Effect of VOx interlayer in Cu /HfOx/TiN cell and its resistive switching mechanism

Abstract

In order to improve the performance of HfOx-based resistive random access memory (RRAM), a VOx buffer layer was introduced in the Cu/HfOx interface of Cu/HfOx/TiN RRAM cell in this paper. Their resistive switching characteristics (such as I-V characteristics, endurance and retention) and the switching mechanism were investigated. Results show that the VOx buffer layer acts as a barrier which avoids excessive Cu ion reaching to HfOx layer as result to improve the device performances. The current conduction mechanism of low resistive state (LRS) is Ohmic conduction while the high resistive state (HRS) is Schottky emission. Based on the negative temperature coefficient of LRS resistance and conduction mechanism, we believe that the resistive switching between HRS and LRS is attributed to the Cu-CF's formation and rupture.