Photoluminescence characterization of SF6O2 plasma etching of silicon

We report on photoluminescence studies of defect formation and of subsequent annealing in silicon after SF6O2 plasma treatment. Substantial damage of the near surface layer, caused by ion bombardment of the silicon surface, is observed, in spite of the high etch rate of SF6O2 plasma. The defects induced give rise to a broad PL band in the 0.70–1.00 eV spectral range and sharp C and G lines. The mechanisms of defect formation and the role of oxygen contamination during SF6O2 reactive-ion etching in these processes are analyzed.