Low temperature identification of interfacial and bulk defects in Al/SiO2/Si capacitor structures by electron beam induced current

A low temperature electron beam induced current (EBIC) study using Al/SiO₂/Si capacitors as probes of defects affecting the electrical properties of the bulk Si, SiO₂ interface and the SiO₂ layer is presented. The technique´s relevance to current research on thin oxides and EBIC image enhancements obtained at reduced temperature are explained. The characteristic EBIC contrast representative of three capacitor bias conditions are reviewed as follows: 1) localized temperature dependent recombination at extended bulk defects for inversion bias, 2) spatial variation of the flat-band voltage due to nonuniform interfacial or oxide charge distributions for weak depletion bias, and 3) electron beam enhancement of SiO₂ leakage currents at defect sites for accumulation bias. Illustrations of these contrast modes are presented for samples containing buried epitaxial misfit dislocations and oxide interface defects