RF-MBE Grown AlGaN/GaN HEMT Structure with High Al Content  

RF-MBE生长的高Al势垒层AlGaN/GaN HEMT结构(英文)

作　　者：王晓亮[1] 王翠梅[1] 胡国新[1] 王军喜[1] 刘新宇[2] 刘键[2] 冉军学[1] 钱鹤[2] 曾一平[1] 李晋闽[1] 

机构地区：[1]中国科学院半导体研究所,北京100083 [2]中国科学院微电子研究所,北京100029

出　　处：《Journal of Semiconductors》2005年第6期1116-1120,共5页半导体学报（英文版）

基　　金：中国科学院知识创新工程,国家自然科学基金(批准号:60136020);国家重点基础研究发展规划(批准号:G20000683,2002CB311903);国家高技术研究发展计划(批准号:2002AA305304)资助项目~~

摘　　要：A Si doped AlGaN/GaN HEMT structure with high Al content (x=43%) in the barrier layer is grown on sapphire substrate by RF-MBE.The structural and electrical properties of the heterostructure are investigated by the triple axis X-ray diffraction and Van der Pauw-Hall measurement,respectively.The observed prominent Bragg peaks of the GaN and AlGaN and the Hall results show that the structure is of high quality with smooth interface.The high 2DEG mobility in excess of 1260cm2/(V·s) is achieved with an electron density of 1.429×10 13cm -2 at 297K,corresponding to a sheet-density-mobility product of 1.8×10 16V -1·s -1.Devices based on the structure are fabricated and characterized.Better DC characteristics,maximum drain current of 1.0A/mm and extrinsic transconductance of 218mS/mm are obtained when compared with HEMTs fabricated using structures with lower Al mole fraction in the AlGaN barrier layer.The results suggest that the high Al content in the AlGaN barrier layer is promising in improving material electrical properties and device performance.采用RFMBE技术,在蓝宝石衬底上生长了高Al组分势垒层AlGaN/GaNHEMT结构.用三晶X射线衍射分析得到AlGaN势垒层的Al组分约为43%,异质结构晶体质量较高,界面比较光滑.变温霍尔测量显示此结构具有良好的电学性能,室温时电子迁移率和电子浓度分别高达1246cm2/(V·s)和1.429×1013cm-2,二者的乘积为1.8×1016V-1·s-1.用此材料研制的器件,直流特性得到了提高,最大漏极输出电流为1.0A/mm,非本征跨导为218mS/mm.结果表明,提高AlGaN势垒层Al的组分有助于提高AlGaN/GaNHEMT结构材料的电学性能和器件性能.

关 键 词：HEMT GAN 2DEG RF-MBE power device 

分 类 号：TN304.2[电子电信—物理电子学]