Vertical geometry InGaN LED

• US 6,610,551 B1
• Filed: 01/05/2000
• Issued: 08/26/2003
• Est. Priority Date: 09/16/1998
• Status: Expired due to Term

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Dieringer, Heidi Marie, Edmond, John Adam, Slater, David B. Jr., Doverspike, Kathleen Marie, Kong, Hua-shuang
• Primary Examiner(s): Mulpuri, Savitri
• Application Number:
  US09/477,982
• Time in Patent Office: 1,329 Days
• Field of Search: 438/22, 438/28, 438/35, 438/46, 438/47, 438/45, 438/483, 438/602, 438/931, 438/604, 257/77, 257/103
• US Class Current: 438/22
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A vertical geometry light emitting diode is disclosed that is capable of emitting light in the red, green, blue, violet and ultraviolet portions of the electromagnetic spectrum. The light emitting diode includes a conductive silicon carbide substrate, an InGaN quantum well, a conductive buffer layer between the substrate and the quantum well, a respective undoped gallium nitride layer on each surface of the quantum well, and ohmic contacts in a vertical geometry orientation.

Claims

1. A method of producing a vertically oriented light emitting diode that is capable of emitting light in the red, green, blue, violet and ultraviolet portions of the electromagnetic spectrum, the method comprising:

successively growing an n-type conductive buffer layer in a hydrogen atmosphere and an n-type gallium nitride layer in the hydrogen atmosphere on a silicon carbide substrate;

thereafter successively growing a first thin layer of undoped gallium nitride in a nitrogen atmospheres an indium gallium nitride quantum well in the nitrogen atmosphere, a second thin layer of undoped gallium nitride in the nitrogen atmosphere, and a thin layer of undoped aluminum gallium nitride in the nitrogen atmosphere;

wherein at least the first layer of undoped gallium nitride and the quantum well are grown at the same temperature and without a growth stop therebetween; and

thereafter successively growing a layer of p-type aluminum gallium nitride in a hydrogen atmosphere and a layer of p-type gallium nitride in the hydrogen atmosphere.

2. A method according to claim 1 comprising adding an ohmic contact to the p-type gallium nitride layer.

3. A method according to claim 2 comprising adding a platinum contact to the p-type gallium nitride layer.

4. A method according to claim 1 comprising adding an ohmic contact to the silicon carbide substrate.

5. A method according to claim 4 comprising increasing the doping of the silicon carbide substrate at the portion where the ohmic contact is added prior to the step of adding the ohmic contact thereto.

6. A method according to claim 5 wherein the step of increasing the doping comprises ion implantation.