Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 61: Poster II: Materials, Interfaces and Heterostructures
HL 61.18: Poster
Donnerstag, 25. März 2010, 18:00–20:00, Poster D1
Iron-related Defect Centers in 4H-SiC Detected by Deep Level Transient Spectroscopy — •Lia Trapaidze, Michael Krieger, and Gerhard Pensl — Lehrstuhl für Angewandte Physik, Universität Erlangen-Nürnberg, Staudtstr. 7 / Bau A3, 91058 Erlangen, Germany
Iron (Fe) is a impurity, which is frequently introduced during the processing of semiconductors. It is known from silicon that Fe forms electrically active defect centers. However, for the wide-bandgap semiconductor silicon carbide (SiC) nothing has been reported in the literature so far.
In order to identify and investigate Fe-related defect centers in 4H-SiC, Fe ions have intentionally been introduced into n-type and p-type 4H-SiC epitaxial layers by means of ion implantation. A Fe box profile with a depth of 1.7 µm and a mean concentration of [Fe] = 1× 1015 cm−3 was formed by multiple implantations of Fe+ ions with different energies at Timpl = 300∘C. Subsequently, the samples were annealed at various temperatures ranging from room temperature up to 1700∘C. Schottky contacts were evaporated using Pd or Ti/Al for n-type or p-type layers, respectively. The samples have been analyzed by means of deep level transient spectroscopy (DLTS).
Compared to the DLTS spectra of not-implanted reference samples, a new defect center at EC-ET = 1080 meV is observed in the DLTS spectra taken on Fe-implanted samples. The dependence of the DLTS spectra on the annealing temperature and on the implanted Fe concentration is discussed.