GaAs metal-semiconductor field effect transistors were exposed to 40 MeV protons at fluences up to
5×109 cm−2.
The extrinsic transconductance decreased from 98 to
68 mS mm−1
over this fluence range, with the drain-source current decreasing by
∼30%
under the same conditions. Based on the increases observed in the reverse breakdown voltage and the channel resistance, the main degradation mechanism appears to be introduction of deep electron traps which reduce the effective doping in the channel. The device threshold voltage and diode ideality factor showed little change upon irradiation. © 2002 The Electrochemical Society. All rights reserved.