高k HfLaO栅介质MoS2晶体管的性能研究  

Study on Multilayer MoS Transistors with La-Doped HfO High-k Gate Dielectric

作　　者：邹霁玥 汪礼胜[2] ZOU Jiyue;WANG Lisheng(School of Information Engineering,Wuhan University of Technology,Wuhan 430070,P.R.China;School of Science,Wuhan University of Technology,Wuhan 430070,P.R.China)

机构地区：[1]武汉理工大学信息工程学院,武汉430070 [2]武汉理工大学理学院,武汉430070

出　　处：《微电子学》2020年第4期564-568,共5页Microelectronics

基　　金：国家自然科学基金资助项目(51702245)。

摘　　要：比较研究了HfO2与HfLaO栅介质多层MoS2场效应晶体管。实验结果表明,与HfO2栅介质MoS2晶体管相比,HfLaO栅介质MoS2晶体管表现出更优的电性能。电流开关比高达1×10^8,亚阈斜率低至76 mV/dec,界面态密度低至1.1×10^12 cm^-2·eV^-1,载流子场效应迁移率高达1×10^9 cm^2·V^-1·s^-1。性能改善的原因在于镧(La)对HfO2的掺杂形成HfLaO化合物,减小栅介质薄膜的表面粗糙度,降低缺陷电荷密度,改善了栅介质/沟道界面特性,从而减小了界面态密度,抑制了库仑散射和界面粗糙散射。最终,提高了多层MoS2晶体管的场效应迁移率,改善了晶体管的亚阈特性。Multilayer two-dimensional molybdenum disulfide(MoS2) field effect transistors with pure HfO2 or La-doped HfO2(HfLaO) as gate dielectrics were studied comparatively. Compared with the MoS2 transistor with HfO2 gate dielectric, the MoS2 transistor with HfLaO gate dielectric exhibited much more excellent electrical characteristics, such as an on-off ratio of 1×108, a subthreshold swing of 76 mV/dec, a low interface-trap density of 1.1×1012 cm-2·eV-1, and a high field effect mobility of 1×109 cm2·V-1·s-1. All these performance enhancement should be attributed to low trap-charge density and small surface roughness of HfLaO film due to La doped into HfO2, thus resulting in superior interface quality between the HfLaO gate dielectric and MoS2 active channel, and suppressing the coulomb scattering and the interface roughness scattering. Ultimately, increased field effect mobility and improved subthreshold characteristics had been achieved for the multilayer MoS2 field effect transistors with HfLaO high-k gate dielectric.

关 键 词：多层二硫化钼 氧化镧铪 场效应晶体管 高K栅介质 

分 类 号：TN325.3[电子电信—物理电子学] TN386.2