangular pattern. In this specification, one-dimensional arrangement is referred to as “one-dimensional dense”, and two-dimensional arrangement is referred to as “two-dimensional dense”. For example, FIG. 1 shows an example of a contact hole to be verified. Each “□” in the figure is a contact hole. Looking at the left and right columns separately, each column is a one-dimensional congestion of contact holes. On the other hand, focusing on the eight contact holes, these contact holes are two-dimensionally dense. In the following description, it is assumed that the minimum interval A of one-dimensional density is smaller than the minimum interval B of two-dimensional density.

Next, the verification device of the present embodiment will be described. FIG. 2 is a block diagram of the verification device 1 for verifying the density of contact holes according to the first embodiment. The verification device 1 includes a storage unit 2 such as a hard disk, a density determination flag generation unit 5, a flag shape determination unit 6, and an error contact hole determination unit 7. Hereinafter, each component will be described. The storage unit 2 includes a layout pattern data file 3 in which a layout pattern to be verified is described, and a verification command file 4 in which data such as contact hole intervals is described. The layout shown in FIG. 1 is described in the layout pattern data file 3. Note that the layout pattern data is composed of a plurality of input layers. This input layer has data corresponding to the pattern of each mask used in the LSI manufacturing process. The verification command file 4 describes data on the interval between contact holes and the like. The density determination flag generation unit 5 generates data (interval determination flag) for filling the parallel portion between the contact holes, performs a certain amount of oversize processing, and generates a density determination flag. Each of these actions
It will be described later with reference to FIG. The flag shape determination unit 6 determines the shape of the density determination flag. The error contact hole determination unit 7 determines a non-one-dimensional dense contact hole as an error contact hole and outputs it.

Hereinafter, a specific operation of the verification device 1 will be described. FIG. 3 is a flowchart showing an operation flow of the verification device 1 (FIG. 2). First, the density determination flag generation unit 5
Receives the layout pattern data file 3 (FIG. 2) and the verification command file 4 (FIG. 2) from the storage unit 2 (FIG. 2). As described above, the layout pattern data file 3 (FIG. 2) describes the pattern data defining the layout pattern of the plurality of contact holes, and the verification command file 4 (FIG. 2) describes each of the plurality of contact holes. Is described. Denseness determination flag generation unit 5 (FIG. 2)
Verifies the interval between contact holes based on these data (step 31). Verification of the interval is performed by comparison with the check value a. The check value a is
When α is a small value of about the minimum grid, it is a value obtained by a = minimum value of two-dimensional density−α.
The “minimum value of two-dimensional density” is a value corresponding to “B” in FIG.

After verifying the distance between the contact holes,
Subsequently, the density determination flag generation unit 5 (FIG. 2) generates an interval determination flag (step 32). The interval judgment flag is
Data on the spacing of each of the plurality of contact holes,
More specifically, it is data for filling the space between contact holes. A specific example will be described. FIGS. 4A to 4C show examples of contact holes in which the interval determination flag has been generated.
(A) shows a one-dimensional dense interval determination flag. (B)
(C) shows a two-dimensional dense interval determination flag.
The interval determination flag is generated for the contact hole for which an error has occurred in step 31.

After generating the interval determination flag, the density determination flag generator 5 (FIG. 2) subsequently generates a density determination flag (step 33). The denseness determination flag is generated by “oversize processing” that increases the interval determination flag by a predetermined amount. The predetermined amount (oversize amount b) is an amount smaller than half the size of the contact hole, and can be expressed as b = (contact hole size) / 2−α using the above α. As a result, the denseness determination flag overlaps the contact hole.

FIGS. 5A to 5C show density determination flags generated from the interval determination flags in FIGS. 4A to 4C, respectively. FIG. 5A shows an example of the shape of the density determination flag for one-dimensional density. As illustrated, each of the two density determination flags is rectangular and is generated without overlapping each other. Next, (b) shows an example of the shape of the density determination flag for two-dimensional density.
In (b), it is understood that any of the density determination flags overlaps with the adjacent density determination flag, and does not have a rectangular shape as a whole. (C) shows an example of the shape of the density determination flag for non-one-dimensional density. It is understood that one of the denseness determination flags in (c) overlaps the other and is not rectangular as a whole, like the denseness determination flag in (b). Note that “non-one-dimensional density” in (c) is synonymous with two-dimensional density.

In summary, it can be concluded that the denseness determination flag exhibits a rectangular shape when the contact holes form a one-dimensional density, but a non-rectangular shape when the contact holes form a non-one-dimensional density. Utilizing this property, it can be determined whether or not one-dimensional density is high.

Referring again to FIG. 3, flag shape determination unit 6
(FIG. 2) determines whether or not the shape of the density determination flag is rectangular (step 34). The error contact hole determination unit 7 (FIG. 2) receives the result of the determination by the flag shape determination unit 6 (FIG. 2), and determines that the adjacent contact holes are one-dimensionally dense if they are rectangular (step 3).
5). If it is not rectangular, the adjacent contact holes are determined as two-dimensional dense (step 36). Thereafter, the determination result is output, and the processing of the verification device 1 (FIG. 2) ends. For example, in the present embodiment, the error contact hole determination unit 7 (FIG. 2) outputs a non-one-dimensional (ie, two-dimensional) dense contact hole as an error contact hole.

As described above, according to the processing of the verification apparatus 1 (FIG. 2) of the present embodiment, if the contact holes are dense, it is determined whether the contact holes are one-dimensional or two-dimensional. Easy to judge. Note that, in the present embodiment, the contact holes exhibiting the two-dimensional denseness are those in which the contact holes that do not satisfy the minimum interval of the two-dimensional denseness are selected, but by appropriately changing the check value a described above,
The interval of the two-dimensional crowd to be determined may be adjusted.

(Embodiment 2) In the embodiment 2, when the contact holes are in a two-dimensional dense state, it is possible to easily and easily determine where any arbitrary contact hole exists in the two-dimensional dense state. The method of verifying without the following will be described.

Hereinafter, the verification device of the present embodiment will be described. FIG. 6 is a block diagram of a verification device 60 that verifies the positions of contact holes in a dense area according to the second embodiment. The verification device 60 includes a storage unit 2 such as a hard disk storing the layout pattern data file 3 and the verification command file 4, a contact hole edge generation unit 61, a position determination flag generation unit 62, and a position determination unit 6.
3 is included. Hereinafter, each component will be described. However, since the layout pattern data file 3 and the verification command file 4 stored in the storage unit 2 are the same as those in the first embodiment, description thereof will be omitted. The contact hole edge generation unit 61 generates edge flags for all edges of a contact hole to be verified. The position determination flag generation unit 62 deletes, from the contact hole edge flags, edges that exist inside the two-dimensional crowd, and generates a position determination flag. The position determining unit 63 determines where each contact hole exists in the two-dimensional density.

Hereinafter, a specific operation of the verification device 60 will be described. FIG. 7 is a flowchart showing the operation flow of the verification device 60 (FIG. 6). First, the contact hole edge generation unit 61 receives the layout pattern data file 3 (FIG. 6) and the verification command file 4 (FIG. 6) from the storage unit 2 (FIG. 6). Then, based on the acquired layout pattern data file 3 (FIG. 6), an edge flag is generated for all edges of the plurality of contact holes (step 71). The edge flag is data relating only to the edge of the contact hole. Note that the flags between adjacent edges need to be completely separated. FIG. 8A shows two types of emphasized edge flags. The black region filling the space between the contact holes is based on dense contact hole data.

Next, dense contact hole data will be described. Referring to FIG. 7 again, position determination flag generation unit 62
(FIG. 6) performs oversize processing and undersize processing on the contact hole to generate a dense contact hole flag that defines the area of the two-dimensional dense part (step 72). Here, the “oversize process” is the same process as described in the first embodiment. On the other hand, the "undersize process" is a process opposite to the oversize process, that is, a process of reducing the size by a predetermined amount (undersize amount). Note that the oversize amount and the undersize amount are the same, and the amount c is given by c = minimum value of two-dimensional density-α. The dense contact hole flag is for considering contact holes within a predetermined range as one dense, and the same amount of oversize / undersize combination will generate data for that purpose. . This dense contact hole flag is represented by (a) in FIG.
And black regions filling the space between the contact holes.

Next, the position determination flag generator 62 (FIG. 6)
Performs a logical difference operation between the edge flag and the dense contact hole flag to generate a position determination flag (step 7).
3). The logical difference operation is a process of removing the area of the dense contact hole flag from the edge flag, that is, a process of removing the overlapping portion of the edge flag and the dense contact hole flag. It should be noted that the area of the dense contact hole flag exists inside the edge of the contact hole that defines the outer periphery of the area defined by the plurality of contact holes. Therefore, when the logical difference operation between the edge flag and the dense contact hole flag is performed, only the edge of the contact hole in the outer peripheral portion is left. This is as shown in FIG. The edge of the contact hole in the outer peripheral portion is generated as a position determination flag. However, each of the position determination flags
It is generated in association with the contact hole at that position. Therefore, when a certain contact hole is designated, the position determination flag corresponding to the contact hole is specified. In some cases, there is no position determination flag corresponding to the contact hole. For example, there is a case of a contact hole existing inside a two-dimensional crowd. At that time, there is no corresponding contact hole. FIG. 8B also shows a dense contact hole flag area for reference.

Next, a description will be given of a process for determining where each contact hole exists in a dense area. In this process, the position determination flag generated by the position determination flag generator 62 is used. The positions that can be determined are the inside, the outer peripheral portion, and the outer peripheral corner portion of the two-dimensional density.

Referring to FIG. 7, when a contact hole whose existence position is to be specified is designated, position determination section 63 (FIG. 6) counts the number of position determination flags corresponding to the contact hole. That is, it is determined whether the number of position determination flags is 0 (step 74) or 1 (step 75). If the number of the position determination flags is 0, the position determination unit 63 (FIG. 6) determines that the contact hole is located inside the two-dimensional dense area (step 76). The reason is that the fact that the number of position determination flags is 0 means that the edge flag of this contact hole overlaps the area of the dense contact hole flag. On the other hand, if the number of the position determination flags is not 0, it is determined next whether or not the number of the position determination flags is 1 (step 75). If there is one, the position determination unit 63 (FIG. 6) determines that the contact hole is located on the outer peripheral portion in the two-dimensional dense area (step 77). This is because the number of position determination flags is one, which means that only one edge of the contact hole exists in the outer peripheral portion. If the number of the position determination flags is neither zero nor one, it is inevitably two or more (two in the present embodiment). Therefore, the position determination part 63 (FIG. 6) It is determined that it is located at the corner (step 78).

By specifying the positions of the contact holes existing in the two-dimensional dense area as described above, the positions of the contact holes can be easily and completely determined. For example, a contact hole existing inside can be treated as an error, and a contact hole existing in an outer peripheral portion can be treated as an error for the purpose of verification. The two-dimensional density interval can be adjusted by adjusting the size of the oversize amount and the undersize amount c described above.

Verification device 1 described in the embodiment of the present invention
The operations of (FIG. 2) and the verification device 60 (FIG. 6) are performed by executing a computer program that defines such processing. For example, in the verification device 1 (FIG. 2), a main CPU (not shown) that controls the operation of each component interprets and executes such a computer program. Computer programs are CD-ROM, D
It can be recorded on a magnetic recording medium such as an optical disk such as a VD, a floppy (registered trademark) disk, and a hard disk 2 (FIG. 1), and transmitted to another computer via an electric communication line such as the Internet. It is recorded on a recording medium such as a memory.

[0035]

According to the present invention, it is determined whether or not the pattern of the plurality of contact holes forms a one-dimensional density according to whether or not the shape of the density determination flag is rectangular.
It can be easily and reliably determined whether one-dimensional or two-dimensional. Specifically, when the shape of the density determination flag is rectangular, it is determined that the pattern of the plurality of contact holes forms one-dimensional density, and when it is not rectangular, it is determined that the pattern is not one-dimensional density. Therefore, the determination can be made very easily, the verification efficiency can be improved, and the design period can be shortened. More specifically, since the density determination flag is generated by increasing the interval determination flag by a predetermined amount, the shape of the density determination flag is rectangular in the case of one-dimensional density. In the case of two-dimensional crowding, the shape of the crowding determination flag is not rectangular. Since the predetermined amount is a value smaller than half the size of the contact hole, in the case of one-dimensional density, the shape of the density determination flag is always rectangular.

According to the present invention, the position judging section 63 (FIG. 6)
Can determine the position of each contact hole in a two-dimensional crowd based on the number of position determination flags (for example, 0, 1, and 2). Therefore, the position of the contact hole can be easily determined without any omission. Therefore, the verification efficiency can be improved and the design period can be shortened.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a contact hole to be verified.

FIG. 2 is a block diagram of a verification device for verifying the density of contact holes according to the first embodiment.

FIG. 3 is a flowchart illustrating an operation flow of the verification device.

FIG. 4 is a diagram illustrating an example of an interval determination flag.

FIG. 5 is a diagram illustrating an example of a density determination flag;

FIG. 6 is a block diagram of a verification device for verifying positions of contact holes in a dense area according to the second embodiment.

FIG. 7 is a flowchart illustrating an operation flow of the verification device.

FIG. 8A is a diagram showing an area of an edge flag and a dense contact hole flag. (B) is a diagram showing a result of performing a logical difference operation between the edge flag and the dense contact hole flag.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 verification device, 2 storage unit, 3 layout pattern data file, 4 verification command file, 5
Denseness determination flag generation unit, 6 flag shape determination unit,
7 error contact hole determination unit, 61 contact hole edge generation unit, 62 position determination flag generation unit, 63 position determination unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B046 AA08 BA04 JA02 5F033 QQ37 UU01 XX34 5F064 EE15 EE27 HH06 HH10 HH11 HH12 HH16

Claims (10)

[Claims] 1. A method for determining whether or not a pattern of a plurality of contact holes of an integrated circuit forms one-dimensional denseness, comprising: pattern data defining a layout pattern of the plurality of contact holes; And acquiring interval data defining intervals of the plurality of contact holes; and densely expanding the intervals of the plurality of contact holes by a predetermined amount based on the acquired pattern data and the acquired interval data. Generating a gender determination flag, and based on whether or not the shape of the denseness determination flag is rectangular,
Determining whether the patterns of the plurality of contact holes form one-dimensional density. 2. The method according to claim 1, wherein the step of determining includes determining that the pattern of the plurality of contact holes forms a one-dimensional density when the shape of the density determination flag is rectangular; The determination method according to claim 1, wherein the determination is performed. 3. The method according to claim 1, wherein the step of generating the density determination flag includes the step of comparing the intervals of the plurality of contact holes with a predetermined verification value based on the acquired interval data to verify the intervals. Generating an interval determination flag for each of the plurality of contact holes based on the obtained pattern data and the interval data; and increasing the generated interval determination flag by a predetermined amount to increase the density. Generating a gender determination flag.
The method according to claim 1. 4. The method according to claim 1, wherein the predetermined amount is smaller than half the size of the contact hole. 5. A method for determining a position of an individual contact hole in a two-dimensional cluster when a plurality of contact holes of an integrated circuit form a two-dimensional cluster, the method comprising: determining a layout pattern of the plurality of contact holes; A step of obtaining specified pattern data and interval data specifying intervals of the plurality of contact holes; and generating an edge flag for all edges of the plurality of contact holes based on the obtained pattern data. Based on the acquired pattern data and the interval data, based on the acquired pattern data, generate a dense contact hole flag that defines a two-dimensional dense area, perform a logical difference operation excluding the dense contact hole flag from the edge flag, Generating a position determination flag; Determining how to, consisting of determining the position of each of the contact holes in the two-dimensional dense based on. 6. The step of determining, when the number of the position determination flags is zero, determining that the contact hole exists inside the two-dimensional crowd, and determining that the number of the position determination flags is one. In this case, it is determined that the contact hole exists at the outer peripheral portion of the two-dimensional dense area. When the number of the position determination flags is two, it is determined that the contact hole is present at the outer peripheral corner portion of the two-dimensional dense area. The determination method according to claim 5. 7. A recording medium recording a computer program for verifying the density by determining whether or not the pattern of a plurality of contact holes of an integrated circuit forms a one-dimensional density, comprising: A step of acquiring pattern data defining a hole layout pattern and interval data defining an interval of each of the plurality of contact holes; each of the plurality of contact holes based on the acquired pattern data and the interval data; Generating a denseness determination flag by expanding the interval of the predetermined amount by a predetermined amount, based on whether the shape of the denseness determination flag is rectangular,
A step of determining whether or not the patterns of the plurality of contact holes form one-dimensional denseness. 8. A computer program for verifying the density by determining the position of each contact hole in the two-dimensional density when the plurality of contact holes of the integrated circuit form a two-dimensional density. A medium, wherein pattern data defining a layout pattern of the plurality of contact holes, and interval data defining an interval between each of the plurality of contact holes; and a plurality of contacts based on the acquired pattern data. Generating an edge flag for every edge of the hole; generating a dense contact hole flag that defines a two-dimensional dense area based on the acquired pattern data and the interval data; Perform logical difference operation excluding dense contact hole flag, A recording medium recording a computer program for performing a determination including: a step of generating a position determination flag; and a step of determining a position of each contact hole in a two-dimensional density based on the number of the position determination flags. 9. A verification device for verifying the congestion by determining whether or not a pattern of a plurality of contact holes of an integrated circuit forms one-dimensional congestion, the verification device comprising: A storage unit storing pattern data to be defined, and interval data defining each interval between the plurality of contact holes; and a plurality of contact holes based on the pattern data and the interval data acquired from the storage unit. A density determination flag generation unit that generates a density determination flag with an interval expanded by a predetermined amount; and a plurality of types based on whether the shape of the density determination flag generated by the density determination flag generation unit is rectangular. And a flag shape determination unit for determining whether or not the contact hole pattern forms one-dimensional denseness. 10. A verification apparatus for verifying a layout by determining a position of each contact hole in a two-dimensional dense area when a plurality of contact holes of the integrated circuit form a two-dimensional dense area. A storage unit storing pattern data defining a layout pattern of the contact holes, and interval data defining intervals of the plurality of contact holes; and a plurality of contact holes based on the pattern data acquired from the storage unit. A contact hole edge generation unit that generates an edge flag for all edges, and a dense contact hole flag that defines a two-dimensional dense area based on the pattern data and the interval data obtained from the storage unit; The contact hole edge generator generates the dense code from the edge flag. A position determination flag generation unit that performs a logical difference operation excluding a contact hole flag to generate a position determination flag; and, based on the number of the position determination flags generated by the position determination flag generation unit, the individual And a position determining unit for determining the position of the contact hole.