Author:
Kushpil V.,Ladygin V.,Kushpil S.
Abstract
The purpose of this study is to understand the change of the SiPM structure after irradiation. We compared the profile of the electric field in the SiPM (KETEK) active region for ten not-irradiated and irradiated detectors. The standard method of measurement of C-V characteristics was applied using two configurations (serial and parallel circuit) to exclude the influence of the serial resistance. Dependencies of capacitance on the frequency were studied in the range from 10 to 1000 KHz. For non-irradiated detectors we detected in CV characteristics the local instability basically connected with accumulation of charge on boundary optical isolation-silicon. In addition, the hysteresis of CV characteristics was detected. For irradiated detectors the local instability was visible as well but the hysteresis of CV characteristics was not detected. The results demonstrate that the applied method can be used for the relative analysis of how SiPM active region properties changed after irradiation.