| 1. |
- Ber, B. Y., et al.
(författare)
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Determination of nitrogen in silicon carbide by secondary ion mass spectrometry
- 2004
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Ingår i: Journal of Analytical Chemistry. - 1061-9348 .- 1608-3199. ; 59:3, s. 250-254
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Tidskriftsartikel (refereegranskat)abstract
- The emission of atomic and complex nitrogen ions, which are the main impurity determining the n type conduction of silicon carbide, is investigated. It is shown that, among all the secondary ions of the CxN and SixN kind (x = 0, 1, 2, 3), the (26)(CN)(-) fragment exhibits the highest ion yield. The use of an ion peak with a specified mass as an analytical signal provides a detection limit for nitrogen in SiC at a level of 10(16) cm(-3). This result is attained in measurements at high mass resolution (M/DeltaM = 7500, interference peak (26)(C-13(2))(-)).
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| 2. |
- Violina, G. N., et al.
(författare)
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Photoelectric properties of p(+)-n junctions based on 4H-SiC ion-implanted with aluminum
- 2002
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 36:6, s. 706-709
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Tidskriftsartikel (refereegranskat)abstract
- The photoelectric properties of p(+)-n junctions that were based on 4H-SiC ion-implanted with aluminum and were formed in lightly doped n-type epitaxial layers grown by chemical vapor deposition were studied. It is shown that such photodetectors combine in full measure the advantages of photostructures formed on the basis of Schottky barriers and epitaxial p-n junctions. The results of the theoretical calculation of spectral characteristics of ion-implanted photodetectors are in good agreement with experimental data. The structures feature an efficiency of collection of nonequilibrium charge carriers close to 100% in the spectral range of the photon energies of 3.5-4.25 eV.
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| 3. |
- Violina, G. N., et al.
(författare)
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Silicon carbide detectors of high-energy particles
- 2002
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 36:6, s. 710-713
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Tidskriftsartikel (refereegranskat)abstract
- The results of studying 4H-SiC p(+)-n junctions ion-implanted with aluminum as detectors of high-energy particles are reported. The junctions were formed in SiC epitaxial films grown by chemical vapor deposition. The concentration of uncompensated donors was (3-5) x 10(15) cm(-3), and the charge-carrier diffusion length was L-p = 2.5 mum. The detectors were irradiated with 4.8-5.5-MeV alpha particles at 20degreesC. The efficiency of collection of the induced charge was as high as 0.35. The possibilities of operating SiC detectors at elevated temperatures (similar to500degreesC) are analyzed.
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| 4. |
- Kalinina, E., et al.
(författare)
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Characterization of Al-implanted 4H SiC high voltage diodes
- 2002
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Ingår i: Physica Scripta. - 0031-8949 .- 1402-4896. ; T101, s. 207-210
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Tidskriftsartikel (refereegranskat)abstract
- The properties of 4H-SiC chemical vapor deposition epitaxial layers were studied by different methods. The effects of structural defects in 4H-SiC epitaxial layers on electrical and luminescence properties of Al high dose ion implanted p(+)-n junctions were studied. It has been shown that the structural imperfections of low-doped layers affect some electrical characteristics of the ion doped p(+)-n junctions created in these epitaxial layers.
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| 5. |
- Kalinina, E., et al.
(författare)
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High-dose Al-implanted 4H-SiC p(+)-n-n(+) junctions
- 2000
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 77:19, s. 3051-3053
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Tidskriftsartikel (refereegranskat)abstract
- p(+)-n-n(+) junctions were fabricated by ion implantation with Al of low-doped epitaxial n layers of 4H-SiC grown by chemical vapor deposition on commercial 4H-SiC wafers both with and without reduction of micropipe densities. It was shown that, using high levels of Al ion doping (5x10(16) cm(-2)) in combination with rapid thermal anneal, single-crystal p(+)-4H-SiC layers can be obtained. These layers do not form barriers at the contact metal-semiconductor interface and do not introduce additional resistance into structures with p(+)-n junctions. This significantly reduces the forward voltage drop across the structure in a wide range of current densities up to 10(4) A cm(-2).
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| 6. |
- Kalinina, E., et al.
(författare)
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Influence of ion implantation on the quality of 4H-SiC CVD epitaxial layers
- 2001
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Ingår i: Applied Surface Science. - 0169-4332 .- 1873-5584. ; 184:04-jan, s. 323-329
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Tidskriftsartikel (refereegranskat)abstract
- The effect of ion implantation doping (ID) with high doses of Al followed by short high-temperature annealing of n-type 4H-SiC epitaxial layers grown by chemical vapor deposition (CVD) has been studied. The comparative investigations of the structural and electrical properties, lateral and as a function of depth, in the CVD layers before and after Al ID p(+)n junction formations were determined by several different methods. Structural improvement of the CVD epitaxial layers close to Al ID p(+)n junction positions was revealed for the first time.
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| 7. |
- Östensson, Jörgen, et al.
(författare)
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A trace formula for differential operators of arbitrary order
- 2012
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Ingår i: A Panorama of Modern Operator Theory and Related Topics. - Basel : Birkhäuser Verlag. - 9783034802208 - 9783034807890 - 9783034802215 ; , s. 541-570
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Bokkapitel (refereegranskat)abstract
- An operator H = H0 +V where H0 = i (N is arbitrary) and V is a differential operator of order N-1 with coefficients decaying sufficiently rapidly at infinity is considered in the space H2(R). The goal of the paper is to find an expression for the trace of the difference of the resolvents (H) -1 and (H0 - z) -1 in terms of the Wronskian of appropriate solutions to the differential equation Hu = zu. This also leads to a representation for the perturbation determinant of the pair H0H.
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