| Summary: | 碩士 === 國立臺灣師範大學 === 光電科技研究所 === 101 === GaN-based high-electron-mobility transistors (HEMTs) are considered to be excellent candidate due to their high sheet-carrier density in the 2-D electron gas (2-DEG) channel and large breakdown field strength (~3.5MV/cm).
In this work , we numerically study the enhancement of breakdown voltage in III-nitride HEMTs by employing the AlGaN/GaN/AlGaN quantum-well (QW) electron-blocking-layer (EBL) by using APSYS. This concept is based on the superior confinement of two dimensional electron gas (2-DEG) provided by the QW EBL, which results in a significant improvement of breakdown voltage and a remarkable suppression of overflowing electrons, and promotes the mobility of transport electron.
The dependence of thickness and composition of QW on the device breakdown is systematically evaluated and discussed in detail for the device optimization. In the present study, the breakdown voltage identified for the conventional HEMT and optimized QW EBL HEMT are 48V and 285V,respectively. Additionally, the QW EBL HEMT structure exhibits the highest electron mobility of 940 cm2/Vs .
As a result, we validate the advantages of the proposed structure over the conventional AlGaN/GaN HEMT. We conclude the AlGaN/GaN/AlGaN QW EBL as a promising way to explore the AlGaN/GaN HEMTs in high-speed power-switching applications.
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