Method for forming refractory metal nitride film

Abstract

A method for forming a refractory metal nitride film having excellent diffusion barrier properties suitable for a dielectric electrode includes a step of depositing a refractory metal film containing nitrogen on a silicon substrate in a mixed gas atmosphere of Ar and N.sub.2, such that the volumetric content of the nitrogen in the mixed gas does not exceed 20%, and a step of forming a completed refractory metal film by subjecting the refractory metal film to a heat treatment in an N.sub.2 or NH.sub.3 atmosphere. The content of nitrogen in the refractory metal film depends on the content of nitrogen in the ambient gas, and the ratio of nitrogen contained in the refractory metal film to the refractory metal does not exceed unity. The refractory metals may be any of the transition metals in Groups IVB, VB, and VIB of the periodic table.

Dependencies are inferred from the claim text.