Femtosecond laser machining of gallium nitride

Ultrashort pulse laser ablation of gallium nitride (GaN) has been studied. Utilizing a 1 kHz femtosecond Ti:sapphire laser with a peak intensity of approximately 10(16) W cm(-2), we have successfully demonstrated controlled ablation of metal organic chemical vapour deposition and hydride vapour phase epitaxy grown GaN. Groove patterns 10-100 mum wide and as deep as 30 mum have been produced both in air and in a vacuum chamber and analyzed by scanning electron microscope and stylus profiling. This approach is demonstrated to be highly suitable for micromachining and controlled definition of features on a tens of micron length scale in materials such as GaN which are resistant to wet chemical etching.