ABSTRACTSynchrotron x-ray pulses from the Cornell High Energy Synchrotron Source
(CHESS) have been used to carry out nanosecond resolution measurements of
the temperature distrubutions in Ge during UV pulsed-laser irradiation. KrF
(249 nm) laser pulses of 25 ns FWHM with an energy density of 0.6 J/cm2 were
used. The temperatures were determined from x-ray Bragg profile measurements
of thermal expansion induced strain on <111> oriented Ge. The data
indicate the presence of a liquid-solid interface near the melting point,
and large (1500-4500°C/pm) temperature gradients in the solid; these Ge
results are analagous to previous ones for Si. The measured temperature
distributions are compared with those obtained from heat flow calculations,
and the overheating and undercooling of the interface relative to the
equilibrium melting point are discussed.
Estimation of Local Crystallization of a-Si:H Thin Films by Nanosecond Pulsed Laser Irradiation Through Local Temperature Simulation