US Patent 7307009 Phosphoric acid free process for polysilicon gate definition

A method of defining a patterned, conductive gate structure for a MOSFET device on a semiconductor substrate includes forming a conductive layer over the semiconductor substrate and forming a capping insulator layer over the conductive layer. An anti-reflective coating (ARC) layer is formed over the capping insulator layer and a patterned photoresist shape is formed on the ARC layer. A first etch procedure using the photoresist shape as an etch mask defines a stack comprised of an ARC shape and a capping insulator shape. A second etch procedure using the stack as an etch mask defines the patterned, conductive gate structure in the conductive layer.