| 1. |
- 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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| 2. |
- Lebedev, A.A., et al.
(författare)
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Amplification of the signal in triode structures of ion detectors based on 6H-SIC epitaxial films
- 2001
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 79:26, s. 4447-4449
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Tidskriftsartikel (refereegranskat)abstract
- The possibility of about 50 times the inneramplification of signals in SiC-based detectors of short-range ions is shown. The detector has an n-p-n+-like structure, where the p-type base was grown epitaxially on a 6H n+-SiC substrate. To complete the structure a Schottky barrier was made on top. Detector parameters were investigated in a "floating base" regime. Alpha particles from 244Cm were used and the augmentation of signal (E) with increasing applied voltage (U) was investigated. A superlinear increase of E was observed with a significant (tens of times) amplification of the introduced by the alpha particle nonequilibrium charge. It was also found that the nonuniformity of the diffusion-drift carrier transport parameters in the films does not exceed 10%. © 2001 American Institute of Physics.
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| 3. |
- Lebedev, A.A., et al.
(författare)
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Radiation hardness of wide-gap semiconductors (using the example of silicon carbide)
- 2002
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 36:11, s. 1270-1275
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Tidskriftsartikel (refereegranskat)abstract
- Results obtained in studying the effect of ionizing radiation on epitaxial layers and devices based on silicon carbide (SiC) are considered. It is shown that, in investigations of wide-gap semiconductors (WGS), account should be taken of how the rate of removal of mobile charge carriers - the standard parameter in determining the radiation hardness of a material - depends on temperature. The use of data obtained only at room temperature may lead to an incorrect assessment of the radiation hardness of WGS. A conclusion is made that the WGS properties combine, on the one hand, high radiation hardness of high-temperature devices based on these semiconductors and, on the other, the possibility of effective radiation-induced doping (e.g., for obtaining semi-insulating local regions in a material at room temperature). © 2002 MAIK "Nauka/Interperiodica".
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| 4. |
- Strokan, N.B., et al.
(författare)
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Detection of strongly and weakly ionizing radiation by triode structure based on SIC films
- 2003
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 93:9, s. 5714-5719
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Tidskriftsartikel (refereegranskat)abstract
- The detection of strongly and weakly ionizing radiation by triode structure based on silicon carbide (SiC) films was discussed. The possibility of alpha particle spectrometry in spite of slow carrier transport via diffusion was demonstrated. Analysis showed that the signal generated by weakly ionizing radiation incident on a film had low amplitude.
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| 5. |
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| 6. |
- Strokan, N.B., et al.
(författare)
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Measurement of micrometer diffusion lengths by nuclear spectrometry
- 2005
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 39:12, s. 1394-1398
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Tidskriftsartikel (refereegranskat)abstract
- A method for determination of diffusion lengths in the range 0.5-50 µm, which corresponds to carrier lifetimes in the nanosecond range, is suggested A calibrated nonequilibrium charge is injected into the base of the reverse-biased diode structure. The injection is provided by alpha particles generated by natural decay in the single-particle counting mode. The nuclear spectrometry technique is used to measure the amount of charge that diffused across the base to the boundary of the electric-field region. The loss of charge during the diffusion is calculated as a function of the depth of alpha particle penetration beyond the electric-field region. The derived power-law functions make it possible to relate the diffusion length with the exponent and numerical factor that describes the loss of charge. The experiment is performed with lightly doped 4H-SiC epitaxial films. © 2005 Pleiades Publishing, Inc.
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| 7. |
- Strokan, N.B., et al.
(författare)
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Radiation resistance of transistor- and diode-type SiC detectors irradiated with 8-MeV protons
- 2004
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 38:7, s. 807-811
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear-particle detectors based on SiC with a structure composed of an n+-type substrate, a p-type epitaxial layer, and a Schottky barrier are studied. Structures with a ~10-µm-thick 6H-SiC layer exhibit transistor properties, whereas those with a ~30-µm-thick 4H-SiC layer exhibit diode properties. It is established that a more than tenfold amplification of the signal is observed in the transistor-type structure. The amplification is retained after irradiation with 8-MeV protons with a dose of at least 5 × 1013 cm-2, in this case, the resolution is =10%. Amplification of the signal was not observed in the structures of diode type. However, there were diode-type detectors with a resolution of ˜3%, which is acceptable for a number of applications, even after irradiation with the highest dose of 2 × 1014 cm-2. © 2004 MAIK "Nauka/Interperiodica".
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| 8. |
- Strokan, N.B., et al.
(författare)
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Silicon carbide transistor structures as detectors of weakly ionizing radiation
- 2003
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 37:1, s. 65-69
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Tidskriftsartikel (refereegranskat)abstract
- SiC-based nuclear radiation detectors figured prominently in the very first attempts of the 1960s to replace gas in ionization chambers with a more condensed semiconducting medium. However, the dynamics of improvement of SiC in those years was markedly inferior to the progress made in the development of competing materials. This study continues with the investigation of triode detector structures based on "pure" SiC films. It is established that for weakly ionizing radiation (as also in the case of strongly ionizing alpha particles) the signal is amplified by no less than a factor of several tens. This allows SiC films with a thickness of about 10 µm to be used to detect penetrating radiation, e.g., X-rays, since the effective thickness of the films is on the order of hundreds of micrometers. © 2003 MAIK "Nauka/Interperiodica".
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| 9. |
- Strokan, N.B., et al.
(författare)
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The limiting energy resolution of SiC detectors in ion spectrometry
- 2005
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Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 39:12, s. 1420-1425
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Tidskriftsartikel (refereegranskat)abstract
- The Monte Carlo method is used to simulate the complete stopping of a particles in SiC. A histogram of energy losses in nuclear-scattering events is obtained. The energy-loss spectrum has the characteristic asymmetric shape with the line full width at the half-maximum FWHMnucl ˜ 4. 22 keV. The final shape of the spectral line is obtained by a convolution with the Gaussian function that describes the contribution of the ionization and noise fluctuations (originated in the detector and instrumentation) to the signal. The resulting value of FWHM for the line is equal to 8.75 keV (at a noise variance of 1.7 keV). The experimental energy resolution of the detectors was found to be poorer than the calculated value by a factor of 2. It is established that the losses of charge during its transport in the detector bulk are insignificant, so that the discrepancy between the calculated and experimental values of the resolution should be attributed to the nonoptimal design of the detector window. © 2005 Pleiades Publishing, Inc.
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| 10. |
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