Patent ID: 8784951

Claim:
A method of forming an insulation film on a semiconductor substrate by plasma enhanced atomic layer deposition (PEALD), which comprises: (i) adsorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in a reaction space, thereby producing a precursor-adsorbed substrate; (ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the oxygen-free reactant, said oxygen-free reactant consisting of NH 3 or a combination of He and N 2 ; and (iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and (iv) repeating steps (i) to (iii) as a cycle, thereby depositing an insulation film on the substrate wherein the insulation film is constituted by SiN or SiCN.