Solid-state image sensor, imaging device, and electronic device
The present technology relates to a solid-state image sensor, an imaging device, and an electronic device capable of switching FD conversion efficiency in all pixels of a solid-state image sensor. A photodiode performs photoelectric conversion on incident light. A floating diffusion (FD) stores charge obtained by the photodiode. FD2, which is a second FD to which the capacity of an additional capacitor MIM is added, adds the capacity to the FD. The additional capacitor MIM is constituted by a first electrode formed by a wiring layer and a second electrode formed by a metallic light blocking film provided on a surface of a substrate on which the photodiode is formed. Switching between the FD and FD+FD2 allows switching of the FD conversion efficiency. The present technology is applicable to a CMOS image sensor.
1. A light detecting device, comprising:
a photoelectric conversion region;
a transfer transistor configured to transfer charges from the photoelectric conversion region to a charge-to-voltage converter;
a switch transistor configured to selectively add a capacity of a capacitor to a capacity of the charge-to-voltage converter; and
a wiring layer including:
a first electrode coupled to the switch transistor; and
a second electrode opposed to the first electrode, the second electrode including a first part and a second part,
wherein the capacitor includes the first electrode and the second electrode, and
wherein a first distance between the first part of the second electrode and the first electrode is different than a second distance between the second part of the second electrode and the first electrode in a plan view.
2. The light detecting device according to claim 1 , wherein the first and second electrodes are disposed in layers that are different from each other.
3. The light detecting device according to claim 2 , wherein the first electrode is provided above the second electrode in a vertical direction.
4. The light detecting device according to claim 1 , wherein the first distance is greater than the second distance.
5. The light detecting device according to claim 1 , wherein a contact region of a wiring coupled to the charge-to-voltage converter is disposed between the switch transistor and a reset transistor.
6. The light detecting device according to claim 1 , wherein the first electrode includes a portion that has rectangular shape in a plan view.
7. The light detecting device according to claim 1 , wherein the second electrode is coupled to a predetermined potential.
8. A light detecting device, comprising:
a photoelectric conversion region;
a transfer transistor configured to transfer charges from the photoelectric conversion region to a charge-to-voltage converter;
a switch transistor configured to selectively add a capacity of a capacitor to a capacity of the charge-to-voltage converter;
an amplification transistor configured to output a pixel signal; and
a wiring layer including:
a first electrode coupled to the switch transistor; and
a second electrode opposed to the first electrode;
wherein the capacitor includes the first electrode and the second electrode, and
wherein the first electrode is different from a third electrode in a plan view.
9. The light detecting device according to claim 8 , wherein a contact region of a wiring coupled to the charge-to-voltage converter is disposed between the switch transistor and a reset transistor.
10. The light detecting device according to claim 9 , wherein the switch transistor, the charge-to-voltage converter, the reset transistor and the amplification transistor all share the same well region.
11. The light detecting device according to claim 9 , wherein the switch transistor, the contact region of the wiring coupled to the charge-to-voltage converter, the reset transistor and the amplification transistor are arranged in this order.
12. The light detecting device according to claim 8 , further comprising a selection transistor.
13. The light detecting device according to claim 8 , wherein a portion of the first electrode has a rectangular shape in a plan view.
14. The light detecting device according to claim 8 , wherein the second electrode is coupled to a predetermined potential.
15. A light detecting device, comprising:
a photoelectric conversion region;
a transfer transistor configured to transfer charges from the photoelectric conversion region to a charge-to-voltage converter;
a switch transistor configured to selectively add a capacity of a capacitor to a capacity of the charge-to-voltage converter;
an amplification transistor configured to output a pixel signal; and
a wiring layer including:
a first electrode coupled to the switch transistor; and
a second electrode opposed to the first electrode,
wherein a contact region of a wiring coupled to the charge-to-voltage converter is disposed between the switch transistor and a reset transistor, and
wherein the capacitor includes the first electrode and the second electrode in a plan view.
16. The light detecting device according to claim 15 , further comprising a selection transistor.
17. The light detecting device according to claim 15 , wherein the switch transistor, the charge-to-voltage converter, the reset transistor and the amplification transistor all share the same well region.
18. The light detecting device according to claim 15 , wherein the switch transistor, the contact region of the charge-to-voltage converter, the reset transistor and the amplification transistor are arranged in this order.
19. The light detecting device according to claim 15 , wherein a portion of the first wiring has a rectangular shape in a plan view.
20. The light detecting device according to claim 15 , wherein the second wiring is coupled to a predetermined potential.