Patent ID: 8552560

Claim:
A pad structure comprising: at least one copper pad; an aluminum pad above the copper pad, and a plurality of recessed pad areas formed in the aluminum pad above one of said at least one copper pad, wherein the aluminum pad provides a plurality of slots each having a top surface and a plurality of islands each having a top surface, wherein the top surface of each of the slots extends deeper than the top surface of each of the islands, wherein the pad structure further comprises oxide blocks in the islands, each of said oxide blocks having a top surface, wherein the top surface of each of the slots extends deeper than the top surface of the oxide blocks in the islands, wherein said plurality of slots comprises a first slot and a second slot, wherein there are a plurality of slots and islands disposed between the first slot and the second slot, above one of said at least one copper pad; a first layer along an entire bottom surface of the aluminum pad and in contact with the top surface of each oxide block; and a second layer along an entire top surface of the at least one copper pad and in contact with both the oxide blocks and portions of the first layer.