초록 ▼

A semiconductor device having high operating performance and reliability, and a manufacturing method thereof are provided. An LDD region 207 provided in an n-channel TFT 302 forming a driving circuit enhances the tolerance for hot carrier injection. LDD regions 217-220 provided in an n-channel TFT

A semiconductor device having high operating performance and reliability, and a manufacturing method thereof are provided. An LDD region 207 provided in an n-channel TFT 302 forming a driving circuit enhances the tolerance for hot carrier injection. LDD regions 217-220 provided in an n-channel TFT (pixel TFT) 304 forming a pixel portion greatly contribute to the decrease in the OFF current value. Here, the LDD region of the n-channel TFT of the driving circuit is formed such that the concentration of the n-type impurity element becomes higher as the distance from an adjoining drain region decreases.

대표청구항 ▼

What is claimed is: 1. A method of manufacturing a semiconductor device comprising: forming a crystalline semiconductor layer over an insulating substrate; forming a gate insulating film on the crystalline semiconductor layer; forming a conductive film on the gate insulating film; and etching the c

What is claimed is: 1. A method of manufacturing a semiconductor device comprising: forming a crystalline semiconductor layer over an insulating substrate; forming a gate insulating film on the crystalline semiconductor layer; forming a conductive film on the gate insulating film; and etching the conductive film so as to form a gate electrode having a tapered cross section by using an inductively coupled plasma chamber having multispiral coils. 2. A method of manufacturing a semiconductor device according to claim 1, wherein the gate electrode comprises at least one selected from the group consisting of tantalum, chromium, tungsten, and silicon having conductivity. 3. A method of manufacturing a semiconductor device according to claim 1, wherein a taper angle of the gate electrode is between 3 and 40째. 4. A method of manufacturing a semiconductor device according to claim 1, wherein the step of etching the conductive film is conducted in a mixture gas containing fluorine and chlorine. 5. A method of manufacturing a semiconductor device according to claim 4, wherein the gas containing fluorine is one selected from the group consisting of CF4, C2F6 and C4 F8. 6. A method of manufacturing a semiconductor device according to claim 4, wherein the gas containing chlorine is one selected from the group consisting of Cl2, SiCl4, and BCl3. 7. A method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor device is at least one of a liquid crystal display device and an EL display device. 8. A method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor device is at least one selected from the group consisting of a personal computer, a video camera, a goggle type display, an image reproduction device, and a projector. 9. A method of manufacturing a semiconductor device comprising: forming a crystalline semiconductor layer over an insulating substrate; forming a gate insulating film on the crystalline semiconductor layer; forming a conductive film on the gate insulating film; and etching the conductive film so as to form a gate electrode having a tapered cross section by using an inductively coupled plasma chamber after determining a flow rate ratio of an etching gas. 10. A method of manufacturing a semiconductor device according to claim 9, wherein the gate electrode comprises at least one selected from the group consisting of tantalum, chromium, tungsten, and silicon having conductivity. 11. A method of manufacturing a semiconductor device according to claim 9, wherein a taper angle of the gate electrode is between 3 and 40째. 12. A method of manufacturing a semiconductor device according to claim 9, wherein the etching gas is a mixture gas containing fluorine and chlorine. 13. A method of manufacturing a semiconductor device according to claim 12, wherein the gas containing fluorine is one selected from the group consisting of CF4, C2F6 and C4F8. 14. A method of manufacturing a semiconductor device according to claim 12, wherein the gas containing chlorine is one selected from the group consisting of Cl2, SiCl4, and BCl3. 15. A method of manufacturing a semiconductor device according to claim 9, wherein the semiconductor device is at least one of a liquid crystal display device and an EL display device. 16. A method of manufacturing a semiconductor device according to claim 9, wherein the semiconductor device is at least one selected from the group consisting of a personal computer, a video camera, a goggle type display, an image reproduction device, and a projector. 17. A method of manufacturing a semiconductor device comprising: forming a crystalline semiconductor layer over an insulating substrate; forming a gate insulating film on the crystalline semiconductor layer; forming a conductive film on the gate insulating film; and etching the conductive film so as to form a gate electrode having a tapered cross section by using an inductively coupled plasma chamber after determining a bias power density. 18. A method of manufacturing a semiconductor device according to claim 17, wherein the gate electrode comprises at least one selected from the group consisting of tantalum, chromium, tungsten, and silicon having conductivity. 19. A method of manufacturing a semiconductor device according to claim 17, wherein a taper angle of the gate electrode is between 3 and 40째. 20. A method of manufacturing a semiconductor device according to claim 17, wherein the step of etching the conductive film is conducted in a mixture gas containing fluorine and chlorine. 21. A method of manufacturing a semiconductor device according to claim 20, wherein the gas containing fluorine is one selected from the group consisting of CF4, C2F6 and C4F8. 22. A method of manufacturing a semiconductor device according to claim 20, wherein the gas containing chlorine is one selected from the group consisting of Cl2, SiCl4, and BCl3. 23. A method of manufacturing a semiconductor device according to claim 17, wherein the semiconductor device is at least one of a liquid crystal display device and an EL display device. 24. A method of manufacturing a semiconductor device according to claim 17, wherein the semiconductor device is at least one selected from the group consisting of a personal computer, a video camera, a goggle type display, an image reproduction device, and a projector. 25. A method of manufacturing a semiconductor device comprising: forming a crystalline semiconductor layer over an insulating substrate; forming a gate insulating film on the crystalline semiconductor layer; forming a conductive film on the gate insulating film; and etching the conductive film so as to form a gate electrode having a tapered cross section by using an inductively coupled plasma chamber having multispiral coils after determining a flow rate ratio of an etching gas. 26. A method of manufacturing a semiconductor device according to claim 25, wherein the gate electrode comprises at least one selected from the group consisting of tantalum, chromium, tungsten, and silicon having conductivity. 27. A method of manufacturing a semiconductor device according to claim 25, wherein a taper angle of the gate electrode is between 3 and 40째. 28. A method of manufacturing a semiconductor device according to claim 25, wherein the etching gas is a mixture gas containing fluorine and chlorine. 29. A method of manufacturing a semiconductor device according to claim 28, wherein the gas containing fluorine is one selected from the group consisting of CF4, C2F6 and C4F8. 30. A method of manufacturing a semiconductor device according to claim 28, wherein the gas containing chlorine is one selected from the group consisting of Cl2, SiCl4, and BCl3. 31. A method of manufacturing a semiconductor device according to claim 25, wherein the semiconductor device is at least one of a liquid crystal display device and an EL display device. 32. A method of manufacturing a semiconductor device according to claim 25, wherein the semiconductor device is at least one selected from the group consisting of a personal computer, a video camera, a goggle type display, an image reproduction device, and a projector. 33. A method of manufacturing a semiconductor device comprising: forming a crystalline semiconductor layer over an insulating substrate; forming a gate insulating film on the crystalline semiconductor layer; forming a conductive film on the gate insulating film; and etching the conductive film so as to form a gate electrode having a tapered cross section by using an inductively coupled plasma chamber having multispiral coils after determining a bias power density. 34. A method of manufacturing a semiconductor device according to claim 33, wherein the gate electrode comprises at least one selected from the group consisting of tantalum, chromium, tungsten, and silicon having conductivity. 35. A method of manufacturing a semiconductor device according to claim 33, wherein a taper angle of the gate electrode is between 3 and 40째. 36. A method of manufacturing a semiconductor device according to claim 33, wherein the step of etching the conductive film is conducted in a mixture gas containing fluorine and chlorine. 37. A method of manufacturing a semiconductor device according to claim 36, wherein the gas containing fluorine is one selected from the group consisting of CF4, C2F6 and C4F8. 38. A method of manufacturing a semiconductor device according to claim 36, wherein the gas containing chlorine is one selected from the group consisting of Cl2, SiCl4, and BCl3. 39. A method of manufacturing a semiconductor device according to claim 33, wherein the semiconductor device is at least one of a liquid crystal display device and an EL display device. 40. A method of manufacturing a semiconductor device according to claim 33, wherein the semiconductor device is at least one selected from the group consisting of a personal computer, a video camera, a goggle type display, an image reproduction device, and a projector. 41. A method of manufacturing a semiconductor device according to claim 1, wherein the gate electrode has a top surface, a side surface, and a bottom surface which is in contact with the gate insulating film, and wherein the bottom surface is larger than the top surface. 42. A method of manufacturing a semiconductor device according to claim 9, wherein the gate electrode has a top surface, a side surface, and a bottom surface which is in contact with the gate insulating film, and wherein the bottom surface is larger than the top surface. 43. A method of manufacturing a semiconductor device according to claim 17, wherein the gate electrode has a top surface, a side surface, and a bottom surface which is in contact with the gate insulating film, and wherein the bottom surface is larger than the top surface. 44. A method of manufacturing a semiconductor device according to claim 25, wherein the gate electrode has a top surface, a side surface, and a bottom surface which is in contact with the gate insulating film, and wherein the bottom surface is larger than the top surface. 45. A method of manufacturing a semiconductor device according to claim 33, wherein the gate electrode has a top surface, a side surface, and a bottom surface which is in contact with the gate insulating film, and wherein the bottom surface is larger than the top surface. 46. A method of manufacturing a semiconductor device comprising: forming a crystalline semiconductor layer over an insulating substrate; forming a gate insulating film on the crystalline semiconductor layer; forming a conductive film on the gate insulating film; and etching the conductive film so as to form a gate electrode having a tapered cross section by using an inductively coupled plasma chamber. 47. A method of manufacturing a semiconductor device according to claim 46, wherein the gate electrode has a top surface, a side surface, and a bottom surface which is in contact with the gate insulating film, and wherein the bottom surface is larger than the top surface. 48. A method of manufacturing a semiconductor device according to claim 46, wherein the gate electrode comprises at least one selected from the group consisting of tantalum, chromium, tungsten, and silicon having conductivity. 49. A method of manufacturing a semiconductor device according to claim 46, wherein a taper angle of the gate electrode is between 3 and 40째. 50. A method of manufacturing a semiconductor device according to claim 46, wherein the step of etching the conductive film is conducted in a mixture gas containing fluorine and chlorine. 51. A method of manufacturing a semiconductor device according to claim 50, wherein the gas containing fluorine is one selected from the group consisting of CF4, C2F6 and C4F8. 52. A method of manufacturing a semiconductor device according to claim 50, wherein the gas containing chlorine is one selected from the group consisting of Cl2, SiCl4, and BCl3. 53. A method of manufacturing a semiconductor device according to claim 46, wherein the semiconductor device is at least one of a liquid crystal display device and an EL display device. 54. A method of manufacturing a semiconductor device according to claim 46, wherein the semiconductor device is at least one selected from the group consisting of a personal computer, a video camera, a goggle type display, an image reproduction device, and a projector.