Deep levels in low‐energy electron‐irradiated 4H‐SiC |
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| Authors: | P Carlsson NT Son F C Beyer H Pedersen J Isoya N Morishita T Ohshima E Janzén |
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| Institution: | 1. Department of Physics, Chemistry and Biology, Link?ping University, 581 83 Link?ping, Sweden;2. Graduate School of Library, Information and Media Studies, University of Tsukuba, 1‐2 Kasuga, Tsukuba, Ibaraki 305‐8550, Japan;3. Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370‐1292, Japan |
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| Abstract: | Deep levels introduced by low‐energy (200 keV) electron irradiation in n‐type 4H‐SiC epitaxial layers grown by chemical vapour deposition were studied by deep level transient spectroscopy (DLTS) and photoexcitation electron paramagnetic resonance (photo‐EPR). After irradiation, several DLTS levels, EH1, EH3, Z1/2, EH5 and EH6/7, often reported in irradiated 4H‐SiC, were observed. In irradiated freestanding films from the same wafer, the EPR signals of the carbon vacancy in the positive and negative charge states, VC+ and VC‐, respectively, can be observed simultaneously under illumination with light of certain photon energies. Comparing the ionization energies obtained from DLTS and photo‐EPR, we suggest that the EH6/7 (at ～EC – 1.6 eV) and EH5 (at ～EC – 1.0 eV) electron traps may be related to the single donor (+ | 0) and the double acceptor (1– | 2–) level of VC, respectively. Judging from the relative intensity of the DLTS signals, the EH6/7 level may also be contributed to by other unidentified defects. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
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| Keywords: | 61 72 jd 61 80 Fe 61 82 Fk 71 55 Ht 76 30 Mi |
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