Cathodoluminescence study of SiO2

Cathodoluminescence spectra from thin films of silicon dioxide on silicon dioxide were investigated. Four luminescence bands are observed in silicon dioxide in a conventional semiconductor device. Band A at 290 nm (4.27 eV) and band C at 560 nm (2.21 eV) increase substantially with increasing electron irradiation and originate from the electron beam induced defects. Band B at 415 nm (2.99 eV) is not intrinsic in pure silicon dioxide, but is observed in carbon implanted silicon dioxide. The depth-dependent concentration of the luminescence centers for band B from carbon implanted oxide was close to the distribution of the implanted carbon and the luminescence center of band B was attributed to carbon in the silicon dioxide. Band D at 650 nm (1.91 eV) may originate from residual and/or adsorbed H2O. The technique of cathodoluminescence presented in this paper will be able to provide useful information on the defects and impurities in silicon dioxide.