| 1. |
- Blank, T. V., et al.
(författare)
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Temperature dependence of the quantum efficiency of 4H-SiC-Based Schottky photodiodes
- 2001
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Ingår i: Technical physics letters. - : Pleiades Publishing Ltd. - 1063-7850 .- 1090-6533. ; 27:9, s. 776-778
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Tidskriftsartikel (refereegranskat)abstract
- Using metal-semiconductor structures based on a pure epitaxial layer of n-4H-SiC (N-d - N-a = 4 x 10(15) cm(-3)), UV photodetectors were created with a maximum photosensitivity at 4.9 eV and a quantum efficiency up to 0.3 el/ph. The photosensitivity spectrum of the base structure is close to the spectrum of bactericidal action of the UV radiation. For photon energies in the 3.4 - 4.7 eV range, the quantum efficiency of the photoelectric conversion exhibits rapid growth with the temperature above 300 K, which is explained by the participation of photons in indirect interband transitions. This growth is not manifested when the photon energy is close to the threshold energy of direct optical transitions in the nondirect-bandgap semiconductor, which allows the threshold energy to be evaluated (similar to4.9 eV).
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| 2. |
- Kalinina, E. V., et al.
(författare)
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Effect of irradiation with fast neutrons on electrical characteristics of devices based on CVD 4H-SiC epitaxial layers
- 2003
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 37:10, s. 1229-1233
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Tidskriftsartikel (refereegranskat)abstract
- The effect of irradiation with 1-MeV neutrons on electrical properties of Al-based Schottky barriers and p(+)-n-n(+) diodes doped by ion-implantation with Al was studied; the devices were formed on the basis of high-resistivity, pure 4H-SiC epitaxial layers possessing n-type conductivity and grown by vapor-transport epitaxy. The use of such structures made it possible to study the radiation defects in the epitaxial layer at temperatures as high as 700 K. Rectifying properties of the diode structures were no longer observed after irradiation of the samples with neutrons with a dose of 6 x 10(14) cm(-2); this effect is caused by high (up to 50 GOmega) resistance of the layer damaged by neutron radiation. However, the diode characteristics of irradiated p(+)-n-n(+) structures were partially recovered after an annealing at 650 K.
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| 3. |
- 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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| 4. |
- Kalinina, E. V., et al.
(författare)
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Optical and electrical properties of 4H-SiC irradiated with fast neutrons and high-energy heavy ions
- 2004
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 38:10, s. 1187-1191
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Tidskriftsartikel (refereegranskat)abstract
- 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(+)-n-n(+) 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 high 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.
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| 5. |
- 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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| 6. |
- Kalinina, E., et al.
(författare)
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Structural, electrical, and optical properties of low-doped 4H-SiC chemical vapor deposited epitaxial layers
- 2001
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 90:10, s. 5402-5409
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Tidskriftsartikel (refereegranskat)abstract
- Results of complex studies of structural, optical, and electrical characteristics of 4H-SiC n-type low-doped epitaxial layers grown by the chemical vapor deposition (CVD) method are presented. Characteristics of CVD layers grown on commercial wafers with and without a thin (<0.1 mum) buffer layer grown by liquid phase epitaxy (LPE) between the commercial wafer and CVD epitaxial layer were compared. It has been shown that the LPE filling process caused a significant improvement in the structural quality of CVD layers. Cathodoluminescence (CL) data and electrical characteristics of Schottky barriers (SB) revealed that the LPE layer also made the concentration profiles of the uncompensated donors and recombination centers for holes as well as the hole diffusion lengths more uniform over the CVD layer. According to CL and secondary ion mass-spectroscopy measurements the presence of aluminum as an impurity was detected in initial commercial wafers, as well as having LPE and CVD epitaxial layers. Forward current-voltage characteristics of SBs formed on CVD layers with and without a LPE buffer layer followed an exponential relationship with an ideality factor of 1.04-1.06 over six to seven orders of magnitude in current density. A noticeable increase of the breakdown voltage was also observed in samples with a LPE layer.
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| 7. |
- 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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| 8. |
- 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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| 9. |
- Ivanov, A M, et al.
(författare)
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High-resolution short range ion detectors based on 4H-SiC films
- 2004
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Ingår i: Technical physics letters. - : Pleiades Publishing Ltd. - 1063-7850 .- 1090-6533. ; 30:7, s. 575-577
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Tidskriftsartikel (refereegranskat)abstract
- The energy resolution of SiC detectors has been studied in application to the spectrometry of alpha particles with 5.1-5.5 MeV energies. The Schottky barrier structure of the detector was based on a CVD-grown epitaxial n-4H-SiC film with a thickness of 26 mum and an uncompensated donor concentration of (1-2) x 10(15) cm(-3). An energy resolution of 0.5% achieved for the first time with SiC detectors allows fine structure of the alpha particle spectrum to be revealed. The average energy of the electron-hole pair formation in 4H-SiC is estimated at 7.71 eV.
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| 10. |
- 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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