US 5,475,766 AGranted

Pattern inspection apparatus with corner rounding of reference pattern data

AssigneeKabushiki Kaisha Toshiba

InventorsHideo Tsuchiya, Toshiyuki Watanabe, Masao Takanashi, Masayuki Hideshima

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Abstract

A pattern inspection apparatus for comparing/collating a test target pattern with a corresponding design pattern to detect the presence/absence of a defect which is present in the test target pattern includes a bit pattern generating circuit for developing the data of the design pattern into bits, a corner pattern detector for scanning a corner pattern detection window having a predetermined range with respect to reference pattern data as a reference of a pattern obtained by bit development performed by the bit pattern generating circuit to extract a contour pattern, and detecting a corner pattern to be subjected to corner rounding processing on the basis of the extracted contour pattern, a memory for storing predetermined change information corresponding to the corner detected by the corner pattern detector, a graphic pattern synthesizing circuit for changing a graphic pattern in accordance with the information in the memory, and a comparing circuit for comparing reference pattern data, obtained by rounding processing performed on the basis of the reference pattern data and the feature of the corresponding pattern, with test pattern data obtained from the test target pattern, and further includes a pattern correcting circuit constituted by an excessive rounding detector for detecting and correcting an inadequate excessive rounding operation, and a pattern changing circuit for changing the pattern data in accordance with the excessive rounding detection result.

Claims14

Dependent claims

A pattern inspection apparatus for comparing/collating test target pattern data obtained from a test target pattern with design pattern data of the pattern to detect the presence/absence of a defect which is present in a test target pattern, comprising:

pattern generating means for developing data of a design pattern corresponding to the test target pattern into bits, corner rounding means for performing corner rounding processing with respect to reference pattern data obtained by the pattern generating means, and comparing means for comparing second reference pattern data which is obtained by rounding the reference pattern data on the basis of the reference pattern data and a feature of the corresponding pattern, with the test pattern data obtained from the test target pattern,
said corner rounding means including:
a corner pattern detector for scanning a corner pattern detection window having a predetermined range with respect to the reference pattern data, obtained by bit development performed by said pattern generating means, to extract a contour pattern in said window in the range, and detecting a corner pattern to be subjected to corner rounding processing in accordance with the extracted contour pattern,
a masking pattern data generator for generating masking pattern data corresponding to the corner pattern detected by said corner pattern detector, and
a graphic pattern synthesizing circuit for synthesizing graphic pattern data using the detected corner pattern in the reference pattern data with masking pattern data corresponding to the graphic pattern data, thereby rounding a corner portion of the reference pattern data;
wherein said comparing means compares the second reference pattern data, obtained by said graphic pattern synthesizing circuit, with the test pattern data using a predetermined threshold value level,
said corner pattern detector comprises a contour portion determining circuit for scanning said corner pattern detection window to independently test a contour pattern in said window, and an internal portion determining circuit for independently testing an internal pattern in said window excluding the contour portion;
and
a logical operation is performed by said corner pattern detector on the basis of a test result obtained by said contour pattern determining circuit and a test result obtained by said internal portion determining circuit to test/determine whether the test target pattern data coincides with the reference pattern data.

6 more elements

pattern generating means for developing data of a design pattern corresponding to the test target pattern into bits, corner rounding means for performing corner rounding processing with respect to reference pattern data obtained by the pattern generating means, and comparing means for comparing second reference pattern data which is obtained by rounding the reference pattern data on the basis of the reference pattern data and a feature of the corresponding pattern, with the test pattern data obtained from the test target pattern,
said corner rounding means including:
a corner pattern detector for scanning a corner pattern detection window having a predetermined range with respect to the reference pattern data, obtained by bit development performed by said pattern generating means, to extract a contour pattern in said window in the range, and detecting a corner pattern to be subjected to corner rounding processing in accordance with the extracted contour pattern,
a masking pattern data generator for generating masking pattern data corresponding to the corner pattern detected by said corner pattern detector, and
a graphic pattern synthesizing circuit for synthesizing graphic pattern data using the detected corner pattern in the reference pattern data with masking pattern data corresponding to the graphic pattern data, thereby rounding a corner portion of the reference pattern data;
wherein said masking pattern data generator comprises at least one storage table for storing/holding a plurality of pattern shapes as the masking pattern data,
an arbitrary pattern shape is selected from said storage table in accordance with a command from a predetermined controller, and
a rounded shape of a corner is changed in accordance with a selected arbitrary pattern shape.

5 more elements

pattern generating means for developing data of a design pattern corresponding to the test target pattern into bits, corner rounding means for performing corner rounding processing with respect to reference pattern data obtained by the pattern generating means, and comparing means for comparing second reference pattern data which is obtained by rounding the reference pattern data on the basis of the reference pattern data and a feature of the corresponding pattern, with the test pattern data obtained from the test target pattern,
said corner rounding means including:
a corner pattern detector for scanning a corner pattern detection window having a predetermined range with respect to the reference pattern data, obtained by bit development performed by said pattern generating means, to extract a contour pattern in said window in the range, and detecting a corner pattern to be subjected to corner rounding processing in accordance with the extracted contour pattern,
a masking pattern data generator for generating masking pattern data corresponding to the corner pattern detected by said corner pattern detector, and
a graphic pattern synthesizing circuit for synthesizing graphic pattern data using the detected corner pattern in the reference pattern data with masking pattern data corresponding to the graphic pattern data, thereby rounding a corner portion of the reference pattern data;
wherein said corner pattern detector comprises a first latch group having a function of latching said reference pattern data, and a memory connected to said first latch group and having a function of storing masking pattern data,
said masking pattern data generator comprises said memory having the function of storing masking pattern data, a second latch group connected to said memory and having a function of latching output data from said memory, and an OR gate group connected to said memory and said second latch group, and
said graphic pattern synthesizing circuit comprises an exclusive-OR gate group.

5 more elements

A pattern inspection apparatus comprising:

bit pattern generating means for generating reference pattern data by bit development of a design pattern into bits;
corner rounding means for selecting a corner portion of said reference pattern data obtained by bit development performed by said bit pattern generating means, and performing corner rounding processing with respect to the corner portion to generate corner-rounded data;
and
comparing means for comparing said corner-rounded data obtained by rounding processing with test pattern data of a test target pattern,
said corner rounding means including
a corner pattern detector for detecting a corner pattern by scanning a corner pattern detection window with respect to the reference pattern data,
a masking pattern data generator for generating masking pattern data corresponding to the corner pattern detected by said corner pattern detector, and
a graphic pattern synthesizing circuit for synthesizing graphic pattern data including the detected corner pattern in the reference pattern data with masking pattern data corresponding to the graphic pattern data, thereby rounding a corner portion of the reference pattern data, and
said pattern inspection apparatus further comprising:
corner-rounded pattern correcting means constituted by an excessive rounding detector for detecting an excessive rounding state, which is caused when corner rounding processing is performed with respect to a plurality of adjacent corners, by scanning the reference pattern data and corresponding masking pattern data, and
a masking pattern changing circuit for changing a masking pattern in accordance with a test result obtained by said excessive rounding detector.

8 more elements

Dependencies are inferred from the claim text.