Modeling of flexoelectric effect on capacitor-voltage and memory window of metal-ferroelectric-insulator-silicon capacitor

Abstract

The flexoelectric effect on electrical behaviors of metal-ferroelectric-insulator-silicon (MFIS) capacitor was investigated by considering stress gradient in Landau–Khalatnikov theory. In the presence of flexoelectric coupling, the compressive stress shifts capacitor-voltage (C-V) loop of MFIS capacitor to the negative voltage axis and enlarges memory window, however, the tensile stress shifts C-V loop to the positive voltage axis and compresses memory window. The magnitudes of stress, flexoelectric coefficient, and characteristic length of stress distribution have a significant influence on C-V characteristic and memory window of MFIS capacitor. The results show stress gradient should be avoided to prevent failure of MFIS capacitor.