Low-Pressure Chemical Vapor Deposition of Cu−Pd Films: Alloy Growth Kinetics

Abstract

We have examined the formation of copper films alloyed with small quantities of palladium. Independent control studies of palladium and copper deposition from palladium bis(hexafluoroacetylacetonate) [Pd(hfac)2] and (hexafluoroacetylacetonato)copper(I)(vinyltrimethylsilane) [(hfac)Cu(I)(vtms)], both in the presence and absence of H2, were carried out. The growth kinetics for both metals were feed-rate-limited under similar reactor conditions. No significant variation in deposition rate (100 nm/min, Pd; 100−500 nm/min, Cu), morphology, resistivity, and purity of the copper films was observed due to the addition of H2. Simultaneous introduction of both precursors yielded Cu−Pd alloy films. The absence of pure palladium grains was confirmed by X-ray diffraction analysis which showed binary solid solutions (Cu99.5Pd0.5−Cu80Pd20) as the only crystalline phases. Auger electron spectroscopy analysis showed a significant reduction in the palladium content of the films as compared to that expected on the basis of ...