Spin-dependent recombination electron paramagnetic resonance spectroscopy was applied for investigation of paramagnetic recombination centers in irradiated Si p–n junction detectors (diodes) formed on float-zone Si wafers. The main radiation defects, associated with spin-dependent recombination electron paramagnetic resonance spectra arising from excited triplet states, were assigned to complexes of 2 substitutional C atoms and 1 interstitial Si atom (CS + SiI + CS) and to O + vacancy (O + V) complexes (A-centers). In spite of the low concentration of O in float-zone Si the A-centers were found to play an important role in the recombination process in the diodes. Below 100K, the spin-dependent recombination electron paramagnetic resonance spectra were well observable by measurements of the microwave conductivity or by detecting a dc forward current IF below a forward-blocking voltage, UFBL. At UFBL, the IF exhibited a steep jump followed by a decrease in the voltage over the diode and a negative resistance region with oscillations of the current. The spin-dependent recombination electron paramagnetic resonance spectrum arising from the (CS + SiI + CS) complexes was found to decrease strongly in the forward biased diodes. This effect could be attributed to coexistence of 2 different configurations of the C related defect in the bulk n-type region of the diodes.

Spin-Dependent Recombination Electron Paramagnetic Resonance Spectroscopy of Defects in Irradiated Silicon Detectors. V.Eremin, D.S.Poloskin, E.Verbitskaya, M.P.Vlasenko, L.S.Vlasenko, R.Laiho, T.O.Niinikoski: Journal of Applied Physics, 2003, 93[12], 9659-64