Optimizing ALD WN Process for 65nm Node CMOS Contact Application

ALD tungsten nitride (WN) becomes attractive for CMOS contact liner/barrier application because of its highly conductive and conformal film properties. Due to the distinct differences in its process nature from the traditional PVD processes, a full optimization from film properties to process integration is necessary for the 65 nm CMOS device fabrication. This paper highlights the issues and shows the approaches to address these issues in implementing the ALD WN process for the CMOS contact application.