Authors: Hideharu Matsuura, K. Aso, S. Kagamihara, Hisaomi Iwata, T. Ishida, K. Nishikawa
751
Authors: Yuki Negoro, Tsunenobu Kimoto, Hiroyuki Matsunami
Abstract: Technological aspects of ion implantation in SiC device processes are described.
Annealing techniques to suppress surface roughening of implanted SiC (0001) are demonstrated. Trials to achieve a low sheet resistance are described for n-type and p-type doping. Implantation into the (11-20) face is also presented. Electrical behaviors of implants near implanted tail regions are discussed based on experiments.
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Authors: Hideharu Matsuura, Nobumasa Minohara, Yusuke Inagawa, Miyuki Takahashi, Takeshi Ohshima, Hisayoshi Itoh
Abstract: From the temperature dependence of the hole concentration p(T) in a lightly Al-doped
4H-SiC epilayer irradiated with several fluences of 200 keV electrons, the density of Al acceptors
with 0.2 V E + eV decreases significantly with increasing fluence, whereas the density of unknown
defects with 0.37 V E + eV increases with fluence and then decreases slightly. Although only C
vacancies increase with fluence because 200 keV electrons can displace only C atoms, only the
increase in the density of C monovacancies cannot explain the changes of p(T) by 200 keV
electron irradiation. It may be necessary to consider the relationship between C vacancies and Al
acceptors.
379
Authors: Bernd Zippelius, Alexander Glas, Heiko B. Weber, Gerhard Pensl, Tsunenobu Kimoto, Michael Krieger
Abstract: Deep Level Transient Spectroscopy (DLTS) and Double-correlated DLTS (DDLTS) measurements have been conducted on Schottky contacts fabricated on n-type 4H-SiC epilayers using different contact metals in order to separate the EH6- and EH7-centers, which usually appear as a broad double peak in DLTS spectra. The activation energy of EH6 (EC - ET(EH6) = 1.203 eV) turns out to be independent of the electric field. As a consequence, EH6 is acceptor-like according to the missing Poole-Frenkel effect. Therefore, it can be excluded that the EH6-center and the prominent acceptor-like Z1/2-center belong to different charge states of the same microscopic defect as theoretically suggested. It is proposed that EH6 is a complex containing a carbon vacancy and another component available at high concentrations. The activation energy of EH7 (EC - ET(EH7) = 1.58 eV) has been evaluated indirectly by fitting the DLTS spectra of the EH6/7 double peak taking the previously determined parameters of EH6 into account.
251
Authors: Kazuki Yoshihara, Masashi Kato, Masaya Ichimura, Tomoaki Hatayama, Takeshi Ohshima
Abstract: We have characterized deep levels in as-grown and electron irradiated p-type 4H-SiC epitaxial layers by the current deep-level transient spectroscopy (I-DLTS) method. A part of the samples were irradiated with electrons in order to introduce defects. As a result, we found that electron irradiation to p-type 4H-SiC created complex defects including carbon vacancy or interstitial. Moreover, we found that observed deep levels are different between before and after annealing, and thus annealing may change structures of defects.
373