Patent ID: 8227343

Claim:
A method comprising: etching a first surface of the substrate to form an annular opening; forming a first passivation layer over sidewalls of the annular opening; filling the annular opening with a first conductive material, such that a metal via is formed, the metal via including a planar end portion covering a portion of the first surface of the substrate and extending on the first surface outward from outer edges of the annular opening; removing a substrate material from a second surface of the substrate including an area surrounded by the metal via, such that a portion of the metal via extends out from the second surface of the substrate; removing at least a portion of the first passivation layer from inner walls and an inner portion of exposed ends of the metal via at the second surface of the substrate; forming a second passivation layer over a portion of the second surface of the substrate surrounding the inner portion of the exposed ends of the metal via, such that a recessed area surrounded by inner walls of the metal via is formed; and coating a layer of a second conductive material on the recessed area to form a conductive socket.