| 1. |
- Glasbey, JC, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 2. |
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| 3. |
- Tabiri, S, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 4. |
- Bravo, L, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 5. |
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| 6. |
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| 7. |
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| 8. |
- Bruzzi, M, et al.
(författare)
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Radiation-hard semiconductor detectors for SuperLHC
- 2005
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 541:1-2, s. 189-201
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Tidskriftsartikel (refereegranskat)abstract
- An option of increasing the luminosity of the Large Hadron Collider (LHC) at CERN to 1035 cm-2 s-1 has been envisaged to extend the physics reach of the machine. An efficient tracking down to a few centimetres from the interaction point will be required to exploit the physics potential of the upgraded LHC. As a consequence, the semiconductor detectors close to the interaction region will receive severe doses of fast hadron irradiation and the inner tracker detectors will need to survive fast hadron fluences of up to above 1016cm-2. The CERN-RD50 project "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" has been established in 2002 to explore detector materials and technologies that will allow to operate devices up to, or beyond, this limit. The strategies followed by RD50 to enhance the radiation tolerance include the development of new or defect engineered detector materials (SiC, GaN, Czochralski and epitaxial silicon, oxygen enriched Float Zone silicon), the improvement of present detector designs and the understanding of the microscopic defects causing the degradation of the irradiated detectors. The latest advancements within the RD50 collaboration on radiation hard semiconductor detectors will be reviewed and discussed in this work.
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| 15. |
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| 16. |
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| 17. |
- Wijns, W, et al.
(författare)
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Myocardial revascularization
- 2011
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Ingår i: REVISTA PORTUGUESA DE CARDIOLOGIA. - : Elsevier BV. - 0870-2551 .- 2174-2049. ; 30:12, s. 951-1005
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Alfieri, G., et al.
(författare)
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Annealing behavior between room temperature and 2000 degrees C of deep level defects in electron-irradiated n-type 4H silicon carbide
- 2005
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 98:4
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Tidskriftsartikel (refereegranskat)abstract
- The annealing behavior of irradiation-induced defects in 4H-SiC epitaxial layers grown by chemical-vapor deposition has been systematically studied by means of deep level transient spectroscopy (DLTS). The nitrogen-doped epitaxial layers have been irradiated with 15-MeV electrons at room temperature and an isochronal annealing series from 100 to 2000 degrees C has been performed. The DLTS measurements, which have been carried out in the temperature range from 120 to 630 K after each annealing step, revealed the presence of six electron traps located in the energy range of 0.45-1.6 eV below the conduction-band edge (E-c). The most prominent and stable ones occur at E-c-0.70 eV (labeled Z(1/2)) and E-c-1.60 eV(EH6/7). After exhibiting a multistage annealing process over a wide temperature range, presumably caused by reactions with migrating defects, a significant fraction of both Z(1/2) and EH6/7 (25%) still persists at 2000 degrees C and activation energies for dissociation in excess of 8 and similar to 7.5 eV are estimated for Z(1/2) and EH6/7, respectively. On the basis of these results, the identity of Z(1/2) and EH6/7 is discussed and related to previous assignments in the literature.
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| 19. |
- Alfieri, G., et al.
(författare)
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Defect energy levels in hydrogen-implanted and electron-irradiated n-type 4H silicon carbide
- 2005
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 98:11
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Tidskriftsartikel (refereegranskat)abstract
- Using deep level transient spectroscopy (DLTS), we have studied the energy position and thermal stability of deep levels in nitrogen doped 4H-SiC epitaxial layers after 1.2 MeV proton implantation and 15 MeV electron irradiation. Isochronal annealing was performed at temperatures from 100 to 1200 degrees C in steps of 50 degrees C. The DLTS measurements, which were carried out in the temperature range from 120 to 630 K after each annealing step, reveal the presence of ten electron traps located in the energy range of 0.45-1.6 eV below the conduction band edge (E-c). Of these ten levels, three traps at 0.69, 0.73, and 1.03 eV below E-c, respectively, are observed only after proton implantation. Dose dependence and depth profiling studies of these levels have been performed. Comparing the experimental data with computer simulations of the implantation and defects profiles, it is suggested that these three new levels, not previously reported in the literature, are hydrogen related. In particular, the E-c-0.73 eV level displays a very narrow depth distribution, confined within the implantation profile, and it originates most likely from a defect involving only one H atom.
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| 20. |
- David, M. L., et al.
(författare)
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Electrically active defects in irradiated 4H-SiC
- 2004
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 95:9, s. 4728-4733
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Tidskriftsartikel (refereegranskat)abstract
- 4H-SiC epilayers were irradiated with either protons or electrons and electrically active defects were studied by means of deep level transient spectroscopy. Motion of defects has been found to occur at temperature as low as 350-400 K. Indeed, the application of an electric field has been found to enhance modifications in defect concentrations that can also occur during long time annealing at elevated temperature. Two levels have been revealed and labeled B and M. Two other levels, referred to as S-1 and S-2 and located at 0.40 and 0.71 eV below the conduction band edge have been studied in detail (capture cross sections, profiling, formation energy, activation energy during annealing). The S-1 and S-2 levels have been found to exhibit a one to one relation and are proposed to be two charge states of the same acceptor center, labeled the S center.
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| 21. |
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| 22. |
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| 23. |
- Martin, David M., et al.
(författare)
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Bistable defect in mega-electron-volt proton implanted 4H silicon carbide
- 2004
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 84:10, s. 1704-1706
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial 4H-SiC n-type layers implanted at room temperature with a low fluence of mega-electron-volt protons have been measured by deep level transient spectroscopy (DLTS). The proton fluence of 1x10(12) cm(-2) creates an estimated initial concentration of intrinsic point defects of about 10(14) cm(-3) of which about 10% remain after the implantation and gives rise to deep states in the upper part of the band gap. Here, we investigate the samples prior to high-temperature annealing and a very complex spectrum is revealed. In particular, a bistable defect M is discovered having two DLTS peaks, M-1 and M-3 at E-C-0.42 and around E-C-0.75 eV, respectively, in one configuration and one peak, M-2 at E-C-0.70 eV in the other configuration. The charge dependent thermal activation energies for the transformation between the bistable defect peaks are 0.90 and 1.40 eV.
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| 24. |
- Monakhov, E. V., et al.
(författare)
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Laplace transform transient spectroscopy study of a divacancy-related double acceptor centre in Si
- 2003
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 15:39, s. S2771-S2777
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Tidskriftsartikel (refereegranskat)abstract
- Radiation-induced divacancy-related levels in high-purity oxygen-enriched n-type silicon have been studied with the use of deep level transient spectroscopy (DLTS) and Laplace-DLTS. It has been shown that heat treatment at 250degreesC results in a shift of the divacancy (V-2)-related peaks observed by 'standard' DLTS. Using Laplace-DLTS it is demonstrated that the shift is due to annealing of V-2 and formation of a new acceptor centre. The new centre has presumably two negative charge states: singly and doubly negative. The formation of the new centre holds a close one-to-one correlation with the annealing of V-2, indicating that the new centre is a result of divacancy interaction with an impurity or a defect. The close position of the electronic levels of the new centre to that of V-2 suggests a similar electronic and microscopic structure of the new centre to V-2, and a tentative identification is a divacancy-oxygen centre.
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| 25. |
- Svensson, B. G., et al.
(författare)
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Defects and diffusion in high purity silicon for detector applications
- 2004
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Ingår i: Conference on Photo-Responsive Materials, Proceedings. - : Wiley-VCH Verlagsgesellschaft. - 3527405526 ; , s. 2250-2257
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Konferensbidrag (refereegranskat)abstract
- In this contribution we review some recent results on defects occurring after irradiation and thermal treatment of silicon detectors for ionizing radiation. In particular, the annealing of the prominent divacancy centre and the concurrent growth of a new double acceptor centre, assigned to the divacancy-oxygen pair, is treated in detail. The detectors were fabricated using oxygenated high purity float zone (FZ) silicon wafers of n-type in order to improve the radiation hardness. The results obtained have important implication on our current understanding of the degradation of silicon detectors at high radiation fluences and suggest that a new concept for optimised impurity/defect engineering needs to be developed.
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| 26. |
- Svensson, B.G., et al.
(författare)
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Ion implantation processing and related effects in SiC
- 2006
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Ingår i: Silicon Carbide and Related Materials 2005, Pts 1 and 2. - 9780878494255 ; , s. 781-786
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Konferensbidrag (refereegranskat)abstract
- A brief survey is given of some recent progress regarding ion implantation processing and related effects in 4H- and 6H-SiC. Four topics are discussed; an empirical ion range distribution simulator, dynamic defect annealing during implantation, formation of highly p(+)-doped layers, and deactivation of N donors by ion-induced defects.
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| 27. |
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| 28. |
- Alfieri, G, et al.
(författare)
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Capacitance spectroscopy study of high energy electron irradiated and annealed 4H-SIC
- 2005
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Ingår i: SILICON CARBIDE AND RELATED MATERIALS 2004. - ZURICH-UETIKON : TRANS TECH PUBLICATIONS LTD. - 0878499636 ; , s. 365-368
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Konferensbidrag (refereegranskat)abstract
- Deep level transient spectroscopy (DLTS) was employed to investigate the annealing behaviour and thermal stability of radiation induced defects in nitrogen doped 4H-SiC epitaxial layers, grown by chemical vapor deposition (CVD). The epilayers have been irradiated with 15 MeV electrons and an isochronal annealing series has been carried out. The measurements have been performed after each annealing step and six electron traps located in the energy band gap range of 0.42-1.6 eV below the conduction band edge (E-c) have been detected.
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| 29. |
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| 30. |
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| 31. |
- Paturzo, M., et al.
(författare)
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Investigation of electric internal field in congruent LiNbO3 by electro-optic effect
- 2004
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Ingår i: Applied physics letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 85, s. 5652-5654
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the effect of the defect-induced internal field on the electro-optic behavior of z-cut congruent lithium niobate crystals. We measure, by a spatially resolved interferometric technique, the phase retardation due to an external applied voltage occurring in two regions with opposite ferroelectric polarization. When measurements are performed just after electrical poling, the two opposite domains show a different electro-optic behavior. We interpret this as due to an elastic component of the internal field. In fact, the asymmetric behavior disappears when the sample is thermally annealed, i.e., when the internal field vanishes
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| 32. |
- Paturzo, M., et al.
(författare)
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On the origin of internal field in lithium niobate crystals directly observed by digital holography
- 2005
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Ingår i: Optics express. - 1094-4087. ; 13:14, s. 5416-
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Tidskriftsartikel (refereegranskat)abstract
- We show the defect dependence of the internal field in Lithium Niobate using a full-field interferometric method and demonstrate that it can be directly measured on some clusters of defects embedded in a stoichiometric matrix. Results show that the value of the internal field grows in proximity of defects and vanishes far from them, which addresses the long-standing issue about its origin in Lithium Niobate crystal.
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| 33. |
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