Patent attributes
A method for forming a silicon nitride film to cover a stepped portion formed by exposed surfaces of first and second base films in a substrate, includes: forming a nitride film or a seed layer to cover the stepped portion, wherein the nitride film is formed by supplying, to the substrate, a nitrogen-containing base-film nitriding gas for nitriding the base films, exposing the substrate to plasma and nitriding the surface of the stepped portion, and the seed layer is composed of a silicon-containing film formed by supplying a raw material gas of silicon to the substrate and is configured such that the silicon nitride film uniformly grows on the surfaces of the base films; and forming the silicon nitride film on the seed layer by supplying, to the substrate, a second raw material gas of silicon and a silicon-nitriding gas for nitriding silicon.