Damage annealing and dopant activation in Al ion implanted α-SiC

Aluminium ions were implanted at room temperature into n-type 6H-SiC single crystals. In order to obtain a quasi rectangular atom distribution over approximately 0.5 μm, two successive implantations were performed up to a maximum energy of 320 keV and a total fluence of 1.6 × 1015 ions cm−2. The samples were then annealed under nitrogen in a rf furnace, allowing a temperature range from 1000 to 1800 °C. The recovery of the lattice disorder was followed by using Rutherford backscattering spectrometry of 2 MeV He+ ions in channeling geometry (RBS/C), in conjunction with optical absorption measurements. The electrical behavior of the implanted material was tested by sheet resistance measurements. The unimplanted side of the target has been characterized by both RBS/C and X-ray photoelectron spectroscopy (XPS). A significant decrease of the surface stoichiometry [Si/C] has been evidenced for the highest annealing temperatures.