Solid-state imaging element, method for manufacturing the same, and electronic apparatus
The present technology relates to a solid-state imaging element configured so that pixels can be more reliably separated, a method for manufacturing the solid-state imaging element, and an electronic apparatus. The solid-state imaging element includes a photoelectric converter, a first separator, and a second separator. The photoelectric converter is configured to perform photoelectric conversion of incident light. The first separator configured to separate the photoelectric converter is formed in a first trench formed from a first surface side. The second separator configured to separate the photoelectric converter is formed in a second trench formed from a second surface side facing a first surface. The present technology is applicable to an individual imaging element mounted on, e.g., a camera and configured to acquire an image of an object.
1. A solid-state imaging element comprising:
a silicon substrate including a plurality of photoelectric conversion regions, the plurality of photoelectric conversion regions including a first photoelectric conversion region and a second photoelectric conversion region; and
a pixel separation region disposed between the first photoelectric conversion region and the second photoelectric conversion region,
wherein the pixel separation region penetrates a surface of the silicon substrate opposite a light receiving surface of the silicon substrate,
wherein the pixel separation region includes a first impurity layer formed of an N-type impurity and a second impurity layer formed of a P-type impurity, and
wherein the pixel separation region includes polysilicon.
2. The solid-state imaging element according to claim 1 , wherein
the pixel separation region includes a first separator and a second separator arranged next to each other in a direction parallel to an optical axis of a lens through which light enters the light receiving surface.
3. The solid-state imaging element according to claim 1 , wherein
the pixel separation region includes a first separator and a second separator arranged next to each other in a direction perpendicular to an optical axis of a lens through which light enters the light receiving surface.
4. The solid-state imaging element according to claim 1 , wherein
the pixel separation region includes a thermally-oxidized film.
5. The solid-state imaging element according to claim 1 , wherein
a wiring layer is disposed on the surface opposite the light receiving surface, and
an optical layer is disposed on the light receiving surface.
6. The solid-state imaging element according to claim 1 , wherein the pixel separation region extends to the light receiving surface of the silicon substrate.
7. The solid-state imaging element according to claim 1 , wherein the polysilicon has a conductivity.
8. The solid-state imaging element according to claim 7 , wherein the polysilicon is an electrode that receives a potential.
9. The solid-state imaging element according to claim 1 , wherein the polysilicon has a first conductivity type with an impurity concentration equal to or greater than 1e16/cm3 and equal to or less than 1e23/cm3.
10. The solid-state imaging element according to claim 1 , wherein the first photoelectric conversion region and the second photoelectric conversion region share a floating diffusion region.
11. The solid-state imaging element according to claim 10 , wherein the floating diffusion region is disposed between the first photoelectric conversion region and the second photoelectric conversion region in a plan view.
12. The solid-state imaging element according to claim 11 , wherein the first photoelectric conversion region and the second photoelectric conversion region are disposed in a first direction and a pixel transistor region is disposed in a second direction which is perpendicular to the first direction.
13. A method for manufacturing a solid-state imaging element, comprising:
forming a first and second photoelectric conversion regions in a silicon substrate;
forming a pixel separation region in the silicon substrate between the first photoelectric conversion region and the second photoelectric conversion region such that the pixel separation region penetrates a surface of the silicon substrate opposite a light receiving surface of the silicon substrate, wherein the pixel separation region includes polysilicon, and wherein the pixel separation region includes a first impurity layer formed of an N-type impurity and a second impurity layer formed of a P-type impurity.
14. An electronic apparatus comprising:
a solid-state imaging element configured to acquire an image of an object; and
a signal processor configured to process an image signal output from the solid-state imaging element,
wherein the solid-state imaging element includes:
a silicon substrate including a plurality of photoelectric conversion regions, the plurality of photoelectric conversion regions including a first photoelectric conversion region and a second photoelectric conversion region; and
a pixel separation region disposed between the first photoelectric conversion region and the second photoelectric conversion region,
wherein the pixel separation region penetrates a surface of the silicon substrate opposite a light receiving surface of the silicon substrate,
wherein the pixel separation region includes a first impurity layer formed of an N-type impurity and a second impurity layer formed of a P-type impurity, and
wherein the pixel separation region includes polysilicon.
15. A solid-state imaging element comprising:
a silicon substrate including a plurality of photoelectric conversion regions, the plurality of photoelectric conversion regions including a first photoelectric conversion region and a second photoelectric conversion region; and
a pixel separation region disposed between the first photoelectric conversion region and the second photoelectric conversion region,
wherein N-type and P-type impurity layers are embedded in the pixel separation region for separating the first photoelectric conversion region and the second photoelectric conversion region, and
wherein the pixel separation region includes a silicon oxide film a formed on the N-type and P-type impurity layers.
16. The solid-state imaging element according to claim 15 , wherein
the N-type and P-type impurity layers are formed by solid-phase diffusion.
17. The solid-state imaging element according to claim 15 , wherein
the N-type impurity layer is formed on a transfer gate side in the pixel separation region, and is not formed on an opposite side of the transfer gate side.
18. The solid-state imaging element according to claim 15 , wherein
an embedded film that receives a predetermined voltage is embedded in the pixel separation region.
19. The solid-state imaging element according to claim 15 , wherein
a fixed charge film with a negative fixed charge is formed on the silicon oxide film.
20. The solid-state imaging element according to claim 15 , wherein
the pixel separation region surrounds a periphery of a pixel.
21. The solid-state imaging element according to claim 15 , wherein
a wiring layer is disposed on a first surface of the silicon substrate, and
an optical layer is disposed on a second surface of the silicon substrate opposite the first surface.