Semiconductor device and method of manufacturing the same

A semiconductor device, comprising:

• a first semiconductor substrate including a first wiring layer having a first conductive pad therein;
• a second semiconductor substrate disposed on the first semiconductor substrate and including a second wiring layer having a second conductive pad therein;
• a first oxide layer disposed on the second semiconductor substrate;
• a third semiconductor substrate disposed on the first oxide layer and including a third wiring layer having a third conductive pad therein;
• an intermediate connection extending vertically in the device within the second semiconductor substrate and the first oxide layer;
• and
• bodies of metal located at respective surfaces of the first oxide layer and the third wiring layer and facing each other so as to together constitute a metal bond,
• wherein the second conductive pad and the third conductive pad are electrically connected via the intermediate connection and the metal bond.

A semiconductor device, comprising:

• a first semiconductor substrate including a first circuit layer and a first wiring layer of the device, the first circuit layer comprising a first integrated circuit (IC) electrically connected to the first wiring layer;
• a second semiconductor substrate including a second circuit layer and a second wiring layer of the device, the second circuit layer comprising a second integrated circuit (IC) electrically connected to the second wiring layer, and the second wiring layer having a conductive pad,
• the second semiconductor substrate disposed on and bonded to the first semiconductor substrate with the second wiring layer being disposed facing and electrically connected to the first wiring layer;
• an intermediate connection extending vertically in the second semiconductor substrate and having a first end, at which the intermediate connection is electrically connected to the conductive pad of the second wiring layer, and a second end;
• a first oxide layer disposed on the second semiconductor substrate, the second end of the intermediate connection extending within the first oxide layer;
• and
• a third semiconductor substrate including a third circuit layer and a third wiring layer of the device, the third circuit layer comprising a third integrated circuit (IC) electrically connected to the third wiring layer, and the third wiring layer having a conductive pad, and
• wherein the third semiconductor substrate is disposed on and bonded to the first oxide layer with the third wiring layer being disposed face-to-face with the first oxide layer such that an interface exists between the third wiring layer and the first oxide layer,
• an integral metal body extends across and is circumscribed by the interface between the third wiring layer and the first oxide layer, and
• the second end of the intermediate connection is electrically connected to the conductive pad of the third wiring layer via the metal body, the integral metal body constituting a metal bond between the intermediate connection and the conductive pad of the third wiring layer.