A 6.5-nm-Thick Anti-Ferroelectric HfAlOxFilm for Energy Storage Device with A High Density of63.7J/cm3

In this work, we experimentally demonstrate comprehensively optimized anti-ferroelectric HfAlOx films, achieving the high saturated polarization charge density and doping concentration in doped-HfO2 films. This produces the ultrathin anti-ferroelectric energy storage device with high energy storage density. With the optimized deposition temperature of 300 oC, Hf:Al ratio of 18:1, and electrode of tungsten, a 6.5-nm-thick anti-ferroelectric HfAlOx film is realized with a high energy storage density of 63.7 J/cm3, which is the thinnest anti-ferroelectric film among all the reported works, associated with such a high energy storage density. This not only provides an effective way to improve the scaling ability of anti-ferroelectric HfAlOx films, but also demonstrate a new approach to strength the control of the phase transition.