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We report on the low-energy electron irradiated 4H-SiC material studied by means of deep-level transient spectroscopy (DLTS) and Laplace-DLTS. Electron irradiation has introduced the following deep level defects: EH1 and EH3 previously assigned to carbon interstitial-related defects, and M-center, a metastable defect also recently assigned to carbon interstitial defects. We propose that EH1 and EH3 are identical to M1 and M3 and assign them to C_i^(= ) (h) and C_i^(0 ) (h), respectively. Moreover, we provide direct evidence that Laplace-DLTS can be used as an excellent tool to distinguish otherwise identical DLTS signals associated with S1 (VSi) and EH1 (Ci)., letter

We report on the metastable defects introduced in the n-type 4H-SiC material by epithermal and fast neutron irradiation. The epithermal and fast neutron irradiation defects in 4H-SiC are much less explored compared to electron or proton irradiation-induced defects. In addition to the carbon vacancy (Vc), silicon vacancy (Vsi) and carbon antisite-carbon vacancy (CAV) complex, the neutron irradiation has introduced four deep-level defects, all arising from the metastable defect, the M-center. The metastable deep-level defects were investigated by deep level transient spectroscopy (DLTS), high-resolution Laplace DLTS (L-DLTS) and isothermal DLTS. The existence of the fourth deep-level defect, M4, recently observed in ion-implanted 4H-SiC, has been additionally confirmed in neutron-irradiated samples. The isothermal DLTS technique has been proven as a useful tool for studying the metastable defects.

Silicij-karbid (SiC) je poluvodički materijal koji se intenzivno istražuje jer može podnijeti uvjete u kojima prevladavaju visoki iznosi temperature, električne snage, frekvencije i zračenja. Posebnu primjenu našao je u izradi poluvodičkih detektora. U ovom radu usporedili smo transportna svojstva SBD (Schottky barrier diode) detektora od silicija (Si) i 4H-SiC, koji imaju podjednaku dopiranost (n-tip, 10^14 cm-3). Korištena su temperaturno ovisna kapacitivno-naponska (C-V) i strujno-naponska (I-V) mjerenja na temperaturama od 100K do 380K. Pokazali smo da u gotovo svim svojstvima važnim za detektore SiC ima bolje karakteristike u odnosu na Si. Struja curenja, koja određuje minimalnu amplitudu signala u poluvodičkim detektorima, kod SiC je više od deset redova veličine manja nego kod Si. Promjena koncentracije slobodnih nosilaca naboja s temperaturom kod SiC je manja, što znači veću stabilnost i preciznost detektora. Povećanje faktora idealnosti sa spuštanjem temperature kod SiC je puno manje izraženo nego kod Si, i znak je da je zanemariva struja rekombinacije u području osiromašenja. To pokazuje da je mala koncentracija rekombinacijsko – generacijskih centara, što je posljedica izvrsne izrade analiziranog SiC uzorka, a omogućava dobru rezoluciju detektora. Detektor od SiC podvrgnuli smo neutronskom zračenju u TRIGA reaktoru na Institutu Jožef Štefan i zaključili da su transportna svojstva pokazala dobru otpornost s obzirom na primijenjene doze.

International audience; Herein, we report on the enhanced sensitivity for the detection of charged particles in single crystal chemical vapour deposition (scCVD) diamond radiation detectors. The experimental results demonstrate charge multiplication in thin planar diamond membrane detectors, upon impact of 18MeV O ions, under high electric field conditions. Avalanche multiplication is widely exploited in devices such as avalanche photo diodes, but has never before been reproducibly observed in intrinsic CVD diamond. Because enhanced sensitivity for charged particle detection is obtained for short charge drift lengths without dark counts, this effect could be further exploited in the development of sensors based on avalanche multiplication and radiation detectors with extreme radiation hardness.