JP3401611B2 - Verification method for drawing graphic data - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention selectively exposes a resist sensitive to ionizing radiation to a desired shape by exposure to ionizing radiation such as electron beam, laser light, ion beam, and X-ray. The present invention relates to a verification method for checking whether the drawing figure data is processed in a state close to the design figure data in the field of the exposure drawing apparatus. In particular, the present invention relates to verification of drawing graphic data in an exposure drawing apparatus used to create a mask pattern of a photomask, reticle, etc. used for manufacturing a circuit such as an LSI, a VLSI, an ultra-ultra LSI.

[0002]

2. Description of the Related Art The degree of integration of LSIs has been increasing year by year, and there has been a demand for further miniaturization of mask patterns such as photomasks and reticles used for patterning LSIs. Therefore, in the manufacture of photomasks and reticles, patterning by an exposure drawing apparatus using electron beams, ultraviolet rays, laser beams, etc. has become the mainstream, instead of patterning by reduction projection using camera work. Among them, a patterning method using an electron beam exposure drawing apparatus using an electron beam is generally known as a method for producing a resist pattern for patterning a resist with high accuracy and high quality. In this method, an electron beam is controlled by an electromagnetic field in a vacuum, and a resist portion which is sensitive to the electron beam on a substrate for a photomask or the like on an XY-controlled stage is selectively exposed to a predetermined resist. A resist pattern is obtained by forming a pattern latent image and developing it. Then, the light shielding layer is etched using the resist pattern as an etching resistant film to obtain a photomask or the like. Here, the ionizing radiation refers to infrared rays, visible light, ultraviolet rays, far ultraviolet rays, laser light, X-rays, ion beams, etc., and an exposure drawing apparatus using ionizing radiation is for drawing these ionizing rays. The devices used for are collectively referred to. Generally, there are an electron beam exposure drawing apparatus, a laser beam exposure drawing apparatus, an ion beam exposure apparatus, an X-ray exposure apparatus, and the like.

When performing the drawing work in the electron beam exposure drawing apparatus, it is important to use drawing data as close as possible to the design figure data, but the drawing data and the design data do not always have the same shape. For example, in FIG.
From the design graphic data 810 with diagonal lines shown in (a),
The drawing graphic data 820 approximated by the rectangular graphic data shown in FIG. 8B may be processed and obtained. Note that FIG.
(B) shows the disagreement points between the two graphic data as graphics c81 to c
This is represented by 89. Further, as shown in FIG. 9, since the basic unit of design data and the basic unit of drawing data are different, an error (also called rounding) may occur due to quantization. In FIG. 9A, the original design figure data is 0.
While 001 μm is used as an address unit, FIG.
In (b), the drawing graphic data has an address unit of 0.05 μm, and the rectangular data a91 of the original design graphic data is
When the mesh size of 0.05 μm is not applied, the rectangular data b91 of the drawing graphic data created from the original design graphic data is quantized at the time of conversion so that the mesh size of 0.05 μm is obtained. , The data can be rounded. Therefore, the rectangular data b9 having a different shape from the rectangular data a91
1 will be generated. Therefore, drawing may be performed contrary to the design concept due to the difference between the design figure data and the drawing data, and the drawing figure data may match the design figure data within the allowable error. It will be necessary to verify whether or not there is. The design data referred to here is graphic data obtained by converting designed re-layout data into trapezoidal base data, and basically no error occurs between the two. In addition, the drawing graphic data is data obtained by converting the graphic data of the formats for various drawing devices that can be input to the drawing device into a trapezoid-based graphic format in ascending order of X and Y, and basically there is an error between the two. Does not occur.

The conventional verification of drawing graphic data will be briefly described with reference to FIG. First, with respect to the original graphic data (design graphic data) and the drawing graphic data processed from now on, the exclusive logical sum (Exclu
(sive-OR) is obtained, and the non-matching graphic data of both are extracted. (S71) Then, X, Y
Reduction processing (also referred to as undersize) is performed in both directions (S72), and a figure having a width or height smaller than the reduction value D0 (hereinafter also referred to as an allowable value) is erased here. Next, enlargement processing (also referred to as oversize) is performed in both X and Y directions on all the graphic data remaining after the reduction processing (S73), and the obtained graphic data (reduction / enlargement drawing) is newly set as inconsistent data. . In this way, only the mismatched pattern data larger than the predetermined allowable value is extracted.

[0005]

However, as the density of semiconductor devices has increased, the number of drawing graphic data has increased, and high-precision data has been required. With the increase in the number of graphic data to be processed shown in FIG.
The number of figure data detected in the process of S71 (step 71) becomes extremely large, processing becomes impossible, or a long time is required for processing, which has become a problem. For example, in the step S71, FIG.
As shown in FIG.
(A)), the number of graphic data obtained by the exclusive OR of both graphic data greatly increases compared to the drawing graphic data 820 (FIG. 8B). Under the above circumstances, the present invention reduces the number of graphic data to be reduced and enlarged shown in FIG. 7 as much as possible when verifying the drawn graphic data, and obtains the same result as before. It is something to try.

[0006]

A method for verifying drawing graphic data according to the present invention is designed to obtain design graphic data obtained from layout data having trapezoidal base graphic data and drawing graphic obtained from the design graphic data. A method for verifying drawing data for extracting a mismatch with data,
(A) Unmatched figure data extraction step of extracting unmatched figure data from both figure data by exclusive OR of figure logic operations, and (B) selecting figure data to be processed from all extracted unmatched figure data. A figure data selection step, (C) an outline processing step in which all the figure data that have been selected are the figure data that are in contact with each other, and (D) an allowable value for the figure data that has been subjected to the outline processing. Enlargement processing is performed to obtain graphic data that is reduced in the X and Y directions by D, and obtain graphic data that is obtained by expanding the obtained graphic data after the reduction processing in the X and Y directions by the allowable value D. It is characterized in that it comprises a reduction / enlargement processing step of the figure data in which only the obtained figure data is newly set as the unmatched figure data. Further, in the above, the design graphic data and the graphic data for drawing are both graphic data groups consisting of trapezoid-based graphic data having a height in the Y direction. , The widths in the X direction that are equal to or smaller than the allowable value D are removed, and those that are larger than the allowable value D are left as the processing target graphic data, and the unmatched graphic data remaining in the first selection process. Against
If there is other graphic data in contact with the Y direction, and if the width in the X direction and the width in the Y direction of at least one of the other graphic data is larger than the allowable value D, the graphic data including the mismatched graphic data and in contact Is output as output graphic data, and if either one of the X-direction width and the Y-direction width of the graphic data is smaller than the allowable value D with respect to all other contacting graphic data, Y of the non-matching graphic data is output. When the width in the direction is larger than the allowable value D, all the contacting figure data including the non-matching figure data is output as output figure data,
When the width in the Y direction is smaller than the allowable value D, the second selection step of discarding the mismatched pattern data and the other unmatched pattern data remaining in the first selection step are contacted in the Y direction. If there is no graphic data, Y of the mismatched graphic data
Check the width in the direction and output it as the output graphic data if the width in the Y direction is larger than the allowable value D, and discard the graphic data if the width in the Y direction is smaller than the allowable value D. Third selection The process is characterized in that the same graphic data as the graphic data already processed as the output graphic data in each selection process is not duplicated as the output graphic data.

[0007]

With the above construction, the method for verifying drawing data of the present invention can reduce the number of graphic data when performing processing such as reduction processing and enlargement processing in verification of drawing graphic data. In addition, it is possible to obtain a pattern close to an actual non-matching figure. Specifically, (A)
From both graphic data by exclusive OR of graphic logical operations,
A non-matching graphic data extracting step of extracting non-matching graphic data; and (B) a graphic data selecting step of selecting graphic data to be processed from all the extracted non-matching graphic data,
(C) An outline processing step in which the figure data that are in contact with all the selected figure data are regarded as one figure data, and (D) an allowable value D in the X direction for the figure data subjected to the outline processing, A reduction process is performed to obtain the figure data reduced in the Y direction, and the obtained figure data after the reduction process is enlarged by the allowable value D to obtain figure data enlarged in the X and Y directions. This is achieved by including a reduction / enlargement processing step of graphic data in which only the data is newly set as the non-matching graphic data. More specifically, by providing a figure data selection step of selecting figure data to be processed from all extracted non-matching figure data, the number of figure data to be processed is reduced as compared with the conventional step shown in FIG. It is also designed to withstand the verification of a large amount of graphic data for drawing, and the actual inconsistency is achieved by providing an outline processing process for all graphic data that have been selected as one graphic data that is in contact with each other. It is possible to extract graphic data close to the graphic data and larger than the allowable value. Specifically, both the design graphic data and the drawing graphic data are a graphic data group composed of trapezoid-based graphic data having a height in the Y direction, and the graphic data selecting step extracts all the mismatched graphic data. Therefore, if the width in the X direction is less than the allowable value D, remove
By having the first selection step of leaving the data larger than the allowable value D as the graphic data to be processed, it is possible to greatly reduce the amount of data to be processed. Then, for each unmatched graphic data remaining in the first selection step, Y
If there is other graphic data in contact with each other in the direction, if the width in the X direction and the width in the Y direction of the other graphic data on one side is larger than the allowable value D, the graphic data in contact including the mismatched graphic data is If all of the other figure data that are in contact with each other are smaller than the allowable value D in the X-direction width or the Y-direction width, all the output figure data are output in the Y-direction. If the width is larger than the permissible value D, all the contacting figure data including the non-matching figure data is output as output figure data, and Y
If the width in the direction is smaller than the allowable value D, the second selection step of discarding the mismatched pattern data and other patterns contacting in the Y direction with respect to each mismatched pattern data remaining in the first selection step If there is no data, check the width in the Y direction of the mismatched pattern data, and if the width in the Y direction is larger than the allowable value D, output it as output graphic data. If the width in the Y direction is smaller than the allowable value D, If there is a third selection step of discarding the graphic data, the graphic data having a shape larger than the allowable value and close to the actual non-matching graphic data does not match through the outline processing step and the reduction / enlargement processing step. It is possible to obtain it as graphic data.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for verifying drawing data according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram specifically showing an example of a flow of a method for verifying drawing data according to the present invention.
The original design graphic data and the drawing graphic data obtained from the design graphic data are both trapezoid-based graphic data having a height in the Y direction. First, the original design graphic data and the drawing graphic data processed from this are subjected to exclusive OR to extract a mismatched graphic. (S1) FIG. 7 shows a process for extracting a mismatched pattern by performing exclusive OR.
It is also used in the conventional verification method shown in (1) and is a generally known method, and this is not mentioned here. Next, with respect to all the extracted non-matching graphic data, each graphic data is taken out one by one in ascending order of Y. (S2) Width (width) in the X direction for each of the extracted graphic data
If is less than the allowable value, it is removed without being processed, and if it is greater than the allowable value, it is passed to the next processing. (S3) If the width of the extracted graphic data in the X direction is larger than the allowable value, it is checked whether or not there is another graphic in contact with the graphic in the Y direction. (S4) If there is no other figure data in contact, check the width (height) in the Y direction of the figure. If the width in the Y direction is larger than the allowable value, output it as it is and make it output data. If it is small, it is removed from the processing target. (S5) If there is another figure data in contact, whether there is any figure data in which either the width in the X direction or the width in the Y direction is larger than the allowable value with respect to all the other figure data in contact. If there is even one, all the contacting figure data including the retrieved figure data is output as output figure data (S6). If there is not, check the width of the mismatched figure data in the Y direction. , If the width in the Y direction is less than or equal to the allowable value, it is removed. If the width in the Y direction is larger than the allowable value, all the contacting graphic data including this non-matching graphic is output and used as output graphic data. (S7) In the sorting step, the same graphic data is not output redundantly. However, in the actual processing, when output processing has been completed, a processed flag or the like is set and the same graphic data is output in duplicate. Prevention is easy.

In this way, step 2 (S2) to step 7 are repeated until all the mismatched figures obtained by performing the exclusive OR of step 1 (S1) are completed, and all the mismatched figures are repeated. At the time when the processing is completed, for all the output graphic data (DATA1) obtained,
Outlining data (DATA2) is created by performing an outline processing in which all the contacting figures are set as one figure data. (S8) Next, the obtained outline data (DATA2)
On the other hand, in the same manner as the conventional method shown in FIG. 7, the reduction processing for reducing the allowable value D by half in the X and Y directions is performed to obtain reduced reduction data (DATA3) (S9). Thereafter, the reduction processing data (DATA3) is further subjected to an enlargement processing for enlarging in the X direction and the Y direction by a half of the allowable value D to obtain an enlarged expansion (S10), and this is outside the allowable range to be obtained. It is considered as unmatched graphic data.

Here, both the original design graphic data and the drawing graphic data obtained from the design graphic data are trapezoid-based graphic data having a height in the Y direction. The height direction is defined as Y and the width direction is defined as X in the figure data.

[0011]

EXAMPLE Next, the method of verifying the drawing data of the present invention will be described more specifically using the graphic data. Figure 2 (a)
Shows the original design graphic data, which is composed of two graphic data a1 and a2. 2 (b) is shown in FIG.
Drawing graphic data obtained by processing the original graphic data shown in (a) with predetermined software or the like, and is composed of five graphic data b1, b2, b3, b4, and b5. A figure in which the mismatch between the original figure data shown in FIG. 2 and the drawing figure data is not within the allowable range is extracted below. The term "tolerable range" as used herein refers to an area located at a distance of one side allowable value d in the X and Y directions from the coincident portion of both graphic data.

First, the original graphic data shown in FIG. 2 (a) and the drawing graphic data shown in FIG. 2 (b) are subjected to exclusive OR of graphic logic operations to obtain graphic data C shown in FIG.
Obtained by extracting 1 to C10. It should be noted that FIG. 3 shows the original figure data shown in FIG. 2A in order to make it easy to understand the disagreement between the original figure data shown in FIG. 2A and the drawing figure data shown in FIG. 2B. The outer shape of the drawing graphic data shown in FIG. The graphic data shown in FIG.
It can be seen that the number is 10 from c1 to c10, and the number is more than 6 which is the total number of figure data of the original figure data and the drawing figure data.

Next, a selection process for selecting a graphic to be processed is performed on all the graphic data obtained by performing the exclusive OR. Take out one figure data at a time,
The processing from step 3 (FIG. 1 (S3)) shown in FIG. 1 onward is performed. One figure data is taken out in ascending order of Y coordinate. First,
The figure data c1 is taken out and the width (width) in the X direction is checked (FIG. 1 (S3)). However, since the width is larger than the allowable value D, it is determined whether or not there is figure data in contact with this figure data in the Y direction. Check. (FIG. 1 (S4)) Since there is contacting graphic data c2 and both the width (height) in the Y direction and the width (width) in the X direction of the graphic data c2 are larger than the allowable value D, the graphic data c1 is included. The graphic data C2 in contact with this is also output and used as output data. The graphic data C2 is already output data and is not newly processed. Next, the graphic data c3 is extracted, X
The width in the direction is checked (FIG. 1 (S3)), but since the width in the X direction is smaller than the allowable value D, it is removed as a figure to be processed. Next, the graphic data c4 is taken out and the width in the X direction is checked (FIG. 1 (S3)). However, since the horizontal width is larger than the allowable value D, it is determined whether or not there is graphic data in contact with this graphic data in the Y direction. Check. (FIG. 1 (S4)) Since the figure data c3 is in contact and the width (width) in the X direction of the figure data c3 is smaller than the allowable value D, the figure data c4 is removed as a figure to be processed. Graphic data c5
With respect to c9, the width (width) in the X direction is less than or equal to the allowable value D, so that the patterns are sequentially removed without being processed. As a result, as shown in FIG. 4A, the graphic data c
Only two of 1 and c2 remain as the processing target.

Then, the outline data c0 and the outline data c2, which are in contact with each other, are subjected to outline processing to obtain outline data c0 (FIG. 4 (b)). The graphic data c0 thus obtained is subjected to a reduction process for reducing the entire image by D in the X and Y directions (S9), and the reduced graphic data cS shown in FIG. 5A is obtained. Further, the reduced figure data cS is enlarged to obtain the figure data c shown in FIG.
I got SL. This figure data cSL is the non-matching figure data which is not within the allowable value range and represents the shaded portion shown in FIG. 5, and the non-matching figure c2 and the non-matching figure c1 shown in FIG.
Corresponds to a part of.

[0015]

According to the present invention, all the inconsistent graphic data of the original design graphic data and the drawing graphic data are not used as they are in the reduction processing and the expansion processing as in the conventional verification method shown in FIG. A process of selecting whether or not to perform processing on the non-coincident graphic data is provided, so that the data capacity of the drawing graphic can be increased. Further, since the reducing / enlarging process is performed after the outlining process in which the figures in contact with each other obtained in the selection process are made into one figure, it is possible to obtain a figure which is larger than the allowable value and is close to the actual non-matching figure.

[Brief description of drawings]

FIG. 1 is a flowchart of a method for verifying drawing graphic data according to the present invention.

FIG. 2 is a diagram showing design graphic data and drawing graphic data.

FIG. 3 is a diagram for explaining an exclusive OR of design graphic data and drawing graphic data.

FIG. 4 is a diagram for explaining outline processing.

FIG. 5 is a diagram for explaining reduction processing and enlargement processing.

FIG. 6 is a diagram showing a relationship between a figure after processing and a mismatched figure before processing.

FIG. 7 is a flowchart of a conventional method for verifying drawing graphic data.

FIG. 8 is a diagram for explaining the reason why a mismatched figure occurs between the design figure data and the drawing figure data.

FIG. 9 is a diagram for explaining the reason why a mismatched figure occurs between the design figure data and the drawing figure data.

[Explanation of symbols]

110, 810 original design graphic data 120, 820 drawing graphic data a1, a2 graphic data b1 to b5 graphic data c1 to c9 graphic data cO (after outline processing) graphic data cS reduction processing graphic data cSL enlargement processing Later graphic data a81, b81 to b83, c81 to c89 Graphic data a91, b91 Graphic data

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03F 1/00-1/16 H01L 21/027

Claims (2)

(57) [Claims] 1. A method of verifying drawing data for extracting a mismatch between design graphic data obtained from layout data and drawing graphic data obtained from the design graphic data, which has trapezoid-based graphic data. And (A)
From both graphic data by exclusive OR of graphic logical operations,
A non-matching graphic data extracting step of extracting non-matching graphic data; and (B) a graphic data selecting step of selecting graphic data to be processed from all the extracted non-matching graphic data,
(C) An outline processing step in which the figure data that are in contact with all the selected figure data are regarded as one figure data, and (D) an allowable value D in the X direction for the figure data subjected to the outline processing, A reduction process is performed to obtain the figure data reduced in the Y direction, and the obtained figure data after the reduction process is enlarged by the allowable value D to obtain figure data enlarged in the X and Y directions. A method for verifying graphic data for drawing, comprising: a reduction / enlargement processing step of graphic data in which only new data is newly set as unmatched graphic data. 2. The design graphic data and drawing graphic data according to claim 1, wherein both the design graphic data and the graphic data for drawing are graphic data groups made up of trapezoid-based graphic data having a height in the Y direction, and the graphic data selecting step is extracted. From all unmatched figure data,
If the width in the X direction is less than or equal to the allowable value D, and the width greater than the allowable value D is left as the processing target graphic data, the first selection process and the non-matching graphic data remaining in the first selection process If there is other graphic data in contact with the Y direction, and if the width in the X direction and the width in the Y direction of the other graphic data on one side is larger than the allowable value D, the non-matching graphic data is included in the contact. When all the figure data is output as the output figure data and either one of the X-direction width and the Y-direction width of the figure data is smaller than the allowable value D with respect to all other contacting figure data, the mismatched figure data If the width in the Y direction is larger than the allowable value D, all the contacting graphic data including the non-matching graphic data is output as output graphic data, and if the width in the Y direction is smaller than the allowable value D, the non-matching graphic De A second selection step of discarding data for each mismatched graphic data remaining in a first selection step,
If there is no other graphic data in contact with the Y direction, the width in the Y direction of the mismatched graphic data is checked, and if the width in the Y direction is larger than the allowable value D, it is output as output graphic data. Is smaller than the permissible value D, the third selection step of discarding the graphic data is performed. In each selection step, the same graphic data that has already been processed as output graphic data is output in duplicate. A method for verifying drawing graphic data, which is not graphic data.