Product Code: ICAL07_M1101

High Quality Laser Micromachining of Silicon: A Crystallographic Comparison of Process Results Achieved with State-of-the-Art Tripled Nd:YAG and IR Lasers
Authors:
Claudio Ferrari, Instituto IMEM CNR; Parma Italy
Lucia Nasi, Instituto IMEM CNR; Parma Italy
Werner Wiechmann, JDSU Corporation; San Jose CA USA
Pellegrino Sergio, LaserPoint sri; Vimodrone Italy
Presented at ICALEO 2007

The ability to cut, scribe, and drill holes and slots in Silicon material is of great interest for many applications in the microelectronics and semiconductor industry. We investigated the use of a Q-switched frequency-tripled Nd:YAG laser for rapid micromachining of Silicon and compared the results to results achieved with a pulsed fiber laser operating near 1060nm. Cutting, drilling, marking and surface ablation were performed by direct writing using a high-speed xy galvano-mechanical beam positioner equipped with a telecentric lens focusing system and a high precision xy stage. The sample morphology was studied by scanning electron microscopy; the results indicate 8-10 times higher surface roughness on the IR processed samples. We also applied X-ray double-crystal topography to analyse the defects and local strain induced by the two laser treatments. The topographs reveal remarkable differences between the cuts generated by the UV laser and the cuts produced by the IR laser. Our results clearly demonstrate the advantages of the short-wavelength laser for damage-free micromachining of Silicon.