Modeling the phase-change processes in pulsed laser-irradiated InSb

Both theoretical and experimental analyses of pulsed laser-induced phase-change processes in the near-surface region of monocrystalline bulk InSb are treated in the paper. In the theoretical part, thermal equilibrium and nonequilibrium models of melting, recrystallization, and evaporation are formulated to describe transport phenomena in the material induced by laser irradiation. In the experimental part, (110) and (111) InSb samples irradiated by ruby [694 nm, 80 ns full width at half maximum (FWHM)], and ArF (193 nm, 10 ns FWHM) lasers were studied. Time-resolved reflectivity measurements were performed in order to determine the melting thresholds and surface-melt durations. Auger electron spectroscopy and low-energy electron diffraction methods were employed to monitor surface modifications. A combination of experimental measurements and computer simulations reveals that, while for ruby laser the material remains crystalline after irradiation, for ArF laser the InSb sample is amorphized; the amorphization threshold is estimated to be ~4--5 m/s. The decomposition of InSb at temperatures close to its melting point was also observed, the decomposition temperature being estimated within the range 900--950 K.