Improvement of switching characteristics by substrate bias in AlGaN/AlN/GaN heterostructure field effect transistors  

作　　者：杨铭 林兆军 赵景涛 王玉堂 李志远 吕元杰 冯志红 

机构地区：[1]School of Physics, Shandong University [2]National Key Laboratory of Application Specific Integrated Circuit ASIC), Hebei Semiconductor Research Institute

出　　处：《Chinese Physics B》2015年第11期406-409,共4页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11174182 and 61306113);the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant No.20110131110005)

摘　　要：A simple and effective approach to improve the switching characteristics of AlGaN/AlN/GaN heterostructure field effect transistors （HFETs） by applying a voltage bias on the substrate is presented. With the increase of the substrate bias, the OFF-state drain current is much reduced and the ON-state current keeps constant. Both the ON/OFF current ratio and the subthreshold swing are demonstrated to be greatly improved. With the thinned substrate, the improvement of the switching characteristics with the substrate bias is found to be even greater. The above improvements of the switching characteristics are attributed to the interaction between the substrate bias induced electrical field and the bulk traps in the GaN buffer layer, which reduces the conductivity of the GaN buffer layer.A simple and effective approach to improve the switching characteristics of AlGaN/AlN/GaN heterostructure field effect transistors （HFETs） by applying a voltage bias on the substrate is presented. With the increase of the substrate bias, the OFF-state drain current is much reduced and the ON-state current keeps constant. Both the ON/OFF current ratio and the subthreshold swing are demonstrated to be greatly improved. With the thinned substrate, the improvement of the switching characteristics with the substrate bias is found to be even greater. The above improvements of the switching characteristics are attributed to the interaction between the substrate bias induced electrical field and the bulk traps in the GaN buffer layer, which reduces the conductivity of the GaN buffer layer.

关 键 词：AlaN/GaN heterostructure field effect transistors （HFETs） switching characteristics substratebias 

分 类 号：TN386[电子电信—物理电子学] TB383[一般工业技术—材料科学与工程]