RBS-Channeling and EPR Studies of Damage in 2 MeV Al~(2+)-implanted 6H-SiC Substrates

摘要

6H-SiC single crystalline substrates were implanted at room temperature with 2 MeV A1~(2+) ions to fluences from 2Xl0~(14) A1~(2+) cm~(-2) to 7Xl0~(14) Al~(2+) cm~(2-) and with different current densities (from 6.6 to 33Xl0~(10) A1~(2+) cm~(-2) s~(-1)). The depth profile of the damage induced by the A1~(2+) ions was determined by Backscattering Spectrometry in channeling geometry (BS/C) with a 3.5 MeV He~(2+) beam. The BS/C spectra were evaluated using the RBX code. The samples were subsequently annealed at 1100 deg C in N_2 for one hour, in order to analyze their structural recovery by BS/C and the amount of the remaining defects by means of Electron Paramagnetic Resonance (EPR). The results from the BS/C spectra corresponding to the as-implanted samples indicate that the damage depends strongly on the total fluence but also, although to a lesser extent, on the beam current density. The BS/C measurements reveal that all the samples, except the one implanted with the highest fluence, recover completely their original crystalline structure after the annealing. Furthermore the angular anisotropy of the EPR spectra indicates that the implanted region recovered a good crystallinity, although some residual defects were observed.