Patent ID: 7563714

Claim:
A method for forming a contact, comprising: forming a dielectric isolation in a substrate having a frontside and an opposing backside, a top surface of said dielectric isolation coplanar with said frontside of said substrate; forming a first dielectric layer on said frontside of said substrate, said first dielectric layer having opposite top and bottom surfaces, said bottom surface of said first dielectric layer on said frontside of said substrate; forming a trench in said first dielectric layer, said trench aligned over and within a perimeter of said dielectric isolation and extending from said top surface of said first dielectric layer to said top surface of said dielectric isolation; extending said trench through said dielectric isolation and into said substrate to a depth less than a thickness of said substrate; filling said trench to form a filled trench and co-planarizing a top surface of said filled trench with said top surface of said first dielectric layer to form an electrically conductive through via; and thinning said substrate from said backside of said substrate to expose said through via.