Changheon Kim

Ferroelectric Properties of New Chemical Solution Derived SBT Thin Films for Non-Volatile Memory Devices

Ferroelectric SBT (Sr/Bi/Ta = 0.8/2.3/2) thin films on Pt/ZrO2/SiO2/Si were successfully prepared by using an alkanolamine modified chemical solution deposition method. Acetic acid as a solvent led to the formation of water in the solution, which might continuously induce the hydrolysis and condensation of the precursors, leading to reducing the stability of the solution with aging time. It was observed that alkanolamine provided the stability to the SBT solution by retarding the hydrolysis and condensation rates. This solution could be used as long as up to 30 days without any appreciable change of the solution properties. The typical hysteresis loop of SBT thin films was obtained at 2 V, and it was fully saturated even below an applied voltage of 3 V (2Pr ≈ 16 μC/cm2). The measured 2Pr value of the SBT thin film at 5 V was almost 20 μC/cm2. Fatigue and breakdown characteristics of the films, measured at 5 V, showed a stable behavior, and negligible degradation was observed up to 1010 cycles.