Patent ID: 8173536

Claim:
A method of making a semiconductor device, comprising: providing a first substrate; forming an interconnect pad over the first substrate; forming a photoresist layer over the first substrate and interconnect pad; removing a portion of the photoresist layer to form a continuous channel around a perimeter of the interconnect pad and expose the perimeter of the interconnect pad while leaving the photoresist layer covering a central area of the interconnect pad within the continuous channel; depositing a first conductive material in the continuous channel of the photoresist layer to form a column of conductive material around the perimeter of the interconnect pad; removing the photoresist layer to leave an open central region within the column of conductive material over the first conductive layer; forming a masking layer around the column of conductive material while exposing the interconnect pad within the column of conductive material; depositing a second conductive material over the interconnect pad within the central region of the column of conductive material, the second conductive material extending above the column of conductive material; removing the masking layer; and reflowing the second conductive material to form a column interconnect structure over the semiconductor device.