Image sensing device

Patent metadata

Field	Value
Publication number	US-11508769-B2
Application number	US-202016859855-A
Country	US
Kind code	B2
Filing date	Apr 27, 2020
Priority date	Oct 8, 2019
Publication date	Nov 22, 2022
Grant date	Nov 22, 2022

Abstract

An image sensing device is disclosed. The image sensing device includes a semiconductor substrate, a plurality of signal detectors, an insulation layer, and at least one gate. The semiconductor substrate includes a first surface and a second surface opposite to the first surface, and generates signal carriers in response to light incident upon the first surface. The signal detectors are formed on the semiconductor substrate and located closer to the second surface than the first surface of the semiconductor substrate, and detect the signal carriers using a difference in electric potential. The insulation layer is disposed at the second surface of the semiconductor substrate, and isolates the signal detectors from each other. The at least one gate is disposed at the insulation layer interposed between the signal detectors, and reflects light arriving at the second surface of the semiconductor substrate back to the semiconductor substrate.

First claim

What is claimed is:

1. An image sensing device comprising:
a semiconductor substrate including a first surface and a second surface opposite to the first surface, and configured to generate signal carriers in response to light incident upon the first surface;
a plurality of signal detectors formed on the semiconductor substrate and located closer to the second surface than the first surface of the semiconductor substrate, and configured to detect the signal carriers using a difference in an electric potential;
an insulation layer disposed at the second surface of the semiconductor substrate, and configured to isolate the signal detectors from each other;
pixel transistors disposed at the second surface of the semiconductor substrate, and configured to read out signal carriers acquired from the signal detectors; and
at least one gate disposed at the insulation layer interposed between the signal detectors, and configured to reflect light arriving at the second surface of the semiconductor substrate back to the semiconductor substrate,
wherein the pixels transistors have a gate having a same stacked structure as that of the at least one gate.

2. The image sensing device according to claim 1 , wherein the insulation layer includes an insulation material buried in a trench.

3. The image sensing device according to claim 1 , wherein each of the signal detectors includes:
a control region including first-type impurities, and configured to generate hole currents in the semiconductor substrate according to a control signal; and
a detection region including second-type impurities having an opposite conductivity to that of the first-type impurities and configured to capture the signal carriers moving by the hole currents.

4. The image sensing device according to claim 3 , wherein the control region and the detection region are isolated from each other by the insulation layer.

5. The image sensing device according to claim 3 , wherein the detection region is arranged to surround the control region.

6. The image sensing device according to claim 1 , wherein the at least one gate has a smaller size than that of the signal detectors.

7. The image sensing device according to claim 1 , wherein the at least one gate is formed to surround side surfaces of the signal detectors located at both sides of the at least one gate.

8. The image sensing device according to claim 1 , further comprising a pixel array of unit pixels supported by the semiconductor substrate and structured to convert incident light from a target object into pixel signals carrying image information of the target object, wherein the plurality of signal detectors are part of the pixel array of unit pixels.

9. The image sensing device according to claim 8 , further comprising a light source and a light control circuit coupled to control the light source to emit modulated light to the target object, wherein the pixel array of unit pixels detects reflected modulated light from the target object to provide the pixel signals that further carry information of a distance between the target object and the pixel array of unit pixels based on detection of the reflected modulated light from the target object.

10. An image sensing device comprising:
a semiconductor substrate including a first surface and a second surface opposite to the first surface, and configured to generate signal carriers in response to light incident upon the first surface;
a plurality of signal detectors formed on the semiconductor substrate and located closer to the second surface than the first surface of the semiconductor substrate, and configured to detect the signal carriers using a difference in an electric potential;
an insulation layer disposed at the second surface of the semiconductor substrate, and configured to isolate the signal detectors from each other;
at least one gate disposed at the insulation layer interposed between the signal detectors, and configured to reflect light arriving at the second surface of the semiconductor substrate back to the semiconductor substrate, and
wherein the at least one gate includes:
a gate insulation layer;
a polysilicon film formed over the gate insulation layer; and
a metal film formed over the polysilicon film.

11. The image sensing device according to claim 10 , wherein the metal film includes a silicide film.

12. An image sensing device comprising:
a pixel array including a plurality of unit pixels arranged in a first direction and a second direction perpendicular to the first direction, the unit pixels configured to generate signal carriers in response to reception of light incident upon a semiconductor substrate,
wherein the pixel array includes:
sub-pixel arrays, each sub-pixel array including unit pixels arranged in the first direction, and one or more gates disposed between the unit pixels, the one or more gates configured to reflect light into the semiconductor substrate; and
a pixel transistor array disposed between the sub-pixel arrays in the second direction and including pixel transistors arranged in the first direction and configured to read out photoelectric conversion signals acquired from the unit pixels, the photoelectric conversion signals corresponding to the signal carriers, and
wherein the pixel transistors have a gate having a same staked structure as that of the one or more gates.

13. The image sensing device according to claim 12 , wherein each of the unit pixels includes:
a plurality of signal detectors configured to generate a potential difference in the semiconductor substrate in response to a control signal, and detect the signal carriers using the potential difference.

14. The image sensing device according to claim 13 , further comprising:
an insulation layer including an insulation material and configured to isolate the signal detectors from each other.

15. The image sensing device according to claim 14 , wherein the one or more gates are disposed over the insulation layer interposed between the signal detectors.

16. The image sensing device according to claim 13 , wherein the one or more gates have a size smaller than that of the signal detectors.

17. The image sensing device according to claim 13 , wherein the one or more gates are disposed between the signal detectors to surround side surfaces of the signal detectors.

18. The image sensing device according to claim 12 , wherein the one or more gates have a structure in which different materials are stacked.

19. The image sensing device according to claim 12 , wherein each of the gates includes:
a gate insulation layer;
a polysilicon film formed over the gate insulation layer; and
a metal film formed over the polysilicon film.

20. The image sensing device according to claim 19 , wherein the metal film includes a silicide film.

Assignees

• Sk Hynix Inc

Inventors

• Kwak Ho Young
• Yoon Hyung June
• Kim Jong Eun

Classifications

• H04N25/79

  Arrangements of circuitry being divided between different or multiple substrates, chips or circuit boards, e.g. stacked image sensors · CPC title

• G01S7/4863

  Detector arrays, e.g. charge-transfer gates · CPC title

• G01B11/24

  for measuring contours or curvatures · CPC title

• G01S17/08

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title

• H04N5/378

  Electricity · mapped topic