Method for the formation of field oxide film in semiconductor device

Abstract

Abstract A method for the formation of field oxide film in a semiconductor device is disclosed. The method comprises the steps of: forming a first nitride film on a silicon substrate, the silicon substrate being previously covered with a pad oxide film; applying etch to the nitride film, the pad oxide film and the silicon substrate in due order, so as to form a trench in a predetermined portion; depositing a polysilicon film entirely on the resulting structure, so as to cover the trench and the nitride film; subjecting the polysilicon film to planarization; forming a second nitride film on the plane polysilicon film and etching back the second film, so as to form a spacer nitride film at either side wall of the first nitride film; etching the plane polysilicon film filling the trench, so as to expose a predetermined portion of the trench, the spacer nitride film and the first nitride film being used as an etch mask; forming a field oxide film in the trench by use of an oxidation process and removing the first nitride film, the spacer nitride film and the pad oxide film. The method is preventive of the stress on silicon substrate and the occurrence of defective in device, whereby highly integrated devices can be fabricated.

Inventors

• 👤 Chung S. Han

Bibliographic Details