1S1R sub-threshold operation in Crossbar arrays for low power BNN inference computing

Abstract

We experimentally validated the sub-threshold reading strategy in OxRAM+OTS crossbar arrays for low precision inference in Binarized Neural Networks. In order to optimize the 1S1R sub-threshold current margin, an experimental and theoretical statistical study on HfO2-based 1S1R stacks with various OTS technologies has been performed. Impact of device features (OxRAM RHRS, OTS non-linearity and OTS threshold current) on 1S1R sub-threshold reading is elucidated. Accuracy and power consumption of a Binarized Neural Network designed in 28nm CMOS have been estimated with Monte Carlo simulations. A gain of 3 orders of magnitude in power consumption is demonstrated in comparison with conventional threshold reading strategy, while preserving the same network accuracy.