Influence of La substitution on the electrical properties of metalferroelectric (BiFeO3)-insulator (CeO2)-semiconductor nonvolatile memory structures
Metalmultiferroic (La-substituted BiFeO3)insulator (CeO2)semiconductor (MFIS) capacitors has been fabricated. The crystalline phase and amount of La3+ substitution at Bi-site were investigated by XRD and XPS in the postannealing temperature range from 500 to 700C, respectively. The microstructure and interfacial layer between CeO2 and Si substrate were characterized by HRTEM. The memory windows as functions of insulator film thickness and DC power for La were measured. The maximum memory window is about 1.9V under 6V applied voltage. The ferroelectric polarization increases with increasing substitution amount. The morphologies of La-substituted BiFeO3 films were also studied by AFM.
ceo2 memory window multiferroic bifeo3