High-voltage AlN Schottky barrier diodes on bulk AlN substrates by MOCVD

Abstract

This letter reports the demonstration of AlN Schottky barrier diodes on bulk AlN substrates by metalorganic chemical vapor phase deposition (MOCVD) with breakdown voltages exceeding 3 kV. The devices exhibited good rectifying characteristics with ON/OFF ratios of 106–108 and excellent thermal stability from 298 to 623 K. The device Schottky barrier height increased from 0.89 to 1.85 eV, and the ideality factor decreased from 4.29 to 1.95 with increasing temperature, ascribed to the inhomogeneous metal/AlN interface. This work demonstrates the potential of AlN as an ultra-wide bandgap semiconductor for developing multi-kV AlN high-voltage and high-power devices.