Photostimulated desorption in laser-assisted etching of silicon

Photodesorption of SiF3 groups, which are the principal adsorbates on a silicon surface during etching by XeF2, is found to be responsible for the etch-rate enhancement observed under illumination by low-power, cw band-gap radiation. It is proposed that desorption is stimulated by photogenerated- charge-carrier mediated chemical reaction, and not the simple charge trapping and recombination mechanism usually invoked for desorption from semiconductor surfaces. © 1988 The American Physical Society.