Electrical characteristics of excimer laser ablated bismuth titanate films on silicon

Abstract

Bismuth titanate thin films were deposited by the excimer laser ablation technique directly onto bare silicon substrates. Current-voltage studies suggested the formation of a heterojunction at the Bi₄Ti₃O₁₂/Si interface. The current characteristics at voltages >1 V were ascribed to trap-limited space-charge conduction. Hysteretic capacitance-voltage data indicated that charge injection was dominant, masking any polarization mode necessary for nonvolatile memory operation. Ferroelectric hysteretic studies, however, indicated that the films were ferroelectric with P_r10 µ C/cm² and E_c150 kV/cm.