US 6,888,958 B1Granted

Method and apparatus for inspecting patterns

AssigneeKabushiki Kaisha Toshiba

InventorsEiji Sawa, Hiromu Inoue, Satoshi Imi

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Abstract

The difference data between the real patter data Sij, and a 5×5 window with a noticed pixel in the center and the design pattern data Rij obtained by the design pattern data of the window being shifted in a plurality of directions with respect to the design pattern data Rij is found by a shift direction operation section, and the design pattern data in the direction in which the total of the pixels is minimum is selected from the difference data by a selection section, the difference between the central pixels Sij, Qij of the selected design pattern data and the central pixels Sij, Qij of the windows of the real pattern data is found by a difference operation section, and the difference and a threshold are compared in a defect judgement section, and thereby the pattern inspection of the object is carried out.

Claims5

Dependent claims

A pattern inspection method comprising:

comparing a real pattern window having real pattern data corresponding to predetermined pixels of the real pattern data obtained by imaging an inspection object to a design pattern window corresponding to the real pattern window and shifted design pattern windows which are obtained by shifting the design pattern windows in a plurality of directions, respectively, wherein a shift width of the shifted design pattern windows is within one pixel;
selecting one window from the design pattern window and shifted design pattern windows;
comparing a center pixel of the real pattern window to a center pixel of the selected design pattern window;
and
performing a pattern inspection of the inspection object, corresponding to the center pixel, according to a result of the comparison;
wherein the performing comprises:
obtaining a difference value by subtracting a noticed pixel of the selected one window and predetermined pixels surrounding the noticed pixel of the selected one window from a noticed pixel of the real pattern window and predetermined pixels surrounding the noticed pixel of the real pattern window,
outputting 1) a “0” difference value in a case where the obtained difference value is within a difference value obtained by shifting the design pattern window by one pixel or less, 2) a difference value obtained by subtracting the minimum value from the obtained difference value in a case where the obtained difference value is less than a minimum value of difference values obtained by shifting the design pattern window and 3) a difference value obtained by subtracting a maximum value of difference values which are obtained by shifting the design pattern window by one pixel or less from the obtained difference value in a case where the obtained difference value is lager than the maximum value, and
performing the pattern inspection of the inspection object by comparing the outputted difference value with a threshold value set in advance.

6 more elements

A pattern inspection device comprising:

means for comparing a real pattern window having real pattern data corresponding to predetermined pixels of the real pattern data obtained by imaging an inspection object to a design pattern window corresponding to the real pattern window and shifted design pattern windows which are obtained by shifting the design pattern windows in a plurality of directions, respectively, wherein a shift width of the shifted design pattern windows is within one pixel;
means for selecting one window from the design pattern window and shifted design pattern windows;
means for comparing a center pixel of the real pattern window to a center pixel of the selected design pattern window;
and
means for performing a pattern inspection of the inspection object, corresponding to the center pixel, according to a result of the comparison;
wherein the means for performing comprises
obtaining a difference value by subtracting a noticed pixel of the selected one window and predetermined pixels surrounding the noticed pixel of the selected one window from a noticed pixel of the real pattern window and predetermined pixels surrounding the noticed pixel of the real pattern window,
outputting 1) a “0” difference value in a case where the obtained difference value is within a difference value obtained by shifting the design pattern window by one pixel or less, 2) a difference value obtained by subtracting the minimum value from the obtained difference value in a case where the obtained difference value is less than a minimum value of difference values obtained by shifting the design pattern window and 3) a difference value obtained by subtracting a maximum value of difference values which are obtained by shifting the design pattern window by one pixel or less from the obtained difference value in a case where the obtained difference value is lager than the maximum value, and
performing the pattern inspection of the inspection object by comparing the outputted difference value with a threshold value set in advance.

6 more elements

A method of manufacturing a mask comprising:

preparing a substrate with a light shielding film on which a mask pattern is formed;
and
inspecting the substrate with the light shielding film on which a mask pattern is formed, wherein the inspecting comprises:
comparing a real pattern window having real pattern data corresponding to predetermined pixels of the real pattern data obtained by imaging the mask pattern to a design pattern window corresponding to the real pattern window and shifted design pattern windows which are obtained by shifting the design pattern windows in a plurality of directions respectively, wherein a shift width of the shifted design pattern windows is within one pixel;
selecting one window from the design pattern window and shifted design pattern windows;
comparing a center pixel of the real pattern window to a center pixel of the selected design pattern window;
and
performing a pattern inspection of the mask pattern corresponding to the center pixel according to a result of the comparison;
wherein the performing comprises:
obtaining a difference value by subtracting a noticed pixel of the selected one window and predetermined pixels surrounding the noticed pixel of the selected one window from a noticed pixel of the real pattern window and predetermined pixels surrounding the noticed pixel of the real pattern window,
outputting 1) a “0” difference value in a case where the obtained difference value is within a difference value obtained by shifting the design pattern window by one pixel or less, 2) a difference value obtained by subtracting the minimum value from the obtained difference value in a case where the obtained difference value is less than a minimum value of difference values obtained by shifting the design pattern window and 3) a difference value obtained by subtracting a maximum value of difference values which are obtained by shifting the design pattern window by one pixel or less from the obtained difference value in a case where the obtained difference value is larger than the maximum value, and
performing the pattern inspection of the mask pattern by comparing the outputted difference value with a threshold value set in advance.

9 more elements

Dependencies are inferred from the claim text.