Reaction-Drift Model for Switching Transients in Pr_(0.7)Ca_(0.3)MnO₃ Based Resistive RAM

Earlier, the DC hole-current modeling of PCMO RRAM by drift-diffusion (DD) including self-heating (SH) in TCAD (but without ionic transport) was able to explain the experimentally observed SCLC characteristics, prior to resistive switching. Further, transient analysis using DD+SH model was able to reproduce the experimentally observed fast current increase at ~100ns timescale followed by saturation increases, prior to resistive switching. However, resistive switching requires the inclusion of ionic transport. We propose a Reaction-Drift (RD) model of oxide ions, which is combined with the DD+SH model. Experimentally, SET operations consist of 3 stages and RESET operations consists of 4 stages. The DD+SH+RD model is able to reproduce the entire transient behavior over 10$^{-8}$-1s range in timescale for both SET and RESET operations for a range of bias, temperature. Remarkably, a universal RESET behaviour of $log(I)\propto m*log(t)$, where $m\approx -1/10$, is reproduced. The quantitatively different voltage time dilemma for SET and RESET is also replicated for a range of ambient temperature. This demonstrates a comprehensive model for resistance switching in PCMO based RRAM.