Light emitting device and manufacturing method thereof

• US 20030227021A1
• Filed: 06/04/2003
• Published: 12/11/2003
• Est. Priority Date: 06/07/2002
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Higaki, Yoshinari, Noda, Takeshi, Yamazaki, Shunpei
• Granted Patent: US 7,897,979 B2
• Time in Patent Office: Days
• US Class Current: 257/83
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/813 characterised by their shape
• CPC Class Codes: H10K 50/818 Reflective anodes, e.g. ITO combined with thick metallic layers
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass

Abstract

A light emission device manufactured by a method of forming a curved surface having a radius of curvature to the upper end of an insulator 19, exposing a portion of the first electrode 18c to form an inclined surface in accordance with the curved surface, and applying etching so as to expose the first electrode 18b in a region to form a light emission region, in which emitted light from the layer containing the organic compound 20 is reflected on the inclined surface of the first electrode 18c to increase the total take-out amount of light in the direction of an arrow shown in FIG. 1A and, further, forming a light absorbing multi-layered film 24 comprising light absorbing multi-layered film on the first electrode 18c other than the region to form the light emission region, thereby obtaining a light emission device of a structure increasing the amount of light emission taken out in one direction in a light emission element, while not all the light formed in the layer containing the organic compound are taken out from the cathode as a transparent electrode toward TFT but the light was emitted also, for example, in the lateral direction (direction parallel with the plane of the substrate).

Claims

1. A light emitting device comprising,

a first electrode connected with a thin film transistor over a substrate having an insulative surface;

a light absorbing multi-layered film over a portion of the first electrode;

an insulator covering an end portion of the first electrode;

a layer containing an organic compound in contact with the first electrode; and

a second electrode in contact with the layer containing the organic compound,

wherein the first electrode has an inclined surface, the inclined surface reflects light emitted from the layer containing the organic compound.

2. A light emitting device according to claim 1,

wherein an inclination angle of the inclined surface is larger than 50°

and smaller than 60°

.

3. A light emitting device according to claim 1,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, HfO₂, Sc₂O₃, TiO₂, ITO and ZnO.

4. A light emitting device according to claim 1,

wherein the light absorbing multi-layered film contains at least one layer of nitride insulation film.

5. A light emitting device according to claim 1,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al, Cu, Au, Mo, Ni, Pt, Rh, Ag, W, Cr, Co, Si, Zr, Ta, Inconel and Nichrome.

6. A light emitting device according to claim 1,

wherein the light absorbing multi-layered film is a laminate comprising a light transmitting nitride insulation film, a metal nitrided film and a light transmitting nitride insulation film.

7. A light emitting device according to claim 1,

wherein the light absorbing multi-layered film comprises a laminate of a silicon nitride film, a titanium nitride film and a silicon nitride film.

8. A light emitting device according to claim 1,

wherein the second electrode is a light transmitting conductive film.

9. A light emitting device according to claim 1,

wherein the inclined surface is formed in a self-alignment manner using the insulator as a mask.

10. A light emitting device according to claim 1,

wherein the first electrode is an anode and the second electrode is a cathode.

11. A light emitting device according to claim 1,

wherein the light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, a personal computer, a DVD player, an electronic game device and a portable information terminal.

12. A light emitting device comprising,

a first electrode connected with a thin film transistor over a substrate having an insulative surface;

a light absorbing multi-layered film over a portion of the first electrode;

an insulator covering an end portion of the first electrode;

a layer containing an organic compound in contact with the first electrode; and

a second electrode in contact with the layer containing the organic compound,

wherein the first electrode has a concaved shape.

13. A light emitting device according to claim 12,

wherein the first electrode has a inclined surface with an angle of inclination larger than 50°

and smaller than 60°

.

14. A light emitting device according to claim 12,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, HfO₂, Sc₂O₃, TiO₂, ITO and ZnO.

15. A light emitting device according to claim 12,

wherein the light absorbing multi-layered film contains at least one layer of nitride insulation film.

16. A light emitting device according to claim 12,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al, Cu, Au, Mo, Ni, Pt, Rh, Ag, W, Cr, Co, Si, Zr, Ta, Inconel and Nichrome.

17. A light emitting device according to claim 12,

wherein the light absorbing multi-layered film is a laminate comprising a light transmitting nitride insulation film, a metal nitrided film and a light transmitting nitride insulation film.

18. A light emitting device according to claim 12,

wherein the light absorbing multi-layered film comprises a laminate of a silicon nitride film, a titanium nitride film and a silicon nitride film.

19. A light emitting device according to claim 12,

wherein the second electrode is a light transmitting conductive film.

20. A light emitting device according to claim 12,

wherein the concaved shape is formed in a self-alignment manner using the insulator as a mask.

21. A light emitting device according to claim 12,

wherein the first electrode is an anode and the second electrode is a cathode.

22. A light emitting device according to claim 12,

wherein the light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, a personal computer, a DVD player, an electronic game device and a portable information terminal.

23. A light emitting device comprising,

a first electrode connected with a thin film transistor over a substrate having an insulative surface;

a light absorbing multi-layered film over a portion of the first electrode;

an insulator covering an end portion of the first electrode;

a layer containing an organic compound in contact with the first electrode; and

a second electrode in contact with the layer containing the organic compound,

wherein the first electrode is in a multi-layered structure, a number of laminate at end region of the first electrode is more than a number of laminate at central region of the first electrode.

24. A light emitting device according to claim 23,

wherein the first electrode has a inclined surface with an angle of inclination larger than 50°

and smaller than 60°

.

25. A light emitting device according to claim 23,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, HfO₂, Sc₂O₃, TiO₂, ITO and ZnO.

26. A light emitting device according to claim 23,

wherein the light absorbing multi-layered film contains at least one layer of nitride insulation film.

27. A light emitting device according to claim 23,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al, Cu, Au, Mo, Ni, Pt, Rh, Ag, W, Cr, Co, Si, Zr, Ta, Inconel and Nichrome.

28. A light emitting device according to claim 23,

wherein the light absorbing multi-layered film is a laminate comprising a light transmitting nitride insulation film, a metal nitrided film and a light transmitting nitride insulation film.

29. A light emitting device according to claim 23,

wherein the light absorbing multi-layered film comprises a laminate of a silicon nitride film, a titanium nitride film and a silicon nitride film.

30. A light emitting device according to claim 23,

wherein the second electrode is a light transmitting conductive film.

31. A light emitting device according to claim 23,

wherein a portion of the first electrode is etched in a self-alignment manner using the insulator as a mask.

32. A light emitting device according to claim 23,

wherein the first electrode is an anode and the second electrode is a cathode.

33. A light emitting device according to claim 23,

wherein the light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, a personal computer, a DVD player, an electronic game device and a portable information terminal.

34. A light emitting device comprising,

a first electrode connected with a thin film transistor over a substrate having an insulative surface;

a light absorbing multi-layered film over a portion of the first electrode;

an insulator covering an end portion of the first electrode;

a layer containing an organic compound in contact with the first electrode; and

a second electrode in contact with the layer containing the organic compound,

wherein wirings or electrodes are formed on the same layer as the first electrode.

35. A light emitting device according to claim 34,

wherein the first electrode has a inclined surface with an angle of inclination larger than 50°

and smaller than 60°

.

36. A light emitting device according to claim 34,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, HfO₂, Sc₂O₃, TiO₂, ITO and ZnO.

37. A light emitting device according to claim 34,

wherein the light absorbing multi-layered film contains at least one layer of nitride insulation film.

38. A light emitting device according to claim 34,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al, Cu, Au, Mo, Ni, Pt, Rh, Ag, W, Cr, Co, Si, Zr, Ta, Inconel and Nichrome.

39. A light emitting device according to claim 34,

wherein the light absorbing multi-layered film is a laminate comprising a light transmitting nitride insulation film, a metal nitrided film and a light transmitting nitride insulation film.

40. A light emitting device according to claim 34,

wherein the light absorbing multi-layered film comprises a laminate of a silicon nitride film, a titanium nitride film and a silicon nitride film.

41. A light emitting device according to claim 34,

wherein the second electrode is a light transmitting conductive film.

42. A light emitting device according to claim 34,

wherein a portion of the first electrode is etched in a self-alignment manner using the insulator as a mask.

43. A light emitting device according to claim 34,

wherein the first electrode is an anode and the second electrode is a cathode.

44. A light emitting device according to claim 34,

wherein the light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation system, a personal computer, a DVD player, an electronic game device and a portable information terminal.

45. A method of manufacturing a light emitting device comprising the steps of;

forming a laminate comprising a first electrode and a light absorbing multi-layered film continuously without exposure to the atmospheric air;

forming an insulator covering an end portion of the first electrode;

conducting etching using the insulator as a mask to reduce the thickness at the central portion of the first electrode such that the inclined surface is exposed;

forming a layer containing an organic compound; and

forming a second electrode comprising a light transmitting metal thin film on the layer containing the organic compound.

46. A method of manufacturing a light emitting device according to claim 45,

wherein the first electrode has a laminate structure comprising a first metal layer containing titanium, a second metal layer containing one of titanium nitride and tungsten nitride, and a third metal layer containing aluminum.

47. A method of manufacturing a light emitting device according to claim 45,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, HfO₂, Sc₂O₃, TiO₂, ITO and ZnO.

48. A method of manufacturing a light emitting device according to claim 45,

wherein the light absorbing multi-layered film contains at least one layer comprising a light transmitting nitride insulation film.

49. A method of manufacturing a light emitting device according to claim 45,

wherein the light absorbing multi-layered film contains at least one layer comprising one selected from the group consisting of Ti, Al, Cu, Au, Mo, Ni, Pt, Rh, Ag, W, Cr, Co, Si, Zr, Ta, Inconel and Nichrome.