Characterization of S centers generated by thermal degradation in SiO[sub 2] on (100)Si.

The structural degradation of thermal SiO[sub 2] on (100)Si under isochronal vacuum annealing in the range T[sub an] = 950 °C-1250 °C was monitored by electron spin resonance (ESR) in terms of point defect creation, including E′[sub γ], E′[sub δ], EX and the elusive predominant degradation-center S. Depth profiling after heating at 1200 °C shows that the S centers predominantly reside near the oxide borders, generally in anticorrelation with the E′[sub γ] distribution. The resulting anisotropic demagnetization effect has enabled inference of the S center susceptibility. As to the nature of the S center, an observed weak hyperfine structure may comply with the S center being of the type Si[sub n]O[sub 3-n]≡Si[sup ·] either the single n = 1 or a mix of both the n = 1,2 variants. [ABSTRACT FROM AUTHOR]