Substantially carbon-free molybdenum-containing and tungsten-containing films in semiconductor device manufacturing

Abstract

Substantially carbon-free molybdenum-containing and tungsten-containing films are deposited on semiconductor substrates using halide-free metalorganic precursors. The precursors do not include metal-carbon bonds, carbonyl ligands, and, preferably do not include beta-hydrogen atoms. Metal-containing films, such as molybdenum nitride, molybdenum oxynitride, molybdenum silicide, and molybdenum boride with carbon content of less than about 5% atomic, such as less than about 3% atomic are deposited. The films are deposited in some embodiments by reacting the metal-containing precursor with a reactant on a surface of a substrate in an absence of plasma, e.g. using several ALD cycles. In some embodiments the formed film is then treated with a second reactant in a plasma to modify its properties (e.g., to densify the film, to reduce resistivity of the film, or to increase its work function). The films can be used as liners, diffusion barriers, and as electrode material in pMOS devices.