1. Investigating the Current Collapse Mechanisms of p-GaN Gate HEMTs by Different Passivation Dielectrics.
- Author
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Li, Xiangdong, Posthuma, Niels, Bakeroot, Benoit, Liang, Hu, You, Shuzhen, Wu, Zhicheng, Zhao, Ming, Groeseneken, Guido, and Decoutere, Stefaan
- Subjects
PASSIVATION ,DIELECTRICS ,MODULATION-doped field-effect transistors ,TEMPERATURE effect ,GATES ,LOGIC circuits - Abstract
In this letter, the dynamic Ron degradation mechanisms of the p-GaN gate HEMTs induced by off-state stress are investigated with different passivation dielectrics AlON and SiN. The degradation mechanisms are twofold, including VTH shift and surface trapping in the gate-to-drain access region, whose impacts are successfully distinguished. Surface trapping by SiN passivation is evidently proved to be the dominant factor that can almost induce a full current collapse. The VTH positive shift diminishes the drain current by shrinking the overdrive VGS, which however, can be compensated by a higher VGS overdrive in applications. SiN passivation can effectively suppress the positive bias temperature instability effect, probably by passivating the p-GaN fast traps with hydrogen during passivation. Last, the transient measurements unveil that both the surface trapping and VTH shift have a very slow recovery process. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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