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 prope rties 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 co nditions are reviewed as follows: 1) localized temperature dependent r ecombination at extended bulk defects for inversion bias, 2) spatial v ariation of the flat-band voltage due to nonuniform interfacial or oxi de 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 de fects.