Effects of interaction between defects on the uniformity of doping HfO₂-based RRAM: a first principle study

Abstract

The physical mechanism of doping effects on switching uniformity and operation voltage in Al-doped HfO2 resistive random access memory (RRAM) devices is proposed from another perspective: defects interactions, based on first principle calculations. In doped HfO2, dopant is proved to have a localized effect on the formation of defects and the interactions between them. In addition, both effects cause oxygen vacancies (VO) to have a tendency to form clusters and these clusters are easy to form around the dopant. It is proved that this process can improve the performance of material through projected density of states (PDOS) analysis. For VO filament-type RRAM devices, these clusters are concluded to be helpful for the controllability of the switching process in which oxygen vacancy filaments form and break. Therefore, improved uniformity and operation voltage of Al-doped HfO2 RRAM devices is achieved.