LIGHT-EMITTING DEVICE

• US 20110278577A1
• Filed: 07/20/2011
• Published: 11/17/2011
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei
• Granted Patent: US 8,680,528 B2
• Time in Patent Office: Days
• US Class Current: 257/59
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 29/458 for thin film silicon, e.g. source or drain electrode
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

It is an object to provide a light-emitting device including a thin film transistor with high electric characteristics and high reliability, and a method for manufacturing the light-emitting device with high productivity. As for a light-emitting device including an inverted staggered thin film transistor of a channel stop type, the inverted staggered thin film transistor includes a gate electrode, a gate insulating film over the gate electrode, a microcrystalline semiconductor film including a channel formation region over the gate insulating film, a buffer layer over the microcrystalline semiconductor film, a channel protective layer which is provided over the buffer layer so as to overlap with the channel formation region of the microcrystalline semiconductor film, a source region and a drain region over the channel protective layer and the buffer layer, and a source electrode and a drain electrode over the source region and the drain region.

Claims

1. A display device comprising:

a gate electrode over a substrate;

a first insulating film over the gate electrode;

a microcrystalline semiconductor film including a channel formation region, the microcrystalline semiconductor film over the gate electrode with the first insulating film interposed therebetween;

a pair of semiconductor films comprising an impurity element imparting one conductivity type, the pair of semiconductor films over the microcrystalline semiconductor film; and

a second insulating film over the microcrystalline semiconductor film and the pair of semiconductor films,

wherein end portions of the microcrystalline semiconductor film are positioned more inwardly than end portions of the gate electrode.

2. The display device according to claim 1,

wherein the gate electrode has an upper surface and a tapered-shape side surface,

wherein the microcrystalline semiconductor film is over the upper surface of the gate electrode, and

wherein the microcrystalline semiconductor film is not overlapped with the tapered-shape side surface.

3. An electronic device having the display device according to claim 1,

wherein the electronic device is one selected from the group consisting of a camera, a goggle-type display, a car navigation system, a projector, a car stereo, a personal computer, a portable information terminal, a television device, and a lamp.

4. A display device comprising:

a gate electrode over a substrate;

an insulating film over the gate electrode;

a microcrystalline semiconductor film including a channel formation region, the microcrystalline semiconductor film over the gate electrode with the insulating film interposed therebetween;

a channel protective layer over the microcrystalline semiconductor film, the channel protective layer overlapping the channel formation region; and

a pair of semiconductor films comprising an impurity element imparting one conductivity type, the pair of semiconductor films over the channel protective layer,

wherein end portions of the microcrystalline semiconductor film are positioned more inwardly than end portions of the gate electrode.

5. The display device according to claim 4,

wherein the gate electrode has an upper surface and a tapered-shape side surface,

wherein the microcrystalline semiconductor film is over the upper surface of the gate electrode, and

wherein the microcrystalline semiconductor film is not overlapped with the tapered-shape side surface.

6. The display device according to claim 4,

wherein the channel protective layer comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, and silicon nitride oxide.

7. The display device according to claim 4,

wherein the channel protective layer comprises a material selected from the group consisting of a photosensitive organic material and a non-photosensitive organic material.

8. The display device according to claim 4,

wherein the channel protective layer comprises a material selected from the group consisting of a photosensitive organic material and a non-photosensitive organic material.

9. An electronic device having the display device according to claim 4,

wherein the electronic device is one selected from the group consisting of a camera, a goggle-type display, a car navigation system, a projector, a car stereo, a personal computer, a portable information terminal, a television device, and a lamp.

10. A display device comprising:

a gate electrode over a substrate;

an insulating film over the gate electrode;

a microcrystalline semiconductor film including a channel formation region, the microcrystalline semiconductor film over the gate electrode with the insulating film interposed therebetween;

an amorphous semiconductor film over and being in contact with the microcrystalline semiconductor film;

a channel protective layer over and being in contact with the amorphous semiconductor film, the channel protective layer overlapping the channel formation region; and

a pair of semiconductor films comprising an impurity element imparting one conductivity type, the pair of semiconductor films over the amorphous semiconductor film and the channel protective layer,

wherein end portions of the microcrystalline semiconductor film are positioned more inwardly than end portions of the gate electrode.

11. The display device according to claim 10,

wherein the amorphous semiconductor film contains nitrogen.

12. The display device according to claim 10,

wherein the amorphous semiconductor film contains hydrogen.

13. The display device according to claim 10,

wherein the amorphous semiconductor film contains fluorine, chlorine, bromine, or iodine.

14. The display device according to claim 10,

wherein the amorphous semiconductor film contains nitrogen, carbon, and oxygen at a total concentration of greater than or equal to 1×

10²⁰ atoms/cm³ and less than or equal to 15×

10²⁰ atoms/cm³.

15. The display device according to claim 10,

wherein the gate electrode has an upper surface and a tapered-shape side surface,

wherein the microcrystalline semiconductor film is over the upper surface of the gate electrode, and

wherein the microcrystalline semiconductor film is not overlapped with the tapered-shape side surface.

16. The display device according to claim 10,

wherein the channel protective layer comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, and silicon nitride oxide.

17. The display device according to claim 10,

wherein the channel protective layer comprises a material selected from the group consisting of a photosensitive organic material and a non-photosensitive organic material.

18. The display device according to claim 10,

wherein the channel protective layer comprises a material selected from the group consisting of a photosensitive organic material and a non-photosensitive organic material.

19. An electronic device having the display device according to claim 10,

wherein the electronic device is one selected from the group consisting of a camera, a goggle-type display, a car navigation system, a projector, a car stereo, a personal computer, a portable information terminal, a television device, and a lamp.

20. A display device comprising:

a gate electrode;

a first insulating film over the gate electrode;

a microcrystalline semiconductor film including a channel formation region over the first insulating film;

an amorphous semiconductor film over and being in contact with the microcrystalline semiconductor film;

a channel protective layer over and being in contact with the amorphous semiconductor film, the channel protective layer overlapping the channel formation region;

a source region and a drain region formed over the channel protective layer and the amorphous semiconductor film;

a source electrode and a drain electrode formed over the source region and the drain region;

a second insulating film formed over the channel protective layer, the source electrode, and the drain electrode;

a pixel electrode electrically connected to one of the source electrode and the drain electrode;

a partition formed over the pixel electrode; and

a light emitting layer formed over the pixel electrode and the partition,

wherein end portions of the microcrystalline semiconductor film are positioned more inwardly than end portions of the gate electrode.

21. The display device according to claim 20, further comprising a common electrode over the light emitting layer.

22. The display device according to claim 20,

wherein an area of the source region and the drain region is larger than an area of the source electrode and the drain electrode.

23. The display device according to claim 20,

wherein the amorphous semiconductor film contains nitrogen.

24. The display device according to claim 20,

wherein the amorphous semiconductor film contains hydrogen.

25. The display device according to claim 20,

wherein the amorphous semiconductor film contains fluorine, chlorine, bromine, or iodine.

26. The display device according to claim 20,

wherein the amorphous semiconductor film contains nitrogen, carbon, and oxygen at a total concentration of greater than or equal to 1×

10²⁰ atoms/cm³ and less than or equal to 15×

10²⁰ atoms/cm³.

27. The display device according to claim 20,

wherein the gate electrode has an upper surface and a tapered-shape side surface,

wherein the microcrystalline semiconductor film is over the upper surface of the gate electrode, and

wherein the microcrystalline semiconductor film is not overlapped with the tapered-shape side surface.

28. The display device according to claim 20,

wherein the channel protective layer comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, and silicon nitride oxide.

29. The display device according to claim 20,

wherein the channel protective layer comprises a material selected from the group consisting of a photosensitive organic material and a non-photosensitive organic material.

30. The display device according to claim 20,

wherein the channel protective layer comprises a material selected from the group consisting of a photosensitive organic material and a non-photosensitive organic material.

31. An electronic device having the display device according to claim 20,

wherein the electronic device is one selected from the group consisting of a camera, a goggle-type display, a car navigation system, a projector, a car stereo, a personal computer, a portable information terminal, a television device, and a lamp.