Low temperature proton irradiation of GaAs MESFETs

Abstract
GaAs MESFETs and resistors were irradiated with 3 MeV protons at irradiation temperatures (T-IRR ranging from 100 K less than or equal to T-IRR less than or equal to 300 K. It was found that irradiation at T-IRR less than or equal to 225 K was about 2.5 times more effective at degrading the DC electrical parameters of the MESFETs than irradiation at room temperature. Isochronal annealing experiments showed that there was no apparent recovery of the radiation induced degradation for annealing temperatures T-ANNEAL < 225 K. Both the MESFETs and resistors exhibited a broad annealing stage near 270 K. The implications for spaceborne GaAs devices operated at cryogenic temperature are discussed.