Proton radiation hardness of single-nanowire transistors using robust organic gate nanodielectrics

In this contribution, the radiation tolerance of single ZnO nanowire field-effect transistors (NW-FETs) fabricated with a self-assembled superlattice (SAS) gate insulator is investigated and compared with that of ZnO NW-FETs fabricated with a $60nm$ $SiO2$ gate insulator. A total-radiation dose study was performed using $10MeV$ protons at doses of 5.71 and $285krad(Si)$⁠. The threshold voltage $(Vth)$ of the SAS-based ZnO NW-FETs is not shifted significantly following irradiation at these doses. In contrast, $Vth$ parameters of the $SiO2$-based ZnO NW-FETs display average shifts of $∼−4.0$ and $∼−10.9V$ for 5.71 and $285krad(Si)$ $H+$ irradiation, respectively. In addition, little change is observed in the subthreshold characteristics (off current, subthreshold slope) of the SAS-based ZnO NW-FETs following $H+$ irradiation. These results strongly argue that the bulk oxide trap density and interface trap density formed within the SAS and/or at the SAS-ZnO NW interface during $H+$ irradiation are significantly lower than those for the corresponding $SiO2$ gate dielectrics. The radiation-robust SAS-based ZnO NW-FETs are thus promising candidates for future space-based applications in electronics and flexible displays.