The factors critical to the fabrication of high-lumen InGaN flip chip LEDs are discussed. It is shown that as the die size and the current density increase, the n-GaN sheet conductivity becomes extremely critical to uniform current spreading and the corresponding uniformity of light emission. It is observed that a thick p-metal is important in reducing hot spot formation. The p-contact is also critical to increasing light extraction efficiency and wall-plug efficiency. The merits and reliability of Al- and Ag-based p-contacts are compared. Reliability issues related to the n-contact are also discussed. Finally, performance data for InGaN blue lamps, for drive currents up to 900 mA is shown.

Date Published: 26 January 2004
PDF: 7 pages
Proc. SPIE 5187, Third International Conference on Solid State Lighting, (26 January 2004); doi: 10.1117/12.514073

Published in SPIE Proceedings Vol. 5187:
Third International Conference on Solid State Lighting
Ian T. Ferguson; Nadarajah Narendran; Steven P. DenBaars; John C. Carrano, Editor(s)