P.N.M. Ngoepe

Electrical Characterization of Defects Introduced in n-Type N-Doped 4H-SiC during Electron Beam Exposure

Deep level transient spectroscopy (DLTS) was used to characterize the defects introduced in n-type, N-doped, 4H-SiC while being exposed to electron beam evaporation conditions. This was done by heating a tungsten source using an electron beam current of 100 mA, which was not sufficient to evaporate tungsten. Two new defects were introduced during the exposure of 4H-SiC samples to electron beam deposition conditions (without metal deposition) after resistively evaporated nickel Schottky contacts. We established the identity of these defects by comparing their signatures to those of high energy particle irradiation induced defects of the same materials. The defect E0.42 had acceptor-like behaviour and could be attributed to be a silicon or carbon vacancy. The E0.71 had intrinsic nature and was linked to a carbon vacancy and/or carbon interstials.