CONTACT REGION FORMING METHOD OF SEMICONDUCTOR DEVICE

摘要

forming a gate oxide film on a semiconductor substrate; forming a first polysilicon layer thereon; forming a contact mask thereon; forming a contact hole by dry etching the exposed first polysilicon layer to use a Cl2/He/SF6 mixture gas; removing carbon chloride formed round the contact hole by dry etching process using an oxygen plasma; removing an oxide formed at lower side of the contact hole; removing the contact mask; cleaning the exposed first polysilicon layer and the semiconductor substrate; and forming a second polysilicon layer on the first polysilicon layer and in the contact hole. Usage of SF6 gas in contact hole forming process, can easily remove the residue of the polysilicon, and prevent the under-cut from forming between the field oxide film and the polysilicon layer.