A Study of the Dielectric Breakdown of Thermally Grown SiO2 by the Self-Quenching Technique

The dielectric breakdown of SiO2 films thermally grown on (100) silicon substrates was studied by the self-quenching technique, using thin aluminum field plates. The breakdown regions show distinct differences among the four possible combinations of substrate type and polarity of applied voltage. With p-type substrate and positive field-plate polarity, an anisotropy is observed which reflects the crystallo-graphic structure of the substrate. A pre-breakdown instability, which is enhanced at lowered temperatures, is ascribed to hole-electron pair production in the oxide followed by hole trapping at or near the negative electrode.