Fabrication of Micro-Hole Arrays in Silicon Using Femtosecond Laser Irradiation and Acid Etching

We demonstrated a method to fabricate through micro-holes with high aspect ratios in silicon by using femtosecond laser irradiation and chemical selective etching. The through micro-hole morphology was characterized using scanning electronic microscopy (SEM). The results showed that the through micro-hole formation was attributed to the chemical reactions of femtosecond laser affected region (LAR) with hydrofluoric acid (HF) solution. The through micro-holes and micro-hole arrays fabricated at different pulse energies and pulse numbers were demonstrated.