Radiation Effects in InP JFETs

Transient and total dose radiation effects were studied in InP JFETs under bias conditions. The transient responses in drain current, ID, and output power, Po, at 4.5 GHz following 50 ns pulses of 40 MeV electrons were small up to 1.7×101l rad(InP)/s. The long term transient response is postulated to result from substrate trapping of radiation induced carriers and consequent backgating. No measureable drift in ID was observed following exposure to 40 MeV pulsed electrons, 1 MeV ele brons from a Van de Graaff, or gamma rays from a Co60 source. No significant degradation was found in ID or Po up to a total dose of 8×108 rad (InP). The hardness level for 1 MeV gamma irradiation is greater than 108 rad and for 1 MeV electron irradiation it is greater than 8×108 rad, exceeding that of GaAs by more than an order of magnitude. Total dose degradation is the result of carrier removal.