Thick epitaxial N-doped layers of 4H-type material were implanted with MeV He and B ions to low doses. The ion energies were selected so as to give a mean projected range of 4μm for both He and B. The respective energies were 1.7 and 5.0MeV. Implantation was carried out at room temperature and 700C. Capacitance-voltage measurements showed that the samples were strongly compensated, in spite of the low doses. The resultant concentration of implantation-produced defects was stable at room temperature. Deep level transient spectroscopic measurements at 77 to 350K revealed acceptor peaks at Ec – 0.18eV and Ec - 0.67eV, but most of the compensation was caused by deeper-lying acceptor traps.

Ion Implantation Induced Defects in Epitaxial 4H-SiC A.Hallén, A.Henry, P.Pellegrino, B.G.Svensson, D.Aberg: Materials Science and Engineering B, 1999, 61-62, 378-81