Electrical characteristics of SrxBi2.4Ta2O9 thin film and Pt/Sr0.85Bi2.4Ta2O9/Al2O3/Si structure

摘要

Sr x Bi2.4Ta2O9 (0.7 ≤ x ≤ 1.3) thin films were processed by metalorganic decomposition and their ferroelectric characteristics were investigated. The Sr-deficient Sr x Bi2.4Ta2O9 films exhibited well-developed ferroelectric hysteresis curves compared to those of the Sr-excess films, and Sr0.85Bi2.4Ta2O9 film had the optimum electrical characteristics among Sr x Bi2.4Ta2O9 films. Electrical characteristics of the Pt/SBT/Al2O3/Si structure using Sr0.85Bi2.4Ta2O9(SBT) film were investigated for metalferroelectric-insulator-semiconductor field-effect-transistor (MFIS-FET) applications. Memory window of C-V hysteresis characteristics of the Pt/SBT/Al2O3/Si structure became large with decreasing the Al2O3 thickness, and the Pt/SBT(400 nm)/Al2O3 (10 nm)/Si structure gave memory window of 2.2 V at sweeping voltages of ±5 V. The Pt/SBT/Al2O3/Si structure can be proposed for MFIS-FET applications.