Dose rate and total dose dependence of the 1/f noise performance of a GaAs operational amplifier during irradiation

Dose rate and total dose dependence of the 1/f noise performance of a custom GaAs MESFET operational amplifier during irradiation are presented. Dose rate dependent 1/f noise degradation during irradiation is believed to be due to electron trapping in deep levels, enhanced by backgating and shallow traps excited during irradiation. The reduction of this effect with accumulated total dose is believed to be due a reduction of deep level site concentration associated with substitutional oxygen. Post irradiation 1/f noise degradation is also presented. The generation-recombination noise observed post irradiation can be attributed to the production of shallow traps due to ionizing radiation.