In-situ etch of multiple layers during formation of local interconnects

摘要

An in-situ etching process for creating local interconnects in a semiconductor device includes using a single etching tool to: etch through a masked dielectric layer to a stop layer using a mixture of C4F8/CH3F/Ar gasses; etch away the mask layer using a mixture of O2/Ar gasses; and etch through the stop layer using a mixture of CH3F/O2 gasses. The semiconductor device is not removed from the etching tool between the different etchings. The method then includes depositing conductive material to form local interconnects within the openings that were etched.