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Title: The effect of irradiation with high-energy protons on 4H-SiC detectors

Abstract

The effect of irradiation of 4H-SiC ionizing-radiation detectors with various doses (as high as 10{sup 16} cm{sup -2}) of 24-GeV protons is studied. Isotopes of B, Be, Li, He, and H were produced in the nuclear spallation reactions of protons with carbon. Isotopes of Al, Mg, Na, Ne, F, O, and N were produced in the reactions of protons with silicon. The total amount of the produced stable isotopes varied in proportion with the radiation dose from 1.2 x 10{sup 11} to 5.9 x 10{sup 13} cm{sup -2}. It is shown that, at high radiation doses, the contact characteristics of the detectors change appreciably. The potential-barrier height increased from the initial value of 0.7-0.75 eV to 0.85 eV; the rectifying characteristics of the Schottky contacts deteriorated appreciably. These effects are attributed to the formation of a disordered structure of the material as a result of irradiation.

Authors:
 [1];  [2]; ;  [3]
  1. Vilnius University, Semiconductor Physics Department and Institute of Materials Science and Applied Research (Lithuania), E-mail: vaidotas.kazukauskas@ff.vu.lt
  2. Institute of Physics (Lithuania)
  3. Vilnius University, Semiconductor Physics Department and Institute of Materials Science and Applied Research (Lithuania)
Publication Date:
OSTI Identifier:
21088097
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductors; Journal Volume: 41; Journal Issue: 3; Other Information: DOI: 10.1134/S1063782607030190; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CARBON; GEV RANGE 10-100; IONIZING RADIATIONS; IRRADIATION; MILLI EV RANGE; PHYSICAL RADIATION EFFECTS; PROTON BEAMS; RADIATION DOSES; SI SEMICONDUCTOR DETECTORS; SILICON; SILICON CARBIDES; SPALLATION; STABLE ISOTOPES

Citation Formats

Kazukauskas, V., Jasiulionis, R., Kalendra, V., and Vaitkus, J.-V.. The effect of irradiation with high-energy protons on 4H-SiC detectors. United States: N. p., 2007. Web. doi:10.1134/S1063782607030190.
Kazukauskas, V., Jasiulionis, R., Kalendra, V., & Vaitkus, J.-V.. The effect of irradiation with high-energy protons on 4H-SiC detectors. United States. doi:10.1134/S1063782607030190.
Kazukauskas, V., Jasiulionis, R., Kalendra, V., and Vaitkus, J.-V.. Thu . "The effect of irradiation with high-energy protons on 4H-SiC detectors". United States. doi:10.1134/S1063782607030190.
@article{osti_21088097,
title = {The effect of irradiation with high-energy protons on 4H-SiC detectors},
author = {Kazukauskas, V. and Jasiulionis, R. and Kalendra, V. and Vaitkus, J.-V.},
abstractNote = {The effect of irradiation of 4H-SiC ionizing-radiation detectors with various doses (as high as 10{sup 16} cm{sup -2}) of 24-GeV protons is studied. Isotopes of B, Be, Li, He, and H were produced in the nuclear spallation reactions of protons with carbon. Isotopes of Al, Mg, Na, Ne, F, O, and N were produced in the reactions of protons with silicon. The total amount of the produced stable isotopes varied in proportion with the radiation dose from 1.2 x 10{sup 11} to 5.9 x 10{sup 13} cm{sup -2}. It is shown that, at high radiation doses, the contact characteristics of the detectors change appreciably. The potential-barrier height increased from the initial value of 0.7-0.75 eV to 0.85 eV; the rectifying characteristics of the Schottky contacts deteriorated appreciably. These effects are attributed to the formation of a disordered structure of the material as a result of irradiation.},
doi = {10.1134/S1063782607030190},
journal = {Semiconductors},
number = 3,
volume = 41,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • The compensation of moderately doped p-4H-SiC samples grown by the chemical vapor deposition (CVD) method under irradiation with 0.9-MeV electrons and 15-MeV protons is studied. The experimentally measured carrier removal rates are 1.2–1.6 cm{sup –1} for electrons and 240–260 cm{sup –1} for protons. The dependence of the concentration of uncompensated acceptors and donors, measured in the study, demonstrates a linear decrease with increasing irradiation dose to the point of complete compensation. This run of the dependence shows that compensation of the samples is due to the transition of carriers to deep centers formed by primary radiation-induced defects. It is demonstratedmore » that, in contrast to n-SiC (CVD), primary defects in the carbon sublattice of moderately doped p-SiC (CVD) only cannot account for the compensation process. In p-SiC, either primary defects in the silicon sublattice, or defects in both sublattices are responsible for conductivity compensation. Also, photoluminescence spectra are examined in relation to the irradiation dose.« less
  • Ultraviolet (UV) photodetectors based on Schottky barriers to 4H-SiC are formed on lightly doped n-type epitaxial layers grown by the chemical vapor deposition method on commercial substrates. The diode structures are irradiated at 25°C by 167-MeV Xe ions with a mass of 131 amu at a fluence of 6 × 10{sup 9} cm{sup −2}. Comparative studies of the optical and electrical properties of as-grown and irradiated structures with Schottky barriers are carried out in the temperature range 23–180°C. The specific features of changes in the photosensitivity and electrical characteristics of the detector structures are accounted for by the capture ofmore » photogenerated carriers into traps formed due to fluctuations of the conduction-band bottom and valence-band top, with subsequent thermal dissociation.« less
  • Spectroscopic performance of Schottky barrier alpha particle detectors fabricated on 50 μm thick n-type 4H-SiC epitaxial layers containing Z{sub 1/2}, EH{sub 5}, and Ci1 deep levels were investigated. The device performance was evaluated on the basis of junction current/capacitance characterization and alpha pulse-height spectroscopy. Capacitance mode deep level transient spectroscopy revealed the presence of the above-mentioned deep levels along with two shallow level defects related to titanium impurities (Ti(h) and Ti(c)) and an unidentified deep electron trap located at 2.4 eV below the conduction band minimum, which is being reported for the first time. The concentration of the lifetime killer Z{sub 1/2}more » defects was found to be 1.7 × 10{sup 13} cm{sup −3}. The charge transport and collection efficiency results obtained from the alpha particle pulse-height spectroscopy were interpreted using a drift-diffusion charge transport model. Based on these investigations, the physics behind the correlation of the detector properties viz., energy resolution and charge collection efficiency, the junction properties like uniformity in barrier-height, leakage current, and effective doping concentration, and the presence of defects has been discussed in details. The studies also revealed that the dominating contribution to the charge collection efficiency was due to the diffusion of charge carriers generated in the neutral region of the detector. The 10 mm{sup 2} large area detectors demonstrated an impressive energy resolution of 1.8% for 5486 keV alpha particles at an optimized operating reverse bias of 130 V.« less