Schottky barrier inhomogeneity of high current density AlN quasi-vertical Schottky barrier diodes on AlN/Sapphire templates

In this work, we investigate the Schottky barrier inhomogeneity of high-current–density (> 1 kA/cm 2 ) quasi-vertical AlN Schottky barrier diodes (SBDs) fabricated on AlN/Sapphire templates. The epilayers were grown using Agnitron Technology’s metal organic chemical vapor deposition system. The devices exhibited an ideality factor of 1.8, a Schottky barrier height of 1.65 eV, a specific on-resistance of 8.8 mΩ cm 2 , and a breakdown voltage of ~ 70 V. Temperature-dependent I–V measurements up to 350 °C confirmed excellent thermal stability, while also revealing inhomogeneous Schottky contact behavior. From the modified Richardson plot, a Richardson constant of 74 A cm −2 K −2 , a mean barrier height of 3.21 eV, and a standard deviation of 0.084 eV were extracted. These findings establish a foundation for the further development of quasi-vertical AlN SBDs on AlN/Sapphire templates, highlighting their promise for next-generation ultrawide-bandgap power electronics with significant potential for high-temperature and high-voltage applications.