Organometallic chemical vapor deposition of cobalt and formation of cobalt disilicide

The deposition of Co thin films by organometallic chemical vapor deposition is reported. Co is of interest in very large scale integration technology as a catalyst for electroless plating of other metals and as a precursor to formation of CoSi2. High purity, conformal films of Co are deposited by pyrolysis of Co2(CO)8 at 200 °C in vacuum. These films exhibit electrical resistivities of 5–10 μΩ cm and excellent adhesion to Si and SiO2. CoSi2 is formed by heating the samples at 700 °C. The CoSi2 films resulting from reaction of the Co films with the Si substrate contain larger grains than the starting film and exhibit electrical resistivities of ∼13–37 μΩ cm. Selective formation of CoSi2 on patterned test wafers shows similar attributes.