Current-Voltage Characterization Of Gaas Detectors And Their Holders Irradiated By High-Energy Electrons

In our radiation hardness studies we observed that SI GaAs detectors irradiated by 5 MeV electrons exhibited different behaviour with applied dose when considering their electrical and spectrometric properties. The detectors were prepared by the same technology using one GaAs wafer differing in the type of holder used to wirebond the detectors. In this paper the commercially available detector holders together with self-prepared ones were irradiated by 5 MeV electrons under the same conditions as the investigated detectors before. Three types of detector holders were studied to evaluate their radiation hardness: holders prepared on a Printed Circuit Board (PCB), Poly-Vinyl-Chloride (PVC) holders and two different ceramic holders. The best radiation stability was obtained with a holder self-made from aluminium oxide ceramics using gold metallization. The PCB and the PVC holders exhibited similar radiation stability. The most unstable at doses over 500 kGy was the holder made by silk-screen printing technology from ceramics with silver metallization. No significant influence of the dose rate used during irradiation (in the range from 20 to 80 kGy/h) was observed in all types of holders.