Method of fabricating vertical structure LEDs

• US 7,462,881 B2
• Filed: 08/30/2007
• Issued: 12/09/2008
• Est. Priority Date: 04/09/2002
• Status: Expired due to Term

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yoo, Myung Cheol, Lee, Jong-Lam, Jeong, In-kwon
• Primary Examiner(s): Pert; Evan
• Assistant Examiner(s): MANDALA, VICTOR A
• Application Number:
  US11/896,307
• Publication Number:
  US 20070295986A1
• Time in Patent Office: 467 Days
• Field of Search: 257/79, 257/99, 257/103, 257/E33.025, 257/E33.028, 257/E33.033, 438/22
• 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. A vertical light emitting device, comprising:

a support layer;

a semiconductor layer comprising a first GaN-based layer, a second GaN-based layer, and an active layer located between the first and second GaN-based layer;

a first electrode located at one side of the semiconductor layer;

a coating on the first electrode that facilitates the support layer to grow on the coating; and

a second electrode located at an opposite side of the semiconductor layer such that the second electrode is vertically aligned with the first electrode and current can flow between the first electrode and the second electrode.

2. The vertical light emitting device according to claim 1, further comprising an at least one of a passivation layer over the exposed portions of the semiconductor layer.

3. The vertical light emitting device according to claim 2, wherein the passivation layer comprises a material including at least one of Si, O and N.

4. The vertical light emitting device according to claim 1, further comprising the support layer, wherein the support layer includes a metal selected from a group including Cu, Cr, Ni, Au, Ag, Mo, Pt, Pd, W, Ti and Al.

5. The vertical light emitting device according to claim 1, wherein the first GaN-based layer is a p-GaN layer and the second GaN-based layer is an n-GaN layer.

6. The vertical light emitting device according to claim 2, further comprising an undoped GaN layer over the second GaN-based layer.

7. The vertical light emitting device according to claim 1, wherein the passivation layer is disposed higher than the second electrode.

8. The vertical light emitting device according to claim 1, wherein the coating includes a metal.

9. The vertical light emitting device according to claim 1, wherein the support layer is grown using at least one of electroplating, electro-less plating, chemical vapor deposition, and sputtering.

10. A vertical light emitting device, comprising:

a support layer;

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

a coating on the first electrode between the first electrode and the support layer;

a second GaN-based layer thicker than the first GaN-based layer over the first GaN-based layer;

a light emitting layer disposed between the first GaN-based layer and the second GaN-based layer; and

a second electrode over the second GaN-based layer, wherein the first electrode is vertically aligned with the second electrode.

11. The vertical light emitting device according to claim 10, further comprising at least one of a passivation layer over exposed portions of the first GaN-based layer, of the light emitting layers, and of the second GaN-based layer.

12. The vertical light emitting device according to claim 11 wherein the passivation layer comprises material including at least one of Si, O and N.

13. The vertical light emitting device according to claim 10, wherein the support layer includes a metal selected from a group including Cu, Cr, Ni, Au, Ag, Mo, Pt, Pd, W, Ti and Al.

14. The vertical light emitting device according to claim 10, wherein the first GaN-based layer is a p-GaN layer and the second GaN-based layer is an n-GaN layer.

15. The vertical light emitting device according to claim 14, further comprising an undoped GaN layer over the second GaN-based layer.

16. The vertical light emitting device according to claim 11, wherein the passivation layer is disposed higher than the second electrode.

17. The vertical light emitting device according to claim 11, wherein the passivation layer is surrounding at least two side portions of first GaN-based layer, of the light emitting layer, and of the second GaN-based layer.

18. The vertical light emitting device according to claim 10, further comprising a passivation layer disposed partially between the support layer and the first GaN-based layer.

19. The vertical light emitting device according to claim 10, wherein the coating includes a metal.

20. The vertical light emitting device according to claim 10, wherein the coating on the first electrode facilitates the support layer to grow on the coating, and support layer is grown using at least one of electroplating, electro-less plating, chemical vapor deposition, and sputtering.