Low Temperature Growth of Bi₄Ti₃O₁₂ Thin Films by MOCVD and their Electrical Properties

Abstract

We have developed a new low temperature growth technique of Bi₄Ti₃O₁₂ thin films using MOCVD method, in which an ultra-thin double buffer layer (5nm-Bi₄Ti₃O₁₂/5nm-TiO₂) was used to control the crystallization and fine grain structure of Bi₄Ti₃O₁₂ thin films. The 100nm-Bi₄Ti₃O₁₂ thin films fabricated at 400°C showed an excellent smooth surface morphology and good electrical properties: large remanent polarization of Pr=11μC/cm², coercive field of Ec=90kV/cm and low leakage current IL=7×10^-9A/cm² at 3V, respectively. In addition, for the first time the fatigue free property, which is very important for nonvolatile ferroelectric memories (NVFRAMs) applications, was confirmed up to 1×10¹² switching cycles.