Photoluminescence study of beryllium implantation induced intrinsic defects in 6H-silicon carbide

Beryllium was implanted into both n- and p-type 6H-SiC and the samples were subsequently annealed at 1600°C. Photoluminescence (PL) measurements were performed and PL lines at 420 and 472nm were observed. The PL lines at around 420nm have been detected from various ion implanted SiC samples and have been attributed to transitions involving some implantation induced intrinsic defect labeled as D_II. The present observation of the PL lines at 420nm from Be implanted 6H-SiC supports the intrinsic model that D_II might be a carbon-di-interstitial defect. The lines at 472nm labeled as D_I in the PL spectra have previously been identified as divacancy defect (V_Si-V_C). We note that it was suggested that the electron traps labeled Z₁/Z₂ observed in deep level transient spectroscopy (DLTS) were due to the same divacancy defect. In our experiments, while the D_I series PL lines are prominent, DLTS results from the same samples show no Z₁/Z₂ related peaks. The PL and DLTS results seem to be against the possibility that Z₁/Z₂ arise from the same defect.