Production of a contact pin of a semiconductor element comprises using a gas mixture containing sulfur hexafluoride, trifluoromethane and carbon tetrafluoride in the back etching of the polysilicon layer

摘要

Back etching of the polysilicon layer is carried out using a gas mixture containing SF6, CHF3 and CF4. Production of a contact pin of a semiconductor element comprises: (a) forming a silicon oxide layer above a lower conducting layer; (b) selectively etching the silicon oxide layer to form a contact hole in the layer and to expose a part of the lower conducting layer; (c) forming a polysilicon layer in the contact hole and on the silicon oxide layer to fill the hole; and (d) back etching the polysilicon layer using a gas mixture until the silicon oxide layer is exposed to form a contact pin. Back etching of the polysilicon layer is carried out using a gas mixture containing SF6, CHF3 and CF4. An Independent claim is also included for a process for the production of a semiconductor element.