Stability and Reliability of van der Waals High-κ SrTiO Field-Effect Transistors with Small Hysteresis.

Single-crystal SrTiO (STO) is an ultrahigh-κ insulator with an expected low interface trap density that promises high breakdown strength and has great potential to boost the reliability of two-dimensional (2D) field-effect transistors (FETs). Here we provide a detailed study of the performance, stability, and reliability of MoS FETs with STO gate insulators. Most importantly, we observe a small hysteresis for electric fields up to 8 MV cm at a sweep rate range spanning 0.01-1 V s and sweep times of kiloseconds. Interestingly, the hysteresis is counterclockwise and bias temperature instability (BTI) is often anomalous, both likely caused by the diffusion of oxygen vacancies. We also show that the hysteresis dynamics in MoS/STO FETs are reproducible over a long time, which underlines their high reliability. Our findings show that STO is a promising gate insulator that might help overcome critical obstacles to highly reliable 2D nanoelectronics.