a Electron Microscopy for Materials Research (EMAT), University of Antwerp (RUCA), B-2020, Antwerp, Belgium
b Dipartimento di Fisica, Università di Catania, Corso Italia 57, I-95129, Catania, Italy
Abstract:
6H SiC single crystals were implanted at room temperature with 1 MeV He+ up to a fluence of 2 × 1017 at./cm2. RBS-channeling analysis with a 2 MeV He+ beam indicated the formation of extended defects or the generation of point defects at a constant concentration over a depth of about 1 μm. Electron microscopy characterisation revealed the presence of two amorphous buried layers at depths of about 1.75 and 4.8 μm. They are due to the implantation and to the analysing RBS beam, respectively. No extended planar or linear faults were found in the region between the surface and the first amorphous layer. However, at the surface, a 50 nm thick amorphous layer was observed in which crystalline inclusions were embedded. Electron diffraction and HREM data of the inclusions were typical for diamond. These inclusions were even found in the crystalline SiC material below this layer, however at a reduced density.