Influence of the Annealing Process for the Metal Contacts of the SiC Semiconductor Radiation Detector

We have studied the radiation response of a prototype SiC radiation detector by using a 6H-SiC wafer. Metal contacts on the surface of the SiC samples were fabricated by using a thermal evaporator in a vacuum condition. Among the SiC samples, several samples were heated by a Rapid Temperature Annealing(RTA) device for 10 minutes at 300°C. The metal contacts on the annealed and non-annealed samples were scanned by using AFM(Atomic Force Microscope) before and after an annealing process. The current-voltage characteristics of the SiC detectors were measured by parameter analyzer and the radiation response was evaluated by 238Pu with 5.5 MeV α-ray at room temperature and a atmospheric pressure. After annealing process, the surface roughness and the current-voltage characteristics decreased. The Schottky barrier heights of non-annealed and annealed SiC samples were determined as 0.638 eV and 0.688 eV, respectively. Also radiation response spectra of the annealed and non-annealed detectors were similar.