Radiation hardness of silicon detectors based on pre-irradiated silicon

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 568; no. 1; pp. 78 - 82
• Main Authors: Litovchenko, P.G., Groza, A.A., Lastovetsky, V.F., Barabash, L.I., Starchik, M.I., Dubovoy, V.K., Bisello, D., Giubilato, P., Candelori, A., Rando, R., Litovchenko, A.P., Khomenkov, V., Wahl, W., Boscardin, M., Zorzi, N., Dalla Betta, G.-F., Cindro, V., Mikelsen, M., Monakhov, E.V., Svensson, B.G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30-11-2006
• Subjects: Defect engineering; Neutron irradiation; Radiation damage; Radiation hardness; Semiconductor detectors; Silicon particle detectors; SLHC; Super-LHC; Defect engineering; SLHC; Semiconductor detectors; Silicon particle detectors; Neutron irradiation; 61.82.Fk; 29.40.Gx; Super-LHC; Radiation hardness; Radiation damage; 29.40.Wk
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2006.05.207

Radiation hardness of planar detectors processed from pre-irradiated and thermo-annealed n-type FZ silicon substrates, and standard FZ as a reference, was studied. The high purity n-Si wafers with carrier concentration 4.8×10
11
cm
−3 were pre-irradiated in Kiev's nuclear research reactor by fast neutrons to fluence of about 10
16
neutrons/cm
2 and thermo-annealed at a temperature of about 850
°C. Silicon diodes were fabricated from standard and pre-irradiated silicon substrates by IRST (Italy). All diodes were subsequently irradiated by fast neutrons at Kiev and Ljubljana nuclear reactors. The dependence of the effective doping concentration as a function of fluence (
N
eff
=f(
Φ)) was measured for reference and pre-irradiated diodes. Pre-irradiation of silicon improves the radiation hardness by decreasing the acceptor introduction rate (
β), thus mitigating the depletion voltage (
V
dep) increase. In particular,
β in reference samples is about 0.017
cm
−1, and for pre-irradiated samples is about 0.008
cm
−1. Therefore, the method of preliminary irradiation can be useful to increase the radiation hardness of silicon devices to be used as sensors or detectors in harsh radiation environments.