Bonding pad structure to prevent inter-metal dielectric cracking and to improve bondability

Abstract

A process of forming a bond pad structure, with a roughened top surface topography, used to improve the bondability of a gold wire bond, to the underlying bond pad structure, has been developed. The process features the use of a tungsten mesh pattern, formed in an IMD layer, and located underlying the bond pad structure, while overlying, and contacting, an underlying upper level, metal interconnect structure. The use of a tungsten mesh pattern, in place of individual tungsten studs, results in the creation of isolated islands, of IMED, reducing the bonding force, experienced by the IMD shapes, during the subsequent gold wire bond procedure. In addition the tungsten mesh pattern is formed via partial filling of a mesh pattern opening, in the IMD layer, resulting in an indented, or notched top surface. This in turn allows a roughened top surface, for the overlying bond pad structure, to be created, resulting in improved bondability of the gold wire, to the roughened top surface of the bond pad structure.