Investigation of $I-V$ Linearity in TaO_x-Based RRAM Devices for Neuromorphic Applications

Abstract

We perform experiments and device simulations to investigate the origin of current-voltage (I-V) linearity of TaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> -based resistive switching memory (RRAM) devices for their possible application as electronic synapses. By using electrical characterization and simulations, we link the electrical characteristics (linear or nonlinear I-V) to the microscopic properties of the conductive filament (CF). Our findings indicate that the shape and the thermal properties of the CF region are crucial to achieve linear I-V characteristics. These results allow optimizing the I-V curve linearity of TaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> -based RRAM devices, explaining the wide range of linear I-V characteristics experimentally observed on RRAM device obtained. When weight sum operation using SPICE simulations is performed, the read current is improved under the condition of linear I-V characteristics due to current loss minimization.