Machining of submicron structures on metals and semiconductors by ultrashort UV-laser pulses

Ablation of submicron structures on copper and silicon by short ultraviolet laser pulses (0.5-50 ps, 248 nm) is presented. Features like periodic line structures with a line-spacing below 400 nm, and holes with characteristic sizes well below 1 mu m are produced on the sample surface by single laser shot exposure. The structures are projection printed by a Schwarzschild-objective (N.A. = 0.4) in air environment. The morphology of ablation sites made with different pulse durations (0.5 ps, 5 ps, 50 ps) is discussed in terms of thermal diffusion effects.