Title :
Surface Texturing of High-Power Flip-Chip LEDs by Femtosecond Laser Direct Structuring
Author :
Kuna, Ladislav ; Haase, Anja ; Reil, Frank ; Sommer, Christian ; Krenn, Joachim R. ; Hartmann, Paul ; Pachler, Peter ; Tasch, Stefan ; Wenzl, Franz Peter
Author_Institution :
Inst. of Nanostructured Mater. & Photonics, Joanneum Res. Forschungsges.mbH, Weiz, Austria
Abstract :
We report on the femtosecond laser direct structuring of the sapphire flipside surfaces of high-power flip-chip LEDs. It is found that diameter and depth of the created submicrometer-sized holes can be manipulated by varying the laser power at a constant number of laser pulses. This method enables the control of the structure sizes with high precision. Our study shows that the light extraction from such LEDs increases strongly with increasing hole sizes.
Keywords :
flip-chip devices; high-speed optical techniques; laser beam applications; light emitting diodes; surface texture; surface treatment; femtosecond laser direct structuring; high-power flip-chip LED; sapphire flipside surfaces; surface texture; LEDs; solid-state lighting;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/JSTQE.2009.2018132
