Gamma irradiation impact on GaN quasi-vertical Schottky barrier diodes. (11th November 2019)

• Record Type: Journal Article
• Authors: Bian, Zhaoke; Su, Kai; Zhang, Jincheng; Zhao, Shenglei; Zhou, Hong; Zhang, Weihang; Zhang, Yachao; Zhang, Tao; Chen, Jiabo; Dang, Kui; Ning, Jing; Hao, Yue
• Is Part Of: Journal of physics. Volume 53:Number 4(2020)
• Publication Date: 2019-11-11
• Subjects: gallium nitride -- gamma irradiation -- vertical devices -- Schottky barrier diode -- Schottky barrier inhomogeneities; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/ab4c6f
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: The impact of gamma irradiation on GaN quasi-vertical Schottky barrier diodes (SBDs) has been investigated for the first time. Compared with original GaN SBDs, the ideality factor decreases from 1.2 to 1.01–1.02 and the on/off ratio increases from 10 9 to 10 12 for the irradiated GaN SBDs. The reduction of dynamic on-resistance from 0.67 mΩ · cm 2 to 0.54 mΩ · cm 2 was observed at the quiescent bias of −100 V compared with the original SBDs. The temperature dependent current characteristics has revealed the existence of Schottky barrier inhomogeneities at the anode/GaN Schottky interface, and the level of barrier inhomogeneities can be effectively suppressed after gamma irradiation. Based on x-ray photoelectron spectroscopy, cathodoluminescence and x-ray diffraction results, the interface state density at the interface and the deep electron trap in the bulk GaN are reduced after gamma irradiation. The voltage dependent capacitance-frequency measurements further confirm that the interface trap states dominate the degraded characteristics of pre-irradiated devices and the trap time constant is estimated to be in the range of 5 μ s to 50 μ s.