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Title: Structural peculiarities of 4H-SiC irradiated by Bi ions

Abstract

X-ray diffraction, photoluminescence, micro-cathodoluminescence, and scanning and transmission electron spectroscopy were used to study the 710 MeV Bi ion irradiation effect in the fluence range of 1.4 x 10{sup 9}-5 x 10{sup 10} cm{sup -2} on the structural and optical characteristics of pure high-resistivity n-type 4H-SiC epitaxial layers grown by chemical vapor deposition. It was established that the distribution of structural damage along the ion trajectory follows the computed profile of radiation defects formed in elastic collisions. The high-density ionization effect on the material characteristics has not been found under the irradiation conditions used. Optical methods revealed a wide spectrum of radiation-induced defects, with some of them contributing to the recombination process. The damaged 4H-SiC crystal lattice party recovers after annealing at 500 deg. C.

Authors:
 [1];  [2]; ; ; ;  [3]
  1. Russian Academy of Sciences, loffe Physicotechnical Institute (Russian Federation), E-mail: evk@pop.ioffe.rssi.ru
  2. Joint Institute for Nuclear Research (Russian Federation)
  3. Russian Academy of Sciences, loffe Physicotechnical Institute (Russian Federation)
Publication Date:
OSTI Identifier:
21088093
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductors; Journal Volume: 41; Journal Issue: 4; Other Information: DOI: 10.1134/S1063782607040021; 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; ANNEALING; BISMUTH IONS; CATHODOLUMINESCENCE; CHEMICAL VAPOR DEPOSITION; CRYSTAL DEFECTS; CRYSTAL LATTICES; ELECTRON SPECTROSCOPY; EPITAXY; IONIZATION; IRRADIATION; LAYERS; MEV RANGE 100-1000; PHOTOLUMINESCENCE; SILICON CARBIDES; TEMPERATURE RANGE 0400-1000 K; X-RAY DIFFRACTION

Citation Formats

Kalinina, E. V., Skuratov, V. A., Sitnikova, A. A., Kolesnikova, E. V., Tregubova, A. S., and Shcheglov, M. P. Structural peculiarities of 4H-SiC irradiated by Bi ions. United States: N. p., 2007. Web. doi:10.1134/S1063782607040021.
Kalinina, E. V., Skuratov, V. A., Sitnikova, A. A., Kolesnikova, E. V., Tregubova, A. S., & Shcheglov, M. P. Structural peculiarities of 4H-SiC irradiated by Bi ions. United States. doi:10.1134/S1063782607040021.
Kalinina, E. V., Skuratov, V. A., Sitnikova, A. A., Kolesnikova, E. V., Tregubova, A. S., and Shcheglov, M. P. Sun . "Structural peculiarities of 4H-SiC irradiated by Bi ions". United States. doi:10.1134/S1063782607040021.
@article{osti_21088093,
title = {Structural peculiarities of 4H-SiC irradiated by Bi ions},
author = {Kalinina, E. V. and Skuratov, V. A. and Sitnikova, A. A. and Kolesnikova, E. V. and Tregubova, A. S. and Shcheglov, M. P.},
abstractNote = {X-ray diffraction, photoluminescence, micro-cathodoluminescence, and scanning and transmission electron spectroscopy were used to study the 710 MeV Bi ion irradiation effect in the fluence range of 1.4 x 10{sup 9}-5 x 10{sup 10} cm{sup -2} on the structural and optical characteristics of pure high-resistivity n-type 4H-SiC epitaxial layers grown by chemical vapor deposition. It was established that the distribution of structural damage along the ion trajectory follows the computed profile of radiation defects formed in elastic collisions. The high-density ionization effect on the material characteristics has not been found under the irradiation conditions used. Optical methods revealed a wide spectrum of radiation-induced defects, with some of them contributing to the recombination process. The damaged 4H-SiC crystal lattice party recovers after annealing at 500 deg. C.},
doi = {10.1134/S1063782607040021},
journal = {Semiconductors},
number = 4,
volume = 41,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}
  • Photoluminescence and deep-level transient spectroscopy are used to study the effect of irradiation with fast neutrons and high-energy Kr (235 MeV) and Bi (710 MeV) ions on the optical and electrical properties of high-resistivity high-purity n-type 4H-SiC epitaxial layers grown by chemical vapor deposition. Electrical characteristics were studied using the barrier structures based on these epitaxial layers: Schottky barriers with Al and Cr contacts and p{sup +}-n-n{sup +} diodes fabricated by Al ion implantation. According to the experimental data obtained, neutrons and high-energy ions give rise to the same defect-related centers. The results show that, even for the extremely highmore » ionization density (34 keV/nm) characteristic of Bi ions, the formation of the defect structure in SiC single crystals is governed by energy losses of particles due to elastic collisions.« less
  • Schottky barriers, 10{sup -2} cm{sup 2} in area, have been prepared by thermal deposition of Cr in vacuum on 50-{mu}m-thick 4H-SiC epitaxial layers grown by chemical vapor deposition. The uncompensated donor concentration in these films is (4-6) x 10{sup 14} cm{sup -3}, which makes it possible to extend the depletion region of the detector to {approx_equal}30 {mu}m by applying a reverse bias of 400 V. The spectrometric characteristics of the detectors are determined using {alpha} particles in the energy range 4.8-7.7 MeV. The energy resolution attained for the 5.0- to 5.5-MeV lines is higher than 20 keV (0.34%), which, bymore » a factor of 2, is second only to precision silicon detectors fabricated by specialized technology. The maximum signal amplitude corresponds, in SiC, to a mean electron-hole pair creation energy of 7.70 eV.« less
  • Capacitance-voltage (C-V) and Deep-Level-Transient Spectroscopy (DLTS) measurements were performed on Metal-Oxide-Semiconductor (MOS) capacitors fabricated on 4H-SiC with the SiO{sub 2} layer grown by Sodium-Enhanced Oxidation. This technique has yielded 4H-SiC MOS transistors with record channel mobility, although with poor bias stability. The effects of the mobile positive charge on the C-V characteristics and DLTS spectra were investigated by applying a sequence of positive and negative bias-temperature stresses, which drifted the sodium ions toward and away from the SiO{sub 2}/4H-SiC interface, respectively. Analytical modeling of the C-V curves shows that the drift of sodium ions in the SiO{sub 2} layer duringmore » the voltage sweep can explain the temperature dependence of the C-V curves. The effects of lateral fluctuations of the surface potential (due to a non-uniform charge distribution) on the inversion layer mobility of MOS transistors are discussed within a two-dimensional percolation model.« 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
  • It is shown that 9-μm-thick semi-insulating surface layers can be formed in moderately doped n-type silicon carbide (donor concentration 2 × 10{sup 16} cm{sup –3}) via the comparatively low-dose (7 × 10{sup 11} cm{sup –2}) implantation of high-energy (53 MeV) argon ions. The free-carrier removal rate is estimated at ~10{sup 4} cm{sup –1}. The resistivity of the semi-insulator is no less than 7 × 10{sup 12} Ω cm. Analysis of the monopolar current of electron injection into the semi-insulator shows that the impurity-conductivity compensation is due to radiation induced defects pinning the equilibrium Fermi level at a depth of 1.16more » eV below the conduction-band bottom. The density of defect states at the Fermi level is 2.7 × 10{sup 16} cm{sup 2} eV{sup –1}.« less