Annealing of Electron Irradiated, Thick, Ultrapure 4H SiC between 1100°C and 1500°C and Measurements of Lifetime and Photoluminescence

Ultra-pure n-type (8x10(13) cm(-3)), 99 mu m thick epitaxial films of 4H SiC were electron irradiated at 170 keV with a fluence of 5 x 10(16) cm(-2) or at 1 MeV with a fluence of 1 x 10(15) cm(-2) in various geometries. Low temperature photoluminescence (LTPL) spectra and microwave photoconductance (mu PCD) lifetime measurements were obtained on all samples prior to annealing and after annealing in Argon in free standing mode or on a POCO carbon (Poco Graphite, Inc.) platform, every 50 degrees C from 1100 degrees C to 1500 degrees C. No improvement in carrier lifetime was obtained. Spurious lines attributable to the use of a Genesis CX 3550 angstrom laser are also reported.