Light emitting device and manufacturing method thereof

• US 7,897,979 B2
• Filed: 06/04/2003
• Issued: 03/01/2011
• Est. Priority Date: 06/07/2002
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Higaki, Yoshinari, Noda, Takeshi, Yamazaki, Shunpei
• Primary Examiner(s): SEFER, AHMED N
• Application Number:
  US10/454,124
• Publication Number:
  US 20030227021A1
• Time in Patent Office: 2,827 Days
• Field of Search: 257 79-103, 257/40, 257/59, 257/72, 257/88, 257/98, 257/99, 313/498, 313/504, 313/506
• 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 electrically connected with a thin film transistor over a substrate having an insulative surface;

a light absorbing multi-layered film formed over a portion of the first electrode wherein the light absorbing multi-layered film comprises a first light transmitting film, a film comprising one selected from the group consisting of Al, Cu, Au, Mo, Ni, Pt, Rh, Ag, W, Cr, Co, Si, Zr, and Ta, and a second light transmitting film;

a bank covering an end portion of the first electrode;

a layer containing an organic compound formed over and in contact with a side surface of the first electrode; and

a second electrode formed over the bank and the layer containing the organic compound,

wherein the first electrode is a multi-layered structure, wherein a number of laminated layers of the first electrode at an end region of the first electrode is more than a number of laminated layers of the first electrode at a central region,

wherein at least one of the first light transmitting film and the second light transmitting film is a nitride insulating film, and

wherein the second electrode is formed over the light absorbing multi-layered film with the bank interposed therebetween.

2. A light emitting device according to claim 1,

wherein the first electrode has an inclined surface with an angle of inclination 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, ZrO₂, HfO₂, Sc₂O₃, TiO₂, ITO and ZnO.

4. A light emitting device according to claim 1,

wherein the second electrode is a light transmitting conductive film.

5. A light emitting device according to claim 1,

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

6. A light emitting device according to claim 1,

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

7. 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.

8. The light emitting device according to claim 1, wherein the organic compound emits light.

9. The light emitting device according to claim 1, wherein the layer containing the organic compound comprises a light emission layer.

10. A light emitting device comprising:

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

a light absorbing multi-layered film formed over a portion of the first electrode wherein the light absorbing multi-layered film comprises a first light transmitting film, a film comprising one selected from the group consisting of Al, Cu, Au, Mo, Ni, Pt, Rh, Ag, W, Cr, Co, Si, Zr, and Ta, and a second light transmitting film over the portion of the first electrode;

a bank covering and in contact with an end portion of the first electrode;

a layer containing an organic compound formed over the first electrode; and

a second electrode formed over the layer containing the organic compound,

wherein at least one of the first light transmitting film and the second light transmitting film comprises metal oxide, and

wherein the second electrode is formed over the light absorbing multi-layered film with the bank interposed therebetween.

11. A light emitting device according to claim 10,

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

and smaller than 60°

.

12. A light emitting device according to claim 10,

wherein the metal oxide is at least one selected from the group consisting of Al₂O₃, ZrO₂, HfO₂, Sc₂O₃, TiO₂, ITO and ZnO.

13. A light emitting device according to claim 10,

wherein the second electrode is a light transmitting conductive film.

14. A light emitting device according to claim 10,

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

15. A light emitting device according to claim 10,

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

16. A light emitting device according to claim 10,

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.

17. The light emitting device according to claim 10, wherein the organic compound emits light.

18. The light emitting device according to claim 10, wherein the layer containing the organic compound comprises a light emission layer.

19. A light emitting device comprising:

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

a light absorbing multi-layered film formed over a portion of the first electrode wherein the light absorbing multi-layered film comprises at least three layers over the portion of the first electrode;

a bank covering and in contact with an end portion of the first electrode;

a layer containing an organic compound formed over the first electrode; and

a second electrode formed over the layer containing the organic compound,

wherein the first electrode is a multi-layered structure,

wherein a number of laminated layers of the first electrode at an end region of the first electrode is more than a number of laminated layers of the first electrode at a central region,

wherein at least one of the three layers is a light transmitting nitride insulating film,

wherein at least one of the three layers comprises a metal nitride film, and

wherein the second electrode is formed over the light absorbing multi-layered film with the bank interposed therebetween.

20. A light emitting device according to claim 19,

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

and smaller than 60°

.

21. A light emitting device according to claim 19,

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

22. A light emitting device according to claim 19,

wherein the three layers are a light transmitting nitride insulation film, the metal nitride film and a light transmitting nitride insulation film.

23. A light emitting device according to claim 19,

wherein the three layers are a silicon nitride film, a titanium nitride film and a silicon nitride film.

24. A light emitting device according to claim 19,

wherein the second electrode is a light transmitting conductive film.

25. A light emitting device according to claim 19,

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

26. A light emitting device according to claim 19,

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

27. A light emitting device according to claim 19,

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.

28. The light emitting device according to claim 19, wherein the organic compound emits light.

29. The light emitting device according to claim 19, wherein the layer containing the organic compound comprises a light emission layer.

30. A light emitting device comprising:

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

a light absorbing multi-layered film formed over a portion of the first electrode and comprising a silicon nitride film, a brown or black metal film, and a silicon nitride film;

a bank formed over the light absorbing multi-layered film covering and in contact with an end portion of the first electrode and an end portion of the light absorbing multi-layered film;

a layer containing an organic compound formed over the first electrode; and

a second electrode formed over the layer containing the organic compound,

wherein a reflectance of the light absorbing multi-layered film is 5% or less, and

wherein the second electrode is formed over the light absorbing multi-layered film with the bank interposed therebetween.

31. A light emitting device according to claim 30,

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

and smaller than 60°

.

32. A light emitting device according to claim 30,

wherein the second electrode is a light transmitting conductive film.

33. A light emitting device according to claim 30,

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

34. A light emitting device according to claim 30,

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

35. A light emitting device according to claim 30,

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.

36. The light emitting device according to claim 30, wherein the organic compound emits light.

37. The light emitting device according to claim 30, wherein the layer containing the organic compound comprises a light emission layer.

38. A light emitting device comprising:

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

a light absorbing multi-layered film formed over a portion of the first electrode and comprising aluminum, wherein the light absorbing multi-layered film comprises a first light transmitting film, an aluminum film, and a second light transmitting film;

a bank formed over the light absorbing film covering and in contact with an end portion of the first electrode and an end portion of the light absorbing film;

a layer containing an organic compound formed over the first electrode; and

a second electrode formed over the layer containing the organic compound,

wherein the first electrode is a multi-layered structure,

wherein a number of laminated layers of the first electrode at an end region of the first electrode is more than a number of laminated layers of the first electrode at a central region,

wherein at least one of the first light transmitting film and the second light transmitting film is a nitride insulating film, and

wherein the second electrode is formed over the light absorbing film with the bank interposed therebetween.

39. A light emitting device according to claim 38,

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

and smaller than 60°

.

40. The light emitting device according to claim 38, wherein the organic compound emits light.

41. The light emitting device according to claim 38, the first electrode is directly connected with the thin film transistor.

42. The light emitting device according to claim 38, wherein the layer containing the organic compound comprises a light emission layer.