Mask calibration method for mask defect detection

A mask calibration method for mask defect detection, comprising the following steps:

• S1, choosing a selected area with a pattern in a mask design file, and outputting vector points of the selected area;
• S2, using an automated optical inspection (AOI) device to acquire an actual image of a corresponding physical mask that corresponds to the selected area;
• S3, setting a horizontal tolerance range in a horizontal direction of the selected area, and performing step S31:
• using different horizontal tolerance compensation values within the horizontal tolerance range to respectively fill and render the vector points output in step S1 into first rendered images;
• respectively registering the first rendered images obtained by rendering with the different horizontal tolerance compensation values with the actual image, employing an evaluation method to evaluate influences of the different horizontal tolerance compensation values on degrees of fit between the first rendered images and the actual image, and taking as a calibrated tolerance in the horizontal direction a horizontal tolerance compensation value for which a best evaluation result is obtained;
• and
• S4, setting a vertical tolerance range in a vertical direction of the selected area, and performing step S41:
• using different vertical tolerance compensation values within the vertical tolerance range to respectively fill and render the vector points output in step S1 into second rendered images;
• respectively registering the second rendered images obtained by rendering with the different vertical tolerance compensation values with the actual image, employing an evaluation method to evaluate influences of the different vertical tolerance compensation values on degrees of fit between the second rendered images and the actual image, and taking as a calibrated tolerance in the vertical direction a vertical tolerance compensation value for which a best evaluation result is obtained.