ANNEALING INDUCED DEGRADATION OF THERMAL SiO 2 ON (1 0 0)Si: POINT DEFECT GENERATION.

The structural degradation of thermal SiO 2 on (1 0 0)Si under isochronal post oxidation vacuum annealing (POVA) has been probed by electron spin resonance (ESR). The degradation process, studied in the range T an  = 950-1250 °C, is established as intense point defect generation including E ′ γ , E ′ δ , EX and the elusive predominant degradation center S . Thermally activated generation is revealed over broad T an ranges for the two most populous defects, S and E ′ γ , with a common activation energy ∼1.6 eV. Depth profiling after heating at 1200 °C shows that the S centers predominantly reside near the oxide borders, generally in anticorrelation with the E ′ γ distribution. The S center susceptibility has been inferred from conventional ESR signal intensity monitoring as well as from revealed anisotropic demagnetisation effects. It is found Curie-Weiss type with critical temperature of ∼1.3 K. Newly observed weak hyperfine structure may comply with the S center being an E ′-like defect. [ABSTRACT FROM AUTHOR]