Understanding the Effect of Oxygen Content on Ferroelectric Properties of Al-Doped HfO Thin Films

To satisfy the demand of high-speed and low-power memory in the field of integrated circuits, different elements doped HfO2 ferroelectric tunnel junctions have been developed. In this work, we investigate the annealing atmosphere effects on the ferroelectric property of the Al-doped HfO2 (HfAlO) ferroelectric tunnel junctions based on first-principles calculation and experiments. The ferroelectric layer/electrode interface has the obvious effect on ferroelectric property of the devices under different oxygen content annealing atmosphere, including 0%, 50% and 100% O2. The first-principle analysis verified that stable o-phase proportion in HfAlO film owing to the co-existence of the Al and oxygen vacancy is the key element to stable ferroelectric performance of device. This work could promote the development of HfAlO ferroelectric tunnel junctions for next-generation in-memory computing applications.