The growth kinetics study of CVD Cu on TiN barriers

Abstract
Chemical vapor deposition of copper films on barrier metals, such as TiN and TaN has been intensively studied since the early 1990's. In contrast to active research on precursors, adhesion, and trench/via filling, the study of the initial growth of copper on barrier films has been rarely conducted. In this paper, the early growth stage of copper films on a titanium nitride coated substrate is fully studied. Two types of nucleation processes, homogeneous and heterogeneous, were observed under well controllable deposition conditions and were characterized through SEM, surface optical reflectance, and SIMS. The kinetics for each growth stage was also studied. The relationship between adhesion and initial nucleation is also discussed.