Ablation of hexagonal boron nitride by UV laser radiation

We report an experimental study of ablation of hexagonal boron nitride ceramics irradiated by 193- and 248-nm laser pulses. The dependences of the material removal rate and the crater wall slope on the energy density in the irradiation spot are obtained. An ablation regime is found, when the material removal rate reaches 5 μm per pulse, which is not typical of nanosecond laser radiation. It is shown that at relatively low radiation intensities (about 5–10 J cm^-2), the slope angle of the formed crater wall does not exceed 20°.