Characteristics of Pt/Bi3.25La0.75Ti3O12/ZrO2/Si structures using ZrO2 as buffer layers for ferroelectric-gate field-effect transistors

Abstract

We investigated the structural and electrical properties of Bi3.25La0.75Ti3O12 (BLT) films grown on Si covered with ZrO2 buffer layer. The BLT thin film and ZrO2 buffer layer were fabricated using a metalorganic decomposition method. The electrical properties of the metal–ferroelectric–insulator–semiconductor (MFIS) structure were investigated by varying thicknesses of the ZrO2 layer. The width of the memory window in the capacitance–voltage curves for the MFIS structure decreased with increasing thickness of the ZrO2 layer. It is considered that the memory window width of MFIS is not affected by remanent polarization. Leakage current density decreased by about 4 orders of magnitude after using ZrO2 buffer layer. Transmission electron microscopy shows no interdiffusion and reaction that was suppressed using the ZrO2 film as a buffer layer.