PHOTOLUMINESCENCE OF DEFECTS INDUCED IN SILICON BY SF6 O-2 REACTIVE-ION ETCHING/

Photoluminescence (PL) studies of SF6/O-2 plasma-induced defect format ion in n-type silicon samples are reported. Ion bombardment of the sil icon surface during the SF6 reactive-ion etching (RIE) is shown to int roduce defects giving rise to a broad PL band in the 0.70-1.00 eV spec tral range and to the carbon-related C and G lines. The role of oxygen during SF6/O-2 RTE on the photoluminescence observed is analyzed. It is argued that oxygen contamination enhances the formation of PL cente rs 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 a s the shift of the phosphorous bound exciton line detected after SF6/O -2 RIE. (C) 1995 American Institute of Physics.