Electroless deposition of Cu thin films with CuCl2-HNO3 based chemistry - II. Kinetics and microstructure

This paper describes the kinetics involved in the acid-based electroless Cu deposition system employing CuCl2-HNO3 chemistry in a HF-NH4F buffer solut ion. The rate equation is set up as a function of concentrations of active chemical components involved, and rate orders are determined to evaluate th e contribution from each component. The deposition rate of Cu is found most sensitive to variation in [Cl-] concentrations, followed by that of [Cu2+] and [F-]. The activation energy derived from deposition at different tempe ratures is 0.445 eV. Grain size of deposited Cu films is influenced strongl y by deposition rate. Electrical resistivity of Cu films is dominated by th e amount of point defects and microvoids present right after deposition, an d by grain size after a 300 degrees C anneal. (C) 2001 The Electrochemical Society.