Method of forming field effect transistor having elevated source and drain regions

摘要

A field effect transistor is manufactured by forming an isolating structure on a semiconductor substrate to define an active area. A gate structure is formed which is insulated from a surface of the active area of the semiconductor substrate. An amorphous silicon film is formed on the gate structure, on the surface of the semiconductor substrate, and on the isolating structure. A first portion of the amorphous silicon film is converted to an epitaxial film and a second portion of the amorphous silicon film is converted to a polysilicon film. Impurities are diffused throughout the polysilicon film and into an upper surface portion of said epitaxial film. The impurity doped polysilicon film and the upper surface portion of the epitaxial film are oxidized to form oxide films and the oxide films are removed so that the epitaxial film remains at least on the active area of the semiconductor substrate. Source and drain regions of the transistor are formed in the active area of the semiconductor substrate.