LASER HEATING OF SILICON: A KINETIC THEORY APPROACH

Abstract

The present study considers laser heating of silicon. A three-dimensional form of electron kinetic theory approach is considered when deriving the governing heat transfer equation. The numerical method employing a finite difference scheme is used to discretize the resulting equations. The step input laser pulse with Gaussian spatial distribution is introduced. The present predictions are compared with the results of the Fourier heating model. It is found that the temperature rise in the surface vicinity depends on the electron lattice site atom collisions. As heating progresses, the internal energy gain dominates the conduction losses in this region. The electron kinetic theory predictions and the Fourier theory results become similar as the laser pulse length increases.