Novel super stack passivation in AlGaN/GaN HEMT for power electronic applications

Abstract

A super-stack passivation technique is proposed for an AlGaN/GaN HEMT in order to improve the breakdown voltage and cutoff frequency. The performance of the proposed technique is benchmarked against a conventional GaN HEMT. The analysis and investigation are carried out using Technology Computer-Aided Design (TCAD). The simulation results are validated with experimental data. It is observed that the breakdown voltage of the conventional and proposed devices is 356V and 449V, respectively. In contrast to the conventional device, the breakdown voltage of the proposed device is improved by 21%. This is the manifestation of the suppression of the electric field by the super-stack passivation technique in the proposed device. Furthermore, it is also observed that the Johnson’s figure of merit in the proposed GaN-HEMT is also improved.

Keywords

• AlGaN/GaN interface
• Johnson figure of merit
• surface passivation
• current collapse