Reliability Enhancement of Flip-Chip GaN-based HEMTs

• Main Authors: Hsu, Chien-Pin, 徐健彬
• Other Authors: Kuei, Ping-Yu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/96008906066274578927

碩士 === 國防大學理工學院 === 光電工程碩士班 === 101 === Due to the fact that gallium nitrides (GaN) exhibits many superior characteristics such as wide band-gap and high electron mobility; AlGaN/GaN high electron mobility transistors (HEMTs) are extremely suitable for the uses of high power and high-frequency microwave devices. However, under high current operation conditions, excess self-heating of the HEMT device will decrease the carrier mobility in the correspondent channel region and limit their power output capabilities. Therefore, flip-chip (FC) technology has been adopted in this study to solve the heat-sink problem, which promotes a higher power output for AlGaN/GaN HEMT. The discussion of electrostatic discharge (ESD) immunity is also another subject we have paid close attention to, the failure fate caused by ESD is an important issue for HEMT devices, especially in the continental regions, where dry climate produces a serious charge accumulation problem. Due to this reason, we propose a 2DEG-MSM varactor structure by alternating different shapes and sizes, its capacitance value and capacitance conversion ratio are increased, thereby increasing the ESD protection capability. In addition, an dielectric film is coated in the bottom of the metal electrodes, where we are able to increase the operating voltage range and facilitate the use of other electronic components. Finally, by using a series 2DEG-MSM varactor, which is connected to the gate of HEMT on an AlN submount, the ESD immunity and the heat-sinking capability of the fabricated FC HEMT is again enhanced and detailed.