Claims
- 1. A display device comprising:a driver circuit portion and a pixel portion both formed over a same substrate; the driver circuit portion comprising a first n-channel thin film transistor and a p-channel thin film transistor, the first n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode has a tapered portion, the p-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, and a channel formation region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode does not have a tapered portion, the pixel portion comprising a second n-channel thin film transistor, the second n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer.
- 2. A display device according to claim 1 wherein the low concentration impurity region of the second n-channel thin film transistor does not overlap the gate electrode of the second n-channel thin film transistor.
- 3. A display device according to claim 1 wherein each of the gate electrodes has a laminate structure.
- 4. A display device according to claim 1 wherein each of the gate electrodes is formed over each of the semiconductor layers.
- 5. A display device according to claim 1 wherein the display device is a liquid crystal display device.
- 6. A display device according to claim 1 wherein the display device is incorporated in at least one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player which uses a recording medium, a digital camera, a projector, a portable telephone, and an electronic book.
- 7. A display device comprising:a driver circuit portion and a pixel portion both formed over a same substrate; the driver circuit portion comprising a first n-channel thin film transistor and a p-channel thin film transistor, the first n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode has a tapered portion, and wherein a portion of the low concentration impurity region overlaps the gate electrode, the p-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, and a channel formation region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode does not have a tapered portion, the pixel portion comprising a second n-channel thin film transistor, the second n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer.
- 8. A display device according to claim 7 wherein the low concentration impurity region of the second n-channel thin film transistor does not overlap the gate electrode of the second n-channel thin film transistor.
- 9. A display device according to claim 7 wherein each of the gate electrodes has a laminate structure.
- 10. A display device according to claim 7 wherein each of the gate electrodes is formed over each of the semiconductor layers.
- 11. A display device according to claim 1 wherein the display device is a liquid crystal display device.
- 12. A display device according to claim 1 wherein the display device is incorporated in at least one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player which uses a recording medium, a digital camera, a projector, a portable telephone, and an electronic book.
- 13. A display device comprising:a driver circuit portion and a pixel portion both formed over a same substrate; the driver circuit portion comprising a first n-channel thin film transistor and a p-channel thin film transistor, the first n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode has a tapered portion, the p-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, and a channel formation region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode does not have a tapered portion, the pixel portion comprising a second n-channel thin film transistor, the second n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode does not have a tapered portion.
- 14. A display device according to claim 13 wherein the low concentration impurity region of the second n-channel thin film transistor does not overlap the gate electrode of the second n-channel thin film transistor.
- 15. A display device according to claim 13 wherein each of the gate electrodes has a laminate structure.
- 16. A display device according to claim 13 wherein each of the gate electrodes is formed over each of the semiconductor layers.
- 17. A display device according to claim 13 wherein the display device is a liquid crystal display device.
- 18. A display device according to claim 13 wherein the display device is incorporated in at least one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player which uses a recording medium, a digital camera, a projector, a portable telephone, and an electronic book.
- 19. A display device comprising:a driver circuit portion and a pixel portion both formed over a same substrate; the driver circuit portion comprising a first n-channel thin film transistor and a p-channel thin film transistor, the first n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode has a tapered portion, the p-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, and a channel formation region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode does not have a tapered portion, the pixel portion comprising a second n-channel thin film transistor, the second n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein each of the gate electrodes comprises at least one element selected from the group consisting of Ta, W, Ti, Mo, Al, Cu, and Si.
- 20. A display device according to claim 19 wherein the low concentration impurity region of the second n-channel thin film transistor does not overlap the gate electrode of the second n-channel thin film transistor.
- 21. A display device according to claim 19 wherein each of the gate electrodes has a laminate structure.
- 22. A display device according to claim 19 wherein each of the gate electrodes is formed over each of the semiconductor layers.
- 23. A display device according to claim 19 wherein the display device is a liquid crystal display device.
- 24. A display device according to claim 19 wherein the display device is incorporated in at least one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player which uses a recording medium, a digital camera, a projector, a portable telephone, and an electronic book.
- 25. A display device comprising:a driver circuit portion and a pixel portion both formed over a same substrate; the driver circuit portion comprising a first n-channel thin film transistor and a p-channel thin film transistor, the first n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode has a tapered portion, and wherein a portion of the low concentration impurity region overlaps the gate electrode, the p-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, and a channel formation region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode does not have a tapered portion, the pixel portion comprising a second n-channel thin film transistor, the second n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein each of the gate electrodes comprises at least one element selected from the group consisting of Ta, W, Ti, Mo, Al, Cu, and Si.
- 26. A display device according to claim 25 wherein the low concentration impurity region of the second n-channel thin film transistor does not overlap the gate electrode of the second n-channel thin film transistor.
- 27. A display device according to claim 25 wherein each of the gate electrodes has a laminate structure.
- 28. A display device according to claim 25 wherein each of the gate is formed over each of the semiconductor layers.
- 29. A display device according to claim 25 wherein the display device is a liquid crystal display device.
- 30. A display device according to claim 25 wherein the display device is incorporated in at least one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player which uses a recording medium, a digital camera, a projector, a portable telephone, and an electronic book.
- 31. A display device comprising:a driver circuit portion and a pixel portion both formed over a same substrate; the driver circuit portion comprising a first n-channel thin film transistor and a p-channel thin film transistor, the first n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode has a tapered portion, the p-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, and a channel formation region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode does not have a tapered portion, the pixel portion comprising a second n-channel thin film transistor, the second n-channel thin film transistor comprising: a semiconductor layer over the substrate, the semiconductor layer comprising a source region, a drain region, a channel formation region, and a low concentration impurity region between the channel formation region and at least one of the source region and the drain region; and a gate electrode adjacent to the semiconductor layer, wherein the gate electrode does not have a tapered portion, and wherein each of the gate electrodes comprises at least one element selected from the group consisting of Ta, W, Ti, Mo, Al, Cu, and Si.
- 32. A display device according to claim 31 wherein the low concentration impurity region of the second n-channel thin film transistor does not overlap the gate electrode of the second n-channel thin film transistor.
- 33. A display device according to claim 31 wherein each of the gate electrodes has a laminate structure.
- 34. A display device according to claim 31 wherein each of the gate electrodes is formed over each of the semiconductor layers.
- 35. A display device according to claim 31 wherein the display device is a liquid crystal display device.
- 36. A display device according to claim 31 wherein the display device is incorporated in at least one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player which uses a recording medium, a digital camera, a projector, a portable telephone, and an electronic book.
Priority Claims (3)
Number |
Date |
Country |
Kind |
2000-230401 |
Jul 2000 |
JP |
|
2000-301389 |
Sep 2000 |
JP |
|
2000-301390 |
Sep 2000 |
JP |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. application Ser. No. 09/916,329, filed on Jul. 30, 2001, which claims the benefit of foreign priority applications filed in Japan, Serial No. 2000-230401, filed Jul. 31, 2000; Ser. No. 2000-301389, filed Sep. 29, 2000; and Serial No. 2000-301390, filed Sep. 29, 2000, all of which are incorporated by reference.
US Referenced Citations (6)
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May 1994 |
JP |
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Sep 1995 |
JP |
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Oct 1996 |
JP |
10-247735 |
Sep 1998 |
JP |