Gamma-Irradiation-Induced Electrical Characteristic Variations in MoS 2 Field-Effect Transistors with Buried Local Back-Gate Structure.

The impact of radiation on MoS 2 -based devices is an important factor in the utilization of two-dimensional semiconductor-based technology in radiation-sensitive environments. In this study, the effects of gamma irradiation on the electrical variations in MoS 2 field-effect transistors with buried local back-gate structures were investigated, and their related effects on Al 2 O 3 gate dielectrics and MoS 2 /Al 2 O 3 interfaces were also analyzed. The transfer and output characteristics were analyzed before and after irradiation. The current levels decreased by 15.7% under an exposure of 3 kGy. Additionally, positive shifts in the threshold voltages of 0.50, 0.99, and 1.15 V were observed under irradiations of 1, 2, and 3 kGy, respectively, compared to the non-irradiated devices. This behavior is attributable to the comprehensive effects of hole accumulation in the Al 2 O 3 dielectric interface near the MoS 2 side and the formation of electron trapping sites at the interface, which increased the electron tunneling at the MoS 2 channel/dielectric interface.