Process of forming a refractory metal thin film

Claim 1

A process of forming a refractory metal film on a substrate by subjecting a gaseous mixture containing a halide of a refractory metal and a hydrogen gas to a plasma chemical vapor deposition, comprising the steps of: adjusting a mixing ratio of said halide of the refractory metal to said hydrogen gas to a first small value at an initial stage of the process; and subsequent to said initial stage of the process, adjusting said mixing ratio of said halide of the refractory metal to said hydrogen gas to a second large value, larger than said first small value; further comprising the steps of subjecting said substrate to a plasma treatment by using at least one gaseous material selected from the group consisting of a hydrogen gas, a silane gas and an argon gas to remove native oxide film on the substrate; and successively treating the surface of said substrate with a gaseous mixture containing a hydrogen gas and said halide of the refractory metal to remove the native oxide film deposited on a surface of the aluminum-series material of said substrate.