Improving Breakdown Voltage for AlGaN/GaN HEMTs with Combined Slant Field-Plate and Conventional Field-Plate

• Main Authors: HUANG, HUAI-ZHUN, 黃懷諄
• Other Authors: CHANG, YANG-HUA
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/jf9jh6

碩士 === 國立雲林科技大學 === 電子工程系 === 106 === ABSTRACT Gallium nitride high-electron-mobility transistor are ideally suitable to high power, high frequency, and high temperature circuit applications due to the excellent material propertyies of gallium nitride (GaN) such as high electron mobility, high breakdown electric field, high thermal conductivity, and high cut-off frequency. In high power transistors, breakdown voltage is a very important indicative characteristic. Therefore, the main purpose of this research is to increase the breakdown voltage of the device. This thesis focuses on improving the breakdown characteristics of AlGaN/GaN HEMTs by using Synopsys TCAD semiconductor simulation software. Firstly, the physical models used in the simulation are introduced. Then physical parameters are properly calibrated. When the simulated current is close to the measured current, the accuracy of the physical models is validated. The initial structure of this study is a dual-channel enhancement-mode AlGaN/GaN HEMT. The breakdown voltage is improved in three steps: (1) a slant gate field plate is used, (2) a conventional gate field plate is added to the edge of the slant field plate, (3) the conventional gate field plate is recessed to a proper depth to smooth the electric field distribution along the chanel. With the composite gate structure, the maximized breakdown voltage is obtained. Keywords： HEMTs, breakdown voltage, gate field plate