The effect of the electron irradiation on the series resistance of Au/Ni/6H-SiC and Au/Ni/4H-SiC Schottky contacts

The effect of electron irradiation on Au/Ni/6H-SiC and Au/Ni/4H-SiC Schottky contacts has been studied by current voltage (I–V) characterization at room temperature. The diodes have been subjected to the electron irradiation at various energies (6, 12 and 15 MeV) and influence of the electron irradiation on the diode parameters such as barrier height, ideality factor, and series resistance has been studied. Cheung functions, Norde model and conductance method have been used to determine the diode parameters. The ideality factor of the diodes is greater than unity indicating activation of some other current transport mechanism(s). The series resistances of the diodes increase by increasing electron energy. The reverse current increases for the Au/Ni/6H-SiC diode after each electron irradiation experiment, while decreasing trend is observed for Au/Ni/4H-SiC diode. Decrease in the barrier height of Au/Ni/4H-SiC diode is observed and mainly attributed to the increase of the reverse current, while the decrease of the forward current is caused by increase in series resistance, for high electron irradiation energies.