Defect correlated emmission and electrical properties of 4H- and 6H-SiC epitaxial layers doped by nuclear transmutation doping (NTD)

摘要

We have investigated 4H-SiC and 6H-SiC epitaxial layers after doping by nuclear transmutation doping (NTD). N-type layers on n-type substrates were characterized by low-temperature photoluminescence (LTPL) and p-type layers on p-type substrates with I―V, C―V and Hall effect measurements. Resulting from irradiations with thermalized neutrons of different energy spectra the samples were doped with phosphorous. Our experiments show defects which are generated by fast neutrons which inevitably exist in the energy spectra of reactor neutrons. We characterized samples by LTPL at temperatures of measurement between 2 and 72 K in the visible range as irradiated and annealed up to 1200℃. l―V curves of pn-junctions which are annealed at 1500℃ and 1600℃ with varied fluences of fast neutrons are presented.