Reactions of interstitial carbon with impurities in silicon particle detectors

We present deep level transient spectroscopy (DLTS) data measured on very high resistivity $n$-type float-zone silicon detectors after irradiation with 6 MeV electrons. The carbon interstitial annealing kinetics is investigated as a function of depth in the detector structure and related to the inhomogeneous depth distribution of oxygen and carbon impurities in the devices. We compare our results with data published in previous works and point out some possible misinterpretation of DLTS data due to detector processing induced inhomogeneous distribution of impurities. Finally, we present a method to determine the absolute concentration of the oxygen and carbon impurities as functions of depth in devices by carefully analyzing the carbon interstitital annealing kinetics.