Group III-V element-based LED having ESD protection capacity

• US 6,593,597 B2
• Filed: 03/05/2002
• Issued: 07/15/2003
• Est. Priority Date: 06/05/2001
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: South Epitaxy Corporation
• Inventors: Sheu, Jinn-Kong
• Primary Examiner(s): Wilson, Allan R.
• Application Number:
  US10/091,941
• Publication Number:
  US 20020179914A1
• Time in Patent Office: 497 Days
• Field of Search: 257/86, 257/94, 257/96, 257/449
• US Class Current: 257/94
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/056 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/06102 the bonding areas being at different heights
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/1703 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]

Abstract

A group III-V element-based flip-chip assembled light-emitting diode structure with electrostatic protection capacity. A first conductive buffer layer and a second conductive buffer layer are formed over a transparent substrate. An active layer structure, a contact layer, an electrode is formed over the first conductive buffer layer. The active layer structure, the contact layer and the electrode together form a light-emitting diode structure. A metallic electrode is formed over the second conductive buffer layer to form a Schottky diode. Alternatively, a doped region is formed within the second conductive buffer layer to form a homo-junction diode structure. The anode and cathode of the diode above the second conductive buffer layer are electrically connected to the cathode and anode of the light-emitting diode, respectively.

Claims

1. A group III-V element-based light-emitting diode (LED) structure having electrostatic protection capacity, comprising:

a transparent substrate;

a nucleation area layer including a first nucleation layer and a second nucleation layer both formed over the transparent substrate, wherein the first and the second nucleation layer are isolated from each other;

a conductive buffer area layer including a first conductive buffer layer and a second conductive buffer layer formed over the first nucleation layer and the second nucleation layer, respectively;

a first confinement layer over the first conductive buffer layer, wherein the first confinement layer and the conductive buffer area layer contain identical dopants;

an active layer over the first confinement layer, wherein material forming the active layer includes doped group III-V element-based semiconductor material;

a second confinement layer over the active layer, wherein the second confinement layer and the first confinement layer contain different dopants;

a contact layer over the second confinement layer, wherein the contact layer and the second confinement layer contain identical dopants;

a first electrode over the contact layer;

a second electrode in contact with the first conductive buffer layer but isolated from the first confinement, layer, the active layer, the second confinement layer, the contact layer and the first electrode;

a third electrode over the second buffer conductive layer and the third electrode together with the second conductive buffer layer forming a Schottky barrier diode, wherein the third electrode connects electrically with the second electrode; and

a fourth electrode over the second conductive buffer layer isolated from the third electrode region, wherein the fourth electrode connects electrically with the first electrode.

2. The LED structure of claim 1, wherein the doped active layer is a group III-V element-based semiconductor material including Al_aIn_bGa₁₋

a−

bN/Al_cIn_dGa<sub>1−

c−

d</sub>N (a,b≧

0;

0≦

a+b<

1;

x>

c>

a) in multiple quantum well.

3. The LED structure of claim 1, wherein material constituting the transparent substrate includes sapphire, silicon carbide (SiC), zinc oxide (ZnO), gallium nitride (GaN), aluminum nitride (AlN), glass or silicon, gallium phosphorus (GaP), gallium arsenic (GaAs), aluminum oxide (Al₂O₃).

4. The LED structure of claim 1, wherein the first electrode includes a transparent electrode.

5. The LED structure of claim 4, wherein material constituting the transparent electrode includes metals and their composite assembly commonly used in semiconductor manufacturing including n-type transparent conductive oxide (TCO), ITO, CTO, Zn₂SnO₄, ZnSnO₃, MgIn₂O₄, GaInO₃, (Ga,In)₂O₃, Zn₂In₂O₅, In₄Sn₃O₁₂, AgInO₂:

Sn or In₂O₃;

Zn, or a p-type TCO such as CuAlO₂, LaCuOS, CuGaO₂ or SrCu₂O₂.

6. The LED structure of claim 1, wherein material constituting the second electrode includes Ti/Al.

7. The LED structure of claim 1, wherein material constituting the third electrode includes metals and a composite assembly thereof commonly used in semiconductor manufacturing.

8. The LED structure of claim 1, wherein material constituting the fourth electrode includes Ti/Al.

9. A group III-V element-based light-emitting diode (LED) structure having electrostatic protection capacity, comprising:

a transparent substrate;

a conductive buffer area layer including a first conductive buffer layer and a second conductive buffer layer formed over a first nucleation layer and a second nucleation layer, respectively;

an active layer structure over the first conductive buffer layer, wherein the active layer is formed using doped group III-V element-based semiconductor material;

a contact layer over the active layer structure, wherein the contact layer and the second confinement layer contain identical dopants;

a first electrode over the contact layer;

a second electrode in contact with the first conductive buffer layer but isolated from the active layer structure, the contact layer and the transparent electrode;

a third electrode over the second conductive buffer layer, wherein the third electrode and the second conductive buffer layer together form a Schottky diode, and the third electrode connects electrically with the second electrode; and

a fourth electrode over the second conductive buffer layer isolated from the third electrode region, wherein the fourth electrode connects electrically with the first electrode.

10. The LED structure of claim 9, wherein the structure includes a nucleation area layer having a first nucleation layer and a second nucleation layer between the transparent substrate and the first and the second conductive buffer layer, respectively, and the first and the second nucleation layer are isolated from each other.

11. The LED structure of claim 9, wherein the active layer structure further includes:

a first confinement layer over the first conductive buffer layer, wherein the first confinement layer and the conductive buffer area layer contain identical dopants;

an active layer over the first confinement layer, wherein the active layer is formed using group III-V element-based semiconductor material; and

a second confinement layer over the active layer, wherein the second confinement layer and the first confinement layer contain different dopants.

12. The LED structure of claim 9, wherein the active layer structure further includes:

a first confinement layer over the first conductive buffer layer, wherein the first confinement layer and the conductive buffer area layer contain identical dopants;

an active layer over the first confinement layer, wherein the active layer is formed using group III-V element-based semiconductor material; and

a second confinement layer over the active layer, wherein the second confinement layer and the first confinement layer contain different dopants.