Solid-state image sensor

Patent metadata

Field	Value
Publication number	US-10038020-B2
Application number	US-201715447756-A
Country	US
Kind code	B2
Filing date	Mar 2, 2017
Priority date	Oct 19, 2012
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

A solid-state image sensor includes: a pixel array that includes first pixels, each having first and second photoelectric conversion units, and second pixels, each having third and fourth photoelectric conversion units; first to fourth transfer gates via which a signal charge respectively generated in the first to fourth photoelectric conversion units is respectively transferred to first to fourth charge voltage conversion units. At least one of a gate width, a gate length and an installation position of at least one transfer gate among the first to fourth transfer gates is altered to achieve uniformity in voltage conversion efficiency at the first to fourth charge voltage conversion units.

First claim

The invention claimed is:

1. An image sensor, comprising:
a first photoelectric conversion area that converts light into an electric charge;
a second photoelectric conversion area that converts light into an electric charge;
a first transfer unit, having a first gate width, that transfers the electric charge of the first photoelectric conversion area to a first floating diffusion area; and
a second transfer unit, having a second gate width different from the first gate width, that transfers the electric charge of the second photoelectric conversion area to a second floating diffusion area.

2. The image sensor according to claim 1 , wherein:
an installation position of the first transfer unit relative to the first photoelectric conversion area is different from an installation position of the second transfer unit relative to the second photoelectric conversion area.

3. The image sensor according to claim 1 , wherein:
an installation position of the first floating diffusion area relative to the first photoelectric conversion area is different from an installation position of the second floating diffusion area relative to the second photoelectric conversion area.

4. The image sensor according to claim 1 , wherein:
the first photoelectric conversion area converts light from a first micro-lens into the electric charge; and
the second photoelectric conversion area converts light from a second micro-lens into the electric charge.

5. The image sensor according to claim 4 , wherein:
the first photoelectric conversion area includes at least a first photoelectric conversion unit that executes photoelectric conversion and a second photoelectric conversion unit that executes photoelectric conversion; and
the second photoelectric conversion area includes at least a third photoelectric conversion unit that executes photoelectric conversion and a fourth photoelectric conversion unit that executes photoelectric conversion.

6. The image sensor according to claim 5 , wherein:
the first photoelectric conversion unit and the second photoelectric conversion unit are arranged along a first direction in the first photoelectric conversion area; and
the third photoelectric conversion unit and the fourth photoelectric conversion unit are arranged along a second direction, which intersects the first direction, in the second photoelectric conversion area.

7. The image sensor according to claim 5 , wherein:
the second photoelectric conversion unit is arranged in a first direction from the first photoelectric conversion unit in the first photoelectric conversion area; and
the fourth photoelectric conversion unit is arranged in a second direction from the third photoelectric conversion unit in the second photoelectric conversion area.

8. The image sensor according to claim 6 , wherein:
the first transfer unit includes a first transfer gate via which electric charge of the first photoelectric conversion unit is transferred and a second transfer gate via which electric charge of the second photoelectric conversion unit is transferred; and
the second transfer unit includes a third transfer gate via which electric charge of the third photoelectric conversion unit is transferred and a fourth transfer gate via which electric charge of the fourth photoelectric conversion unit is transferred.

9. The image sensor according to claim 8 , wherein:
the first transfer gate and the second transfer gate are arranged along the first direction; and
the third transfer gate and the fourth transfer gate are arranged apart in the second direction so as not to be arranged along the first direction.

10. The image sensor according to claim 8 , wherein:
the first transfer gate and the second transfer gate are arranged along the first direction; and
the third transfer gate and the fourth transfer gate are arranged along a third direction which intersects the first direction and the second direction.

11. The image sensor according to claim 8 , wherein:
the first photoelectric conversion unit, the second photoelectric conversion unit, the first transfer gate, and the second transfer gate are arranged along the first direction in order of the first transfer gate, the first photoelectric conversion unit, the second photoelectric conversion unit, and the second transfer gate; and
the third photoelectric conversion unit, the fourth photoelectric conversion unit, the third transfer gate, and the fourth transfer gate are arranged along a third direction, which intersects the first direction and the second direction, in order of the third transfer gate, the third photoelectric conversion unit, the fourth photoelectric conversion unit, and the fourth transfer gate.

12. The image sensor according to claim 8 , wherein:
the first floating diffusion area includes (i) a first charge voltage conversion unit to which the electric charge from the first photoelectric conversion unit is transferred via the first transfer gate and (ii) a second charge voltage conversion unit to which the electric charge from the second photoelectric conversion unit is transferred via the second transfer gate; and
the second floating diffusion area includes (i) a third charge voltage conversion unit to which the electric charge from the third photoelectric conversion unit is transferred via the third transfer gate and (ii) a fourth charge voltage conversion unit to which the electric charge from the fourth photoelectric conversion unit is transferred via the fourth transfer gate.

13. The image sensor according to claim 12 , further comprising:
a first signal line that outputs a signal based upon a voltage of the first charge voltage conversion unit;
a second signal line that outputs a signal based upon a voltage of the second charge voltage conversion unit;
a third signal line that outputs a signal based upon a voltage of the third charge voltage conversion unit; and
a fourth signal line that outputs a signal based upon a voltage of the fourth charge voltage conversion unit.

14. An image sensor, comprising:
a first photoelectric conversion area that converts light into an electric charge;
a second photoelectric conversion area that converts light into an electric charge;
a first transfer unit, having a first gate length, that transfers the electric charge of the first photoelectric conversion area to a first floating diffusion area; and
a second transfer unit, having a second gate length different from the first gate length, that transfers the electric charge of the second photoelectric conversion area to a second floating diffusion area.

15. The image sensor according to claim 14 , wherein:
an installation position of the first transfer unit relative to the first photoelectric conversion area is different from an installation position of the second transfer unit relative to the second photoelectric conversion area.

16. The image sensor according to claim 14 , wherein:
an installation position of the first floating diffusion area relative to the first photoelectric conversion area is different from an installation position of the second floating diffusion area relative to the second photoelectric conversion area.

17. The image sensor according to claim 14 , wherein:
the first photoelectric conversion area converts light from a first micro-lens into the electric charge; and
the second photoelectric conversion area converts light from a second micro-lens into the electric charge.

18. The image sensor according to claim 17 , wherein:
the first photoelectric conversion area includes at least a fir

Assignees

• Nikon Corp

Inventors

• Suzuki Satoshi

Classifications

• H04N25/677

  for reducing the column or line fixed pattern noise · CPC title

• H04N25/77

  Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components · CPC title

• H04N25/616

  involving a correlated sampling function, e.g. correlated double sampling [CDS] or triple sampling · CPC title

• H01L27/14614 Primary

  Electricity · mapped topic

• H04N5/378

  Electricity · mapped topic