Investigation of Phase Transformation in HfO2 Ferroelectric Capacitor by Means of a ZrO2 Capping Layer

Abstract

In this paper, the ferroelectric polarization effect of ZrO2 capping layer on HfO2 NUM capacitor was investigated. Based on crystallinity analysis, the phase transformation from monoclinic to orthorhombic phase in HfO2 film can be induced by a thin ZrO2 capping layer. The thickness of ZrO2 capping layer plays an important role in the ferroelectric polarization of HfO2 MFM capacitor. Compared to mixed HfZrO film, the stacked ZrO2/HfO2 film shows the advantage for suppressing the leakage issue during high-temperature ferroelectric phase transition.