JPH06167801A - Figure calculation processing method - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the efficiency of phase shifter layout and design by performing automatic phase shifter layout processing. A second graphic group which is opposed to the first graphic extracted in the first processing 1 with a shortest distance, and has a second graphic group in which an attribute of a phase having the longest side is undetermined is defined as a second graphic group. Extracted in the third processing 2 and 3, the phase of the second figure group is reversed from that of the first figure. The second attribute whose phase attribute is undetermined in the fourth processing 4
Is extracted, and in the fifth processing 5, the third figure which is opposed to the second figure with the shortest distance and has the attribute of the phase having the longest length of the opposite sides is determined. The phase of the second figure is opposite to that of the third figure. When the phase attribute of each figure is set in this way, the phase of each figure is automatically set so that the phase attributes of the figures that are closest to each other and have the longest facing sides have opposite phases. Can be determined automatically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically generates a figure of a photomask pattern used for lithography or the like in the manufacture of a semiconductor device having a fine pattern of half micron or less using an electronic computer and verifies it. The present invention relates to a graphic calculation processing method to be performed.

[0002]

2. Description of the Related Art The so-called phase shift method is a method for improving the resolution limit in a reduction projection exposure method by Levenson et al., IE Transactions on Electron Device ED.
Volume 29 Issue 12 December 1982 (IEEE TRANSACTIONS O
N ELECTRON DEVICES, VOL.ED-29, NO.12, DECEMBER 198
Proposed in 2). According to the phase shift method, the resolution limit is improved by several steps as compared with the exposure method using an ordinary transmissive mask.

An example of the conventional phase shift method described above will be described below with reference to the drawings. FIG. 6 is a plan view of a mask used in the phase shift method.
Is a quartz plate that transmits light, 42 is a chrome film that blocks light,
43 and 44 are light transmitting parts, and 45 is a phase of the transmitted light.
° This is a phase shifter that changes.

In the phase shift mask device configured as described above, the light passing through the transmitting portion 43 and the transmitting portion 44 has a phase difference of 180 °, and therefore light interference occurs.
Since the lights have the effect of canceling each other, the transmitted light intensity becomes almost zero in the light shielding portion 46 sandwiched between the transmission portion 43 and the transmission portion 44. As a result, even if the width of the light shielding portion 46 is narrow, the contrast of light is improved and a finer pattern can be formed.

[0005]

However, in the above structure, the phase shifter must be arranged manually. This requires the skill and experience of the designer,
There is a problem in that a great deal of cost and time are required to design the mask. Therefore, the object of the present invention is to
It is an object of the present invention to provide a graphic operation processing method capable of improving the efficiency of phase shifter layout and design by performing automatic phase shifter layout processing.

[0006]

According to a method for calculating a figure according to a first aspect of the present invention, first, an arbitrary first figure is extracted from figures whose phase attributes are undetermined, and the phase of the first figure is extracted. The first processing is performed in which the attribute of is a normal phase. Then, a second process of extracting a first graphic group whose distance from the first graphic is equal to or less than a predetermined value is performed. Then, from the first figure group, a second figure group facing the first figure at the shortest distance and having the longest side length is extracted, and the phase of the second figure group is extracted. A third process is performed in which the attribute has a negative phase. After the third processing, the fourth processing of arbitrarily extracting the second graphic from the graphics in which the phase attribute is undetermined is performed. Then,
Among the figures whose distance to the second figure extracted in the fourth process is less than or equal to a predetermined value, the distance to the second figure is the shortest, and the lengths of the sides facing each other across the shortest distance are the shortest. long,
And extracting the third figure whose phase attribute is default
Process.

In the fifth process, if there is no corresponding figure as the third figure, figures other than the second figure are arbitrarily extracted, and this figure is taken as the second figure, and the fifth process is performed. It is executed again as the process of 6. Next, a seventh process is performed in which the phase attribute of the second graphic is the opposite phase of that of the third graphic. Next, after the seventh processing is completed, it is determined whether or not there is a figure whose phase attribute is undetermined. When there is a figure whose phase attribute is undetermined, the fourth to seventh processing is performed again. This process is repeated as the eighth process.

A graphic operation processing method according to a second aspect is the fifth aspect.
If there are a plurality of third figures and the attributes of these figures are different from each other in the processing of step 5, the fifth processing is interrupted, and it is determined that the phase attribute of the second figure cannot be determined. , Including processing to warn. According to a third aspect of the present invention, in the figure calculation processing method, after the seventh processing is completed, a figure group belonging to either positive or negative phase attribute is enlarged by a predetermined size to form a phase shifter pattern. It is a group of figures.

[0009]

According to the first aspect of the invention, a second figure group that opposes the first figure at the shortest distance and has a phase whose longest opposing side has the undetermined phase attribute is extracted. And then the second
The phase of the figure group is reversed from that of the first figure. The second figure whose phase attribute is undetermined is extracted, and the third figure that faces the second figure with the shortest distance and has the longest length of the facing side is extracted. Then, the phase of the second graphic is reversed from the phase of the third graphic.

When the phase attributes of the respective figures are set in this manner, the figures of the shapes closest to each other and having the longest opposing sides are automatically opposite in phase to each other. The phase of can be determined automatically. Therefore, the layout and design efficiency of the phase shifter can be improved. According to the configuration described in claim 2, when a plurality of third figures are present and the phase attribute of the second figure cannot be determined, a warning can be issued and the figure can be verified.

According to the third aspect of the invention, the phase shifter pattern can be automatically created.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A graphic operation processing method according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a processing flow of a graphic operation processing method in an embodiment of the present invention. In FIG. 1, 1 is the first process, 2
Is a second process, 3 is a third process, 4 is a fourth process, 5 is a fifth process, 6 is a sixth process, 7 is a seventh process, and 8 is an eighth process.

A processing procedure of the graphic operation processing method configured as described above will be described below with reference to FIGS. 1 and 2. FIG. 1 is a flow chart showing an algorithm for determining the phase of a figure, and FIG. 2 shows the process of processing a given figure. In this example, the phase of a figure is given in the following order. .

First, by the first processing 1, as a first figure, for example, the figure 11 is selected from the figures whose phase is undetermined.
Are arbitrarily extracted (see FIG. 2A). The figure 11 is given, for example, a positive phase as a phase attribute. Next, the second
By the process 2 of FIG. 2, the distance to the graphic 11 is shorter than the predetermined distance L, the graphic 12, the graphic 13, the graphic 1
4, the figure 15 is extracted (see FIG. 2B).

Subsequently, in the figure 12, figure 13, figure 14, figure 15 extracted by the third processing 3, figure 1
A graphic that faces 1 with the shortest distance and has the longest side is extracted. In this example, the lengths of the opposing sides of the two figures 12, 14 are equal, so the figures 12, 14
Are extracted. Then, a negative phase opposite to that of the figure 11 is given as the phase attribute of the figures 12 and 14 (see FIG.
(See (c)).

Subsequently, the third process is performed by the fourth process 4.
After processing 3 of FIG. 3, any one of the figures whose attributes are undetermined, that is, figure 13, figure 15, figure 16, figure 17, figure 18, and figure 19 is extracted (FIG. 2).
(See (d)). Next, by the fifth processing 5, the graphic 1
A graphic having a shortest distance from 3 and having the longest opposing sides and the phase attribute already determined is extracted. In this case, the figure 11 corresponds.

In the sixth processing 6, since the graphic corresponding to the fifth processing 5 exists, the processing is continued. Next, by the seventh processing 7, the attribute of the phase of the graphic 11 is the positive phase, so the attribute of the phase of the graphic 13 is set to the negative phase (see FIG. 2E). Next, by the eighth processing 8, graphics whose phase attributes are undetermined at this point, that is, graphics 15, graphics 16, graphics 17, graphics 18, graphics 1
9 is extracted, and the fourth processing 4 is continuously executed again.

For example, the graphic 15 is arbitrarily selected in the fourth processing 4. Then, the fifth process 5 is again executed this time for the graphic 15
Is replaced with the figure 13 to start. That is, the figure 15
And a shortest distance are separated from each other, and a figure in which the opposing sides have the longest length and the phase attribute is already determined is extracted (see FIG. 2F). Also in this case, the figure 11 corresponds.

In the sixth process 6, since the graphic corresponding to the fifth process 5 exists, the process is continued. Next, in the seventh processing 7, the attribute of the phase of the graphic 11 is the positive phase, so the attribute of the phase of the graphic 15 is set to the negative phase (see FIG. 2 (g)). Next, by the eighth processing 8, the graphics whose phase attributes are undetermined at this point, that is, the graphics 16, the graphics 17, the graphics 18, and the graphics 19, are extracted, and the fourth processing 4 is executed again. For example, figure 1
6 is arbitrarily selected.

Again, the fifth processing 5 is started this time by replacing the graphic 16 with the graphic 15. That is, the figure 16 is separated from the figure 16 by the shortest distance, and the figure in which the opposing sides have the longest length and the phase attribute is already determined is extracted (see FIG. 2 (h)). In this case, the figure 13 corresponds.
In the sixth processing 6, since the graphic corresponding to the fifth processing 5 exists, the processing is continued.

Next, by the seventh processing 7, the graphic 13
Since the attribute of the phase of is the negative phase, the attribute of the phase of the graphic 16 is set to the positive phase (see FIG. 2 (i)). Thereafter, by repeating the same processing, the phase attributes are finally arranged as shown in FIG. Of these, the figure to which one of the phase attributes, for example, the positive phase attribute is given, is used as a mask for the normal transmission portion, and the figure to which the negative phase attribute is given is shifted the phase of transmitted light by 180 °. In this example, the figures 12, 13, 14, and 15 having the negative phase attribute are subjected to figure calculation processing for expanding, for example, about 1/4 of the minimum line width, and the results are shown in figures 22, 23, 24, and 25. As a result, as shown in FIG.
4 and 25 can realize the phase shifter pattern, which is the so-called Levenson type phase shift mask device.

Using the pattern figure described above, FIG.
The phase shift mask device shown in can be produced.
In FIG. 5, 31 is a phase shifter (broken line portion), 32
Is a transmission part, and 33 is a light shielding part. In addition, in the above embodiment, all the figures are not separated by a predetermined distance. However, for the figures positioned by a predetermined distance, the phase attribute may be either positive or negative. Good. This is for shapes located a specified distance apart,
This is because the effect of the phase shift method disappears, and in such a case, the formation of a pattern by the phase shift method is not affected by giving either a positive attribute or a negative attribute.

In the above embodiment, the fifth
In the processing 5 of step 5, when there are a plurality of the third graphics and the attributes of these graphics are different from each other, the fifth graphics
Processing 5 is interrupted, and it is judged that the phase attribute of the second figure cannot be determined, and a warning is issued.

[0024]

According to the figure operation processing method of the first aspect, the second figure is opposed to the first figure with the shortest distance, and the attribute of the phase whose length of the opposite side is the longest is undetermined. The group is extracted, the phase of the second figure group is reversed from that of the first figure, the second figure whose phase attribute is undetermined is extracted, and the second figure is opposed to the second figure with the shortest distance between them. The attribute of the phase of each figure is extracted by extracting the third figure in which the attribute of the phase having the longest length of the opposite side is the default and reversing the phase of the second figure from the phase of the third figure. Is set, it is possible to automatically determine the phase of each figure so that the phase attributes of the figures that are closest to each other and have the longest sides facing each other have opposite phase attributes. Therefore, the layout and design efficiency of the phase shifter can be improved.

According to the figure operation processing method of the second aspect, when a plurality of third figures exist and the phase attribute of the second figure cannot be determined, a warning can be issued and the figure verification. It can be performed. According to the graphic operation processing method of the third aspect, the phase shifter pattern can also be automatically created.

[Brief description of drawings]

FIG. 1 is a flowchart showing a processing process in a graphic operation processing method according to an embodiment of the present invention.

FIGS. 2A to 2I are process diagrams of figures for explaining the operation in the embodiment.

FIG. 3 is a diagram showing a result of phase attribute arrangement for explaining the operation in the embodiment.

FIG. 4 is a schematic view of a phase shifter pattern in the same embodiment.

FIG. 5 is a schematic view of a phase shift mask device in the example.

FIG. 6 is a schematic view of a conventional phase shift mask device.

[Explanation of symbols]

 1 1st process 2 2nd process 3 3rd process 4 4th process 5 5th process 6 6th process 7 7th process 8 8th process 11-19 figure 22-25 figure 31 Phase Shifter 32 Transparent part 33 Light-shielding part

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[Procedure amendment]

[Submission date] December 27, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a flowchart showing a processing process in a graphic operation processing method according to an embodiment of the present invention.

[2] the first figure for explaining the operation in the same embodiment
It is a process diagram of a process.

FIG. 3 is a second figure for explaining the operation in the embodiment .
It is a process chart of a process.

FIG. 4 is a third figure for explaining the operation in the embodiment .
It is a process chart of a process.

FIG. 5 is a fourth figure for explaining the operation in the embodiment .
It is a process chart of a process.

FIG. 6 is a fifth diagram for explaining the operation in the embodiment .
It is a process chart of a process.

FIG. 7 is a sixth figure for explaining the operation in the embodiment .
It is a process chart of a process.

FIG. 8 is a seventh figure for explaining the operation in the embodiment .
It is a process chart of a process.

FIG. 9 is an eighth figure for explaining the operation in the embodiment .
It is a process chart of a process.

FIG. 10 is a first diagram for explaining the operation in the embodiment.
It is a process chart of 9 processes.

FIG. 11 is a diagram showing a result of phase attribute arrangement for explaining the operation in the embodiment.

FIG. 12 is a schematic view of a phase shifter pattern in the same example.

FIG. 13 is a schematic view of a phase shift mask device in the example.

FIG. 14 is a schematic view of a conventional phase shift mask device.

[Explanation of Codes] 1 First processing 2 Second processing 3 Third processing 4 Fourth processing 5 Fifth processing 6 Sixth processing 7 Seventh processing 8 Eighth processing 11 to 19 Figures 22 ~ 25 Figure 31 Phase shifter 32 Transmission part 33 Light shielding part

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 1]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 10]

[Figure 9]

FIG. 11

[Fig. 12]

[Fig. 13]

FIG. 14

Claims (3)

[Claims] 1. A first process of extracting an arbitrary first figure from figures whose phase attributes are undetermined and setting the phase attribute of the first figure as a positive phase, the first process A second process of extracting a first figure group whose distance to the figure is less than or equal to a predetermined value; and facing the first figure with a shortest distance from the first figure group, And a third process for extracting a second graphic group having the longest side length and setting the phase attribute of this second graphic group as a negative phase; A fourth process of arbitrarily extracting a second graphic from the confirmed graphics, and a graphic whose distance to the second graphic extracted in the fourth processing is less than or equal to a predetermined value The third figure in which the distance to the second figure is the shortest, the sides facing each other with the shortest distance therebetween are the longest, and the phase attribute is predetermined. In the fifth process of extracting a figure, if a figure corresponding to the third figure does not exist in the fifth step, a figure other than the second figure is arbitrarily extracted, and the figure is referred to as the first figure. A sixth process for executing the fifth process again as a second graphic; a seventh process for setting the phase attribute of the second graphic to a phase opposite to that of the third graphic; After the processing of (1) is finished, it is determined whether or not there is a figure whose phase attribute is undetermined, and when there is a figure whose phase attribute is undetermined, the above fourth to seventh processing is performed again A graphic operation processing method comprising the eighth processing which is repeatedly performed. 2. In the fifth processing, when there are a plurality of the third graphics and the attributes of these graphics are different from each other, the fifth processing is interrupted and the second graphics is interrupted. 2. The graphic operation processing method according to claim 1, further comprising: a process of determining that the graphic attribute of the phase cannot be determined and issuing a warning. 3. A graphic group for phase shifter pattern formation, wherein after the seventh processing is completed, a graphic group whose phase attribute belongs to either positive or negative is enlarged by a predetermined size to form a phase shifter pattern forming graphic group. The graphic calculation processing method described in 1.