The Study on High-Energy Surge Suppress Ability of the Gan-Based Double Gate Msm Varactor Diodes

For both military and civilian technology, the excellent features of aluminum gallium nitride/gallium nitride high electron mobility transistor (AlGaN/GaN HEMT) are crucial in radar, satellite, telecommunications and other high-frequency, high-power applications. That also escalates the reliability of the HEMT proper rate and equipments’ lifetime. However, the trend toward electronic components is light and small, and which resulting in a serious problem of heat accumulation for the high-frequency power microwave device. Moreover, the lighter the electronic components the weaker the withstand capability of the surge attacks and electromagnetic pulse attacks. Consequently, it seriously affects devices’ reliability, and furthermore causes damages of the system characteristics. Traditionally, the metal oxide varistor is most representative element that used in Anti-surge application, but it has several dozens of pF parasitic capacitance in parallel with the transceiver module (T / R Module) circuit. Which will generate a large insertion loss at high frequency operation, and is unfavorable for the future development in communication system of 5GHz(~10GHz). Therefore, it is necessary to propose a new surge protection technology which contains a filter of protection with a two-dimensional electron gas (2DEG) varactor with a metal-semiconductor-metal (MSM) GaN structure. It will protect the communication system from high-energy surge pulse attacks under the natural or man-made situation. Furthermore, it should also have the advantage of low insertion loss .In the beginning of this study, AlN-submount flip-chip technology and AlGaN/GaN MSM-2DEG varactor are integrated together to enhance the reliability. Furthermore, we would like to analyze on the physical characters of AlGaN/GaN varactor deeply, and explore how to control its turn-on and cut-off capacitance ratio. In the application field, we tend to acquire the benefits of high capacitance ratio (Cmax / Cmin) and low leakage current. At the final stage, this study will apply above completed MSM device into an anti-surge AlN micro strip filter which has excellent heat-dissipation property, in order to enhance both aspects for the surge protect capability of high-frequency circuits and device-system integration.

Project ID:PB10708-2127
External Project ID:MOST107-2221-E182-045