Formation of grooves in SiO2 coated silicon using femtosecond ytterbium DPSS laser

Abstract

Femtosecond laser micromachining of grooves in the SiO2 coated crystal silicon is investigated using 300 fs laser pulses at a center wavelength of 1030 nm. A novel chirped pulse amplified femtosecond Yb:KGW laser source (Pharos, Light Conversion, Lithuania) with high pulse repetition rate of 1- 350 kHz and high average power up to 8 W is employed. The ablation depth of grooves as a function of pulse repetition rate, number of passes over the same groove, and the light polarization relative to the cutting direction is investigated. Different scanning algorithms as well as influence of the focal plane height relative to the sample are investigated.