利用閘極掘入方式製作增強型高截止電壓氮化鋁鎵/氮化鎵/氮化鋁鎵金屬-絕緣體-半導體高電子遷移率電晶體之研究

AlGaN/GaN/AlGaN enhancement-mode high electron mobility transistor (HEMT) is extensively studied in recent years. However, there is still no solution to fabricate a HEMT with high threshold voltage, which means that it will cause mis-operation in high voltage operation. For enhancement mode operation (E-mode), metal-oxide-semiconductor field effect transistor (MOS-FET), though it has higher threshold voltage, it is not commercialized due to the immature process techniques and higher on-resistance than HEMT. In this thesis, gate recess technique is used to fabricate E-mode AlGaN/GaN/AlGaN metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT). This structure has simpler process and lower on-resistance in comparison with MOS-FET. Additionally, this structure can achieve very high threshold voltage to avoid the mis-operation of the device. Schottky diode was used for process parameter evaluation to find out the optimum process condition, and then the recessed E-mode MIS-HEMT standard process was established. The device demonstrated 2 mA/mm, 0.8 mS/mm, and more than 200V for channel current, transconductance, and three-terminal breakdown voltage, respectively. Furthermore, the device shows 9V threshold voltage. The structure can also be applied to conventional D-mode HEMT application with ID = 280mA/mm and Gm = 75 mS/mm. These characteristics indicate that the structure is promising for high voltage electronic applications.