Laser-induced chemical etching of silicon in chlorine atmosphere

Abstract

Chemical etching of single-crystalline (100)Si induced by pulsed laser irradiation at 308, 423, and 583 nm has been investigated as a function of the laser fluence and C12 pressure. Without laser-induced surface melting, etching requires Cl radicals which are produced only at laser wavelengths below 500 nm. With low laser fluences (Φ(308 nm) 440 mJ/cm2) etching is thermally activated. In the intermediate region both thermal and non-thermal mechanisms contribute to the etch rate.