ABLATION OF SUBMICRON STRUCTURES ON METALS AND SEMICONDUCTORS BY FEMTOSECOND UV-LASER PULSES

Ablation of submicron structures on nickel, aluminum, copper, chromium , gold, silicon and germanium is presented by short ultraviolet laser pulses (0.5 ps, 248 nm). Features like periodic line structures with a line-spacing below 400 nm, and holes with characteristic sizes well b elow 1 mu m are produced on the sample surface by single laser shot ex posure. The structures are projection printed by a Schwarzschild-objec tive (N.A. = 0.4) in air environment. A comparison of the morphology o f ablation sites of various materials with different pulse durations ( 100 fs-50 ps) is presented. The role of thermal diffusion effects is d iscussed.