Fast statistical model of TiO2 thin-film memristor and design implication

The emerging memristor devices have recently received increased attention since HP Lab reported the first TiO₂-based memristive structure. As it is at nano-scale geometry size, the uniformity of memristor device is difficult to control due to the process variations in the fabrication process. The incurred design concerns in a memristor-based computing system, e.g, neuromorphic computing, can be very severe because the analog states of memristors are heavily utilized. Therefore, the understanding and quantitative characterization of the impact of process variations on the electrical properties of memristors become crucial for the corresponding VLSI designs. In this work, we examined the theoretical model of TiO₂ thin-film memristors and studied the relationships between the electrical parameters and the process variations of the devices. A statistical model based on a process-variation aware memristor device structure is extracted accordingly. Simulations show that our proposed model is 3 ~ 4 magnitude faster than the existing Monte-Carlo simulation method, with only ~ 2% accuracy degradation. A variable gain amplifier (VGA) is used as the case study to demonstrate the applications of our model in memristor-based circuit designs.