Chemical vapor deposition of cobalt silicide

Abstract

We have deposited polycrystalline cobalt silicide films by chemical vapor deposition using Co2(CO)8 or HCo(CO)4 as the Co source and SiH4 or Si2H6 as the Si source. The Co:Si ratio of the films is controlled by changing the deposition temperature, and CoSi2 stoichiometry is obtained at 300 °C using SiH4 or at 225 °C when Si2H6 is the Si precursor. Carbon or oxygen contamination of the films is <0.5 at. % at deposition temperatures above 200 °C. Resistivities of films deposited near CoSi2 stoichiometry are typically 200 μΩ cm and drop to 40 μΩ cm upon annealing at 900 °C.