It was recalled that previous electron spin resonance data had revealed distinct variations in the g|| of Pb interface defects (oSi=Si3) in (111) Si/SiO2 structures upon increasing the temperature within the oxidation range of 750 to 850C. These included a decrease in g|| of about 0.00008, and a collapse in the root mean square spread of g|| of about 0.00032 at temperatures of up to 750C. These changes had been attributed to an average re-structuring of the Pb defects. The observed drop of about 0.00008 was suggested to correspond to an average back-relaxation of the defect Si atom towards a more planar structure over a distance of about 0.013nm. The change of 0.00032 was suggested to imply a vertical positional spread of about 0.053nm. These results were reinterpreted here in terms of a new and improved theory of the Si unpaired bond. Although it did not affect the overall conclusions, the improved approach led to an order of magnitude smaller variations in the relaxation movement and in the Pb energy level.

A.Stesmans: Solid State Communications, 1995, 96[6], 397-9