Patent ID: 7285461

Claim:
A method of manufacturing a semiconductor device comprising: forming a trench on a surface of a substrate; filling said trench with a first polycrystalline semiconductor film in such a degree that said trench is not completely filled with said first polycrystalline semiconductor film up to the top of opening of said trench; depositing a metal nitride film to cover a portion of sidewall of said trench which is not yet filled with said first polycrystalline semiconductor film; heat-treating the sidewall of said trench and said metal nitride film which is contacted with said sidewall to permit a reaction to take place between them to convert said metal nitride film contacting with the sidewall of said trench into a metal semiconductor nitride layer comprising metal and nitrogen included in said metal nitride film, and a semiconductor constituting said semiconductor substrate; removing said metal nitride film while permitting said metal semiconductor nitride layer to be left remain; depositing a second polycrystalline semiconductor film in said trench; and forming a diffusion layer on a surface region of said substrate, said diffusion layer being electrically connected, via said metal semiconductor nitride layer, with said second polycrystalline semiconductor film.