The influence of high-energy electrons irradiation on the electrical properties of Schottky barrier detectors based on semi-insulating GaAs

In this work we fabricated detectors based on semi-insulating GaAs and studied their electrical properties (current-voltage characteristics, galvanomagnetic measurements) after irradiation with 5 MeV electrons from a linear accelerator up to a dose of 104 kGy. A series of detectors were prepared using Ti/Pt/Au Schottky contact with 1mm diameter. The thickness of the base material was about 230 mu m. A whole area Ni/AuGe/Au ohmic contact was evaporated on the back side. For galvanomagnetic measurements we used three samples from the same wafer. All samples were irradiated by a pulse beam of 5 MeV electrons using the linear accelerator in 11 steps, where the accumulative dose increased from 1 kGy up to 104 kGy. Also different dose rates (20, 40 and 80 kGy/h) were applied to the samples. After each irradiation step we performed electrical measurement of each sample. We analyze the electron Hall mobility, resistivity, electron Hall concentration, breakdown voltage and reverse current of samples before and after irradiation using different dose rates.