JP2000155405A - Photomask data certification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to discover the abnormality of photomask data in an early time on the design side by a CAD system by converting CAD data and the photomask data to raster data and detecting the difference between both. SOLUTION: The CAD data corresponding to the graphics selected from the graphics stored in an external memory device 12 is converted to the raster data which is displayed by a bit map at a display device 18. Further, the photomask data to be certified is read out of the photomask data stored in the external memory device 12 and is converted to the raster data which is displayed by the bit map on the display device 18. Both pieces of the converted raster data are stored in the prescribed region of a memory device 14. Next, the raster data converting the CAD data stored in the memory device 14 and the raster data converting the photomask data are read out and are subjected to bit map comparison processing. If the difference between both occurs, an error point is displayed at the display device 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photomask data verification system, and more particularly, to a photomask data verification system for verifying photomask data in NC data as shape data for a manufacturing apparatus. More particularly, the present invention relates to a photomask data verification system capable of comparing and verifying CAD data generated by a CAD system with photomask data.

[0002]

2. Description of the Related Art In a CAD system, the CAD
The CAD data handled in the system and the photomask data in the NC data that is the shape data for a manufacturing apparatus output from the CAD system are different in the method of expressing the shape (geometry).

Further, the above-mentioned CAD data and photomask data are different in accuracy and unit.

[0004] Therefore, in order to evaluate the validity of the photomask data, the photomask data is checked visually or an NC editing CAD system is separately prepared and the NC editing CAD system is prepared. Therefore, it is necessary to check the photomask data.

[0005] Conventionally, after the validity of the photomask data is evaluated as described above, a problem part in the evaluation result is corrected by a CAD system, and then the photomask data is output again from the CAD system. However, there is a problem in that the work of re-evaluating the validity of the output photomask data is repeated until no problem is found.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and a purpose thereof is to provide a photomask on the design side of a CAD system at an early stage. An object of the present invention is to provide a photomask data verification system capable of evaluating the validity of data and detecting an abnormality, thereby reducing a cycle of correcting a problem portion and reducing manufacturing man-hours. It is.

[0007]

According to an aspect of the present invention, there is provided a photomask data verification system for verifying photomask data output from a CAD system. First conversion means for converting CAD data into raster data, second conversion means for converting photomask data into raster data, raster data converted by the first conversion means, and second conversion means Comparison means for comparing the raster data converted by the first conversion means with the raster data converted by the second conversion means in accordance with the comparison result of the comparison means. And detecting means for detecting an error when they do not match.

Accordingly, according to the first aspect of the present invention,
The CAD data and the photomask data are converted into raster data, the difference between them is detected as an error, and the verification of the photomask data is automatically performed.

For this reason, it is possible for the design side of the CAD system to evaluate the validity of the photomask data at an early stage and find an abnormality, thereby reducing the cycle of correcting the problem portion and reducing the number of manufacturing steps. Will be able to do it.

Here, the comparing means converts the raster data converted by the first converting means and the raster data converted by the second converting means into bits, as in the second aspect of the present invention. It can be compared by a map.

According to a third aspect of the present invention, the detecting means includes “window missing”, “short pattern”, “occurrence of island”, and “window” according to the comparison result of the comparing means. , "Pattern division" and "island erasure" can be detected as errors.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a photomask data verification system according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a hardware configuration of a CAD system having a photomask data verification system according to the present invention.

The CAD system includes a processing device 10 for controlling the entire system using a microcomputer to perform processing, an external storage device 12 for storing various data such as CAD data and photomask data, which will be described later, and a processing device. A memory device 14 including a read only memory (ROM) storing a program for operating the apparatus and a random access memory (RAM) having an area as a working area of the processing apparatus; And a display device 18 for displaying raster data converted from CAD data or photomask data, and the like.

Next, the C configured as described above is used.
The operation of the AD system will be described.

The operation of the CAD system is the same as that of the conventional CAD system with respect to the creation of CAD data and the creation of photomask data, so that a detailed description thereof will be omitted. Only the process of verifying the photomask data related to the embodiment of the invention will be described.

That is, FIG. 2 shows a flowchart of a processing routine related to a process of verifying photomask data.

When the flowchart shown in FIG. 2 is started, first, the C stored in the external storage device 12 is stored.
The AD data is read (step S20).
2).

Next, a process of selecting a graphic corresponding to the graphic indicated by the photomask data to be verified from the graphics stored in the CAD data is performed (step S20).
4).

In the process of selecting figures, the operator uses the input device 16 to select figures.

Next, the CAD data corresponding to the figure selected in step S204 is converted into raster data, and displayed on the display device 18 as a bit map (step S206).

Further, photomask data to be verified (that is, photomask data corresponding to the figure selected in step S204) is read from the photomask data stored in the external storage device 12. (Step S208).

Next, the photomask data read in step S208 is converted into raster data and displayed on the display device 18 as a bitmap (step S208).
210).

Further, C displayed on the display device 18
The raster data obtained by converting the AD data is stored in a memory device 14.
(Step S212).

The raster data obtained by converting the photomask data displayed on the display device 18 is stored in a predetermined area of the memory device 14 (step S214).

Next, raster data converted from the CAD data and raster data converted from the photomask data stored in a predetermined area of the memory device 14 are read out.
A bitmap comparison process is performed (step S216). The details of the bitmap comparison process will be described later.

In the bitmap comparison process in step S216, an error location (in this specification, the error location refers to a bitmap comparison process between raster data converted from CAD data and raster data converted from photomask data). In this case, it means the difference between the two.)
The error location is displayed on the display device 18, and the processing routine ends.

Next, the bitmap comparison process in step S216 will be described with reference to the conceptual diagrams of the bitmaps shown in FIGS.

First, FIG. 3A shows a bit map of raster data (hereinafter, referred to as "data A") obtained by converting the CAD data displayed on the display device 18 by the process of step S206. S210
It is assumed that the bit map of the raster data (hereinafter, referred to as “data B”) obtained by converting the photomask data by the processing of FIG.

In FIG. 3 and FIG. 4 described later,
It is assumed that bits are set up in black portions and bits are not set in white portions.

Here, the bit map of the data A and the bit map of the data B are compared, and a portion where a bit is set in the data B and a bit is not set in the data A (hereinafter, a bit of the data A) By comparing the map with the bit map of data B, a portion where a bit is set in data B and no bit is set in data A is determined by [B-
A]. ) Is created (FIG. 4).

The bit map shown in FIG. 4 makes it possible to obtain a portion of the photomask data that extends beyond the CAD data.

On the contrary, the bit map of the data A is compared with the bit map of the data B,
Where the bit is set and the bit is not set in the data B (hereinafter, the bit map of the data A is compared with the bit map of the data B, and the bit is set in the data A and the bit is set in the data B By creating a bitmap indicating a portion where no bit is set in B as [AB], it is possible to obtain a portion of the CAD data that has not been output to the photomask data.

Next, regarding the bit map shown in FIG.
A process of assigning an ID to the island of [BA] (where the bit is set) is performed. FIG. 5 shows a state in which IDs are assigned to the island [BA].

When assigning IDs to the islands of [BA], IDs are assigned so that portions where the islands are in contact vertically, horizontally and diagonally have the same numbers.

Further, as shown in FIG. 6, a process of assigning an ID to the island of data A is performed. Here, when assigning IDs to the islands of the data A, IDs are assigned so that the portions where the islands are obliquely contacting vertically, horizontally, and obliquely have the same number, and “ID = 0” is assigned to the non-island portions. An ID is assigned.

When a bitmap indicating [AB] is created in place of the bitmap indicating [BA] (FIG. 4), processing for assigning IDs to the islands of data B is performed. become.

Next, the number of the ID assigned in the data A is detected with respect to the same portion of the island of the same ID in [BA] that is obliquely contacted in the up, down, left, and right directions. The verification of the photomask data is performed based on the state of the ID thus obtained.

For example, in [BA], “ID =
The locations around the island of “2” are dA to E, eA, eE, and fA to E (see FIG. 5). ”,“ ID =
IDs "2" and "ID = 3" are obtained.

As described above, since there are a plurality of IDs other than 0 in the data A, the portions which are separate islands in the data A are connected by the island of “ID = 2” in [BA]. It is determined that it has been completed. Therefore, the island of “ID = 2” in [BA]
It is recognized that a so-called “short pattern” error has occurred at that location.

FIG. 7 shows, according to the state of the obtained ID,
It shows what kind of error is recognized as having occurred.

That is, in the case of the comparison in [BA], that is, with respect to the location of data A corresponding to the location around the island to which the ID is assigned in [BA], one location without including 0 is included. If there is only an ID, the ID in [BA]
Is recognized as having a so-called "window missing" error at that location.

As shown in the above example, [B-
A], that is, when there are a plurality of IDs other than 0 in the location of the data A corresponding to the location around the island assigned the ID in [BA],
A], the island given the ID in that location,
It is recognized that a so-called “short pattern” error has occurred.

Further, in the case of the comparison in [BA], that is, when the ID is only 0 with respect to the location of data A corresponding to the location around the island to which the ID is assigned in [BA], The island given the ID in [BA] is
It is recognized that a so-called “island occurrence” error has occurred at that location.

As shown in FIG. 7, in the case of comparison at [AB], that is, with respect to the location of data B corresponding to the location around the island assigned the ID in [AB], 0
When there is only one ID without including the [A-
B], the island given the ID is
It is recognized that a so-called “window has occurred” error has occurred.

As shown in FIG. 7, in the case of comparison at [AB], that is, with respect to the location of data B corresponding to the location around the island assigned the ID in [AB], 0
When there are a plurality of IDs other than the above, the island to which the ID in [AB] is assigned has a so-called “
It is recognized that an error of “pattern division” has occurred.

Further, as shown in FIG. 7, in the case of comparison at [AB], that is, with respect to the location of data B corresponding to the location around the island to which the ID is assigned in [AB],
When the ID is only 0, the ID in [AB]
Is recognized as having a so-called "island erasure" error at that location.

Therefore, as shown in FIG. 7, when the verification is performed in both the case of the comparison with [BA] and the case of the comparison with [AB], the "missing window" It can recognize six types of error states of "short pattern", "island occurrence", "window occurrence", "pattern division", and "island erasure".

In the examples shown in FIGS. 3A, 3B and 6, the island of “ID = 1” of [BA] is recognized as not an error pattern, and the island of [BA] is recognized as an error pattern. "ID = 2"
Are recognized as having an error of “short pattern”, and the island of “ID = 3” in [BA] is recognized as having an error of “missing window”. The island with “ID = 4” is recognized as having an error of “occurrence of island”.

The location where an error has been recognized by the above processing is displayed on the display device 18 as an error location in step S218.

Further, the island determined to be not an error pattern by the above processing (in the above example, [B-
A] is the island of “ID = 1”. )
A check is made for locations that are farther than the specified number of pixels.

In this check, a process for detecting a deviation occurring due to the precision of data as an error occurrence is performed.

Further, the location where an error has been detected by this processing is also displayed on the display device 18 as an error location in step S218.

In the above-described embodiment, the photomask data verification system is described as being incorporated in a CAD system. However, the present invention is not limited to this, and the photomask data verification system is independent of the CAD system. A system may be configured.

The photomask data and the CAD data are not limited to data generated by the same CAD system, but may be data generated by different systems.

[0056]

Since the present invention is configured as described above, the design side of the CAD system can evaluate the validity of the photomask data at an early stage and find an abnormality. This has an excellent effect that the number of man-hours can be reduced by reducing the number of cycles of correcting parts.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a hardware configuration of a CAD system including a photomask data verification system according to the present invention.

FIG. 2 is a flowchart illustrating a processing routine related to a process of verifying photomask data.

FIG. 3 is a conceptual diagram of a bitmap for explaining the operation of the photomask data verification system according to the present invention;
(A) is a bitmap of raster data (data A) converted from CAD data, and (b) is a bitmap of raster data (data B) converted from photomask data.

FIG. 4 compares a bitmap of data A shown in FIG. 3A with a bitmap of data B shown in FIG.
9 is a bit map showing a portion where a bit is set in data B and a bit is not set in data A ([BA]).

FIG. 5 is a diagram showing an example in which the island of the bit map of [BA] shown in FIG.
It is a chart showing the state where D was allocated.

6 is a chart showing a state where IDs are assigned to islands of the bitmap of data A shown in FIG.

FIG. 7 is a table showing what kind of error is recognized as having occurred depending on the state of the obtained ID.

[Explanation of symbols]

 Reference Signs List 10 processing device 12 external storage device 14 memory device 16 input device 18 display device

Claims (3)

[Claims] 1. A photomask data verification system for verifying photomask data output from a CAD system, comprising: first conversion means for converting CAD data into raster data; and first conversion means for converting photomask data into raster data. Conversion means for comparing the raster data converted by the first conversion means with the raster data converted by the second conversion means; and A photomask data verification system, comprising: a detection unit that detects an error when the raster data converted by the first conversion unit and the raster data converted by the second conversion unit do not match. 2. The photomask data verification system according to claim 1, wherein the comparing unit converts the raster data converted by the first converting unit and the raster data converted by the second converting unit. A photomask data verification system that uses bitmaps for comparison. 3. The photomask data verification system according to claim 1, wherein said detection unit is configured to:
"Open windows", "Short patterns", "Island emergence",
A photomask data verification system that detects "window generation", "pattern division", and "island erasure" as errors.