Analysis of breakdown voltage of field-plate AlGaN/GaN HEMTs as affected by buffer layer's acceptor density. (22nd May 2019)

• Record Type: Journal Article
• Authors: Akiyama, Shinya; Kondo, Masahiro; Wada, Leona; Horio, Kazushige
• Is Part Of: Japanese journal of applied physics. Volume 58:Number 6(2019)
• Publication Date: 2019-05-22
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/1347-4065/ab1e8f
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We perform a numerical analysis of field-plate AlGaN/GaN HEMTs with a Fe-doped buffer layer with only a deep acceptor as a deep level and study how its density N DA and the length of field-plate L FP affect the breakdown voltage V br . The calculated characteristics usually show abrupt increases in gate and drain currents due to impact ionization, resulting in breakdown. But, in some cases, V br is limited by current flow through the buffer, and this current is higher for lower N DA . Therefore, V br becomes higher for higher N DA . V br takes a maximum value at some L FP, and the highest average electric field between gate and drain becomes about 3.2 MV cm −1 when the breakdown occurs.