A bonding pad structure includes a semiconductor substrate having thereon a plurality of inter-metal dielectric (IMD) layers comprising at least a topmost IMD layer; a bondable metal pad layer disposed on a surface of the topmost IMD layer within a pad forming region; a passivation layer covering a periphery of the bondable metal pad layer and the surface of the topmost IMD layer; and a plurality of via plugs disposed in the topmost IMD layer within an annular region of the pad forming region, wherein the via plugs are not formed in a central region of the pad forming region.