Integration of direct plating of Cu onto a CVD Ru liner

Abstract

In order to integrate the direct plating metallization scheme, the following four unit processes must be modified accordingly: the liner deposition, Cu electroplating, annealing, and chemical mechanical polishing (CMP). In this paper, phase, resistivity, barrier performance and step coverage data from an organo-metallic CVD Ru film will be presented. Issues associated with directly plating onto this material will be discussed, and the ability to produce void-free 250, 130, and 90 nm groundrule features will be demonstrated. Issues associated with polishing a liner stack consisting of Ru will be described, and the development of a successful Ru CMP process, which enabled further parametric testing of patterned wafer lots, will be shown. © 2005 Materials Research Society.