Semiconductor device

A semiconductor device comprising:

• a semiconductor substrate having a first surface and a second surface, the first surface being configured for formation of a semiconductor element;
• a wiring pattern formed along the first surface;
• a through hole extending through the semiconductor substrate and reaching a portion of the wiring pattern;
• and
• a through electrode disposed in the through hole and connected to the wiring pattern at the first surface, the through electrode including an insulating film disposed along a sidewall of the through hole, a conductive layer comprising a titanium film disposed along the insulating film and a copper film disposed along a surface of the titanium film, and an electrode layer comprising a nickel film filled inside the through hole over the conductive layer, the conductive layer being softer than the electrode layer, the electrode layer having a melting point higher than a melting point of the conductive layer, and the electrode layer including a void portion enclosed therein and having an end portion disposed near the second surface of the semiconductor substrate.