Laser Trepan Drilling of Silicon in Air and under Water

Micromachining of silicon was conducted using 355 etam-X AVIA laser that generates laser fluence in the range of 2-7 Jcm^-2. Laser ablation drilling tests were conducted on a silicon workpiece in air and under water. Low pulse frequency and high peak powers generate smaller spatter deposition area. At high pulse frequencies, the spatter distributed can be changed as the results of laser ejected material interaction. Focal plane positions of below the surface of 0.15 mm gave less number of scanning and produced relatively smaller areas of spatter deposition. Low scanning velocity generates smaller deposition area in comparison to higher scanning velocity. The differences between laser ablation in air and under water are identified.