Femto- and nanosecond pulse laser ablation dependence on irradiation area: The role of defects in metals and semiconductors

Abstract

Pulse laser ablation experiments at semiconductor-grade silicon 〈111〉 and SAE 304 stainless steel were performed with femto- and nanosecond pulse durations. Threshold fluences in dependence of beam radius (1.6–100μm) and density of low-density defects (LDDs) have been determined for both materials and pulse durations. The experimental findings are supported by a recent quantitative model describing the strong dependence of the modification/ablation/damage threshold fluence on beam radius and pulse number. The importance of LDDs in the ablation mechanism has been confirmed.