Massive CD metrology for EUV failure characterization and EPE metrology

Traditionally, the performance of a lithography or patterning step is described by its mean size and the spread at a 3 sigma probability. Recent papers by Bristol, Brunner and others have shown this is insufficient to describe the process capability in EUV lithography. To address this challenge, an enormous increase of sampling CD (critical dimension) values is needed to describe the actual distribution on the wafer. We will show how we can address this by leveraging the HMI eP5 e-Beam system to acquire a set of CDs of previously unknown size. We will further show that extended sampling leads to better understanding of this phenomena, as we can probe full distribution behavior even on a limited number of repeated exposures on a wafer.