Wake‐Up Effect in HfO2‐Based Ferroelectric Films

Abstract HfO 2 ‐based ferroelectric materials are promising candidates for next‐generation nonvolatile memories. Since the first report on Si‐doped HfO 2 ferroelectric thin film in 2011, it has been confirmed that various dopants can induce ferroelectricity in HfO 2 ‐based films, and the “wake‐up” effect in HfO 2 films with different dopants deposited by different processes has been studied extensively. Recent developments in the wake‐up effect of doped HfO 2 ‐based films are presented. Aside from the differences between the various ferroelectric materials and their deposition methods, the electrodes used in a ferroelectric capacitor, which determine the nature of the interface between the electrode and the ferroelectric layer, can strongly influence the characteristics of the wake‐up effect. The rate of variation of the remanent polarization shows certain trends with different dopants. Based on the wake‐up mechanisms, many methods to optimize and control this effect are presented in this letter. Until now, the reported mechanism explanations of the wake‐up effect all aimed at one type of specific dopant or deposition technique, but can't systematically interpret why the root causes might be different with different dopants and deposition processes. There is also a lack of in‐depth research on the effects of interfacial layer with respect to different electrode material.