Semiconductor device and method for fabricating semiconductor device

A semiconductor device comprising:

• a plurality of semiconductor chips stacked on each other, each of the plurality of semiconductor chips having a semiconductor substrate and a wiring layer;
• a through electrode penetrating the semiconductor substrate in a thickness direction and which are electrically connected to each other between the semiconductor chips adjacent to each other;
• a conductor penetrating the semiconductor substrate in the thickness direction and which are not electrically connected between the other semiconductor chips;
• and
• an insulating separator penetrating the semiconductor substrate in the thickness direction and formed in a shape of a ring surrounding the conductor.

A method for fabricating a semiconductor device, comprising:

• preparing a first semiconductor chip having a conductor and a insulating separator, the conductor penetrating the first semiconductor chip in a thickness direction and being not electrically connected to any element formed on the first semiconductor chip, the insulating separator penetrating the first semiconductor chip in the thickness direction and being formed in a ring so as to surround the conductor;
• aligning a second semiconductor chip with the first semiconductor chip by using the conductor of the first semiconductor chip;
• and
• stacking the second semiconductor chip on the first semiconductor chip.