Improved reverse-bias breakdown behavior in fully-vertical GaN-on-Si Schottky barrier diodes with a thin AlN layer within the GaN drift layer

Abstract

In this study, we investigated the effect of inserting a 1 nm thick AlN thin-film layer in the drift layer of a GaN-on-Si Schottky barrier diode to improve the reverse-bias breakdown voltage. The breakdown voltage was significantly improved from 258 V (without an AlN layer) to 338 V (with an AlN layer placed at the bottom of the drift layer), indicating that the AlN thin layer played an important role in the breakdown voltage characteristics. Furthermore, x-ray diffraction measurements and stress evaluations indicate that the AlN thin-film layer inserted at the bottom of the drift layer can significantly reduce the film stress and improve the breakdown voltage of the device.