WS_(2)场效应晶体管的表面电子掺杂  

Surface electron doping of WS_(2) FET

作　　者：李海鸥[1] 冯天旸 刘兴鹏 LI Haiou;FENG Tianyang;LIU Xingpeng(School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学信息与通信学院,广西桂林541004

出　　处：《桂林电子科技大学学报》2024年第2期111-117,共7页Journal of Guilin University of Electronic Technology

基　　金：国家自然科学基金(61874036,61805053);广西精密导航技术及应用重点实验室基金(DH202020,DH202001)。

摘　　要：二硫化钨(WS_(2))属于过渡金属硫族化合物(TMDs)材料,具有较宽的可调带隙(1.3~2.1 e V),缺陷密度相对较低,且有超高的表面积比,可通过外界掺杂或相变处理来改善载流子传输性能,在低功耗场效应晶体管和超灵敏光电探测器等领域有广阔的应用前景。采用微机械剥离的方法将多层WS_(2)薄膜转移到氧化铪(HfO2)介质层上,制备出具有高栅控、低功耗的WS_(2)背栅场效应晶体管,通过注入三乙胺(TEA)实现WS_(2)薄膜的表面电子掺杂。实验结果表明,修饰后的多层WS_(2)薄膜的面内振动模式有轻微位移,拉曼特征峰强度变弱,证明三乙胺溶液能有效增加WS_(2)薄膜内的电子浓度;薄膜与金属电极之间的欧姆接触良好,器件的电子迁移率由10.87 cm^(2)·V^(-1)·s^(-1)提升到24.89 cm^(2)·V^(-1)·s^(-1),室温下的电流开关比保持在106,亚阈值摆幅为190.11 m V/dec。结合理论分析TEA对WS_(2)原子薄层的掺杂机理,TEA通过表面电荷转移的方式来增加WS_(2)半导体内的电子浓度,完成WS_(2)背栅场效应晶体管的n型掺杂。器件较高的电流开关比及电子迁移率的提升证明了TEA的表面修饰能有效调控多层WS_(2)晶体管器件的电子传输特性。Tungsten disulfide(WS_(2))is a transition metal chiogenide(TMDs)material,which has a wide adjustable band gap(1.3-2.1 eV),relatively low defect density and high ratio of surface and volume.The carrier transport performance can be improved by external doping or phase transformation treatment.It has broad application prospects in the fields of low power FET and ultra-sensitive photodetector.The multilayer WS_(2)thin film was transferred to the hafnium oxide(HfO2)dielectric layer by micromechanical stripping method,and WS_(2)back gate FET with high grid control and low power consumption was prepared.The surface electron doping of WS_(2)thin film was realized by injecting trethylamine(TEA).The experimental results show that the in-plane vibration mode of the modified multilayer WS_(2)film shifts slightly,and the intensity of Raman characteristic peak weaken,which prove that triethylamine solution could effectively increase the electron concentration in WS_(2)film,and the ohmic contact between the film and the metal electrode is good.The electron mobility of the device increases from 10.87 cm^(2)·V^(−1)·s^(−1)to 24.89 cm^(2)·V^(−1)·s^(−1).The ON/OFF ratio of output current is 106 at room temperature,and the subthreshold swing is 190.11 Mv/Dec.The doping of TEA as a reducing agent on WS_(2)atom thin layer is analyzed in combination with the theory.TEA increases the electron concentration in WS_(2)semiconductor by means of surface charge transfer,and completes the n-type doping of WS_(2)backgate FET.The higher current switching ratio and improved electron mobility of WS_(2)devices prove that the surface modification of TEA can effectively regulate the electron transport characteristics of WS_(2)multilayer transistors.

关 键 词：二硫化钨 HIGH-K 三乙胺 背栅晶体管 电学性能 

分 类 号：TN43[电子电信—微电子学与固体电子学]