Bi3.25La0.75Ti3O12 thin films on ultrathin Al2O3 buffered Si for ferroelectric memory application

Abstract

We have investigated the physical and electrical properties of Bi3.25La0.75Ti3O12 (BLT) thin films on Pt/Ti/SiO2/Si and on Al2O3(6 nm)/Si, which are used for one-transistor-one-capacitor and one-transistor ferroelectric memory, respectively. The BLT thin films on both substrates show good capacitance-voltage characteristics and the same threshold voltage shift of 1.6 V at applied +/-10 V bias. However, the leakage current of BLT on Al2O3/Si at -100 kV/cm is two orders of magnitude lower than that on Pt. The comparable memory characteristics and much reduced leakage current of BLT on Al2O3/Si are the strong advantages as compared with BLT on Pt because it is directly related to switching energy and device scaling down. (C) 2002 American Institute of Physics.