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 6×10¹³ n/cm² to 2×10¹⁵ n/cm ². At 6×10¹³ n/cm² the device degradation was negligible while at 2×10¹⁵ n/cm² 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^-1 in the n region of the JFET resulted in calculated threshold voltage shifts consistent with those observed experimentally