Solution‐processed high‐ k oxide dielectric via deep ultraviolet and rapid thermal annealing for high‐performance MoS 2 FETs

So far most of MoS 2 ‐based devices have been demonstrated on oxide gate dielectrics (e.g., SiO 2 , Al 2 O 3 , HfO 2 , etc) deposited by vacuum process or on polymer gate dielectrics. In this study, we report electrical characteristics of multilayer MoS 2 transistors fabricated on solution‐processed high‐ k AlO x gate dielectric via deep ultraviolet (DUV) activation in combination with rapid thermal annealing process at 250 °C. The solution‐processed AlO x sol–gel film exhibited low leakage current of about 1.49 μA cm −2 at 1 MV cm −1 and a relative dielectric constant ( k ) of ∼6.1 at 1 kHz. The fabricated MoS 2 ‐FETs exhibit median field‐effect mobility of ∼23.3 cm 2  V −1 s −1 , threshold voltage of ∼ 0.79 V, subthreshold slope of ∼0.30 V dec −1 , and on/off current ratio of ∼10 7 . The electrical performance can be further improved by optimizing the AlO x sol–gel film as well as the device structure, and the result implies that the solution‐processed high‐ k AlO x is promising for TMDC–based device applications.