Influence of growth conditions on irradiation induced defects in low doped 4H-SiC epitaxial layers

Abstract

Nitrogen doped 4H-SiC epitaxial layers were investigated by deep level transient spectroscopy after irradiation with 6MeV electrons. The influence of C∕Si ratio, N doping level, and growth rate on the behavior of the prominent Z1,2 and EH6,7 levels during irradiation and subsequent annealing was studied. Both Z1,2 and EH6,7 increase in concentration with the N doping as well as with the C∕Si ratio. It is demonstrated that the growth conditions play a decisive role for the annihilation of the EH6,7 level and a possible identity of the EH6,7 defect is discussed.