Effects of charge and dipole on flatband voltage in an MOS device with a Gd-doped HfO_2 dielectric  

作　　者：韩锴 王晓磊 杨红 王文武 

机构地区：[1]Department of Physics and Electronic Science, Weifang University [2]Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences

出　　处：《Chinese Physics B》2013年第11期585-588,共4页中国物理B（英文版）

基　　金：Project supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2009ZX02035);the National Natural Science of China(Grant Nos.61176091 and 50932001)

摘　　要：Gd-doped HfO2 has drawn worldwide interest for its interesting features. It is considered to be a suitable material for N-type metal-oxide-semiconductor （MOS） devices due to a negative flatband voltage （Vfb） shift caused by the Gd doping. In this work, an anomalous positive shift was observed when Gd was doped into HfO2. The cause for such a phenomenon was systematically investigated by distinguishing the effects of different factors, such as Fermi level pinning （FLP）, a dipole at the dielectric/SiO2 interface, fixed interracial charge, and bulk charge, on Vfb. It was found that the FLP and interfacial dipole could make Vfb negatively shifted, which is in agreement with the conventional dipole theory. The increase in interfacial fixed charge resulting from Gd doping plays a major role in positive Vfb shift.Gd-doped HfO2 has drawn worldwide interest for its interesting features. It is considered to be a suitable material for N-type metal-oxide-semiconductor （MOS） devices due to a negative flatband voltage （Vfb） shift caused by the Gd doping. In this work, an anomalous positive shift was observed when Gd was doped into HfO2. The cause for such a phenomenon was systematically investigated by distinguishing the effects of different factors, such as Fermi level pinning （FLP）, a dipole at the dielectric/SiO2 interface, fixed interracial charge, and bulk charge, on Vfb. It was found that the FLP and interfacial dipole could make Vfb negatively shifted, which is in agreement with the conventional dipole theory. The increase in interfacial fixed charge resulting from Gd doping plays a major role in positive Vfb shift.

关 键 词：high-k dielectric HfGdOx interface dipole flatband voltage shift 

分 类 号：TN386.1[电子电信—物理电子学] TN405.7