Time-resolved conductance and reflectance measurements of silicon during pulsed-laser annealing

Abstract

The dynamics of silicon solidification from the melt during pulsed-ruby-laser annealing have been investigated with the use of time-resolved electrical-conductance and optical-reflectance measurements. Melt duration was found to increase with laser-energy density to over 450 nsec at the highest energy used (3.1 J/${\mathrm{cm}}^2$). Resolidification velocity was found to vary with time and laser-energy density over a range of 2 to 3 m/sec. The melt threshold was observed to be 0.8 J/${\mathrm{cm}}^2$. Measurements of the laser energy absorbed in the sample were made to determine energy coupling parameters for use in numerical calculations. The numerical calculations, based on a thermal model for laser melting, are found to be in good agreement with the experimental results.