The effect of high-energy electrons irradiation on the current-voltage characteristics of Schottky barriers detectors based on semi-insulating GaAs

In this work we report the study of electrical properties of irradiated samples base on SI GaAs Schottky diodes with high-energy electrons. We report the influence of irradiation dose to breakdown voltage and reverse current of detector structure because these parameters are important in light of spectrometric performances of detectors. We have investigated the influence of irradiation with 5 MeV electrons on reverse current-voltage characteristics of SI GaAs Schottky detector diodes. The total irradiation dose of 88 kGy was cumulated in 10 steps whereby after each the breakdown voltage and reverse current were analyzed. Samples were divided into three groups according to different dose rate (20, 40 and 80 kGy/h) which was studied. Results demonstrate progressive degradation and at total dose of 88 kGy the breakdown voltage decreased about 20 - 25 % of value measured on untouched samples according to used dose rate. Very similar dependence was observed also for reverse current flowing through detector structures. This behaviour can be assigned to creation of point defects like vacancies, anti-sites, and interstitials after irradiation with high-energy electrons. Experiments will be continuing until samples are capable of operation. (authors)