SEMICONDUCTOR DEVICE AND ELECTRONIC DEVICE USING THE SAME

• US 20120049185A1
• Filed: 11/09/2011
• Published: 03/01/2012
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KIMURA, Hajime
• Granted Patent: US 8,288,807 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14692 Thin film technologies, e.g. amorphous, poly, micro- or nanocrystalline silicon
• CPC Class Codes: H01L 31/1055 the devices comprising amorphous materials of Group IV of the Periodic Table
• CPC Class Codes: H04N 25/57 Control of the dynamic range
• CPC Class Codes: H04N 25/573 the logarithmic type
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

To provide a semiconductor device which can detect low illuminance. A photoelectric conversion element, a diode-connected first transistor, and a second transistor are included. A gate of the first transistor is electrically connected to a gate of the second transistor. 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 through the photoelectric conversion element. The other of the source and the drain of the first transistor is electrically connected to the other of the source and the drain of the second transistor. By using transistors which have different threshold voltages for the first transistor and the second transistor, a semiconductor device which can perform detecting of low illuminance can be obtained.

Claims

1. A semiconductor device comprising:

a first terminal;

a second terminal;

a photoelectric conversion element;

a resister; and

a transistor,

wherein one of a source and a drain of the transistor is electrically connected to the first terminal,

wherein the other of the source and the drain of the transistor is electrically connected to the second terminal,

wherein a gate of the transistor is electrically connected to a first terminal of the resister,

wherein the first terminal of the resister is electrically connected to the first terminal through the photoelectric conversion element, and

wherein a second terminal of the resister is electrically connected to the second terminal.

2. The semiconductor device according to claim 1, wherein the photoelectric conversion element is a photodiode.

3. The semiconductor device according to claim 1, wherein the transistor comprises an oxide semiconductor.

4. The semiconductor device according to claim 3, wherein the oxide semiconductor is zinc oxide, amorphous oxide, indium zinc oxide, indium tin oxide, or tin oxide.

5. The semiconductor device according to claim 1, wherein the transistor is formed over a semiconductor substrate.

6. The semiconductor device according to claim 2, wherein the first terminal of the resister is electrically connected to an anode of the photodiode.

7. The semiconductor device according to claim 2, wherein the first terminal of the resister is electrically connected to a cathode of the photodiode.

8. The semiconductor device according to claim 1, wherein the transistor is a depletion transistor.

9. The semiconductor device according to claim 1, wherein one or more transistors is electrically connected to the transistor in parallel.

10. The semiconductor device according to claim 1, wherein the semiconductor device is electrically connected to a resistor element.

11. An electronic device comprising the semiconductor device according to claim 1, wherein the electronic device is selected from the group consisting of a mobile phone, a computer, a camera, a display device and a TV receiver.

12. A semiconductor device comprising:

a first terminal;

a second terminal;

a photoelectric conversion element;

a diode; and

a transistor,

wherein one of a source and a drain of the transistor is electrically connected to the first terminal,

wherein the other of the source and the drain of the transistor is electrically connected to the second terminal,

wherein a gate of the transistor is electrically connected to a first terminal of the diode,

wherein the first terminal of the diode is electrically connected to the first terminal through the photoelectric conversion element, and

wherein a second terminal of the diode is electrically connected to the second terminal.

13. The semiconductor device according to claim 12, wherein the photoelectric conversion element is a photodiode.

14. The semiconductor device according to claim 12, wherein the transistor comprises an oxide semiconductor.

15. The semiconductor device according to claim 14, wherein the oxide semiconductor is zinc oxide, amorphous oxide, indium zinc oxide, indium tin oxide, or tin oxide.

16. The semiconductor device according to claim 12, wherein the transistor is formed over a semiconductor substrate.

17. The semiconductor device according to claim 13,

wherein the first terminal of the diode is an anode, and

wherein the anode of the diode is electrically connected to an anode of the photodiode.

18. The semiconductor device according to claim 13,

wherein the first terminal of the diode is a cathode, and

wherein the cathode of the diode is electrically connected to a cathode of the photodiode.

19. The semiconductor device according to claim 12, wherein the transistor is a depletion transistor.

20. The semiconductor device according to claim 12, wherein one or more transistors is electrically connected to the transistor in parallel.

21. The semiconductor device according to claim 12, wherein the semiconductor device is electrically connected to a resistor element.

22. An electronic device comprising the semiconductor device according to claim 12, wherein the electronic device is selected from the group consisting of a mobile phone, a computer, a camera, a display device and a TV receiver.

23. A semiconductor device comprising:

a photoelectric conversion element;

a diode-connected first transistor; and

a second transistor,

wherein one of a source and a drain of the diode-connected first transistor is electrically connected to one of a source and a drain of the second transistor through the photoelectric conversion element,

wherein the other of the source and the drain of the diode-connected first transistor is electrically connected to the other of the source and the drain of the second transistor,

wherein a gate of the second transistor is electrically connected to the one of the source and the drain of the diode-connected first transistor,

wherein the diode-connected first transistor and the second transistor comprise an oxide semiconductor, and

wherein the diode-connected first transistor and the second transistor have different threshold voltages.

24. The semiconductor device according to claim 23, wherein the photoelectric conversion element is a photodiode.

25. The semiconductor device according to claim 23, wherein the oxide semiconductor is zinc oxide, amorphous oxide, indium zinc oxide, indium tin oxide, or tin oxide.

26. The semiconductor device according to claim 23, wherein the diode-connected first transistor and the second transistor are formed over a semiconductor substrate.

27. The semiconductor device according to claim 23, wherein the diode-connected first transistor is an enhancement transistor.

28. The semiconductor device according to claim 23, wherein the second transistor is a depletion transistor.

29. The semiconductor device according to claim 23, wherein a difference between the threshold voltage of the diode-connected first transistor and the threshold voltage of the second transistor is 1V or higher.

30. The semiconductor device according to claim 23, wherein the diode-connected first transistor and the second transistor have the same conductivity type.

31. The semiconductor device according to claim 23, wherein one or more transistors is electrically connected to the diode-connected first transistor in parallel.

32. The semiconductor device according to claim 23, wherein one or more transistors is electrically connected to the second transistor in parallel.

33. The semiconductor device according to claim 23, wherein the semiconductor device is electrically connected to a resistor element.

34. An electronic device comprising the semiconductor device according to claim 23, wherein the electronic device is selected from the group consisting of a mobile phone, a computer, a camera, a display device and a TV receiver.