Single shot ablation of silicon-on-insulator using femtosecond violet laser pulses, BBO, SHG

Abstract

In this thesis, the process of second harmonic generation (SHG) was explained in detail, and an introduction to the physical processes that lead to ablation was given. We generated the second harmonic by the use of beta-barium-borate, to obtain a wavelength of 400 nm out of 800 nm. With this wavelength, we ablated silicon-on-insulator and observed the formation of nanotips and craters. Because of experimental shortcomings we could not yet determine a precise relation between the crater depth and fluence. We have however shown for the first time, that ablation using 400\,nm light is perfectly possible, that the damage threshold is approximately 0.14 J/cm^2, and that craters with a diameter of at least 200 nm can be formed. Further research remains to be done in order to obtain these numbers with higher precision.