Mechanism of charge storage in electron-beam or corona-charged silicon-dioxide electrets

Thermally-stimulated-discharge (TSD) measurements performed to investigate the electret charges on 1- mu m-thick, wet-grown SiO/sub 2/ are discussed. Charge decay curves at room temperature for a time period of more than three years are given. Influences of charging methods and substrate doping on charge stability are also discussed. Measurements of charge decay in short- and open-circuit TSD experiments show interesting phenomena that are interpreted, including discharge current peaks at temperatures >250 degrees C that were found in positively charged samples. An unexpected current reversal was observed in these experiments, and an explanation for this reversal is given. The generation by irradiation of traps in the bulk of SiO/sub 2/ with an electron beam is described. The Sessler method is used to calculate the traps' mean-spatial depths.<
>