GaN/AlGaN lateral Schottky barrier diodes for high frequency applications

We report on epitaxial growth, processing, characterization and firsts photoresponse experiments performed on GaN/AlGaN lateral Schottky barrier diodes. The epitaxial GaN/AlGaN epistructures were fabricated by molecular beam epitaxy under metal rich conditions on the freestanding GaN substrates. The lateral Schottky barrier diodes were performed using modified transistor processing, which was based on the laser writer lithography. The standard characterization techniques for epitaxial structures and separated lateral Schottky diodes confirmed high quality of the epitaxy and the device processing. The extremely low reverse currents, the high breakdown voltage and high separation resistance between mesa devices testified the very high quality of epitaxial layers and their low residual doping. We present the photoresponse experiments in sub-THz range, which were performed on wafer and for separated lateral diode chips. These results confirm possibility of applications of lateral GaN/AlGaN Schottky diodes as the building blocks of sub-THz devices.