The Effect Of A Strong Static Electric Field And Heating On Characteristics Of The High-Frequency Impedance Of Metal--Ferroelectric--Semiconductor Structures

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-pSi 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 121oC 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-xSrxTiO3 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. Keywords: High-frequency field characteristics of the impedance, the field stress, hysteresis loops, the generation of additional localized electronic states, delay effects, fluctuation processes, smearing of the phase transition.