Sub-100-nA-Operating Si-Compatible Ni/Ti/HfO2/SiO2/Si RRAM Device for High-Density Integration and Low-Power Applications

Abstract

In this study, we examined the switching behavior of a bipolar resistive random-access memory (RRAM) in a Ni/Ti/HfO2/SiO2/p+Si structure and its fabrication process for compatibility with complementary metal-oxide-semiconductor (CMOS). The HfO2-based RRAM device embedding SiO2 layer demonstrated ultra-low resistive switching of sub-100-nA. Also, more accurate models are proposed to explain the resistive switching and conduction mechanisms of the device. The SiO2 reduces the switching current as a tunneling barrier and the HfO2 layer plays a primary role in resistive switching by trapping and de-trapping the electrons. Furthermore, a large number of switching cycles with low reset current (41.5-nA) were demonstrated from the results of DC endurance tests.