Browsing by Author "Capan, I"

Now showing 1 - 7 of 7
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    Developing electronic devices capable of withstanding harsh radiation
    (2013-05-13) Pastuovic, Z; Vittone, E; Siegele, R; Capan, I; Vizkelethy, G; Cohen, DD; Jakšić, M
    Studies performed by Zeljko Pastuovic at ANSTO’s microprobe facility, in collaboration with a team of international researchers, are helping to understand, model and predict the detrimental influence of ionising radiation on semiconducting materials required in millions of electronic devices. The research aims to develop materials and devices that are able to better withstand the damaging effects of high energy particles present in harsh radiation environments, such as solar cells, and power satellites in space, as well as materials used in high-energy physics and accelerators. These studies will help semiconductor, aerospace and other industries to better understand and extend the life of electronic devices.
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    Engineering silicon carbide for enhanced borders and ports security
    (Springer, 2019-09-17) Capan, I; Brodar, T; Pastuovic, Z; Bernat, R; Coutinho, J; Radulović, V; Snoj, L; Torres, V; Sarbutt, A; Ohshima, T.; Ereš, Z; Ambrožič, K; Yamazaki, Y; Makino, T
    Developing new state-of-the-art, low-cost and radiation hard detectors is an extremely difficult challenge which can be tackled only by a multisciplinary group of scientists and engineers from various fields having access to different infrastructure. In our project, Engineering silicon carbide for enhanced borders and ports security (-SiCure) funded by the NATO SPS programme [project number G5215] five partners from Australia (ANSTO), Croatia (RBI), Japan (QST), Portugal (UA) and Slovenia (JSI) have created a team whose main goal is to develop a SiC detector of special nuclear materials. © 2023 Springer Nature Switzerland AG
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    Generation of vacancy cluster-related defects during single MeV silicon ion implantation of silicon
    (Elsevier, 2014-08-01) Pastuovic, Z; Capan, I; Siegele, R; Jacimovic, R; Forneris, J; Cohen, DD; Vittone, E
    Deep Level Transient Spectroscopy (DLTS) has been used to study defects formed in bulk silicon after implantation of 8.3 MeV 28Si3+ ions at room temperature. For this study, Schottky diodes prepared from n-type Czohralski-grown silicon wafers have been implanted in the single ion regime up to fluence value of 1 × 1010 cm−2 utilizing the scanning focused ion microbeam as implantation tool and the Ion Beam Induced Current (IBIC) technique for ion counting. Differential DLTS analysis of the vacancy-rich region in self-implanted silicon reveals a formation of the broad vacancy-related defect state(s) at Ec −0.4 eV. Direct measurements of the electron capture kinetics associated with this trap at Ec −0.4 eV, prior to any annealing do not show an exponential behaviour typical for the simple point-like defects. The logarithmic capture kinetics is in accordance with the theory of majority carrier capture at extended or cluster-related defects. We have detected formation of two deep electron traps at Ec −0.56 eV and Ec −0.61 eV in the interstitial-rich region of the self-implanted silicon, before any annealing. No DLTS signal originating from vacancy-oxygen trap at Ec −0.17 eV, present in the sample irradiated with 0.8 MeV neutrons, has been recorded in the self-implanted sample. © 2014, Elsevier B.V.
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    Probability of divacancy trap production in silicon diodes exposed to focused ion beam irradiation
    (American Institute of Physics, 2011-02-28) Pastuovic, Z; Vittone, E; Capan, I; Jakšić, M
    We present ion beam induced charge (IBIC) measurements of the critical displacement damage dose D(d) values and modeling of the probability of divacancy trap production in p(+)-n-n(+) silicon diodes exposed to megaelectron volt energy ion beam irradiation. The normalized induced charge (Q(0)/Q) measured by He ion probe in tested silicon diodes irradiated by focused He, Li, O, and Cl ion beams with energies of about 0.3 MeV/u increases linearly with D(d) according to the modified radiation damage function and nonionizing energy loss (NIEL) theory. A simple IBIC model based on Gunn theorem showed clear dependence of the induced charge Q and corresponding equivalent damage factor Ked value on both a depth profile of charge created by ionizing particle (probe) and a depth distribution of stable defects created from primary defects produced by damaging ions. The average probability of the divacancy production (defined as the ratio of the final electrical active defect quantity and primary ion induced vacancy quantity for each impinging ion) of 0.18 (18%) was calculated by the IBIC modeling for all damaging ions. (C) 2011 American Institute of Physics. [doi:10.1063/1.3559000]
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    Radiation hardness of n-type SiC Schottky barrier diodes irradiated with MeV He ion microbeam
    (Elsevier, 2015-04-01) Pastuovic, Z; Capan, I; Cohen, DD; Forneris, J; Iwamoto, N; Ohshima, T; Siegele, R; Hoshino, N; Tsuchida, H
    We studied the radiation hardness of 4H-SiC Schottky barrier diodes (SBD) for the light ion detection and spectroscopy in harsh radiation environments. n-Type SBD prepared on nitrogen-doped (similar to 4 x 10(14) cm(-3)) epitaxial grown 4H-SiC thin wafers have been irradiated by a raster scanning alpha particle microbeam (2 and 4 MeV He2+ ions separately) in order to create patterned damage structures at different depths within a sensitive volume of tested diodes. Deep Level Transient Spectroscopy (DLTS) analysis revealed the formation of two deep electron traps in the irradiated and not thermally treated 4H-SiC within the ion implantation range (E1 and E2). The E2 state resembles the well-known Z(1/2) center, while the E1 state could not be assigned to any particular defect reported in the literature. Ion Beam Induced Charge (IBIC) microscopy with multiple He ion probe microbeams (1-6 MeV) having different penetration depths in tested partly damaged 4H-SiC SBD has been used to determine the degradation of the charge collection efficiency (CCE) over a wide fluence range of damaging alpha particle. A non-linear behavior of the CCE decrease and a significant degradation of the spectroscopic performance with increasing He ion fluence were observed above the value of 10(11) cm(-2). © 2015 Published by Elsevier B.V.
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    Radiation hardness of n-type SiC Schottky diodes
    (Coop Libraria Editrice Universita di padova, 2014-07-07) Pastuovic, Z; Vittone, E; Siegele, R; Ohshima, T; Iwamoto, N; Forneris, J; Cohen, DD; Capan, I
    The results of recent IBIC and DLTS studies of radation damage in silicon carbide (SiC) diodes will be presented. n-type Schottky diodes prepared on an epitaxial grown 4H-SiC thin wafers have been irradiated by a raster scanned alpha particle microbeam (2 & 4 MeV He2+ ions separately) in order to create patterned damage structures at different depths within sensitive volume of tested diodes suitable for Ion Beam Induced Current (IBIC) microscopy. Deep level transient spectroscopy (DLTS) was used to characterize defects created in SiC after implantation of single alpha particles. Robust and proven IBIC experimental protocol [1] has been used to determine a degradation of the charge collection efficiency over a wide fluence range of damaging alpha particle. The radiation hardness of these SiC wafers is compared with the hardness of n-type silicon wafers grown by the Floating zone and Czochralski methods obtained by the same experimental protocol. A suitability of as prepared SiC diodes for the light ion detection and spectroscopy in the MeV range will be discussed from the perspecetive of applications in harsh radiation environments.
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    Vacancy-related defects in n-type Si implanted with a rarefied microbeam of accelerated heavy ions in the MeV range
    (Elsevier, 2016-04-01) Capan, I; Pastuovic, Z; Siegele, R; Jacimovic, R
    Deep level transient spectroscopy (DLTS) has been used to study vacancy-related defects formed in bulk n-type Czochralski-grown silicon after implantation of accelerated heavy ions: 6.5 MeV O, 10.5 MeV Si, 10.5 MeV Ge, and 11 MeV Er in the single ion regime with fluences from 109 cm−2 to 1010 cm−2 and a direct comparison made with defects formed in the same material irradiated with 0.7 MeV fast neutron fluences up to 1012 cm−2. A scanning ion microprobe was used as the ion implantation tool of n-Cz:Si samples prepared as Schottky diodes, while the ion beam induced current (IBIC) technique was utilized for direct ion counting. The single acceptor state of the divacancy V2(−/0) is the most prominent defect state observed in DLTS spectra of n-CZ:Si samples implanted by selected ions and the sample irradiated by neutrons. The complete suppression of the DLTS signal related to the double acceptor state of divacancy, V2(=/−) has been observed in all samples irradiated by ions and neutrons. Moreover, the DLTS peak associated with formation of the vacancy-oxygen complex VO in the neutron irradiated sample was also completely suppressed in DLTS spectra of samples implanted with the raster scanned ion microbeam. The reason for such behaviour is twofold, (i) the local depletion of the carrier concentration in the highly disordered regions, and (ii) the effect of the microprobe-assisted single ion implantation. The activation energy for electron emission for states assigned to the V2(−/0) defect formed in samples implanted by single ions follows the Meyer–Neldel rule. An increase of the activation energy is strongly correlated with increasing ion mass. © 2016, Elsevier B.V.