Deep Levels Responsible for Semi-insulating Behaviour in Vanadium-doped 4H-SiC Substrates
2009 (English)In: Materials Science Forum, Vols. 600-603, Trans Tech Publications , 2009, 401-404 p.Conference paper (Refereed)
Semi-insulating (SI) 4H-SiC substrates doped with vanadium (V) in the range 5.5×1015 –1.1×1017 cm–3 were studied by electron paramagnetic resonance. We show that only in heavily V-doped 4H-SiC vanadium is responsible for the SI behavior, whereas in moderate V-doped substrates with the V concentration comparable or slightly higher than that of the shallow N donor or B acceptor, the SI properties are thermally unstable and determined by intrinsic defects. The results show that the commonly observed thermal activation energy Ea~1.1 eV in V-doped 4H-SiC, which was previously assigned to the single acceptor V4+/3+ level, may be related to deep levels of the carbon vacancy. Carrier compensation processes involving deep levels of V and intrinsic defects are discussed and possible thermal activation energies are suggested.
Place, publisher, year, edition, pages
Trans Tech Publications , 2009. 401-404 p.
IdentifiersURN: urn:nbn:se:liu:diva-41957DOI: 10.4028/www.scientific.net/MSF.600-603.401Local ID: 59416OAI: oai:DiVA.org:liu-41957DiVA: diva2:262812
12th International Conference on Silicon Carbide and Related Materials, ICSCRM 2007; Otsu; Japan