Development of the self-aligned top-gate MoS2 transistor with the recorded radiation tolerance

Abstract

In this study, top-gate molybdenum disulfide (MoS2) field-effect transistors (FETs) with a recorded electron irradiation tolerance up to 1016 e/cm2 fluence were fabricated. To quantify the radiation effects, MoS2 FETs with various channel length (L) and dielectric thickness (tox) values were exposed to electron irradiation with fluences of 1014, 1015, and 1016 e/cm2, and the radiation-induced performance degradations were extracted. Thanks to the 7.1 × 1010 eV−1 · cm−2 ultra-low interface state density in MoS2 FETs, the radiation-induced charge trapping can be largely suppressed, guaranteeing high-radiation tolerance. The largest degradation was observed after a 1015 e/cm2 radiation. Moreover, comparative studies indicated that increasing L and reducing tox can further enhance the radiation tolerance, reducing the threshold voltage shift and subthreshold swing enlargement to −0.29 V and 2.1 mV/dec, respectively. These results surpass those in all published thin-film transistors, promoting MoS2 FETs for applications in space exploration and nuclear technology.