Analysis of GaN cap layer effecting on critical voltage for electrical degradation of AlGaN/GaN HEMT. Issue 1 (10th October 2014)

• Record Type: Journal Article
• Authors: Qu, Shenqi; Wang, Xiaoliang; Xiao, Hongling; Wang, Cuimei; Jiang, Lijuan; Feng, Chun; Chen, Hong; Yin, Haibo; Yan, Junda; Peng, Enchao; Kang, He; Wang, Zhanguo; Hou, Xun
• Is Part Of: European physical journal. Number 68:Issue 1(2014:Oct.)
• Publication Date: 2014-10-10
• Subjects: Physics -- Periodicals; Microscopy -- Periodicals; Microchemistry -- Periodicals; Microstructure -- Periodicals; 530
• DOI: 10.1051/epjap/2014140019
• Languages: English
• ISSNs: 1286-0042

Abstract

Abstract : We present calculation of critical voltage for AlGaN/GaN high electron mobility transistors (HEMTs) with GaN cap layer. The calculation includes mechanical stress and relaxable energy in the GaN/AlGaN barrier layer. Under high voltage conditions, the high electric field results in an increase in stored relaxable energy. If this exceeds a critical value, crystallographic defects are formed. This degradation mechanism is voltage driven and characterized by a critical voltage beyond which non-reversible degradation takes place. The dependence of the GaN cap layer's thickness on the critical voltage has been discussed. The calculated results indicate that thicker GaN cap layer results in higher critical voltage.