New intrinsic defect in as-grown thermal SiO2 on (111)Si.

Abstract

K-band electron-spin resonance (ESR) has revealed an isotropic signal of g=2.002 46\ifmmode\pm\else\textpm\fi{}0.000 03 in as-prepared ${\mathrm{SiO}}_{2}$ thermally grown on (111)Si in dry ${\mathrm{O}}_{2}$ at 700\char21{}860\ifmmode^\circ\else\textdegree\fi{}C. The spectrum comprises a symmetric central signal of peak-to-peak width \ensuremath{\Delta}${\mathrm{\ensuremath{\beta}}}_{\mathrm{pp}}$=1.0 G amid a $^{29}\mathrm{Si}$ hyperfine doublet of splitting ${\mathit{a}}_{\mathrm{hf}}$=16.1 G. The salient ESR features point to an intrinsic defect in ${\mathrm{SiO}}_{2}$ characterized by an unpaired spin occupying an effectively nearly pure s state, which is not primarily localized at a Si site while exchanging a $^{29}\mathrm{Si}$ superhyperfine interaction with three equivalent neighboring Si sites.