Characterization of vacancy-type defects in Alq and Nq co-implanted SiC by slow positron implantation spectroscopy

6H–SiC n-type wafers were implanted with Alq and Nq ions in two ways: first Alq followed by Nq and vice versa. The implantation was carried out at four different substrate temperatures between 200 and 8008C. Depth profiles of the defects were evaluated from measured Doppler broadening profiles of the annihilation radiation as a function of incident positron energy for both co-implantation sequences. Differences in the defect distribution and in the defect size are shown and discussed. q1999 Elsevier Science B.V. All rights reserved