Improvement of Breakdown Voltage and Device Reliability of AlGaN/GaN HEMTs with Integrated Slant-Gate

• Main Author: 張育維
• Other Authors: 張翼
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/e546n8

碩士 === 國立交通大學 === 照明與能源光電研究所 === 101 === AlGaN/GaN HEMTs have been widely investigated and demonstrated for its capability for high-frequency with power applications. For breakdown voltage improvement, field plate structures are generally used in GaN power HEMTs. Through a well design of device configuration, the slant-gate is equivalent to an integrated field plate that can be used to improve the performance of the power device. In this study, both computer simulation results and device test results were compared for normal gate and slant-gate devices. The gate geometry was modified according to the simulation to get a vintage slanted sidewall gate structure, and AlGaN/GaN HEMTs with slant-gate have been fabricated by deep-UV lithography to verify the simulation results. The fabricated slant-gate AlGaN/GaN HEMT on Si substrate exhibited a maximum transconductance of 120 mS/mm, and the breakdown voltage was increased from 130 V to 200 V. Bias stress test was performed to investigate the reliability of the power device, it‘s verified that slant-gate structure has only slightly current degradation rate and is more effective for the current recovery as compared with the normal gate device, and it means that the slant-gate device has better reliability for long time operating as compared to the normal gate device.