高k纳米MOSFET的关态泄漏电流的研究  

Research on Off-State Leakage Current in Nano-Scale MOSFET with High-k Gate Dielectrics

作　　者：杨建红[1] 李桂芳[1] 刘辉兰[1] 

机构地区：[1]兰州大学物理科学与技术学院微电子研究所,兰州730000

出　　处：《微纳电子技术》2007年第12期1043-1047,共5页Micronanoelectronic Technology

基　　金：中国博士后基金资助项目(G2000068306);辽宁省教育厅资助项目(90201038)

摘　　要：对纳米MOSFET关断态的栅电流、漏电流和衬底电流进行了模拟,指出边缘直接隧穿电流(IEDT)远远大于传统的栅诱导泄漏电流(IGIDL)、亚阈区泄漏电流(ISUB)及带间隧穿电流(IBTBT)。对50 nm和90 nm MOSFET器件的Id-Vg特性进行了比较,发现在高Vdd下,关态泄漏电流(Ioff)随IEDT的增加而不断增大,并且器件尺寸越小,Ioff越大。高k栅介质能够减小IEDT,进而减小了Ioff,其中HfSiON、HfLaO可以使边缘隧穿电流减小2～5个数量级且边缘诱导的势垒降低(FIBL)效应很小。但当栅介质的k>25以后,由于FIBL效应,关态泄漏电流反而增大。Simulation of the off-state gate current, drain current and substrate current in nano-scale MOSFET indicated that the edge direct tunneling current （IEDT） was far larger than conventional gate induced drain leakage current （IGDU） , subthreshold leakage current （ISUB） , and band-to-band tunneling current （IBTBT） , thus becoming the dominating off-state leakage current. An comparison of Ia- Vg characteristics for 50 nm and 90 nm MOSFET observed that the off-state leakage current increased greatly with the edge direct tunneling current at high Vad , and the smaller the device is in size, the larger is the Ioff induced by the edge direct tunneling. An comparison of the IEDT＇ S in various gate dielectrics including SiO2, Si3N4 and HfO2 showed that Ioff can be decreased by using high-k gate dielectrics to reduce IEDT, but an investigation of Id-Vg characteristics for various gate dielectrics revealed that the increase in Ioff was due to the edge induced barrier-lowing effect, when k〉25. HfLaO and HfSiON can reduce IEDT by 2-5 orders of magnitude, with small FIBL.

关 键 词：关态泄漏电流 边缘直接隧穿电流 边缘诱导的势垒降低 高K栅介质 

分 类 号：TN386.1[电子电信—物理电子学]