Evidence for as doping effects on resolidification dynamics during pulsed laser melting

The effects of arsenic doping on the resolidification dynamics duirng pulsed melting of silicon with 694 nm laser irradiation has been studied using the transient conductance technique. At concentrations below 1 at. %, the incorporation of the As into the Si lattice results in negligible differences in the resolidification dynamics. At 7 at. % arsenic, however, the interface velocity is dramatically modified as the liquid-solid interface crosses the As containing region. These velocity changes are consistent with a reduced melting temperature in the As containing regions. For concentrations above 11 at. %, the depression in the melting temperature is sufficient to allow the surface to solidify while considerable melt remains buried within the sample. At 16 at. %, the melting temperature is sufficiently reduced to allow internal nucleation of melt prior to surface melting. 11 references and figures.