Oxygen scavenging of HfZrO2-based capacitors for improving ferroelectric properties

Abstract

HfO₂-based ferroelectric (FE) materials have emerged as a promising material for non-volatile memory applications because of remanent polarization, scalability of thickness below 10 nm, and compatibility with complementary metal–oxide–semiconductor technology. However, in the metal/FE/insulator/semiconductor, it is difficult to improve switching voltage (V_sw), endurance, and retention properties due to the interfacial layer (IL), which inevitably grows during the fabrication. Here, we proposed and demonstrated oxygen scavenging to reduce the IL thickness in an HfZrO_x-based capacitor and the thinner IL was confirmed by cross-sectional transmission electron microscopy. V_sw of a capacitor with scavenging decreased by 18% and the same P_r could be obtained at a lower voltage than a capacitor without scavenging. In addition, excellent endurance properties up to 10⁶ cycles were achieved. We believe oxygen scavenging has great potential for future HfZrO_x-based memory device applications.