The breakdown behavior of GaN epitaxial material on silicon

Abstract

In this paper, the leakage path and breakdown behavior of GaN on silicon substrate were studied systematically. Three terminal breakdown voltage characteristics of the samples with various ohmic contacts spacing were evaluated. With increasing the spacing between the contacts, the breakdown voltage increased linearly first and then saturated. In order to clarify the breakdown behavior, leakage path after breakdown test was further analyzed and the breakdown behaviors were identified. Furthermore, the burnt buffer layer was observed by FIB SEM after device breakdown intuitively. It manifested that the spacing dependent breakdown characteristics of the epitaxial layer was ascribe to that different leakage paths dominated the breakdown at different spacing.