5th RD50 - Workshop
on |
Abstract display
(Generated from database on 18-October-2004 - 5:49:08 PM)
| INTERACTION OF RESIDUAL HYDROGEN WITH
RADIATION DEFECTS IN SILICON PARTICLE DETECTORS L.F. Makarenko*, F.P. Korshunov**, S.B. Lastovski**, N.M. Kazuchits*, M.S. Rusetsky*, E. Fretwurst***, G. Lindström***, M. Moll****, I. Pintilie*****, N.I. Zamiatin****** * Belarusian State University, Minsk, Belarus **Institute of Solid State and Semiconductor Physics, Minsk, Belarus ***Hamburg University, Hamburg, Germany ****CERN, Geneva, Switzerland *****National Institute of Materials Physics, Bucharest-Magurele, Romania ******Joint Institute for Nuclear Research, Dubna, Russia |
| Hydrogen penetrates silicon crystals during wet chemical etching and high temperature oxidation etc [1]. Therefore possibly all silicon particle detectors contain hydrogen which remained in these structures after fabrication. However the behavior of hydrogen in detector-grade silicon and detectors processed from that material is poorly studied. This work aims to investigate the interaction between hydrogen and radiation defects in silicon particle detectors. We used detector structures made from high purity silicon crystals (produced by Wacker Chemitronics, Germany) by different producers: 1) CiS Institute for Microsensors, Erfurt, Germany (C-diodes); 2) ST Microelectronics, Catania, Italy (W-diodes); 3) ELMA, Zelenograd, Russia (Z-diodes). Radiation defects were introduced by irradiation with electrons with an energy of 3.5 or 6 MeV and Co-60 gamma-rays. After irradiation, isochronous annealing (30 min) was performed in air in the temperature range of 50–350 °C. Defect reactions have been studied using deep level transient spectroscopy (DLTS) and C-V measurements. The appearance of the vacancy-oxygen-hydrogen (V-O-H) complex has been used to detect hydrogen availability in the structures under study. It has been found that in these three structures hydrogen activation begins at different temperatures: in Z-diodes – at 100 °C, in W-diodes – at 250 °C, in C-diodes – at 350°C. The formation of the V-O-H complex is accompanied by elimination not only of the vacancy-oxygen complex but additionally of the divacancy (V-V). In Z-diodes the divacancy concentration is decreasing in a wide temperature range (100-250 °C). In W- and C-diodes divacancies have been eliminated in a very narrow temperature interval (/delta/T<50 K). This behavior is explained by an inhomogeneous distribution of hydrogen in W- and C-diodes. From studies of hydrogenated diodes, it has shown that hydrogen pentration depth at 300 °C can be more than 0.1 mm. The different behavior of the three detector sets is suggested to be due to different regimes during their manufacturing after oxide etching. 1. S.J. Pearton, J.W. Corbett, and M. Stavola, Hydrogen in Crystalline Semiconductors. Springer-Verlag, Berlin, 1992 |
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5th RD50
Workshop on Radiation hard semiconductor devices
for very high luminosity colliders, |