An IR-reflectivity and X-ray diffraction study of high energy He-ion implantation-induced damage in 4H-SiC

Due to recent progress in silicon carbide (SiC) technology, understanding the behaviour of defects in SiC is a crucial challenge for the industrial development of SiC-based devices. High energy helium ion implantation at high fluence in SiC creates a few microns deep damaged layers with nanocavities, which are expected to play in important role in gettering of unwanted impurities. Post-implantation evolution of the ion implantation-induced damage is then controlled by thermal annealing. Results of an infrared reflectivity (IRR) and X-ray diffraction (XRD) study of ion implantation-induced damage in crystalline (0 0 0 1) n-type 4H-SiC implanted at room temperature with 1.6 MeV He ions at the fluence of 10(17) cm(-2) show the formation of two layers above the unperturbed crystal: a 3.4 mum deep defective strained surface layer on a 0.4 mum thick strongly perturbed interface layer, Thermal annealing at 1500 degreesC for 30 min under high vacuum was shown to induce structural recovery of the surface layer. (C) 2002 Elsevier Science B.V. All rights reserved.