Patent ID: 7696106

Claim:
A film formation method for forming a multi-layered resist structure to be used as an etching mask for manufacturing semiconductor devices, the method comprising: placing a plurality of target objects at intervals in a vertical direction in an inner space inside a process container of a film formation apparatus, each of the target objects including an etching target film thereon; then, setting the inner space of the process container at a first vacuum pressure and a first heating temperature, and supplying ethylene gas into the inner space, thereby forming a carbon film by first CVD on the etching target film; and then, setting the inner space of the process container at a second vacuum pressure and a second heating temperature, and supplying an organic silicon source gas and a reactive gas selected from the group consisting of an oxidizing gas and a nitriding gas into the inner space, thereby forming an Si-containing inorganic film by second CVD on the carbon film, the Si-containing inorganic film being selected from the group consisting of an SiO 2 film, an SiN film, and a multi-layer film thereof, wherein the first CVD for forming the carbon film is performed as thermal CVD with the first heating temperature falling within a range of 600 to 800° C. while the ethylene gas is supplied into the inner space without being excited by plasma, the second vacuum pressure and the second heating temperature are lower than the first vacuum pressure and the first heating temperature, respectively, the first vacuum pressure is shifted to the second vacuum pressure while the inner space is maintained in a vacuum state, the second CVD for forming the Si-containing inorganic film is performed as MLD (Molecule Layered Deposition) CVD using a plasma assist, and is arranged to repeat a prescribed cycle a plurality of times, the prescribed cycle comprising a first sub step of supplying the organic silicon source gas into the inner space without supplying the reactive gas into the inner space, then, a second sub step of supplying a purge gas into the inner space and vacuum-exhausting the inner space without supplying the organic silicon source gas and the reactive gas into the inner space, then, a third sub step of supplying the reactive gas into the inner space without supplying the organic silicon source gas into the inner space, the third sub step being arranged to supply the reactive gas into the inner space while exciting the reactive gas by plasma in a plasma generation area adjacent to the inner space, and then, a fourth sub step of supplying a purge gas into the inner space and vacuum-exhausting the inner space without supplying the organic silicon source gas and the reactive gas into the inner space.