EXTREME ULTRAVIOLET LITHOGRAPHY PROCESS AND MASK

摘要

A process of an extreme ultraviolet lithography (EUVL) is disclosed. The process includes receiving an extreme ultraviolet (EUV) mask with multiple states. Different states of the EUV mask are assigned to adjacent polygons and adjacent sub-resolution polygons. The EUV mask is exposed by a nearly on-axis illumination (ONI) with partial coherence sigma less than 0.3 to produce diffracted lights and non-diffracted lights. Most of the non-diffracted lights are removed. The diffracted lights and the not removed non-diffracted lights are collected and directed to expose a target by a projection optics box.