Critical dimension uniformity monitoring for extreme ultraviolet reticles

An inspection system for inspecting an EUV reticle, comprising:

• a light source for generating an incident beam;
• an illumination optics module for directing the incident beam onto an EUV reticle;
• a collection optics module for directing an output beam that is reflected from the EUV reticle in response to the incident beam;
• a sensor for detecting the output beam and generating an image or signal for the output beam;
• and
• a controller that is configured to perform the following operations:
• obtaining a test image or signal from an EUV test reticle in response to the incident beam, wherein the test image or signal specifies an intensity variation across the EUV test reticle;
• converting the intensity variation of the test image or signal to a critical dimension (CD) variation across the EUV test reticle so as to generate a critical dimension uniformity (CDU) map, wherein the CDU map is generated by removing a correction CD variation that originates from design data for fabricating such EUV test reticle and such correction CD variation is designed to compensate for differences that are present across a field of view (FOV) of a photolithography tool during a photolithography process;
• and
• storing the CDU map in one or more memory devices or displaying the CDU map on a display device.