Semiconductor device

• US 6,236,063 B1
• Filed: 05/11/1999
• Issued: 05/22/2001
• Est. Priority Date: 05/15/1998
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun, Yamazaki, Shunpei
• Primary Examiner(s): Thomas, Tom
• Assistant Examiner(s): Hu, Shouxiang
• Application Number:
  US09/309,966
• Time in Patent Office: 742 Days
• Field of Search: 257/59, 257/72, 257/347, 257/64, 257/65, 257/66, 257/67, 257/69, 257/70, 438/149, 349/116, 349/42, 349/2, 349/48, 348/308, 250/208.1
• US Class Current: 257/59
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G02F 1/1336 Illuminating devices
• CPC Class Codes: G02F 1/133604 with lamps
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1218 with a particular composition or structure of the substrate
• CPC Class Codes: H01L 27/14665 Imagers using a photoconductor layer
• CPC Class Codes: H01L 29/78633 with a light shield

Abstract

There is provided a semiconductor device including a picture display function and a picture capturing function on the same substrate. The semiconductor device includes a pixel matrix, an image sensor, and a peripheral circuit for driving those, which are provided on the same substrate. Moreover, in the semiconductor device, the structure/manufacturing process of the image sensor is made coincident with the structure/manufacturing process of the pixel matrix and the peripheral driver circuit, so that the semiconductor device can be manufactured at low cost.

Claims

1. A semiconductor device having an active matrix type display portion and an image sensor portion on a substrate, comprising:

a plurality of cells formed on said substrate in a matrix form, each cell comprising a pixel portion having at least a pixel TFT and a pixel electrode, and a sensor portion having at least a sensor TFT and a photoelectric conversion element;

a pixel source driver circuit and a pixel gate driver circuit connected to said pixel TFT, said pixel source driver circuit and said pixel gate driver circuit formed on said substrate;

a sensor horizontal driver circuit and a sensor vertical driver circuit connected to said sensor TFT, said sensor horizontal driver circuit and sensor vertical driver circuit formed on said substrate; and

a backlight disposed on a back surface of the substrate.

2. A device according to claim 1, wherein said pixel electrode is transparent.

3. A device according to claim 1, wherein said sensor portion further has a reset TFT and a signal amplifying TFT on said substrate.

4. A device according to claim 1, wherein each of said pixel TFT and said sensor TFT comprises a crystalline semiconductor film formed over said substrate as an active layer.

5. A device according to claim 1, wherein a lower electrode of said photoelectric conversion element is connected to one of source and drain electrodes of said sensor TFT.

6. A semiconductor device having an active matrix type display portion and an image sensor portion on a substrate, comprising:

a plurality of cells formed on said substrate in a matrix form, each cell comprising a pixel portion having at least a pixel TFT and a pixel electrode, and a sensor portion having at least a sensor TFT and a photoelectric conversion element;

a backlight disposed on a back surface of the substrate,

wherein said pixel TFT and said sensor TFT are formed on the same layer on the substrate.

7. A device according to claim 6, wherein said pixel electrode is transparent.

8. A device according to claim 6, wherein said sensor portion further has a reset TFT and a signal amplifying TFT on said substrate.

9. A device according to claim 6, wherein each of said pixel TFT and said sensor TFT comprises a crystalline semiconductor film formed over said substrate as an active layer.

10. A device according to claim 6, wherein a lower electrode of said photoelectric conversion element is connected to one of source and drain electrodes of said sensor TFT.

11. A semiconductor device having an active matrix type display portion and an image sensor portion on a substrate, comprising:

a plurality of cells formed on said substrate in a matrix form, each cell comprising a pixel portion having at least a pixel TFT and a pixel electrode, and a sensor portion having at least a sensor TFT and a photoelectric conversion element;

a backlight disposed on a back surface of the substrate,

wherein said photo conversion element is formed over said pixel TFT and said sensor TFT and under said pixel electrode.

12. A device according to claim 11, wherein said pixel electrode is transparent.

13. A device according to claim 11, wherein said sensor portion further has a reset TFT and a signal amplifying TFT on said substrate.

14. A device according to claim 11, wherein each of said pixel TFT and said sensor TFT comprises a crystalline semiconductor film formed over said substrate as an active layer.

15. A device according to claim 11, wherein a lower electrode of said photoelectric conversion element is connected to one of source and drain electrodes of said sensor TFT.

16. A semiconductor device having an active matrix type display portion and an image sensor portion on a transparent substrate, comprising:

a plurality of light shielding films on said transparent substrate;

a plurality of first and second thin film transistors disposed over said light shielding films;

a first interlayer insulating film over said first and second thin film transistors;

a plurality of photoelectric conversion elements disposed on said first interlayer insulating film, said photoelectric conversion elements connected to said first thin film transistors;

a second insulating film over said photoelectric conversion elements and said first and second thin film transistors;

a pixel electrode over said first and second thin film transistors with said photoelectric conversion elements interposed therebetween, said pixel electrode connected to said second thin film transistors; and

a backlight disposed on a back surface of the transparent substrate;

wherein the backlight is to be used as a light source when an external picture is read.

17. A device according to claim 16, wherein each of said first and second thin film transistors comprises:

a crystalline semiconductor layer over said substrate, said semiconductor layer having at least a channel forming region, a source region, and a drain region; and

a gate electrode adjacent to said channel regions of said crystalline semiconductor layer with a gate insulating film interposed therebetween.

18. A device according to claim 16, wherein each of said photoelectric conversion elements comprises:

a lower electrode on said first insulating layer, said lower electrode connected to one of source and drain electrodes of said first thin film transistor;

a photoelectric conversion layer on said lower electrode; and

an upper transparent electrode on said photoelectric conversion layer.

19. A device according to claim 16, wherein said external picture is put over said pixel electrode when it is read.

20. A device according to claim 16, wherein active layers of said first and second thin film transistors are formed on the same layer.

21. A device according to claim 16, further comprising a pixel source driver circuit, a pixel gate driver circuit, a sensor horizontal driver circuit, and a sensor vertical driver circuit formed on said substrate.

22. A semiconductor device having an active matrix type display portion and an image sensor portion on a transparent substrate, comprising:

a plurality of light shielding films on said transparent substrate;

a plurality of first and second thin film transistors disposed over said light shielding films;

a first interlayer insulating film over said first and second thin film transistors;

a plurality of photoelectric conversion elements disposed on said first interlayer insulating film, said photoelectric conversion elements connected to said first thin film transistors;

a second insulating film over said photoelectric conversion elements and said first and second thin film transistors;

a plurality of transparent pixel electrodes over said first and second thin film transistors with said photoelectric conversion elements interposed therebetween, said transparent pixel electrodes connected to said second thin film transistors; and

a backlight disposed on a back surface of the transparent substrate;

wherein the backlight is to be used as a light source when an external picture is read.

23. A device according to claim 22, wherein each of said first and second thin film transistors comprises:

a crystalline semiconductor layer over said substrate, said semiconductor layer having at least a channel forming region, a source region, and a drain region; and

a gate electrode adjacent to said channel regions of said crystalline semiconductor layer with a gate insulating film interposed therebetween.

24. A device according to claim 22, wherein each of photoelectric conversion elements comprises:

a lower electrode on said first insulating layer, said lower electrode connected to one of source and drain electrodes of said first thin film transistor;

a photoelectric conversion layer on said lower electrode; and

an upper transparent electrode on said photoelectric conversion layer.

25. A device according to claim 22, wherein said external picture is put over said transparent pixel electrode when it is read.

26. A device according to claim 22, wherein active layers of said first and second thin film transistors are formed on the same layer.

27. A device according to claim 22, further comprising a pixel source driver circurit, a pixel gate driver circuit, a sensor horizontal driver circuit, and a sensor vertical driver circuit formed on said substrate.