Enhanced Radiation Tolerance of MoS₂ FET via Al₂O₃ Insertion on SiO₂ Dielectric

Molybdenum disulfide (MoS2) combines a tunable bandgap and high carrier mobility, making it promising for nanoelectronics. Its inherent radiation tolerance further promotes the development of radiation-hardened devices for extreme environments, such as outer space exploration. Although research has been conducted on the damage mechanisms of MoS2 field-effect transistors (FETs) under ionizing irradiation, studies on the modulation of charge trapping through gate dielectric engineering to enhance their radiation tolerance remain relatively scarce. In this work, we designed back-gated MoS2 FETs by inserting a traditional high-κ dielectric alumina (Al2O3) between the MoS2 and silicon dioxide (SiO2), forming a MoS2/Al2O3/SiO2 structure, and compared them with MoS2/SiO2 FETs. The devices were subjected to 200 keV proton irradiation at a dose of 1 × 1014 cm–2, and the comparative results show that the MoS2 FET with Al2O3 exhibits significantly enhanced radiation tolerance. This improvement is primarily attributed to the high dielectric screening effect of Al2O3, which greatly reduces Coulomb scattering, thereby not only mitigating displacement damage in the MoS2 channel but also effectively suppressing the generation of interface and oxide trapped charges. Therefore, dielectric engineering serves as a critical strategy to provide support for the development of two-dimensional electronic systems that can operate reliably in extreme radiation environments.