Radiation-proof characteristic of ZnO/ZnMgO HFETs

We studied the radiation hardness of the ZnO/ZnMgO heterostructure field-effect transistors (HFETs) by irradiating 200 MeV proton beam for fluences up to 3.6 × 10
¹⁴
p/cm
²
. The change of the characteristics was monitored and compared with those of GaAs HEMTs. The saturation drain current for the ZnO/ZnMgO HFETs decreased by 10% while that of GaAs HEMTs decreased by 50% at proton beam fluence of 3.6 × 10
¹⁴
p/cm
²
. The results demonstrate the superior radiation hardness of the ZnO/ZnMgO HFETs. The fact that little resistance change was observed for the as-grown ZnO/ZnMgO heterostructure implies the reduced drain current observed for HFETs might be caused by degradation of gate dielectric.