Light emitting diode having vertical topology and method of making the same

• US 20080023691A1
• Filed: 09/11/2007
• Published: 01/31/2008
• Est. Priority Date: 06/23/2006
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG ELECTRONICS INC. AND LG INNOTEK CO., LTD
• Inventors: Cho, Hyun, Kim, Sun, Choi, Jae, Park, Jong, Lee, Jeong, Jang, Jun, Bae, Duk
• Granted Patent: US 7,768,025 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• 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 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

An LED having vertical topology and a method of making the same is capable of improving a luminous efficiency and reliability, and is also capable of achieving mass productivity. The method includes forming a semiconductor layer on a substrate; forming a first electrode on the semiconductor layer; forming a supporting layer on the first electrode; generating an acoustic stress wave at the interface between the substrate and semiconductor layer, thereby separating the substrate from the semiconductor layer; and forming a second electrode on the semiconductor layer exposed by the separation of the substrate.

Claims

1-33. -33. (canceled)

34. A light emitting device, comprising;

a supporting layer;

a first electrode on the supporting layer;

a plurality of semiconductor layers;

a passivation layer disposed on at least a portion of the first electrode and on at least one surface of the semiconductor layers,

wherein the area of the first electrode is different from the area of the semiconductor layers.

35. The device according to claim 34, further including a connection metal layer between the supporting layer and the first electrode.

36. The device according to claim 35, wherein the connection metal layer is reflective layer.

37. The device according to claim 35, wherein the connection metal layer has a multi-layer structure.

38. The device according to claim 35, wherein the connection metal layer is a bonding layer for attaching the supporting layer.

39. The device according to claim 34, wherein the supporting layer is a semiconductor wafer.

40. The device according to claim 34, further including a light-extraction structure formed on at least a portion of the semiconductor layers.

41. The device according to claim 34, wherein the plurality of semiconductor layers include:

a p-type semiconductor layer;

an active layer disposed on the p-type semiconductor layer; and

a n-type semiconductor layer disposed on the active layer.

42. The device according to claim 41, further comprising:

a current diffusion layer including an InGaN layer or an InGaN/GaN superlattice layer, between on the p-type semiconductor layer and the first electrode.

43. The device according to claim 34, wherein the passivation layer includes at least one of SiO₂, SiN, epoxy-based photoresist, acrylic-based photoresist, SOG, and polyimide.

44. The device according to claim 34, wherein the thickness of the supporting layer has a value ranging from 50 to 150 μ

m.

45. The device according to claim 34, wherein the first electrode has a multi-layer structure.

46. The device according to claim 34, wherein the passivation layer includes at least two layers, the passivation layer includes:

a first passivation layer; and

a second passivation layer on the first passivation layer.

47. The device according to claim 46, wherein the first passivation layer is an inorganic layer and the second passivation layer is organic layer.

48. The device according to claim 34, wherein the first electrode includes;

a reflective electrode electrically connected to the connection metal layer; and

a transparent conductive oxide layer (transparent electrode) on the reflective electrode.

49. The device according to claim 34, wherein the thickness of the first electrode is 100 Å

to 5000 Å

.

50. The device according to claim 34, wherein the thickness of the first electrode is more than 5000 Å

.

51. The device according to claim 34, wherein the passivation layer is formed to be outer periphery of a light emitting surface of the device.

52. The device according to claim 34, wherein the supporting layer includes a metallic layer.

53. A light emitting device, comprising:

a supporting layer;

a connection metal layer on the supporting layer;

a first electrode on at least one portion of the connection metal layer;

a plurality of semiconductor;

a second electrode on the plurality of semiconductor layers; and

a passivation layer between the connection metal layer and the plurality of semiconductor layers.

54. The device according to claim 53, wherein the supporting layer has an edge portion such that a recess is formed.

55. The device according to claim 53, further including a metal layer between the passivation layer and the connection metal layer.

56. A light emitting device, comprising:

a supporting layer made of at least one of Si, Ge, and metal;

a connection metal layer on the supporting layer;

a first electrode on at least one portion of the connection metal layer;

a plurality of semiconductor layers;

a second electrode on the plurality of semiconductor layers; and

a passivation layer between the connection metal layer and the plurality of semiconductor layers.

57. The device according to claim 56, wherein the passivation layer includes:

a first passivation layer; and

a second passivation layer on the first passivation layer.

58. A light emitting device, comprising:

a supporting layer having a thickness of 50 to 150 μ

m;

a connection metal layer on the supporting layer;

a first electrode on at least one portion of the connection metal layer;

a plurality of semiconductor layers;

a second electrode on the plurality of semiconductor layers; and

a light-extraction structure formed on at least a portion of the semiconductor layers.