Method of fabricating vertical structure LEDs

• US 20090278161A1
• Filed: 07/21/2009
• Published: 11/12/2009
• Est. Priority Date: 04/09/2002
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yoo, Myung Cheol, Jeong, In-Kwon, Lee, Jong-Lam
• Granted Patent: US 7,816,705 B2
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: H01C 7/006 Thin film resistors
• CPC Class Codes: H01C 7/008 Thermistors H01C7/02 - H01C7/06 take precedence
• CPC Class Codes: H01L 27/0802 Resistors only
• CPC Class Codes: H01L 28/20 Resistors
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/36 characterised by the electrodes
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: Y10S 438/958 Passivation layer
• CPC Class Codes: Y10S 438/977 Thinning or removal of substrate

Abstract

A method of fabricating semiconductor devices, such as GaN LEDs, on insulating substrates, such as sapphire. Semiconductor layers are produced on the insulating substrate using normal semiconductor processing techniques. Trenches that define the boundaries of the individual devices are then formed through the semiconductor layers and into the insulating substrate, beneficially by using inductive coupled plasma reactive ion etching. The trenches are then filled with an easily removed layer. A metal support structure is then formed on the semiconductor layers (such as by plating or by deposition) and the insulating substrate is removed. Electrical contacts, a passivation layer, and metallic pads are then added to the individual devices, and the individual devices are then diced out.

Claims

1-42. -42. (canceled)

43. A vertical light-emitting device, comprising:

a conductive support structure;

a first electrode over the conductive support structure;

a semiconductor structure over the first electrode, the semiconductor structure including a first-type semiconductor layer over the first electrode, an active layer over the first-type semiconductor layer and a second-type semiconductor layer over the active layer;

a passivation layer contacting at least the first-type semiconductor layer of the semiconductor structure, wherein the portion of the passivation layer that contacts the first-type semiconductor layer is located above at least a portion of the upper surface of the conductive support structure; and

a second electrode over the semiconductor structure, wherein the first electrode and the second electrode are respectively located at opposite sides of the semiconductor structure.

44. The vertical light-emitting device according to claim 43, further comprising a metallic pad over the second electrode.

45. The vertical light-emitting device according to claim 43, wherein the passivation layer is positioned such that the passivation layer is located on a part of the second electrode.

46. The vertical light-emitting device according to claim 43, wherein the passivation layer comprises material including at least one of Si, O, and N.

47. The vertical light-emitting device according to claim 43, wherein the conductive support structure comprises a metal layer.

48. The vertical light-emitting device according to claim 47, wherein the metal layer is a metal support layer.

49. The vertical light-emitting device according to claim 47, wherein the metal layer is a metal coating in contact with the first electrode.

50. The vertical light-emitting device according to claim 47, wherein the metal layer comprises a metal selected from a group including Cu, Cr, Ni, Au, Ag, Mo, Pt, Pd, W, Ti, and Al.

51. The vertical light-emitting device according to claim 43, wherein the passivation layer is disposed higher than the second electrode.

52. The vertical light-emitting device according to claim 43, further comprising a metal coating disposed between the conductive support structure and the first electrode.

53. The vertical light-emitting device according to claim 43, wherein the first-type semiconductor layer is a p-type layer and the second-type semiconductor layer is an n-type layer.

54. The vertical light-emitting device according to claim 43, wherein the passivation layer located adjacent to the second-type semiconductor layer extends to at least an upper surface of the conductive support structure.

55. The vertical light-emitting device according to claim 43, wherein the conductive support structure comprises at least one metal structure.

56. The vertical light-emitting device according to claim 43, wherein the second electrode contacts a light emitting surface of the semiconductor structure.

57. The vertical light-emitting device according to claim 56, wherein the passivation layer contacts at least a part of the light emitting surface of the semiconductor structure.

58. The vertical light-emitting device according to claim 57, wherein the first electrode contacts the semiconductor structure, and wherein the contact area between the first electrode and the semiconductor structure is greater than the contact area between the passivation layer and the light emitting surface of the semiconductor structure.

59. The vertical light-emitting device according to claim 57, wherein the passivation layer extends along the light emitting surface of the semiconductor structure in the direction of the second electrode.

60. The vertical light-emitting device according to claim 59, wherein the passivation layer extends along the light emitting surface of the semiconductor structure and is in contact with the second electrode.

61. A vertical light-emitting device, comprising:

a conductive support structure;

a first-type semiconductor layer over the conductive support structure;

a first electrode disposed between the conductive support structure and the first-type semiconductor layer such that first-type semiconductor layer is over the first electrode;

a second-type semiconductor layer over the first-type semiconductor layer;

a light emitting layer disposed between the first-type semiconductor layer and the second-type semiconductor layer;

a passivation layer contacting the first-type semiconductor layer, the light emitting layer, the second-type semiconductor layer and the first electrode, wherein the portion of the passivation layer contacting the first-type semiconductor layer is located above at least a portion of the conductive support structure; and

a second electrode over the second-type semiconductor layer.

62. The vertical light-emitting device according to claim 61, wherein the first-type semiconductor layer is a p-GaN based layer and the second-type semiconductor layer is an n-GaN based layer.

63. The vertical light-emitting device according to claim 61, wherein the first-type semiconductor layer is an n-GaN based layer and the second-type semiconductor layer is a p-GaN based layer.

64. The vertical light-emitting device according to claim 61, wherein the passivation layer surrounds a side portion of the first-type semiconductor layer, the light emitting layer and the second-type semiconductor layer.

65. The vertical light-emitting device according to claim 61, wherein the passivation layer comprises material including at least one of Si, O, and N.

66. The vertical light-emitting device according to claim 61, wherein the conductive support structure comprises metallic material.

67. The vertical light-emitting device according to claim 61, wherein the conductive support structure comprises a metal selected from a group including Cu, Cr, Ni, Au, Ag, Mo, Pt, Pd, W, Ti, and Al.

68. The vertical light-emitting device according to claim 61, wherein the passivation layer located adjacent to the second-type semiconductor layer extends to at least an upper level of the conductive support structure.

69. The vertical light-emitting device according to claim 61, wherein the conductive support structure comprises at least one metal structure.

70. The vertical light-emitting device according to claim 61, further comprising a metal coating disposed between the conductive support structure and the first electrode.

71. The vertical light-emitting device according to claim 61, wherein the conductive support structure comprises a metal layer.

72. The vertical light-emitting device according to claim 71, wherein the metal layer is a metal support layer.

73. The vertical light-emitting device according to claim 71, wherein the metal layer is a metal coating in contact with the first electrode.

74. A vertical light-emitting device, comprising:

a conductive support structure;

a p-type GaN-based layer over the conductive support structure;

a first electrode disposed between the conductive support structure and the p-type GaN-based layer such that p-type GaN-based layer is disposed over the first electrode;

an n-type GaN-based layer over the p-type GaN-based layer;

a light emitting layer disposed between the p-type GaN-based layer and the n-type GaN-based layer;

a passivation layer contacting the p-type GaN-based layer, the light emitting layer, the n-type GaN-based layer and the first electrode;

a second electrode over the n-type GaN-based layer, wherein the contact area between the passivation layer and the n-type GaN-based layer is greater than the contact area between the passivation layer and the p-type GaN-based layer.

75. The vertical light-emitting device according to claim 74, wherein the passivation layer is disposed partially between the conductive support structure and the p-type GaN-based layer.

76. The vertical light-emitting device according to claim 74, the passivation layer is over an upper surface of the n-type GaN-based layer.

77. The vertical light-emitting device according to claim 74, wherein the passivation layer is in contact with at least one surface of the second electrode.

78. The vertical light-emitting device according to claim 74, wherein the first electrode comprises at least two layers including a first layer and a second layer, wherein the first layer and the second layer include different materials.

79. The vertical light-emitting device according to claim 78, wherein one of the first layer and the second layer includes a transparent conductive material.

80. The vertical light-emitting device according to claim 74, further comprising a metal coating disposed between the conductive support structure and the first electrode.

81. The vertical light-emitting device according to claim 74, wherein the conductive support structure comprises a metal support layer.

82. A vertical light-emitting device, comprising:

a conductive support structure;

a first electrode over the conductive support structure;

a semiconductor structure over the first electrode, the semiconductor structure including a first-type semiconductor layer over the first electrode, an active layer over the first-type semiconductor layer and a second-type semiconductor layer over the active layer;

a passivation layer contacting the semiconductor structure; and

a second electrode over the semiconductor structure, wherein the first electrode and the second electrode are respectively located at opposite sides of the semiconductor structure, and wherein a metal coating is disposed between the conductive support structure and the first electrode.

83. The vertical light-emitting device according to claim 82, wherein the metal coating is in contact with the first electrode.

84. The vertical light-emitting device according to claim 82, wherein the metal coating is in contact with the conductive support structure.

85. The vertical light-emitting device according to claim 82, wherein the metal coating is in contact with the passivation layer.

86. The vertical light-emitting device according to claim 82, wherein the conductive support structure comprises a metal layer.

87. The vertical light-emitting device according to claim 86, wherein the metal layer comprises a metal selected from a group including Cu, Cr, Ni, Au, Ag, Mo, Pt, Pd, W, Ti, and Al.

88. The vertical light-emitting device according to claim 82, wherein the conductive support structure comprises a metal support layer.

89. The vertical light-emitting device according to claim 82, wherein the passivation layer further contacts the first electrode.