Deep Levels Generated by Ion-implantation in n- and p-type 4H-SiC

The authors have investigated deep levels in the whole energy range of bandgap of 4H-SiC. which are generated by N+, P+, Al+ implantation, by deep level transient spectroscopy (DLTS). Ne+-implanted samples have been also prepared to investigate the pure implantation damage. In the n-type as-grown material, Z(1/2) (E-c - 0.63 eV) and EH6/7 (E-c - 1.6 eV) are dominant deep levels. When the implant dose is low, seven peaks (IN1, IN3 similar to IN6, IN8, IN9) have emerged by implantation and annealing at 1000 degrees C in the DLTS spectra from all n-type samples. After high-temperature annealing at 1700 degrees C, however, most DLTS peaks disappeared, and two peaks, Z(1/2) and EH6/7 survive. In the p-type as-grown material, D center (E-v + 0.40 eV) and HK4 (E-v + 1.4 eV) are dominant. When the implant dose is low, two peaks (IP1, IP3) have emerged by implantation and annealing at 1000 degrees C and four traps IP2, IP4 (E-v + 0.72 eV), IP7 (E-v + 1.3 eV), an IP8 (E-v + 1.4 eV) are dominant after annealing at 1700 degrees C.