On the identity of a crucial defect contributing to leakage current in silicon particle detectors
2008; American Institute of Physics; Volume: 92; Issue: 13 Linguagem: Inglês
10.1063/1.2896313
ISSN1520-8842
AutoresJ. H. Bleka, Л.И. Мурин, Edouard V. Monakhov, B. S. Avset, Bengt Svensson,
Tópico(s)Radiation Detection and Scintillator Technologies
ResumoThe annealing kinetics of the so-called E4/E5 center or E4a/E4b center in electron-irradiated Si particle detectors has been studied at four different temperatures from 23to65°C using deep-level transient spectroscopy (DLTS). The center gives rise to two energy levels at 0.37 and 0.45eV below the conduction-band edge, and the annealing process is found to be of dissociative nature with an energy barrier of 1.1–1.2eV. A striking similarity of the annealing rates (and kinetics) is revealed with that obtained for the 936-cm−1 infrared absorption band, studied by Fourier-transform infrared spectroscopy using identical type of Si material as in the DLTS study but irradiated with neutrons. The result strongly suggest that the E4/E5 levels and the 936-cm−1 band originate from the same defect, and the latter has been attributed to a di-interstitial-oxygen (I2O) complex. The E4/E5 center plays a crucial role for the detrimental leakage current in irradiated Si particle detectors, and an assignment of E4/E5 to I2O implies that oxygen-lean Si material (<1014cm−3) should be advantageous to enhance detector performance.
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