IN-SITU RAMAN-SPECTROSCOPY OF SILICON SURFACES DURING SF6 PLASMA-ETCHING

In situ Raman scattering spectroscopy is performed in order to probe t he chemical dynamics and structure modifications at Ar and SF6 low-pre ssure plasma-etched silicon surfaces. An Ar plasma induces relatively slight perturbation of the silicon surface, while a SF6 plasma creates highly disordered overlayers induced by the fluorine atoms reacting a t ion-induced defects. The overlayer structure is a mixing of an amorp hous phase and 10 angstrom microcrystallites expected to be close to p orous silicon structure.