Degradation mechanism differences between TiN- and TaN-electrode HZO-based FeRAMs analyzed by current mechanism fitting

Abstract

This paper investigates the difference in electrical performance and reliability arising from using either titanium nitride (TiN) or tantalum nitride (TaN) as the electrode in ferroelectric random access memories. Because the lattice constant of TaN is better matched to HZO, the TaN-electrode device exhibits better characteristic. However, the leakage of TaN-electrode device increases significantly after wake up. To figure out this phenomenon, current fitting is implemented. According to the fitting results of conduction mechanisms, the existence of oxygen vacancies in the TaN-electrode device provides a reliable explanation to propose models to clarify the degradation mechanisms observed from the TiN- and TaN-electode devices.