Pulsed laser etching of silicon: Dopant profile modification and dopant desorption induced by surface melting

摘要

Laserhyphen;induced modification of dopant profile and desorption of the dopant are measured for silicon and several dopants (B, As, Sb). The experimental conditions are laser melting and chemical etching by chlorine, and laser annealing. The laser fluence is above the melting threshold, and the Si dosing by chlorine is pulsed under a very low static Cl2pressure. Successive dopant profiles evolve very differently for these three dopants. The desorption efficiency is shown to depend strongly on the dopant atom, increasing from boron to arsenic to antimony. The implications of etching, doping, and annealing experiments are discussed.