Excimer-laser ablation and micro-patterning of ceramic Si3N4

Excimer-laser ablation and micro-patterning of ceramic Si3N4 has been investigated. The ablation threshold in air, Phi(th), is around 0.3 +/- 0.1 J/cm(2) with ArF- and 0.9 +/- 0.2 J/cm(2) with KrF-laser radiation. With fluences Phi(th) < Phi less than or equal to 4 J/cm(2) the irradiated surface is either very flat or it ex hibits a cone-type structure, depending on the number of laser pulses employed. With fluences of 5 to 10 J/cm(2), the sample surface becomes very smooth, much smoother than the original mechanically polished surface. Pores, scratches, and cracks observed on the non-irradiated surface are absent within the illuminated area. In this regime, the ablation rates are typically 0.1 to 0.2 mu m/pulse.