Papers by Keyword: Charge Transient Spectroscopy

Abstract: Defect levels in high purity semi-insulating 4H silicon carbide substrates are studied by charge transient spectroscopy using 5.5 MeV alpha particles. A shallow defect level with the activation energy around 0.3 eV is found in all samples annealed at temperatures from 1400 to 1600 °C. Some other defect levels lying at deeper in the bandgap are found in samples annealed at 1400 and 1500 °C. As these deep levels are annealed out by 1600 °C, the series resistance of samples is decreased.

Abstract: Defects in electron-irradiated 6H-SiC diodes have been studied by single alpha particle induced charge transient spectroscopy and deep level transient spectroscopy (DLTS) in order to identify critical defects responsible for the charge collection efficiency (CCE) decreased by high-energy electron irradiation. The defect X2 detected by the charge transient spectroscopy and the electron trap Ei detected by the DLTS had a similar activation energy of around 0.50 eV. In addition, the annealing at 200oC completely removed defects X2 and Ei, and restored the CCE. The defect X2 is attributed to the electron trap Ei, and responsible for the decreased CCE.