High-efficiency radiating device

• US 7,253,445 B2
• Filed: 10/15/2004
• Issued: 08/07/2007
• Est. Priority Date: 07/28/1998
• Status: Expired due to Term

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: IMEC International, Vrije Universiteit Brussel
• Inventors: Heremans, Paul, Kuijk, Maarten, Windisch, Reiner, Borghs, Gustaaf
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US10/966,560
• Publication Number:
  US 20050110033A1
• Time in Patent Office: 1,026 Days
• Field of Search: 257/98, 257/95, 257/E33.068, 257/E33.072, 257/E33.074
• US Class Current: 257/95
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

A device emits radiation at a predetermined wavelength. The device includes a light-emitting structure which generates the radiation. The device further includes at least one reflective edge in radiative communication with the light-emitting structure, the reflective edge having a dielectric portion. The device further includes at least one electrical contact extending through the dielectric portion of the reflective edge, the contact in electrical communication with the light-emitting structure.

Claims

1. A device for emitting radiation at a predetermined wavelength, the device comprising:

a light-emitting structure which generates the radiation;

at least one reflective edge in radiative communication with the light-emitting structure, the reflective edge having a dielectric portion; and

at least one electrical contact extending through the dielectric portion of the reflective edge, the contact in electrical communication with the light-emitting structure.

2. The device of claim 1, wherein the reflective edge is not electrically conductive.

3. The device of claim 1, wherein the reflective edge is a dielectric-coated metal mirror.

4. The device of claim 3, wherein the contact comprises part of the metal mirror.

5. The device of claim 3, wherein the contact extending through the dielectric portion of the reflective edge is formed through holes in the dielectric portion of the dielectric-coated metal mirror.

6. The device of claim 1, further comprising a carrier substrate.

7. The device of claim 6, wherein the carrier substrate is transparent to the radiation.

8. The device of claim 7, wherein the light-emitting structure is mounted on the transparent carrier substrate.

9. The device of claim 6, wherein the carrier substrate comprises a fiber-optic face plate.

10. The device of claim 6, wherein the carrier substrate is heat conductive.

11. The device of claim 10, wherein the carrier substrate is actively cooled.

12. The device of claim 6, wherein the carrier substrate is electrically conductive and serves as an electrode contact to the light-emitting structure.

13. The device of claim 6, wherein the carrier substrate is electrically conductive and serves as a lead to provide current to the light-emitting structure.

14. The device of claim 6, wherein the carrier substrate is attached to the reflective edge by solder.

15. The device of claim 6, wherein the carrier substrate is wafer-bonded to the reflective edge.

16. The device of claim 1, further comprising at least one edge having a substantially random diffraction grating structure in radiative communication with the light-emitting structure.

17. The device of claim 16, wherein the edge having the substantially random diffraction grating structure abuts or extends in the light-emitting structure.

18. The device of claim 16, wherein the edge having the substantially random diffraction grating structure is a mirror surface.

19. The device of claim 16, wherein the edge having the substantially random diffraction grating structure is reflective.

20. The device of claim 16, wherein the substantially random diffraction grating structure is produced by a method comprising lithography.

21. The device of claim 16, wherein the substantially random diffraction grating structure is produced by a method comprising etching.

22. The device of claim 21, wherein the substantially random diffraction grating structure is produced by a method comprising wet etching.

23. The device of claim 21, wherein the substantially random diffraction grating structure is produced by a method comprising dry etching.

24. The device of claim 23, wherein the substantially random diffraction grating structure is produced by a method comprising chemically-assisted ion-beam etching.

25. The device of claim 24, wherein the substantially random diffraction grating structure is produced by a method comprising chlorine-assisted argon etching.

26. The device of claim 16, wherein the substantially random diffraction grating structure is a regular repetition of a random grating.

27. The device of claim 16, wherein the substantially random diffraction grating structure is a pseudo-random grating.

28. The device of claim 16, wherein the substantially random diffraction grating structure has a plurality of differently spaced ridges and valleys.

29. The device of claim 1, further comprising a waveguide which is in radiative communication with the light-emitting structure.

30. The device of claim 29, further comprising at least one edge having a substantially random diffraction grating structure, wherein the edge having the substantially random diffraction grating structure is coextensive with at least one edge of the waveguide.

31. The device of claim 1, wherein the contact provides charge carriers to the light-emitting structure.

32. The device of claim 1, wherein the light-emitting structure comprises a p-type layer, an n-type layer, and an active layer between the p-type layer and the n-type layer.

33. A device for emitting radiation at a predetermined wavelength, the device comprising:

a light-emitting structure which generates the radiation;

at least one mirror in radiative communication with the light-emitting structure, the mirror comprising an electrically conductive portion and an electrically insulating portion, the conductive portion extending through the insulating portion and in electrical communication with the light-emitting structure, thereby providing electrical contact to the light-emitting structure; and

at least one edge having a substantially random diffraction grating structure in radiative communication with the light-emitting structure.

34. The device of claim 33, further comprising a waveguide which is in radiative communication with the light-emitting structure.

35. The device of claim 34, wherein the edge having the substantially random diffraction grating structure is coextensive with at least one edge of the waveguide.

36. The device of claim 33, wherein the edge having the substantially random diffraction grating structure abuts or extends in the light-emitting structure.

37. The device of claim 33, wherein the substantially random diffraction grating structure is produced by a method comprising lithography.

38. The device of claim 33, wherein the substantially random diffraction grating structure is produced by a method comprising etching.

39. The device of claim 38, wherein the substantially random diffraction grating structure is produced by a method comprising wet etching.

40. The device of claim 38, wherein the substantially random diffraction grating structure is produced by a method comprising dry etching.

41. The device of claim 40, wherein the substantially random diffraction grating structure is produced by a method comprising chemically-assisted ion-beam etching.

42. The device of claim 41, wherein the substantially random diffraction grating structure is produced by a method comprising chlorine-assisted argon etching.

43. The device of claim 33, wherein the substantially random diffraction grating structure is a regular repetition of a random grating.

44. The device of claim 33, wherein the substantially random diffraction grating structure is a pseudo-random grating.

45. The device of claim 33, wherein the substantially random diffraction grating structure has a plurality of differently spaced ridges and valleys.

46. The device of claim 33, further comprising a carrier substrate.

47. The device of claim 46, wherein the carrier substrate is wafer-bonded to the mirror.

48. The device of claim 46, wherein the carrier substrate is transparent to the radiation.

49. The device of claim 48, wherein the light-emitting structure is mounted on the transparent carrier substrate.

50. The device of claim 33, wherein the electrically conductive portion provides charge carriers to the light-emitting structure.

51. The device of claim 33, wherein the light-emitting structure comprises a p-type layer, an n-type layer, and an active layer between the p-type layer and the n-type layer.

52. A device for emitting radiation at a predetermined wavelength, the device comprising:

a light-emitting structure which generates the radiation;

at least one metal mirror in radiative communication with the light-emitting structure, the metal mirror providing electrical contact to the light-emitting structure; and

at least one edge having a substantially random diffraction grating structure in radiative communication with the light-emitting structure, wherein the edge having the substantially random diffraction grating structure is a mirror surface.

53. A device for emitting radiation at a predetermined wavelength, the device comprising:

a light-emitting structure which generates the radiation;

at least one metal mirror in radiative communication with the light-emitting structure, the metal mirror providing electrical contact to the light-emitting structure; and

at least one edge having a substantially random diffraction grating structure in radiative communication with the light-emitting structure, wherein the edge having the substantially random diffraction grating structure is reflective.

54. A device for emitting radiation at a predetermined wavelength, the device comprising:

a light-emitting structure which generates the radiation;

at least one metal mirror in radiative communication with the light-emitting structure, the metal mirror providing electrical contact to the light-emitting structure;

a carrier substrate positioned at the metal mirror; and

at least one edge having a substantially random diffraction grating structure in radiative communication with the light-emitting structure, wherein the carrier substrate is heat conductive.

55. The device of claim 54, wherein the carrier substrate is actively cooled.

56. A device for emitting radiation at a predetermined wavelength, the device comprising:

a light-emitting structure which generates the radiation;

at least one metal mirror in radiative communication with the light-emitting structure, the metal mirror providing electrical contact to the light-emitting structure;

a carrier substrate positioned at the metal mirror; and

at least one edge having a substantially random diffraction grating structure in radiative communication with the light-emitting structure, wherein the carrier substrate is electrically conductive and serves as an electrode contact to the light-emitting structure.

57. A device for emitting radiation at a predetermined wavelength, the device comprising:

a light-emitting structure which generates the radiation;

at least one metal mirror in radiative communication with the light-emitting structure, the metal mirror providing electrical contact to the light-emitting structure;

a carrier substrate positioned at the metal mirror; and

at least one edge having a substantially random diffraction grating structure in radiative communication with the light-emitting structure, wherein the carrier substrate is electrically conductive and serves as lead for providing current to the light-emitting structure.

58. A device for emitting radiation at a predetermined wavelength, the device comprising:

a light-emitting structure which generates the radiation;

at least one metal mirror in radiative communication with the light-emitting structure, the metal mirror providing electrical contact to the light-emitting structure;

a carrier substrate positioned at the metal mirror; and

at least one edge having a substantially random diffraction grating structure in radiative communication with the light-emitting structure, wherein the carrier substrate is attached to the metal mirror by solder.