LOW-TEMPERATURE PROTON IRRADIATION OF GAAS-MESFETS

GaAs MESFETs and resistors were irradiated with 3 MeV protons at irrad iation 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-IR R less than or equal to 225 K was about 2.5 times more effective at de grading the DC electrical parameters of the MESFETs than irradiation a t room temperature. Isochronal annealing experiments showed that there was no apparent recovery of the radiation induced degradation for ann ealing temperatures T-ANNEAL < 225 K. Both the MESFETs and resistors e xhibited a broad annealing stage near 270 K. The implications for spac eborne GaAs devices operated at cryogenic temperature are discussed.