Patent ID: 6656810
Filing Date: 2003-12-02
Classification: H01L

Abstract:
A semiconductor device fabricating method comprising:providing an SOI substrate comprising a substrate comprising silicon, an insulating layer and an SOI layer; successively forming, on the SOI substrate, a first oxide film and a nitride film; forming an opening in the nitride film; selectively oxidizing the SOI layer and forming a selection oxide film on the remaining SOI layer at an area of the opening in the nitride film, wherein the nitride film in which the opening is formed is used as a mask; etching the selection oxide film using the nitride film in which the opening is formed as a mask; forming a gate oxide film in an area where the selection oxide film was etched; forming a gate electrode comprising polysilicon over the gate oxide film at least partially inside the opening of the nitride film by forming a layer comprising polysilicon on the SOI substrate and etching back the layer comprising polysilicon; removing at least portions of the nitride film, the selection oxide film and the first oxide film after formation of the gate electrode; after said removing of at least portions of the nitride film, the selection oxide film and the first oxide film, forming a portion that becomes an LDD region in the SOI layer by implanting low-concentration impurity ions into the SOI layer using the gate electrode as a mask; forming an oxide film spacer on side wall sides of the gate electrode by forming a second oxide film on the SOI substrate and subjecting the second oxide film to anisotropic etching; and after implanting the low-concentration impurity ions to form the portion to become the LDD region, forming a source junction region and a drain junction region in the SOI layer by implanting high-concentration impurity ions into the SOI layer using the gate electrode and the oxide film spacer as a mask.