整合MBE與MOCVD磊晶技術於三族氮化物高頻功率電晶體磊晶結構之開發(I)

Abstract

國立交通大學電子所 計畫名稱：整合MBE 與MOCVD 磊晶技術於三族氮化物高頻功率電晶體磊 晶結構之開發 研究者：張俊彥 經費來源：行政院國家科學委員會 關鍵詞：氮化鎵、高功率元件、分子束磊晶、有機金屬化學氣相沈積 結合 MBE 與MOCVD 技術成長GaN-HEMT 元件是目前最有潛力的方法， 因為MBE 擁有成長超陡峭 (abrupt) 複合物接面 (junction)、良好的厚度控制能 力和極低的雜質污染等優點。但是，高穿通式差排 (threading dislocations)缺陷 對MBE 是個很大的挑戰，電子遷移率會受到穿通式缺陷的限制，尤其是成長在 異質基板上，缺陷密度高達1 ×1010 cm-2。MOCVD 技術的成長速率快可以成長 無壓應力、低缺陷密度的氮化鎵塊材，可以彌補MBE 之缺點。高品質的 GaN-HEMT 元件結構須具備－超陡峭接面、高純度本質磊晶層、低壓應力、低 缺陷密度等特性。因此，結合MOCVD 非常低差排缺陷密度的GaN-template 基 板與MBE 可成長非常高電子遷移率的二維電子氣 (2DEG， two dimension electron gas) 結構的能力，是現階段製作GaN-HEMT 元件最具潛力的方式。本 計畫主要目標在整合MBE 與MOCVD 技術於成長高可靠度、高功率放大器異 質磊晶結構，並進一步改良磊晶結構提升放大器之線性度及操作頻率。為了配 合子計畫(二)之應用在不同波段的磊晶結構之設計，同時提高元件磊晶品質。提 供各個子計畫 GaN-HEMT 元件量測分析、製程開發、模擬、參數萃取及電路設 計。並與子計畫(三)、（四）合作建立高頻等效電路模型，以供將來MMIC 高頻 電路設計之用。本計畫預計完成AlGaN/AlN/GaN HEMT 之高功率放大器元件， 並且開發具備高可靠度與高線性度的AlGaN/GaN/InGaN D-HEMT 之高功率放 大器元件。

National Chiao Tung University Department of Electronics Engineering Title：Development of the III-nitride high power high frequency HEMT structures grown by integration of MBE and MOCVD technologies Principal Investigator：Chun-Yen Chang Sponsor：National Science Council Keywords：GaN、HEMT、MBE、MOCVD The combination of both MBE and MOCVD techniques is most promising method to achieve high quality material for GaN-HEMT devices. The advantages of MBE include abrupt material junction (sharp interface) and precise layer thickness controls as well as the extremely low impurities growth environment. However, to grow GaN material with low threading dislocation (TD) density is a huge challenge for MBE. The presence of TDs in GaN as high as 1x1010 cm-2 when growth on a foreign substrate is greatly limited the electron mobility. MOCVD technique, with faster growth rate to achieve stress-free and low dislocation density GaN buffer, can compensate the drawback of MBE. High quality GaN-HEMT device structures require abrupt junctions (sharp interface) and high purity material with low stress and low defect density. Therefore, the combination technique of MOCVD to grow low dislocation density GaN-template and MBE to grow high electron mobility (2DEG) structure is the most promising method to obtain high quality GaN-HEMT devices. The main objective of this project is to optimize these two growth techniques in order to achieve high quality materials for the GaN high power high frequency device fabrication with good linearity and reliability. Particularly, this sub-project (1) will provide the high quality GaN materials for device fabrication at different power and frequency applications in sub-project (2). The results from sub-project (2) on fabricated device performance and from sub-project (3) on device simulations will be the feedbacks to improve the material growth in this sub-project (1). The characteristics of GaN-HEMTs are to be used for the circuit modeling for MMIC application in sub-project (4). The HEMT structures to be grown in the sub-project (1) include the AlGaN/AlN/GaN for high power application and AlGaN/GaN/InGaN D-HEMT for high power high frequency application with good linearity and reliability.