Patent ID: 7737005

Claim:
A film formation method for forming a Ti film and a TiN film on an underlayer comprising an Si-containing substrate or a metal silicide film disposed on a substrate, the film formation method comprising: cleaning a surface of the underlayer; forming a Ti film to have a film thickness of not less than 2 nm but less than 10 nm on the underlayer by CVD using a Ti compound gas; nitriding the Ti film; and forming a TiN film on the Ti film thus nitrided, by CVD using a Ti compound gas and a gas containing N and H, wherein said cleaning a surface of the underlayer comprises removing a natural oxide film of Si present on the surface of the underlayer, and said removing a natural oxide film comprises, supplying HF gas and NH 3 gas onto the surface of the underlayer without generating plasma thereof to cause the HF gas and the NH 3 gas to chemically react with the natural oxide film, thereby turning the natural oxide film into an intermediate product film that is thermally decomposable, and them performing a heat process of heating the intermediate product film at a certain temperature, thereby thermally decomposing the intermediate product film while vaporizing and exhausting decomposition products thus generated.