Solid-state imaging device, method of manufacturing solid-state imaging device, and electronic apparatus
The present technology relates to a solid-state imaging device that can reduce the number of steps and enhance mechanical strength, a method of manufacturing the solid-state imaging device, and an electronic apparatus. The solid-state imaging device includes a laminate including a first semiconductor substrate having a pixel region and at least one second semiconductor substrate having a logic circuit, the at least one second semiconductor substrate being bonded to the first semiconductor substrate such that the first semiconductor substrate becomes an uppermost layer, and a penetration connecting portion that penetrates from the first semiconductor substrate into the second semiconductor substrate and connects a first wiring layer formed in the first semiconductor substrate to a second wiring layer formed in the second semiconductor substrate. The first wiring layer is formed with Al or Cu. The present technology is applicable, for example, to a back-surface irradiation type CMOS image sensor.
1. A solid-state imaging device, comprising:
a laminate including a first semiconductor substrate having a pixel region and at least one second semiconductor substrate having a logic circuit,
wherein the at least one second semiconductor substrate is bonded to the first semiconductor substrate such that the first semiconductor substrate becomes an uppermost layer of the solid-state imaging device; and
a penetration connecting portion that penetrates from the first semiconductor substrate into the at least one second semiconductor substrate, wherein
the penetration connecting portion connects a first wiring layer to a second wiring layer,
the first wiring layer is in the first semiconductor substrate,
the second wiring layer is in the at least one second semiconductor substrate,
the first wiring layer comprises one of Al or Cu,
the first wiring layer comprises an electrode pad, and
a first surface of the electrode pad is exposed through an opening and a second surface, opposite to the first surface, of the electrode pad is in contact with the connected penetration connecting portion.
2. The solid-state imaging device according to claim 1 , wherein
the first semiconductor substrate is bonded to the at least one second semiconductor substrate with a back surface of the first semiconductor substrate upward, and
the first wiring layer is embedded on the back surface of the first semiconductor substrate.
3. The solid-state imaging device according to claim 2 , further comprising a connecting portion that connects the first wiring layer to a third wiring layer, wherein
the third wiring layer is in a layer below the first wiring layer in the first semiconductor substrate, and
the connecting portion, the first wiring layer, and the penetration connecting portion constitute an inter-substrate wiring that electrically connects the first semiconductor substrate and the at least one second semiconductor substrate.
4. The solid-state imaging device according to claim 1 , wherein
the first wiring layer and the second wiring layer are connected through a plurality of penetration connecting portions, and
the plurality of penetration connecting portions includes the penetration connecting portion.
5. The solid-state imaging device according to claim 1 , wherein the opening is at outside of the pixel region in the first semiconductor substrate.