Effect of Hf metal layer on the switching characteristic of HfOX-based Resistive Random Access Memory

In this study, we propose the insertion of an ultrathin Hf layer at the interface between TiN (top electrode) and HfO
_x
(electrolyte), and then studied its effect on the device electrical properties. In order to obtain the desired switching characteristics, the Hf layer thickness must be precisely engineered. The device with optimized Hf layer thickness exhibits better uniformity and lower forming voltage. This could be explained by the role of Hf layer in the creation of permanent oxygen vacancies in the oxide layer, which facilitates the switching phenomena.