SrBi 2 Ta 2 O 9 memory capacitor on Si with a silicon nitride buffer

Abstract

We have made ferroelectric memory capacitors by depositing a SrBi2Ta2O9 thin film on a Si substrate separated by an ultrathin buffer layer of silicon nitride film. The hysteresis in the capacitance–voltage curves suggests a sizable memory window of 2 V with a programming voltage swing of ±7 V. The switching time is estimated to be on the order of nanosecond based on the results of a one-shot pulse experiment. The results from the fatigue test indicate a slight degradation of the memory window after 1011 switching cycles. These properties are encouraging for the development of ferroelectric memory transistors.