Polarity-dependent threshold voltage shift in ovonic threshold switches: Challenges and opportunities

In this paper we investigate the operation of Si-Ge-As-Te Ovonic Threshold Switch (OTS) selectors under bipolar pulses. We observe that the threshold voltage increases noticeably if the previous pulse had opposite polarity. This effect is consistently present under different test conditions and persists for a long time (>1000s). We also investigate its impact on 1S1R operation, and discuss possible applications, such as OTS-only memory element.