Charge and energy deposition in thick silicon depletion layers by environmental ionizing radiation and terrestrial cosmic rays

摘要

This paper reports about the results of a long-term experiment intended to measure the energy and the charge deposited by environmental ionizing radiation in thick silicon depletion layers, which are representative of the situation encountered in some high-voltage semiconductors. These measurements have been carried out to provide quantitative and statistically consistent data to support the design of robust and reliable power devices as well as the related TCAD simulations. Special attention is paid to the charge deposition immediately before the onset of charge multiplication. The proposed experimental setup uses a calibrated, almost abrupt PiN junction detector with a 100 μm thick depletion layer, where the maximum electric filed is kept below 12 kV/cm to avoid local charge multiplication while achieving full charge collection. The dedicated spectrometry chain is capable of measuring charge deposition in the 1 to 1000 fC range to detect interactions due to terrestrial cosmic neutrons, terrestrial cosmic muons and environmental gamma radiation. The experiment has been performed in Central Europe starting from August 2017 for a duration of six months, under none, moderate, and high shielding conditions, and it has been designed to resolve fluxes above 0.00023 cm−2 h−1with 90% confidence level.