Surface modifications of crystalline silicon created by high intensity 1064 nm picosecond Nd:YAG laser pulses

A study of silicon modification induced by a high intensity picosecond Nd:YAG laser, emitting at 1064 nm, is presented. It is shown that laser intensities in the range of 5 × 1010-0.7 × 1012 W cm−2 drastically modified the silicon surface. The main modifications and effects can be considered as the appearance of a crater, hydrodynamic/deposition features, plasma, etc. The highest intensity of ∼0.7 × 1012 W cm−2 leads to the burning through a 500 μm thick sample. At these intensities, the surface morphology exhibits the transpiring of the explosive boiling/phase explosion (EB) in the interaction area. The picosecond Nd:YAG laser-silicon interaction was typically accompanied by massive ejection of target material in the surrounding environment. The threshold for the explosive boiling/phase explosion (TEB) was estimated to be in the interval 1.0 × 1010 W cm−2 < TEB ≤ 3.8 × 1010 W cm−2.