METHOD OF ETCHING INSULATION FILM OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method of etching an insulating layer in a semiconductor device is to effectively remove a nitride film used as an oxidation preventive layer in a LOCOS(Local Oxidation of Silicon) and control thickness of a pad oxide underlying the nitride film. CONSTITUTION: A semiconductor substrate(200) on which a pad oxide film(202) and a nitride film(204) are orderly formed is prepared. A mask pattern exposing an isolation region of the semiconductor substrate is formed on the nitride film. An F+ ion is implanted into the nitride film. The F+ ion-doped nitride film is dry-etched using a mixing gas of SF6+He or CH4+CHF3+Ar as a source gas and thus the pad oxide is exposed. The exposed pad oxide is thermally oxidized to form a field oxide at the isolation region. The F+ ion is implanted at a dose of 1.0E12-1.0E14 and implantation energy of 50 KeV to 140 KeV.