Radiation Effect on the Parameters of Field Effect Transistors with Schottky Barrier on GaAs

In the present work, we report the result of the study of electron and γ-radiation effect on the parameters of normally open and normally closed field effect transistors with Shottky barrier on GaAs. It has been shown that normally closed transistors are more sensitive to the action of radiation than normally opened transistors. Both transistors are more sensitive to the electron radiation. As substrates ware used epitaxial structures of GaAs of n-type conductivity doped with tellurium with N_D=2×10¹⁷ cm³ with surface orientation [100]. Electron irradiation was conducted on the linear accelerator of RELUS type with electron energy 4 MeV at the room temperature, with the intensity of electrons flow of 2.5×10¹² e/cm² sec. Integral doses made 1×10¹⁴ e/cm², 5×10¹⁴ e/cm², 1×10¹⁵ e/cm² and 3×10¹⁵ e/cm². The γ-radiation was conducted using the source ⁶⁰Co at the room temperature with the intensity of 5×10³ P/sec. For the γ-radiation, visible changes of saturation flow current are observed at the doses of more than 10⁵ Grey (GaAs). As whole, the γ-radiation makes an action on the parameters of MESFET in the less degree than electron irradiation. The annealing of the irradiated samples of MESFET at the temperature of 573 K in the nitrogen atmosphere for 45 min provides complete restoration of their parameters. The possible reasons for the mentioned effects are given. (paper)