Defects in swift heavy ion irradiated n-4H-SiC

We have used confocal Raman spectroscopy, atomic force microscopy (AFM), Binary collision approximations and Deep level transient spectroscopy (DLTS) to study the defects introduced in n-type 4H-SiC by 167 MeV Xe²⁶⁺ ions (swift heavy ions (SHIs)). Moderately doped epitaxial layers were irradiated with SHIs to a fluence of 5 × 10¹¹ cm⁻² at room temperature. Raman spectroscopy was used to investigate the effects of irradiation on the crystal structure. Raman intensity reduced after irradiation but the overall bond structure was conserved. Cluster spectra from confocal Raman spectroscopy showed a damage impact that was consistent with SRIM simulations. AFM showed that the incident radiation resulted in elongated protrusions. The virgin samples contained the E_0.09, E_0.12, E_0.15 and E_0.65 as the only electrically active defects. After irradiation the E_0.40 and E_0.71 defects were introduced.