Solid-state imaging device

• US 20070170478A1
• Filed: 01/22/2007
• Published: 07/26/2007
• Est. Priority Date: 01/24/2006
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Araki, Yasushi
• Granted Patent: US 7,619,267 B2
• Time in Patent Office: Days
• US Class Current: 257/292
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H10K 39/32 Organic image sensors

Abstract

A solid-state imaging device comprising a plurality of pixels arrayed on a plane, wherein each of the pixels includes a semiconductor substrate and a plurality of photoelectric conversion devices, the plurality of photoelectric conversion devices include at least one on-substrate photoelectric conversion device stacked in an upper portion of the semiconductor substrate and at least one in-substrate photoelectric conversion device provided within the semiconductor substrate in a lower portion of the on-substrate photoelectric conversion device, and the plurality of photoelectric conversion devices have a different photoelectric conversion sensitivity from each other.

Claims

1. A solid-state imaging device comprising a plurality of pixels arrayed on a plane, wherein

each of the pixels includes a semiconductor substrate and a plurality of photoelectric conversion devices,

the plurality of photoelectric conversion devices include at least one on-substrate photoelectric conversion device stacked in an upper portion of the semiconductor substrate and at least one in-substrate photoelectric conversion device provided within the semiconductor substrate in a lower portion of the on-substrate photoelectric conversion device, and

the plurality of photoelectric conversion devices have a different photoelectric conversion sensitivity from each other.

2. The solid-state imaging device according to claim 1, wherein the in-substrate photoelectric conversion device has a photoelectric conversion sensitivity higher than a photoelectric conversion sensitivity of the on-substrate photoelectric conversion device.

3. The solid-state imaging device according to claim 2,

wherein the plurality of photoelectric conversion devices include at least two on-substrate photoelectric devices stacked in an upper portion of the semiconductor substrate, and

in the at least two on-substrate photoelectric devices, the on-substrate photoelectric conversion device closer to the semiconductor substrate has lower photoelectric conversion sensitivity.

4. The solid-state imaging device according to claim 1, wherein a wavelength region of light to be detected is different among the plurality of photoelectric conversion devices.

5. The solid-state imaging device according to claim 4, wherein

the plurality of photoelectric conversion devices are two on-substrate photoelectric conversion devices stacked in an upper portion of the semiconductor substrate and one in-substrate photoelectric conversion device provided within the semiconductor substrate in a lower portion of the on-substrate photoelectric conversion devices, and

lights of red, green and blue wavelength regions are detected by the two on-substrate photoelectric conversion devices and the one in-substrate photoelectric conversion device.

6. The solid-state imaging device according to claim 4, wherein

the plurality of pixels are divided into units each made of a plurality of pixels, and

the adjacent on-substrate photoelectric conversion devices within the unit detect light of a different wavelength region from each other, and the adjacent in-substrate photoelectric conversion devices within the unit detect light of a different wavelength region from each other.

7. The solid-state imaging device according to claim 1, wherein

wavelength regions of lights to be detected by the plurality of photoelectric conversion devices are same from each other,

the plurality of pixels include a red pixel provided with the plurality of photoelectric conversion devices for detecting light of a red wavelength region, a green pixel provided with the plurality of photoelectric conversion devices for detecting light of a green wavelength region, and a blue pixel provided with the plurality of photoelectric conversion devices for detecting light of a blue wavelength region, and

a ratio of a number of the red pixels to a number of the green pixels to a number of the blue pixels included in the solid-state imaging device is 1/2/1.

8. The solid-state imaging device according to claim 1, wherein

the plurality of photoelectric conversion devices include at least two on-substrate photoelectric conversion devices stacked in an upper portion of the semiconductor substrate, each of the on-substrate photoelectric conversion devices including a photoelectric conversion element, and

in the at least two photoelectric conversion elements, the photoelectric conversion element closer to the semiconductor substrate has a higher external quantum efficiency.

9. The solid-state imaging device according to claim 8, wherein the on-substrate photoelectric conversion device includes a pair of electrodes and the photoelectric conversion element provided between the electrodes.

10. The solid-state imaging device according to claim 1, wherein the on-substrate photoelectric conversion device includes a pair of electrodes and a photoelectric conversion element provided between the electrodes.

11. The solid-state imaging device according to claim 8, wherein the photoelectric conversion element contains an organic material.

12. The solid-state imaging device according to claim 11, wherein the organic material contains a hole transporting organic material and an electron transporting organic material.

13. The solid-state imaging device according to claim 12, wherein the hole transporting organic material and the electron transporting organic material are provided so that the semiconductor substrate, the hole transporting organic material and the electron transporting organic material are in this order.

14. The solid-state imaging device according to claim 1, wherein in one pixel, a light receiving area of the in-substrate photoelectric conversion device in top view is from 20% to 90% of a light receiving area of the on-substrate photoelectric conversion device in top view.

15. The solid-state imaging device according to claim 1, wherein in one pixel, a deviation between a center of a light receiving region of the in-substrate photoelectric conversion device in top view and a center of a light receiving region of the on-substrate photoelectric conversion device in top view is not more than 30% of a width of the light receiving region of the on-substrate photoelectric conversion device.