近年來環保意識抬頭，綠能產業已成為工業發展趨勢，利用氮化鎵功率元件應用在開關電路中將可大幅降低能源的損耗。本論文主要探討大電流氮化鎵電晶體之製作，及使用不同的閘極絕緣層材料對於單根指叉元件特性的影響。為了實現大電流電晶體元件，實驗中採用多根指叉的光罩設計，在元件總閘極寬度為20 mm、閘極偏壓為0 V、汲極偏壓10 V且pulse width為200 μs時，成功的達成8.3安培的電流特性，且正規化後的開啟電阻為3.6 mΩ-cm2。其動態電阻約為直流電阻的1.67倍。 本實驗亦設計與探討了多種閘極絕緣層材料，分別為二氧化矽、氮化矽和氧化鋁，以及二氧化矽/氧化鋁和氮化矽/氧化鋁的複合式絕緣層結構。發現使用氧化鋁和氮化矽為絕緣層的元件具有較低的開啟電阻為3.4 mΩ-cm2和3.1 mΩ-cm2。但在截止特性方面，惟具有二氧化矽為絕緣層材料的元件崩潰電壓能超過200 V，而其他種元件皆有提早崩潰的現象。此外，不同閘極絕緣層之元件在動態特性上也有不同的表現，藉由C-V量測後可以發現主要由於半-絕接面的深層缺陷能階密度不同所導致。 This thesis focuses on the fabrication of high current GaN transistors and the influence of different gate insulator materials on the single finger devices. In order to achieve high current transistors, this study designed the multi-finger type layout with the total gate width of 20 mm. High current AlGaN/GaN MISFETs grown on 6” Si substrate were successfully demonstrated. When the device is under gate bias of 0 V, drain bias of 10 V and pulse width of 200 μs, the maximum current and specific on-state resistance (Ron) reached 8.3 A and 3.6 mΩ-cm2, respectively. In addition, the measured dynamic Ron is about 1.67 times magnitude of the static Ron. This study designed a variety of gate insulator materials, including Al2O3、SiO2、Si3N4 and SiO2/Al2O3 composite layer, and found out that the devices with Al2O3 and Si3N4 gate insulator had lower Ron of 3.4 mΩ-cm2 and 3.1 mΩ-cm2. In the off-state characteristics, the devices with SiO2 and SiO2/Al2O3 composite layer have higher breakdown voltage over 200 V, while the other two devices have the problem of early breakdown. In addition, devices with different insulators have different performances on the dynamic Ron. By C-V measurement, the density of deep level trap between insulator and semiconductor could be obtained to analyze the difference of dynamic characteristics.
