Systems and methods for producing white-light light emitting diodes

• US 20060157721A1
• Filed: 01/11/2005
• Published: 07/20/2006
• Est. Priority Date: 01/11/2005
• Status: Active Grant

• Current Assignee: Lumens Co., Ltd.
• Original Assignee: SemiLEDs Corporation (SemiLEDs Inc)
• Inventors: Tran, Chuong Anh, Doan, Trung Tri
• Granted Patent: US 7,195,944 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/4918 being disposed on at least two different sides of the body, e.g. dual array
• 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 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01021 Scandium [Sc]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/641 characterized by the materials

Abstract

A vertical light emitting diode (LED) includes a metal substrate; a p-electrode coupled to the metal substrate; a p-contact coupled to the p-electrode; a p-GaN portion coupled to the p electrode; an active region coupled to the p-GaN portion; an n-GaN portion coupled to the active region; and a phosphor layer coupled to the n-GaN.

Claims

7-1. The LED of claim 1, wherein the phosphor layer is patterned.

11. A method for fabricating phosphor n-GaN up LED wafer, comprising:

providing a carrier substrate;

depositing a n-GaN portion above the carrier substrate;

depositing active layers above the n-GaN portion;

depositing a p-GaN portion above the active layers;

depositing one or more metal layers

applying a masking layer;

etching the metal, p-GaN layer, active layers and n-GaN layer,

removing the masking layer;

depositing a passivation layer;

removing portion of the passivation layer on top of the p-GaN to expose the metal,

depositing one or more layers,

depositing a metal substrate,

removing the carrier substrate to expose the n-GaN surface

applying a phosphor layer above the n-GaN surface.

2. The LED of claim 1, wherein the metal substrate is deposited using one of:

electrochemical plating, electroless chemical plating, sputtering, chemical vapor deposition, e-beam evaporation, thermal spray.

12. The method of claim 11, wherein the phosphor n-GaN up LED wafer is substantial smooth and flat.

13. The method of claim 12, wherein the phosphor n-GaN up LED wafer has a surface roughness less than 10000 angstrom before the phosphor layer is applied.

14. The method of claim 11 wherein the carrier substrate is sapphire

15. The LED wafer of claim 11, wherein the metal substrate is deposited using one of:

electro-chemical plating, electroless chemical plating, sputtering, chemical vapor deposition, e-beam evaporation, thermal spray.

16. The LED of claim 11, wherein the metal substrate is a metal or metal alloy comprises one of Copper, nickel, aluminum.

17. The method of claim 11, wherein the carrier substrate is removed using one of:

laser lift-off (LLO), wet etching, chemical mechanical polish.

18. The method of claim 11, wherin the p-contact comprises a light reflector.

20. The method of claim 11, comprising a bondpad coupled to the phosphor layer.

20-2. The method of claim 11, wherein the phosphor layer applied at the wafer level is coupled to n-GaN surface of the n-side up vertical LED.