Optimized Reading Window for Crossbar Arrays Thanks to Ge-Se-Sb-N-based OTS Selectors

In this paper, we investigate the impact of Ovonic Threshold Switching (OTS) selector electrical parameters, such as the threshold and the holding current, on the reliability of the reading operation in 1S1R memory devices. Through physico-chemical analysis and electrical characterization of Se-rich Ge-Se-based OTS selectors, performed up to 400 °C, we demonstrate the possibility to reduce the fire voltage as well the leakage current thanks to N- and Sb-doping. Moreover, we describe the correlation that exists between the leakage current and the threshold current in OTS devices. We highlight the subsequent trade-off between the reading window and the array size in an OTS-based Memory Crossbar Array, evaluated up to an operating temperature of 150 °C. Finally, thanks to OTS engineering, we demonstrate how the reading window can be optimized for a target array size and application.