Impact of argon-ambient annealing in hafnium oxide Resistive Random Access Memory

Resistive Random Access Memory (ReRAM) gained significant interest recently, as they offer new means of performing data storage and processing. This is attributed to its simple structure, low power consumption, high endurance, and high density of integration [1], [2]. Even though recent performance results are encouraging, several obstacles hinder market adoption. Among them is the initial high-voltage forming step needed to initiate resistive switching, which presents issues in device integration and reliability. Many approaches have been explored to remove/reduce the forming voltage, such as using a thin switching oxide [3]. Others studies focused on controlling the concentration of oxygen vacancies by doping the oxide [4,5], or by using an oxygen exchange layer [6]. In this work, we study the effect of annealing in Ar on the forming voltage and electrical characteristics of HfO_x ReRAM. A study on amorphous HfO_x thin films showed that annealing in Ar results in the introduction of copious amount of oxygen vacancies as evidenced by an enhanced photoluminescence emission in the visible range [7].