Print check repeater defect detection

A non-transitory computer-readable medium, storing program instructions executed on one or more computer subsystems for performing a computer-implemented method for detecting defects on a reticle, wherein the computer-implemented method comprises:

• acquiring images generated for a wafer by an inspection subsystem, wherein a reticle is used to print features on the wafer in a lithography process;
• detecting first defects in at least first and second test images included in the images, wherein detecting the first defects comprises separately comparing each of the at least first and second test images to two different reference images corresponding to said each of the at least first and second test images, and wherein the at least first and second test images correspond to different instances of the same area on the reticle printed on the wafer;
• detecting stacked defects in at least the first test image by separately comparing a stacked test image generated for the first test image to two different stacked reference images corresponding to the stacked test image;
• performing a first repeater defect detection by identifying any of the first defects detected at corresponding locations in two or more of the at least first and second test images and any of the stacked defects as first repeater defect candidates;
• performing at least one additional repeater defect detection on the first repeater defect candidates to thereby identify final repeater defect candidates;
• and
• identifying defects on the reticle based on the final repeater defect candidates, wherein acquiring the images, detecting the first defects, detecting the stacked defects, performing the first repeater defect detection, performing the at least one additional repeater defect detection, and identifying the defects on the reticle are performed by the one or more computer subsystems coupled to the inspection subsystem.

A computer-implemented method for detecting defects on a reticle, comprising:

• acquiring images generated for a wafer by an inspection subsystem, wherein a reticle is used to print features on the wafer in a lithography process;
• detecting first defects in at least first and second test images included in the images, wherein detecting the first defects comprises separately comparing each of the at least first and second test images to two different reference images corresponding to said each of the at least first and second test images, and wherein the at least first and second test images correspond to different instances of the same area on the reticle printed on the wafer;
• detecting stacked defects in at least the first test image by separately comparing a stacked test image generated for the first test image to two different stacked reference images corresponding to the stacked test image;
• performing a first repeater defect detection by identifying any of the first defects detected at corresponding locations in two or more of the at least first and second test images and any of the stacked defects as first repeater defect candidates;
• performing at least one additional repeater defect detection on the first repeater defect candidates to thereby identify final repeater defect candidates;
• and
• identifying defects on the reticle based on the final repeater defect candidates, wherein acquiring the images, detecting the first defects, detecting the stacked defects, performing the first repeater defect detection, performing the at least one additional repeater defect detection, and identifying the defects on the reticle are performed by one or more computer subsystems coupled to the inspection subsystem.