Overlay metrology for next generation lithography at CMS

Abstract

The center for measurement standards (CMS) has a research program in optical overlay metrology. The main goal of this work is to improve overlay measurement accuracy. Two main threads are developed to the work - novel in-chip overlay target design, and best algorithm. The former is hoped to prove a capability for measuring overlay error inside the active area of product devices. The later is for extracting the most from image detail.