Metalorganic Chemical Vapor Deposition of Copper Using (Hexafluoroacetylacetonate)Cu(I)(3,3-dimethyl-1-butene) with a Liquid Delivery System

Abstract

From variable temperature (VT) 1H-nuclear magnetic resonance (NMR) and a heating test, it was found that (hexafluoroacetylacetonate)Cu(I)(3,3-dimethyl-1-butene) [(hfac)Cu(I)(DMB)] was stable up to 65°C. The effects of various process conditions such as substrate temperature, liquid precursor flow rate and hydrogen carrier gas flow rate on the deposition rate, texture, microhardness, surface roughness and uniformity were studied using a direct liquid injection 200 mm metalorganic chemical vapor deposition (MOCVD) reactor with hollow-cathode magnetron (HCM) sputter-deposited Cu substrate on silicon wafer. The MOCVD Cu process with (hfac)Cu(I)(DMB) showed good conformality, continuous film morphology and low resistivity at a substrate temperature of 190°C, vaporizer temperature of 55°C, total pressure of 2.5 Torr and precursor flow rate of 0.5 cm3/min. X-ray diffraction (XRD) analyses demonstrated a strong (111) texture of the copper film. The higher (111) peak intensity and the narrower width at half maximum were obtained when the source feed rate was low. Also the higher (111) peak intensity was observed at higher substrate temperature. At temperature below about 200°C, the microhardness was increased with increasing substrate temperature. In the high temperature regime (>200°C), the hardness was decreased.