Patent ID: 7259093

Claim:
A method of forming a conductive contact through a dielectric, comprising: forming a dielectric over a node location on a semiconductor substrate; the dielectric comprising an insulative material over the node location, an insulative polish stop layer over the insulative material, and an insulator layer over the insulative polish stop layer; the insulative polish stop layer comprising an insulative metal oxide comprising at least one of tantalum oxide, aluminum oxide and hafnium oxide, including mixtures thereof; forming a contact opening into the insulator layer, the insulative polish stop layer and the insulative material to proximate the node location; widening at least a portion of the contact opening with an etching chemistry that is selective to widen the contact opening within the insulative material to a degree greater than any widening of the contact opening within the insulative polish stop layer; after the widening, depositing conductive material over the insulator layer and to within the contact opening; and polishing the conductive material and the insulator layer to at least a portion of the insulative polish stop layer such that some portion of the insulative metal oxide of the polish stop layer remains after stopping the polishing.