Taiwan Semiconductor Manufacturing Company Limited
LOW-RESISTANCE CONTACT TO TOP ELECTRODES FOR MEMORY CELLS AND METHODS FOR FORMING THE SAME

Abstract:

A magnetic tunnel junction (MTJ) memory cell and a metallic etch mask portion are formed over a substrate. At least one dielectric etch stop layer is deposited over the metallic etch mask portion, and a via-level dielectric layer is deposited over the at least one dielectric etch stop layer. A via cavity may be etched through the via-level dielectric layer, and a top surface of the at least one dielectric etch stop layer is physically exposed. The via cavity may be vertically extended by removing portions of the at least one dielectric etch stop layer and the metallic etch mask portion. A contact via structure is formed directly on a top surface of the top electrode in the via cavity to provide a low-resistance contact to the top electrode.