Electrical properties of Al/Al4C3/4H-SiC diodes

The impact of aluminum carbide (Al4C3) at the metal/silicon-carbide (SiC) interface is presented here with respect to 4H-SiC Schottky barrier diodes (SBDs). A post-annealing process at a high temperature (1000 °C) has been employed for the reaction between the aluminum and the carbon. The current density of the fabricated device was measured as ~ 13.4 A/cm2 at 5 V with a leakage current density of less than ~ 6.84 × 10−9 A/cm2 at − 5 V. The thermal-activation energy (EA = 0.35 eV) extracted from the Arrhenius plot decreased by ~ 37% via the formation of the Al4C3. According to the experiment results, the sample with the Al4C3 layer yields a rectification ratio of 1.95 × 109 that is 33 times higher than that of the reference SBDs. The structural defects of the SiC interface may be available for the formation of the Al4C3 layer.