Protection of isolated and active regions in AlGaN/GaN HEMTs using selective laser annealing  

作　　者：Mingchen Hou Gang Xie Qing Guo Kuang Sheng 侯明辰;谢刚;郭清;盛况(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China;Hangzhou Innovation Center,Zhejiang University,Hangzhou 310027,China;Ningbo Chipex Semiconductor Co.,LTD.,Ningbo 315000,China)

机构地区：[1]College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China [2]Hangzhou Innovation Center,Zhejiang University,Hangzhou 310027,China [3]Ningbo Chipex Semiconductor Co.,LTD.,Ningbo 315000,China

出　　处：《Chinese Physics B》2021年第9期483-489,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.51577169 and 51777187)the National Key Research and Development Program of China(Grant No.2017YFB0402804);the“Science and Technology Innovation 2025”Major Program of Ningbo(Grant No.2018B10098).

摘　　要：AlGaN/GaN high-electron-mobility transistors with Au-free ohmic contacts are fabricated by selective laser annealing and conventional rapid thermal annealing.The current transport mechanism of ohmic contacts is investigated.High-temperature annealing can be avoided in the isolated region and the active region by selective laser annealing.The implanted isolation leakage current is maintained 10^(-6) mA/mm even at 1000 V after selective laser annealing.On the contrary,high-temperature annealing will cause obvious degradation of the isolation.The morphology of AlGaN surface is measured by atomic force microscope.No noticeable change of the AlGaN surface morphology after selective laser annealing,while the root-mean-square roughness value markedly increases after rapid thermal annealing.The smaller frequency dispersion of capacitance-voltage characteristics confirms the lower density of surface states after selective laser annealing.Thus,dynamic on-resistance is effectively suppressed.

关 键 词：gallium nitride ohmic contacts laser annealing 

分 类 号：TN386[电子电信—物理电子学] TB34[一般工业技术—材料科学与工程]