High-drive current (>1MA/cm2) and highly nonlinear (>103) TiN/amorphous-Silicon/TiN scalable bidirectional selector with excellent reliability and its variability impact on the 1S1R array performance

Abstract

An optimized TiN/amorphous-Silicon/TiN (MSM) two-terminal bidirectional selector is proposed for high density RRAM arrays. The devices show superior performance with high drive current exceeding 1MA/cm2 and half-bias nonlinearity of 1500. Excellent reliability is fully demonstrated on 40nm-size crossbar structures, with statistical ability to withstand bipolar cycling of over 106 cycles at drive current conditions and thermal stability of device operation exceeding 3hours at 125°C. Furthermore, for the first time, we address the impact of selector variability in a 1S1R memory array, by including circuit simulations in a Monte Carlo loop and point out the importance of selector variability for the low resistive state and its implications on the read margin and power consumption.