Approaches to integrate the deep contact module

摘要

A method of improving the deep contact processing window is described. Semiconductor device structures in and on a semiconductor substrate are covered with a dielectric layer. A polysilicon layer is deposited overlying the dielectric layer. The polysilicon layer is etched away where it is not covered by a photoresist mask to form a polysilicon hard mask. A contact opening is etched through the dielectric layer to the semiconductor substrate where the deep contact is to be made where the dielectric layer is not covered by the polysilicon hard mask. Thereafter the photoresist mask is removed. A photoresist layer is deposited overlying the polysilicon hard mask and filling the contact opening. The polysilicon hard mask and the photoresist layer not within the contact opening are polished away wherein the photoresist layer remaining within the contact opening protects the contact opening from contamination during polishing. Thereafter, the photoresist layer within the contact opening is removed and a metal layer is deposited within the contact opening to complete the deep contact in the fabrication of an integrated circuit device.