Analyzing the synergistic effect of ionization and displacement damage in carbon nanotube field-effect transistors using protons irradiation

While CNT FETs have been demonstrated to exhibit excellent resistance to irradiation, the radiation effects in complex environments remain relatively understudied. This paper investigates the synergistic effect of CNT FETs under the combined action of ionization and displacement damage using proton irradiation. It was observed that the Vth degradation (0.06 V) induced by 40 MeV protons was twice that (0.03 V) induced by 70 MeV protons with the same ionization dose. The numerical simulations indicated that the 40 MeV proton irradiation results in the formation of displacement defects in closer proximity to the semiconductor channel. This increased the hole capture rate, leading to a higher concentration of fixed charge in the SiO2 layer and a larger threshold voltage shift.