Method for forming tantalum nitride film

Abstract

A tantalum nitride film-forming method comprises the steps of introducing a raw gas consisting of a coordination compound constituted by an elemental tantalum (Ta) having a coordinated ligand represented by the general formula: N═(R,R') (in the formula, R and R′ may be the same or different and each represents an alkyl group having 1 to 6 carbon atoms), and a halogen gas into a vacuum chamber; and reacting these components with one another on a substrate to thus form a surface adsorption film comprising a mono-atomic or multi (several)-atomic layer and composed of a compound represented by the following general formula: TaN(Hal)(R, R′)(in the formula, Hal represents a halogen atom), then introducing radicals generated from an H atom-containing compound to thus remove Ta—N bonds present in the resulting compound through breakage thereof and remove, at the same time, the remaining R(R′) groups bonded to the N atoms present in the compound through the cleavage thereof and to thus form a tantalum nitride film rich in tantalum atoms. The resulting tantalum nitride film has a low resistance, low contents of C and N atoms, and a high compositional ratio: Ta/N, can ensure sufficiently high adherence to the distributing wire-forming film and can thus be useful as a barrier film. Moreover, tantalum particles are implanted in the resulting film according to the sputtering technique to thus further enrich the film with tantalum.