Methods and systems for detecting defects on a reticle

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

• acquiring first images of first areas on a wafer, wherein the first images are generated by a wafer inspection system, wherein a reticle is printed in different first areas using different values of a parameter of a lithography process, and wherein the reticle is a single die reticle;
• acquiring one or more second images of at least one second area on the wafer, wherein the one or more second images are generated by the wafer inspection system, and wherein the reticle is printed in the at least one second area using a nominal value of the parameter;
• separately comparing the first images acquired for different first areas to at least one of the one or more second images to determine variation in the first images compared to the at least one second image;
• and
• detecting defects on the reticle based on first portions of the first images in which the variations are greater than second portions of the first images and the first portions that are common to two or more of the first images, wherein the defects comprise crystal growth defects on the reticle.