DAMAGE ANNEALING AND DOPANT ACTIVATION IN AL ION-IMPLANTED ALPHA-SIC

Aluminium ions were implanted at room temperature into n-type 6H-SiC s ingle crystals. In order to obtain a quasi rectangular atom distributi on over approximately 0.5 mu m, two successive implantations were perf ormed up to a maximum energy of 320 keV and a total fluence of 1.6 x 1 0(15) ions cm(-2). The samples were then annealed under nitrogen in a rf furnace, allowing a temperature range from 1000 to 1800 degrees C. The recovery of the lattice disorder was followed by using Rutherford backscattering spectrometry of 2 MeV He+ ions in chanelling geometry ( RBS/C), in conjunction with optical absorption measurements. The elect rical behavior of the implanted material was tested by sheet resistanc e measurements. The unimplanted side of the target has been characteri zed by both RBS/C and X-ray photoelectron spectroscopy (XPS). A signif icant decrease of the surface stoichiometry [Si/C] has been evidenced for the highest annealing temperatures. (C) 1997 Elsevier Science S.A.