METHOD FOR ETCHING THIN FLIM OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for etching a thin film is provided to improve the etch uniformity and remove remnants using an etch gas using the characteristic of an etch gas in a plasma etch equipment. CONSTITUTION: A method for etching a thin film forms an insulating film(22) on a semiconductor substrate(21). The insulating film(22) is selectively etched so that a given portion on the surface of the semiconductor substrate(21) can be exposed, thus forming a contact hole. A polysilicon layer is formed on the entire surface of the semiconductor substrate(21) including the contact hole. The polysilicon layer is firstly etched by a given thickness using an etch gas of Cl2+N3. The polysilicon layer is secondly etched using an etch gas in which O2 or Ar is added to SF3 so that it remains only within the contact hole, thus forming a plug(24a).