Влияние сильного статического электрического поля и нагрева на характеристики высокочастотного импеданса структур металл--сегнетоэлектрик--полупроводник

Abstract

Studies have been carried out on the effect of heating and a strong field, but pre-breakdown, effects on high-frequency characteristics of the impedance of heteroepitaxial structures Ni-Ba0.8Sr0.2TiO3-рSi with a ferroelectric thickness of 50 nm. It was shown, that regardless of the polarity of the field stress, characteristics shifted towards a positive bias, and the width of hysteresis loops decreased; plateau levels remained virtually unchanged. Heating up to 121°C led to a change in levels of the upper plateau of characteristics: for the capacity it decreased, and for the conductivity it increased; branches on the loop not only narrowed and shifted, but changed places in comparison with the original dependence (loop reverse). These results can be explained: under the field action, by the generation of additional electronic states, localized in the buffer layer at the Si-Ba1-xSrхTiO3 interface, and by heating, by the appearance of delay effects due to the development of fluctuation processes, underlying the smearing of the phase transition from ferroelectric to paraelectric condition.