Photoluminescence of defects induced in silicon by SF6/O2reactive‐ion etching

Photoluminescence (PL) studies of SF6/O2 plasma‐induced defect formation in n‐type silicon samples are reported. Ion bombardment of the silicon surface during the SF6 reactive‐ion etching (RIE) is shown to introduce defects giving rise to a broad PL band in the 0.70–1.00 eV spectral range and to the carbon‐related C and G lines. The role of oxygen during SF6/O2 RIE on the photoluminescence observed is analyzed. It is argued that oxygen contamination enhances the formation of PL centers via the creation of extended defects, such as oxygen precipitates. A lattice contraction nearby these extended defects is suggested to be responsible for the observed splitting of the C and G lines as well as the shift of the phosphorous bound exciton line detected after SF6/O2 RIE.