Formation of ohmic contacts in III-nitride light emitting devices

US6657300B2 · kind B2 · utility

Assignee

• Lumileds Lighting US, LLC · US

Inventors

• Werner Goetz · Palo Alto, US
• Michael D. Camras · San Jose, US
• Changhua Chen · San Jose, US
• Gina L. Christenson · Sunnyvale, US
• R. Scott Kern · San Jose, US
• Chihping Kuo · Milpitas, US
• Paul Scott Martin · Pleasanton, US
• Daniel A. Steigerwald · Eindhoven, NL

Key dates

• Filing date: Jan 5, 2001
• Grant date: Dec 2, 2003
• Expiry date: Feb 26, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S5/32341
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

P-type layers of a GaN based light-emitting device are optimized for formation of Ohmic contact with metal. In a first embodiment, a p-type GaN transition layer with a resistivity greater than or equal to about 7 &OHgr;cm is formed between a p-type conductivity layer and a metal contact. In a second embodiment, the p-type transition layer is any III-V semiconductor. In a third embodiment, the p-type transition layer is a superlattice. In a fourth embodiment, a single p-type layer of varying composition and varying concentration of dopant is formed.