DLTS measurement of energetic levels in silicon detector damaged by neutrons

DLTS is one of several methods for detecting and characterizing deep levels in semiconductors. Its major strength is that it is spectroscopic, i.e. it gives a unique line or peak for each deep level detected, in a way which makes it quick and easy to relate the spectrum to the concentration and energy of each defect - at least in quantitative sense. Quantitative information is obtained from the spectra with a small amount of analysis and the signatures of common defects. The key to the DLTS measurement is that as the electron are emitted to the conduction band they leave behind a (net) positive charge - increasing the space charge density. The measured results show that after a high dose of neutron irradiation thus creating a number of clusters of failures, whose effects are reflected in the result in the impossibility of measuring capacity of the PN junction: only after annealing failure occurs the separation of different point defects, which have measurable energy levels in the forbidden band. We can conclude that in case of such high dose can be measured changes in VA characteristics and used measured results for dosimetry for determine dose determination. Dosimeters for high doses are used today in chemistry, sterilization, nuclear technology, in experiments with large accelerators, etc. (authors)