Semiconductor LED flip-chip with high reflectivity dielectric coating on the mesa

US6630689B2 · kind B2 · utility

Assignee

• Lumileds Lighting US, LLC · US

Inventors

• Jerome Chandra Bhat · San Francisco, US
• Daniel A. Steigerwald · Eindhoven, NL

Key dates

• Filing date: May 9, 2001
• Grant date: Oct 7, 2003
• Expiry date: May 15, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/835

Abstract

In one embodiment of the present invention, a highly reflective dielectric stack is formed on the mesa wall of a flip-chip LED. The layers of the dielectric stack are selected to maximize reflection of light incident at angles ranging from −10 to 30 degrees, relative to the substrate. The dielectric stack is comprised of alternating low refractive index and high refractive index layers. In some embodiments, the LED is a III-nitride device with a p-contact containing silver, the dielectric stack layer adjacent to the mesa wall has a low refractive index compared to GaN, and the low refractive index layers are Al2O3.