Anomalous Positive Bias Stress Instability in MoS2 Transistors With High-Hydrogen-Concentration SiO2 Gate Dielectrics

For the first time, in this letter, the anomalous positive bias stress instability of the back gated monolayer polycrystal molybdenum disulfide (MoS
₂
) field-effect transistors with high-hydrogen-concentration SiO
₂
gate dielectrics is reported. It is found that the threshold voltage shifts exhibit a pronounced turnaround behavior from a positive shift to a negative shift when enlarging the stress voltage and stress time. We relate this anomalous positive bias instability to two physical processes, charge trapping and hydrogen release and migration.