Capacitance temperature dependence analysis of GaN-on-Si power transistors
Résumé
Many kinds of defects are present in the different layers of GaN-on-Si epitaxy. Their study is very important, especially because they play a significant role on the device characteristics. This paper investigates the cause of the temperature dependence of the output and Miller capacitance at three different temperatures: 25°C, 75°C and 150°C of GaN-on-Si power transistors. In particular, this study focus on the temperature dependence of depletion voltage seen in these characteristics due to the progressive depletion of the Two-Dimensional Electron Gas (2DEG) under the device field plates. First, variations of the epitaxial growth are studied, showing that the intrinsic carbon concentration does not play a significant role. Secondly, the deep acceptor trap origin of the temperature dependence is analyzed with a TCAD simulation study. Thirdly, by performing a fit between TCAD simulation and experimental data, a linear relationship between the acceptor trap energy and its cross-section is obtained. The comparison of these properties with the acceptor traps identified in the state of the art suggests that the origin is a gallium vacancy tied to oxygen atom(s) on the N site.
Domaines
Electronique| Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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