Nitrogen ion implantation isolation technology for normally‐off GaN MISFETs on p‐GaN substrate

Nitrogen ion implanted isolation technology to prevent leakage current between adjacent devices fabricated on p-GaN layers on sapphire substrate is described. Leakage current due to n-type inversion layers caused by Fermi level pinning at the p-GaN surface and buffer layers between sapphire substrate and GaN epitaxial layer is greatly reduced. With nitrogen ion implanted isolation technology of this study, leakage current between adjacent devices reduced five orders of magnitude compared to that without isolation layers. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)