This paper studies the repeatability and the reliability of CDUs from a mask inspector and their correlation with CD SEM measurements on various pattern attributes such as feature sizes, tones, and orientations. Full-mask image analysis with a mask inspector is one of potential solutions for overcoming the sampling rate limitation of a mask CD SEM. By comparing the design database with the inspected dimension, the complete CDU behavior of specific patterns can be obtained without extra work and tool time. These measurements can be mapped and averaged over various spatial lengths to determine changes in relative CDU across the mask. Eventually, success of this methodology relies on the optical system of the inspector being highly stable.

Date Published: 8 November 2012
PDF: 7 pages
Proc. SPIE 8522, Photomask Technology 2012, 85220C (8 November 2012); doi: 10.1117/12.977944

Published in SPIE Proceedings Vol. 8522:
Photomask Technology 2012
Frank E. Abboud; Thomas B. Faure, Editor(s)