Patent ID: 8110900

Claim:
A semiconductor device comprising: a semiconductor substrate having a first surface and a second surface opposite to the first surface; a semiconductor element formed on the first surface of the semiconductor substrate; a first insulating film formed on and covering the second surface of the semiconductor substrate; a first electrode formed on the first insulating film and connected to an external electrode; a through hole penetrating through the semiconductor substrate from the first surface to the second surface, to the insulating layer, and exposing the first electrode; a seed layer including a first portion formed on inner walls of the through hole and a second portion formed on the second surface of the semiconductor substrate around the through hole, wherein the first portion is directly contacted the substrate, the first insulating film, and the first electrode; and a second electrode including a first portion formed on the second surface of the semiconductor substrate around the through hole and a second portion formed on the inner walls of the through hole, the second electrode is directly contacted the seed layer, wherein the semiconductor device further comprises: a ring-shaped trench formed in the semiconductor substrate around the through hole so as to have a predetermined distance from the through hole; and a second insulating film formed inside the ring-shaped trench and between the second surface of the semiconductor substrate and the seed layer, and a space is present inside the through hole after the second electrode is formed.