Effects of buffer leakage current on breakdown characteristics in AlGaN/GaN HEMTs with a high-k passivation layer
| Autor: | Yoshiki Satoh, Hideyuki Hanawa, Kazushige Horio |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Permittivity
Materials science Passivation business.industry Analytical chemistry Relative permittivity Condensed Matter Physics Acceptor Atomic and Molecular Physics and Optics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Impact ionization Electric field Optoelectronics Breakdown voltage Electrical and Electronic Engineering business Leakage (electronics) |
| Zdroj: | Microelectronic Engineering. 147:96-99 |
| ISSN: | 0167-9317 |
| Popis: | Display Omitted Breakdown voltage of AlGaN/GaN HEMTs Vbr is estimated by two-dimensional simulation.Buffer leakage determines Vbr when passivation layer's permittivity er is high.Vbr increases as er increases because the buffer leakage current is reduced.When the gate voltage is more negative, Vbr increases in the high er region. A two-dimensional analysis of off-state breakdown characteristics in AlGaN/GaN HEMTs is performed by considering a deep donor and a deep acceptor in a buffer layer, with the relative permittivity of passivation layer er as a parameter. The analysis is made with and without impact ionization of carriers to study how the buffer leakage current affects the breakdown performance. It is shown that when er is low, the breakdown voltage is determined by the impact ionization of carriers, and when er becomes high, it is determined by the buffer leakage current. This buffer leakage current decreases as er increases because the electric field at the drain edge of the gate is weakened, and hence the breakdown voltage increases as er increases. It is also shown that when the gate voltage is more negative, the breakdown voltage in the high er region becomes higher because the buffer leakage current becomes smaller. |
| Databáze: | OpenAIRE |
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