Low-thermal-budget Au-free ohmic contact to an ultrathin barrier AlGaN/GaN heterostructure utilizing a micro-patterned ohmic recess  

作　　者：Wen Shi Sen Huang Xinhua Wang Qimeng Jiang Yixu Yao Lan Bi Yuchen Li Kexin Deng Jie Fan Haibo Yin Ke Wei Yankui Li Jingyuan Shi Haojie Jiang Junfeng Li Xinyu Liu 

机构地区：[1]Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China [2]Institute of Microelectronics,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Semiconductors》2021年第9期61-65,共5页半导体学报（英文版）

基　　金：supported by National Natural Science Foundation of China under Grant 61822407,Grant 62074161,and Grant 11634002;in part by the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(CAS)under Grant QYZDB-SSW-JSC012;in part by the National Key Research and Development Program of China under Grant 2016YFB0400105 and Grant 2017YFB0403000;in part by the Youth Innovation Promotion Association of CAS;in part by the University of Chinese Academy of Sciences;and in part by the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,CAS.

摘　　要：A pre-ohmic micro-patterned recess process,is utilized to fabricate Ti/Al/Ti/TiN ohmic contact to an ultrathin-barrier(UTB)AlGaN/GaN heterostructure,featuring a significantly reduced ohmic contact resistivity of 0.56Ω·mm at an alloy temperature of 550℃.The sheet resistances increase with the temperature following a power law with the index of +2.58,while the specific contact resistivity decreases with the temperature.The contact mechanism can be well described by thermionic field emission(TFE).The extracted Schottky barrier height and electron concentration are 0.31 eV and 5.52×10^(18) cm^(−3),which suggests an intimate contact between ohmic metal and the UTB-AlGaN as well as GaN buffer.A good correlation between ohmic transfer length and the micro-pattern size is revealed,though in-depth investigation is needed.A preliminary CMOS-process-compatible metal-insulator-semiconductor high-mobility transistor(MIS-HEMT)was fabricated with the proposed Au-free ohmic contact technique.

关 键 词：ultrathin-barrier AlGaN/GaN heterostructure low thermal budget Au-free ohmic contact micro-patterned ohmic recess MIS-HEMTs transfer length 

分 类 号：TN386[电子电信—物理电子学]