Abstract: Ablation of submicron structures on metals and semiconductors is presented using subpicosecond laser pulses at 248 nm. Morphology changes as a function of pulse duration have been investigated. The dynamics of the surface modification has been studied using a pump-probe technique. Diffracted signals of a probe beam on laser induced gratings provide information on the dynamics of the electron phonon interaction, melting and material removal simultaneously. For metals, in the first 5 - 10 ps following irradiation the electron-phonon relaxation dominates the process, followed by melting, expansion and violent material ejection. For semiconductors, rapid amorphization of the surface occurs within a couple of hundred femtoseconds following irradiation, with less pronounced indication for the development of molten material.!17
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