Patent ID: 8110473

Claim:
A method for fabricating a semiconductor device comprising a multilayer dielectric film disposed on a semiconductor substrate, the method comprising: forming a first type-one dielectric film over the semiconductor substrate, wherein the first type-one dielectric film comprises a first substance and has a tetragonal crystalline structure; forming a preliminary first type-two dielectric film over the semiconductor substrate, a first portion of the preliminary first type-two dielectric film having a tetragonal crystalline structure and a second portion of the preliminary first type-two dielectric film being amorphous; and heat treating the first type-one dielectric film and the preliminary first type-two dielectric film to convert the amorphous second portion of the preliminary first type-two dielectric to a tetragonal crystalline structure so as to form a first type-two dielectric film over the semiconductor substrate, wherein the first type-two dielectric film has a tetragonal crystalline structure and comprises a second substance different from the first substance, wherein the first type-two dielectric film has a greater dielectric constant than the first type-one dielectric film, wherein the multilayer dielectric film comprises the first type-one dielectric film and the first type-two dielectric film.