Extent of Annealed or Melted Regions as a Function of Energy of Pulsed Laser Irradiation

摘要

The depth of melt front penetration induced by Q-switched ruby laser irradiation has been studied by electron microscopy for laser pulses of different duration and energy density in thermally diffused and ion implanted silicon. In thermally diffused specimens, dissolution of dislocation loops and precipitates by the laser radiation provides evidence for melting and the depth over which loops and precipitates are dissolved provides a measure of the melt front penetration depth. In ion implanted specimens, if the melt front does not exceed the thickness of the implanted layer, dislocation tangles and polycrystalline regions are observed after the laser irradiation. A complete annealing of displacement damage is achieved at an energy density (threshold) where the melt front penetrates beyond the damage layer. (ERA citation 04:030787)