Improvement in non-volatile ferroelectric storage properties of metal-ferroelectric-insulating-silicon (MFIS) FETs using Al-LiNbO3-HfO2-Si structure

The RF sputtering deposition of HfO 2 as a high dielectric insulating material and LiNbO 3 as the perovskite ferroelectric material, to fabricate the Metal - Ferroelectric - Insulator - Semiconductor (MFIS) structure for the application in non-volatile memory storage is investigated. The interfacial layer between the substrate and the ferroelectric film generally causes deleterious effects in the capacitance, yet the other distinctive properties of the interfacial layers provide advantageous results. The inserted HfO 2 insulating layer thickness is optimized at 10 nm and the ferroelectric film has a thickness of 30 nm deposited. The leakage current is reduced by a factor of 10 and the improved memory window of 2.3 V for the voltage sweep of + 10 V to −10 V is obtained. Endurance of (∼10 ¹¹ cycles) is achieved. The low coercive voltage of ∼2.4 V during the polarization characterization of the structure also shows its potential for low-power memory application.