Imaging device and electronic device

Patent metadata

Field	Value
Publication number	US-9704899-B2
Application number	US-201514921175-A
Country	US
Kind code	B2
Filing date	Oct 23, 2015
Priority date	Oct 24, 2014
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

An imaging device with excellent imaging performance is provided. In the imaging device, a first layer, a second layer, and a third layer have a region overlapping with one another, the first layer and the second layer each include transistors, and the third layer includes a photoelectric conversion element. Off-state currents of the transistors formed in the first layer are lower than those of the transistors formed in the second layer, and field-effect mobilities of the transistors formed in the second layer are higher than those of the transistors formed in the first layer.

First claim

What is claimed is:

1. An imaging device comprising:
a first layer;
a second layer; and
a third layer,
wherein the first layer, the second layer, and the third layer overlap with one another,
wherein the first layer includes a first transistor and a second transistor,
wherein the second layer includes a third transistor and a fourth transistor,
wherein each of active layers of the first transistor, the second transistor, the third transistor, and the fourth transistor includes an oxide semiconductor,
wherein the third layer includes a photoelectric conversion element,
wherein one of a source and a drain of the first transistor is electrically connected to one of a source and a drain of the second transistor,
wherein the one of the source and the drain of the second transistor is electrically connected to a gate of the third transistor,
wherein one of a source and a drain of the third transistor is electrically connected to one of a source and a drain of the fourth transistor,
wherein one electrode of the photoelectric conversion element is electrically connected to the other one of the source and the drain of the first transistor,
wherein off-state currents of the first transistor and the second transistor are lower than those of the third transistor and the fourth transistor, and
wherein field-effect mobilities of the third transistor and the fourth transistor are higher than those of the first transistor and the second transistor.

2. The imaging device according to claim 1 ,
wherein the first layer, the second layer, and the third layer are arranged in an order of the first layer, the second layer, and the third layer in a height direction or in an order of the second layer, the first layer, and the third layer in a height direction.

3. The imaging device according to claim 1 ,
wherein the active layers of the first transistor and the second transistor have larger bandgaps than the active layers of the third transistor and the fourth transistor.

4. The imaging device according to claim 1 ,
wherein the active layers of the third transistor and the fourth transistor are thicker than the active layers of the first transistor and the second transistor.

5. The imaging device according to claim 1 ,
wherein one of a source and a drain of the first transistor is electrically connected to one electrode of a capacitor.

6. The imaging device according to claim 1 ,
wherein the oxide semiconductor includes In, Zn, and M, and
wherein M is Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf.

7. The imaging device according to claim 1 ,
wherein the photoelectric conversion element includes a photoelectric conversion layer including selenium or a compound containing selenium.

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

9. An imaging device comprising:
a first layer;
a second layer;
a third layer; and
a fourth layer,
wherein the first layer, the second layer, the third layer, and the fourth layer overlap with one another,
wherein the first layer includes a photoelectric conversion element,
wherein the second layer includes a first transistor and a second transistor,
wherein the third layer includes a third transistor and a fourth transistor,
wherein the fourth layer includes a fifth transistor,
wherein each of active layers of the first transistor, the second transistor, the third transistor, and the fourth transistor includes an oxide semiconductor,
wherein an active region of the fifth transistor or an active layer of the fifth transistor includes silicon,
wherein the first transistor, the second transistor, the third transistor, and the fourth transistor form a first circuit,
wherein the fifth transistor forms a second circuit,
wherein one of a source and a drain of the first transistor is electrically connected to one of a source and a drain of the second transistor,
wherein the one of the source and the drain of the second transistor is electrically connected to a gate of the third transistor,
wherein one of a source and a drain of the third transistor is electrically connected to one of a source and a drain of the fourth transistor,
wherein one electrode of the photoelectric conversion element is electrically connected to the other one of the source and the drain of the first transistor,
wherein off-state currents of the first transistor and the second transistor are lower than those of the third transistor and the fourth transistor, and
wherein field-effect mobilities of the third transistor and the fourth transistor are higher than those of the first transistor and the second transistor.

10. The imaging device according to claim 9 ,
wherein the first layer, the second layer, the third layer, and the fourth layer are arranged in an order of the first layer, the second layer, the third layer, and the fourth layer in a height direction or in an order of the first layer, the third layer, the second layer, and the fourth layer in a height direction.

11. The imaging device according to claim 9 ,
wherein the active layers of the first transistor and the second transistor have larger bandgaps than the active layers of the third transistor and the fourth transistor.

12. The imaging device according to claim 9 ,
wherein the active layers of the third transistor and the fourth transistor are thicker than the active layers of the first transistor and the second transistor.

13. The imaging device according to claim 9 ,
wherein one of a source and a drain of the first transistor is electrically connected to one electrode of a capacitor.

14. The imaging device according to claim 9 ,
wherein the oxide semiconductor includes In, Zn, and M, and
wherein M is Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf.

15. The imaging device according to claim 9 ,
wherein the photoelectric conversion element includes a photoelectric conversion layer including selenium or a compound containing selenium.

16. An imaging device comprising a stack, the stack comprising:
a first layer;
a second layer;
a third layer; and
a fourth layer,
wherein the first layer, the second layer, the third layer, and the fourth layer overlap with one another,
wherein the first layer includes a photoelectric conversion element,
wherein the second layer includes a first transistor and a second transistor,
wherein the third layer includes a third transistor, a fourth transistor, and a fifth transistor,
wherein the fourth layer includes a sixth transistor,
wherein each of active layers of the first transistor, the second transistor, the third transistor, the fourth transistor, and the fifth transistor includes an oxide semiconductor,
wherein an active region of the sixth transistor or an active layer of the sixth transistor includes silicon,
wherein the first transistor, the second transistor, the third transistor, and the fourth transistor form a first circuit,
wherein the fifth transistor and the sixth transistor form a second circuit,
wherein one of a source and a drain of the first transistor is electrically connected to one of a source and a drain of the second transistor,
wherein the one of the source and the drain of the second transistor is electrically connected to a gate of the third transistor,
wherein one of a source and a drain of the third transistor is electrically connected to one of a source and a drain of the fourth transistor,
wherein one electrode of the photoelectric conversion element is electrically connected to the other one of the source and the drain of the first transistor,
wherein off-

Assignees

• Semiconductor Energy Lab

Inventors

• Kurokawa Yoshiyuki

Classifications

• H01L31/0272

  Electricity · mapped topic

• H01L27/1225

  Electricity · mapped topic

• H01L27/1233

  Electricity · mapped topic

• H01L29/24

  Electricity · mapped topic

• H01L27/14632

  Electricity · mapped topic