Electron spin resonance observations of dangling-bond states on the (111)-(7 x 7) surface were described here for the first time. Electron spin resonance spectra clearly showed that reaction of molecular O with the (111)-(7 x 7) surface was associated with the appearance of a new dangling-bond center at unreacted Si adatoms. Most of the oxidized surface sites did not produce electron spin resonance signals but a new type of surface defect was detected in a restricted part of the surface. The well known Pb, center at the SiO2/Si interface was found to evolve at oxide thicknesses as low as 0.3nm.

Electron Spin Resonance Observation of the Si(111)-(7 x 7) Surface and its Oxidation Process. T.Umeda, M.Nishizawa, T.Yasuda, J.Isoya, S.Yamasaki, K.Tanaka: Physical Review Letters, 2001, 86[6], 1054-7