Long Term Transient Radiation Response of GaAs FETs Fabricated on an AlGaAs Buffer Layer

A radiation hardening method for GaAs FETs has been developed using an AlGaAs buffer layer. The long term transient response resulting from irradiation with 40 MeV electrons and flash x-rays was reduced by an order of magnitude compared to FETs fabricated without the buffer layer. A model is discussed to explain the reduced transient effect in which the buffer layer plays the role of isolating the active layer from radiation induced stored charge in the substrate.