Effects of Illumination on Ar+-Implanted n-Type 6H-SiC Epitaxial Layers

Argon ions were implanted into n-type 6H-SiC epitaxial layers at 600°C. Postimplantation annealing was carried out at 1,600°C for 5 min in an Ar ambient. Four implantation-induced defect levels were observed at EC-0.28 eV, EC-0.34 eV, EC-0.46 eV, and EC-0.62 eV by deep level transient spectroscopy. The defect center at EC-0.28 eV is correlated with ED1/ED2 and with ID5. The defect at EC-0.46 eV with a capture cross section of 7.8 × 10−16 cm2 is correlated with E1/E2, while the defect at EC-0.62 eV with a capture cross section of 2.6 × 10−14 cm2 is correlated with Z1/Z2. Photo deep level transient spectroscopy was also used to study these defects. Upon illumination, the amplitudes of the deep level transient spectroscopy (DLTS) peaks increased considerably. Two emission components of Z1/Z2 were revealed: one fast and the other slow. The fast component could only be observed with a narrow rate window. In addition, a new defect was observed on the low-temperature side of the defect at EC-0.28 eV when the sample was illuminated.