Phenomenological model for pisosecond-pulse laser annealing of semiconductors

A system of three coupled diffusion equations describing the equilibration process in the premelt phase of laser annealing is solved and analyzed for a short pulse—20,30 psec—on a thin (d=150 Å) and thick Si,Ge slabs. We find the carrier temperature to be a very sensitive gauge for the electron-phonon relaxation time constant τ0. The existing data (Si, λL =0.533 μm and EL =0.25 J/cm2) are consistent with τ0≂0.4–1.0 psec, and the carrier peak temperature is predicted to be in the range 2000–4300 °K.