Abstract

Band gap illumination of a semiconductor surface produces elevated populations of charge carriers which can directly influence surface reactions as well as recombine to generate heat. Previous studies have established that when light intensities are low, i.e., heating is minimal, photogenerated charge carriers can enhance the rate of reaction between silicon and XeF₂.^1,2 The mechanism for this has been proposed to involve trapping of electrons and holes at the surface, thereby increasing the relative reactivity of precursors to the etch products. These data, obtained at low levels of illumination, are not directly applicable to the more complicated situation of laser-induced etching under high-power-density conditions, where surface heating and substrate phase changes are important.

© 1986 Optical Society of America