The implantation of aluminum into 4H-SiC is studied using secondary ion mass spectrometry. In particular, two-dimensional concentration profiles are obtained, which allow the investigation of lateral straggling and its dependence on the crystallographic orientation. A high dose, medium energy aluminum implantation is studied in great detail. It shows an asymmetric distribution due to the 4°-off axis growth of the epitaxial layer. The lateral straggling is found to be in the range of several micrometers for a concentration of 1×1015 cm−3, which is contrary to the expectation given by most simulation studies. Implantations performed at different orientations support the idea that lateral straggling highly depends on the particular channeling opening.
The Research Council of Norway is acknowledged for the support to the Norwegian Micro- and Nano-Fabrication Facility, NorFab, Project No. 245963.