軍用射頻關鍵元組件技術研究

Abstract

本計劃之主要研究為發展「主動相位陣列雷達」所需之高頻、高功率、高線性度及高效率的氮化鎵(GaN)高電子遷移率電晶體，首先將磊晶技術、元件製程、及散熱封裝等方向做整合性研發，以建立完整且系統化之氮化鎵射頻高功率元件之關鍵技術。研究方法為首先以有機金屬氣相沉積設備(MOCVD)磊晶技術，在具高熱傳特性之碳化矽基板(SiC)上磊晶三族氮化物，並研發出調控碳化矽基板與磊晶三族氮化物間晶格不匹配(lattice mismatch)與熱膨脹系數匹配等問題，成長符合軍用射頻之高輸出功率密度放大器之磊晶結構，預期目標可達到電子遷移率大於1800 cm2/Vs及載子密度達1×1013cm-2。接著開發先進之氮化鎵高載子遷移率電晶體(HEMT)製程技術，結合背晶貫孔技術之開發，製作出穩定高性能之GaN HEMT高功率元件，並佐以DC及RF量測系統做元件之分析驗證，預期在X-band下操作，元件之功率密度可達5W/mm。此外亦將進行氮化鎵之HEMT高功率密度輸出元件其散熱封裝之模擬與設計，開發高散熱性氮化鎵/氮化鋁鎵HEMT on SiC高電子遷移率射頻功率元件製程技術。

The main objective of this project is to develop GaN high electron mobility transistor (HEMT) device with high operation frequency, high output power and high linearity performances for the application in the Active Phased Array Radars (APAR). The study intents to build the critical GaN device technologies for RF power applications by integrating the complete process flow, including epitaxy growth, device fabrication and device packaging for heat dissipation techniques. We will start with growing GaN materials on SiC substrate using metal-organic chemical vapor deposition (MOCVD) system. High crystal quality GaN materials should be achieved by using the buffer which could effective minimize the lattice constant and thermal expansion coefficient mismatches between the GaN and SiC substrate. The targeted carrier mobility and sheet density are larger than 1800 cm2/V-s and 1x1013 cm-2, respectively. After that, the device fabrication technology, including the back side via-hole process, will be developed to produce high output power GaN HEMT with high performance and good stability. Under the X-band frequency operation, the GaN HEMT device should produce power density up to 5W/mm. Besides, the GaN HEMT device packaging simulation and design will also be studied to enhance the device heat dissipation at high power operation.