摘要
在本篇論文中，首先利用TCAD擬和氮化鋁鎵/氮化鎵異質結構的Transmission Line Model(TLM)模型，再進一步模擬自熱效應觀察元件內部現象。利用建立好的模型模擬氮化鋁鎵/氮化鎵雙金屬蕭基二極體，其電流誤差在±10%。 此外設計P型氮化鎵MOS-HEMT達到常關型元件，使用氧化鋁材料作為閘極介電質可降低漏電流，藉由調變通道長度及摻雜濃度可有效調整元件達最佳化。加入本質氮化鎵當作通道，可以提升特性元件，大幅降低臨界電壓達到更高的飽和電流，並估算在通道長度為0.4µm且閘極-汲極長度為10µm的本質氮化鎵通道MOS-HEMT，導通電阻為3.7 mΩ•cm2，而通道導通電阻為0.41mΩ•cm2，佔總阻值的11%，最大阻值來源於閘極-汲極端約1.75 mΩ•cm2佔總阻值的47%。
並列摘要
In this thesis, we used TCAD for fitting AlGaN/GaN heterojunction Transmission Line Model (TLM) I-V characteristics. A physics-based model of self-heating is included in TCAD simulations to investigate the internal device behavior. A dual metal Schottky Barrier Diode (SBD) is also simulated with the constructed models. The fitting errors of less than ±10% for DC I-V characteristics in both cases have been achieved. Another topic of this thesis is to design a normally-off p-GaN MOS-HEMT. A p-GaN MOS-HEMT with Al2O3 as the gate dielectric can significantly reduce the gate leakage current and achieve normally-off operation. To build the best performing device we optimized the channel length and doping concentration of the p-GaN. A p-GaN MOS-HEMT performance can also be improved by adding an i-GaN layer as the channel layer. Compared with a p-GaN MOS-HEMT, the i-GaN layer design reduced the threshold voltage and increased the saturation current. The i-GaN channel MOS-HEMT with a channel length of 0.4µm and a gate-drain length of 10µm shows a specific on-resistance as low as 3.7mΩ•cm2. The channel region resistance is 0.41mΩ•cm2 which contributes about 11% of the total resistance. The largest part of the total resistance is 1.75mΩ•cm2 from the gate-drain distance and it contributes about 47%.
參考文獻
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