Imaging device and electronic device

Patent metadata

Field	Value
Publication number	US-9634048-B2
Application number	US-201615078741-A
Country	US
Kind code	B2
Filing date	Mar 23, 2016
Priority date	Mar 24, 2015
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

An imaging device with excellent imaging performance is provided. The imaging device has a first circuit including a first photoelectric conversion element and a second circuit including a second photoelectric conversion element. The second circuit is shielded from light. In the imaging device, a current mirror circuit in which a transistor connected to the second photoelectric conversion element serves as an input transistor and a transistor connected to the first photoelectric conversion element serves as an output transistor is formed. With such a configuration, the amount of photocurrent in the first circuit from which the contribution of the dark current of the first photoelectric conversion element has been excluded can be detected.

First claim

What is claimed is:

1. An imaging device comprising:
a first circuit; and
a second circuit,
wherein the first circuit comprises:
a first transistor;
a second transistor;
a third transistor;
a fourth transistor; and
a first photoelectric conversion element,

wherein one of electrodes of the first photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the first transistor,
wherein the one of the electrodes of the first photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the second transistor,
wherein the other of the source electrode and the drain electrode of the second transistor is electrically connected to a gate electrode of the third transistor,
wherein one of a source electrode and a drain electrode of the third transistor is electrically connected to one of a source electrode and a drain electrode of the fourth transistor,
wherein the second circuit comprises:
a fifth transistor;
a sixth transistor;
a seventh transistor;
an eighth transistor; and
a second photoelectric conversion element,

wherein one of electrodes of the second photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the fifth transistor,
wherein the one of the electrodes of the second photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the sixth transistor,
wherein the one of the source electrode and the drain electrode of the fifth transistor is electrically connected to a gate electrode of the fifth transistor,
wherein the other of the source electrode and the drain electrode of the sixth transistor is electrically connected to a gate electrode of the seventh transistor,
wherein one of a source electrode and a drain electrode of the seventh transistor is electrically connected to one of a source electrode and a drain electrode of the eighth transistor, and
wherein a gate electrode of the first transistor is electrically connected to the gate electrode of the fifth transistor.

2. The imaging device according to claim 1 ,
wherein first circuits each comprise the first circuit and second circuits each comprise the second circuit,
wherein the first circuits and the second circuits are arranged in a matrix of m rows and n columns,
wherein the second circuits are positioned in a first column and an n-th column of the n columns, and
wherein m is a natural number greater than or equal to 1, and n is a natural number greater than or equal to 3.

3. The imaging device according to claim 1 ,
wherein the second circuit is shielded from light.

4. The imaging device according to claim 1 ,
wherein the first transistor, the second transistor, and the fifth transistor each include an oxide semiconductor in an active layer,
wherein the oxide semiconductor contains In, Zn, and M, and
wherein M is Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf.

5. The imaging device according to claim 1 ,
wherein the first photoelectric conversion element and the second photoelectric conversion element each include a material containing selenium.

6. An electronic device comprising:
the imaging device according to claim 1 ; and
a display device.

7. An imaging device comprising:
a first circuit; and
a second circuit,
wherein the first circuit comprises:
a first transistor;
a second transistor;
a third transistor;
a fourth transistor; and
a first photoelectric conversion element,

wherein one of electrodes of the first photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the first transistor,
wherein the one of the electrodes of the first photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the second transistor,
wherein the other of the source electrode and the drain electrode of the second transistor is electrically connected to a gate electrode of the third transistor,
wherein one of a source electrode and a drain electrode of the third transistor is electrically connected to one of a source electrode and a drain electrode of the fourth transistor,
wherein the second circuit comprises:
a fifth transistor; and
a second photoelectric conversion element,

wherein one of electrodes of the second photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the fifth transistor,
wherein the one of the source electrode and the drain electrode of the fifth transistor is electrically connected to a gate electrode of the fifth transistor, and
wherein a gate electrode of the first transistor is electrically connected to the gate electrode of the fifth transistor.

8. The imaging device according to claim 7 ,
wherein first circuits each comprise the first circuit and second circuits each comprise the second circuit,
wherein the first circuits and the second circuits are arranged in a matrix of m rows and n columns,
wherein the second circuits are positioned in a first column and an n-th column of the n columns, and
wherein m is a natural number greater than or equal to 1, and n is a natural number greater than or equal to 3.

9. The imaging device according to claim 7 ,
wherein the second circuit is shielded from light.

10. The imaging device according to claim 7 ,
wherein the first transistor, the second transistor, and the fifth transistor each include an oxide semiconductor in an active layer,
wherein the oxide semiconductor contains In, Zn, and M, and
wherein M is Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf.

11. The imaging device according to claim 7 ,
wherein the first photoelectric conversion element and the second photoelectric conversion element each include a material containing selenium.

12. An electronic device comprising:
the imaging device according to claim 7 ; and
a display device.

13. An imaging device comprising:
a first circuit; and
a second circuit,
wherein the first circuit comprises:
a first transistor;
a second transistor;
a third transistor;
a fourth transistor; and
a first photoelectric conversion element,

wherein one of electrodes of the first photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the first transistor,
wherein the one of the electrodes of the first photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the second transistor,
wherein the other of the source electrode and the drain electrode of the second transistor is electrically connected to a gate electrode of the third transistor,
wherein one of a source electrode and a drain electrode of the third transistor is electrically connected to one of a source electrode and a drain electrode of the fourth transistor,
wherein the second circuit comprises:
a fifth transistor; and
a second photoelectric conversion element,

wherein one of electrodes of the second photoelectric conversion element is electrically connected to one of a source electrode and a drain electrode of the fifth transistor,
wherein the one of the source electrode and the drain electrode of the fifth transistor is electrically connected to a gate electrode of the fifth transistor, and
wherein a gate electrode of the first transistor is electrically connected to the gate electrode of the fifth transistor, and
wherein the first transistor, the second transistor, and the fifth transistor each include an oxide semiconductor in an ac

Assignees

• Semiconductor Energy Lab

Inventors

• Kurokawa Yoshiyuki

Classifications

• H01L27/14623

  Electricity · mapped topic

• H01L27/14645

  Electricity · mapped topic

• H01L27/14641

  Electricity · mapped topic

• H01L27/14676

  Electricity · mapped topic

• H01L27/14603

  Electricity · mapped topic