Photo sensor array and method for manufacturing the same

• US 20010030324A1
• Filed: 04/05/2001
• Published: 10/18/2001
• Est. Priority Date: 04/12/2000
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Sasaki, Makoto, Morikawa, Shigeru
• Granted Patent: US 6,566,685 B2
• Time in Patent Office: Days
• US Class Current: 257/59
• 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

Abstract

A photo sensor array comprises a plurality of photoelectric conversion elements separated from each other in a predetermined direction to be arranged, each photo conversion element including a semiconductor layer having an incidence effective region on which excited light is incident, source-drain electrodes provided respectively on both ends of the semiconductor layer, a first gate electrode provided below the semiconductor layer via the first gate insulating film. A second gate electrode provided above the semiconductor layer via the second gate insulating film. A source terminal commonly connects to the source electrodes of the photoelectric conversion elements, and a drain terminal commonly connects the drain electrodes of the photoelectric conversion elements, a first gate terminal commonly connects the first gate electrodes of the photoelectric conversion elements, and a second gate terminal commonly connects the second gate terminal of the photoelectric conversion elements.

Claims

1. A photo sensor array comprising:

a plurality of photo conversion elements separated from each other in a predetermined direction to be arranged, each photo conversion element including

a semiconductor layer having an incidence effective region on which excited light is incident,

source-drain electrodes respectively provided at both ends of the semiconductor layer,

a first gate electrode provided below the semiconductor layer via the first gate insulating film, and

a second gate electrode provided above the semiconductor layer via the second gate insulating film;

a source terminal commonly connected to the source electrodes of the photo conversion elements;

a drain terminal commonly connected to the drain electrodes of the photo conversion elements;

a first gate terminal commonly connected to the first gate electrodes of the photo conversion elements; and

a second gate terminal commonly connected to the second gate electrodes of the photo conversion elements;

at least one of the first gate electrode and the second gate electrode provided on the photo conversion elements being constructed by a first transparent electrode layer, and

at least one of the source terminal, the drain terminal, and the first gate terminal having the first transparent electrode layer.

2. The photo sensor array according to

claim 1

, wherein the uppermost layer of at least one of the source terminal, the drain terminal, and the first gate terminal may be constituted of the first transparent electrode layer.

3. The photo sensor array according to

claim 1

, wherein the photo sensor array comprises an electrostatic electricity discharging and contact sensing electrode provided above the photoelectric conversion elements via an insulating film, and

at least one of the source terminal, the drain terminal, the first gate terminal, and the second gate terminal is constituted with the second transparent electrode layer constituting the electrostatic electricity discharging and sensing electrode.

4. The photo sensor array according to

claim 1

, wherein the semiconductor layer is extended under the source and the drain electrodes, the source and the drain terminals, a wiring connecting the source electrode and source terminal, and a wiring connecting the drain electrode and drain terminal.

5. The photo sensor array according to

claim 1

, further comprising

a drain driver a first gate driver and a second gate driver, and wherein the photoelectric conversion elements are connected to the drain driver, the first gate driver and the second gate driver via the source and the drain terminals, the first gate terminal, and the second gate terminal.

6. The photo array sensor according to

claim 1

, wherein the semiconductor layer has a plurality of incidence effective regions, and these regions are arranged in parallel with the channel direction of the semiconductor layer.

7. The photo sensor array according to

claim 1

, wherein the source and the drain electrodes are opaque to the excited light.

8. The photo sensor array according to

claim 1

, wherein the photoelectric conversion elements are arranged in a delta-like configuration.

9. The photo sensor array according to

claim 1

, wherein the semiconductor layer of each of the photoelectric conversion elements is separated into a plurality of layer positions so that source electrodes and drain electrodes are provided respectively on the layer portion, and the source electrodes are connected to each other and the drain electrodes are connected to each other.

10. The photo sensor array according to

claim 9

, wherein the semiconductor layers of the photoelectric conversion elements are arranged in parallel in the channel length direction of the semiconductor layer.

11. A method for manufacturing a photo sensor array, comprising:

forming a first gate electrode on an insulating film and a first gate base pad connected to the first gate electrode on a gate terminal portion;

forming a first gate insulating film on at least the first gate electrode and the first gate terminal portion, then forming a semiconductor layer having a predetermined configuration above the first gate electrode for generating a carrier with excited light;

forming a first open portion for exposing the first gate base pad to the first gate terminal portion;

forming source-drain electrodes respectively provided on both ends of the semiconductor layer, a drain base pad connected to the drain electrode on the drain terminal portion, and a first gate terminal lower layer on the first gate terminal portion via the first open portion;

forming a second insulating film on at least the first gate terminal lower layer, the source-drain electrode, and the drain terminal portion, then forming a second open portion for exposing at least one of the first gate terminal lower layer and the drain base pad; and

forming a second gate electrode having a predetermined configuration and a second gate base pad connecting the second gate electrode, the second gate terminal portion above the semiconductor layer while forming via the second open portion at least one of the first gate terminal upper layer connected to the first gate terminal lower layer and a drain terminal upper layer connected to the drain base pad.

12. The method for manufacturing a photo sensor array according to

claim 11

, wherein at least the first gate terminal upper layer or the drain terminal upper layer is constituted of the same transparent electrode layer as the second gate electrode.

13. The method for manufacturing a photo sensor array according to

claim 11

, comprising:

forming a protection insulating film on at least the first gate terminal portion, the drain terminal portion, the second gate electrode, and the second gate terminal portion, then forming a third open portion for exposing at least any one of the first gate terminal portion, the first drain terminal portion and the second gate terminal portion; and

forming an electrostatic electricity discharging and contact sensing electrode having a predetermined configuration on an insulating film and forming at least one of a first gate terminal uppermost layer on the first gate terminal portion, a drain terminal uppermost layer on the drain terminal portion, a second gate terminal upper layer on the second gate terminal portion via the third open portion.

14. The method for manufacturing a photo sensor array according to

claim 13

, wherein the first gate terminal uppermost layer or the drain terminal uppermost layer or the second gate terminal upper layer is constituted of the same transparent electrode layer as the electrostatic electricity discharging and contact sensing electrode.

15. The method for manufacturing a photo sensor array according to

claim 11

, wherein the semiconductor layer is extended and provided below the wiring layer connecting at least connecting the source and the drain electrodes, and the source drain terminal portions.