Neutron radiation effects in GaAs junction field effect transistors

The effect of high-energy neutrons on GaAs junction field-effect transistors (JFETs) was investigated. The device threshold voltage, transconductance, and saturation current were measured before irradiation and following neutron irradiations with fluences from 6*10/sup 13/ n/cm/sup 2/ to 2*10/sup 15/ n/cm/sup 2/. At 6*10/sup 13/ n/cm/sup 2/ the device degradation was negligible while at 2*10/sup 15/ n/cm/sup 2/ the threshold voltage shift was 0.410 V, and the transconductance and saturation current were degraded to 49% and 17% of their original values, respectively. The threshold voltage shift was successfully modeled by applying nonuniform carrier removal to a Gaussian approximation of the p- and n-type doping profiles of the JFET. An average carrier removal rate of 19 cm/sup -1/ in the n region of the JFET resulted in calculated threshold voltage shifts consistent with those observed experimentally.<
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