Imaging device to capture images of subjects in plurality of directions

1. An imaging device comprising:

a silicon substrate having a photoelectric conversion element therein;

a wiring layer on a front-surface side of the silicon substrate, wherein the photoelectric conversion element performs:

photoelectric conversion on light which enters the photoelectric conversion element from the front-surface side of the silicon substrate; and

photoelectric conversion on light which enters the photoelectric conversion element from a back-surface side of the silicon substrate; and

an electrode portion which serves as an external terminal for a wiring element in the wiring layer, wherein the electrode portion is formed on a front-surface side of the wiring layer, and exposed on a back-surface side of the electrode portion.

2. The imaging device according to claim 1 , wherein the wiring element is disposed in a region in the wiring layer other than a region serving as a light path for light which enters the photoelectric conversion element.

3. The imaging device according to claim 2 , wherein the light path is provided with a waveguide.

4. The imaging device according to claim 1 , further comprising:

a color filter on the back-surface side of the photoelectric conversion element; and

a filter on the front-surface side of the photoelectric conversion element, the filter not being a color filter.

5. The imaging device according to claim 4 , wherein the filter includes at least one of an infrared transmitting filter or a white-pixel filter.

6. The imaging device according to claim 4 , wherein the color filter is provided for each of pixels, and the color filter for each of the pixels is separated from another color filter by an inorganic film.

7. The imaging device according to claim 1 , further comprising:

a first on-chip lens on the back-surface side of the photoelectric conversion element; and

a second on-chip lens on the front-surface side of the photoelectric conversion element.

8. The imaging device according to claim 7 , wherein the first on-chip lens and the second on-chip lens are made of an inorganic material.

9. The imaging device according to claim 1 , further comprising:

an on-chip lens on the back-surface side of the photoelectric conversion element.

10. The imaging device according to claim 1 , wherein the silicon substrate has a vertical spectroscopic structure including a plurality of photoelectric conversion elements, wherein each of the plurality of photoelectric conversion elements is the photoelectric conversion element, as a configuration of each pixel.

11. The imaging device according to claim 1 ,

wherein the silicon substrate and the wiring layer have an opening which allows the electrode portion to be exposed on the back-surface side.

12. The imaging device according to claim 1 , wherein the electrode portion has a predefined thickness such that a component stacked on the electrode portion is closer to the front-surface side than a component formed in a pixel region in which the photoelectric conversion element is formed.

13. The imaging device according to claim 1 , further comprising:

a support substrate through which light passes and which is bonded to the front-surface side of the silicon substrate by using an adhesive material.

14. The imaging device according to claim 1 , further comprising:

a support substrate through which light passes and which is bonded to the front-surface side of the silicon substrate using plasma bonding.

15. The imaging device according to claim 1 , further comprising:

a support substrate through which light passes and which is disposed on the front-surface side of the silicon substrate; and

a circuit in the support substrate, the circuit being disposed in a region other than a pixel region in which the photoelectric conversion element is formed.

16. The imaging device according to claim 1 , further comprising:

a pixel in which light incident on one of the back-surface side and the front-surface side of the photoelectric conversion element is blocked by either or both of the wiring element and a light-shielding film, and in which the photoelectric conversion element performs photoelectric conversion on light incident on other of the back-surface side and the front-surface side.

17. The imaging device according to claim 1 , further comprising:

a first shutter which is on the back-surface side of the photoelectric conversion element and which controls entering of light from the back-surface side; and a second shutter which is on the front-surface side of the photoelectric conversion element and which controls entering of light from the front-surface side,

wherein the first shutter and the second shutter are driven independently from each other.

18. The imaging device according to claim 1 , wherein a pixel region on one side of the photoelectric conversion element is divided into regions by a light-shielding plate, and pixels in the regions are used for detecting different wavelength ranges.