Improved performance of back-gate MoS2 transistors by NH3-plasma treating high-k gate dielectrics  

作　　者：Jian-Ying Chen Xin-Yuan Zhao Lu Liu Jing-Ping Xu 陈建颖;赵心愿;刘璐;徐静平(Ningbo Information Technology Service Center,Ningbo 315400,China;School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]Ningbo Information Technology Service Center,Ningbo 315400,China [2]School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Chinese Physics B》2019年第12期338-344,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.61774064)

摘　　要：NH3-plasma treatment is used to improve the quality of the gate dielectric and interface. Al2O3 is adopted as a buffer layer between HfO2 and MoS2 to decrease the interface-state density. Four groups of MOS capacitors and back-gate transistors with different gate dielectrics are fabricated and their C–V and I–V characteristics are compared. It is found that the Al2O3/HfO2 back-gate transistor with NH3-plasma treatment shows the best electrical performance: high on–off current ratio of 1.53 × 107, higher field-effect mobility of 26.51 cm2/V·s, and lower subthreshold swing of 145 m V/dec.These are attributed to the improvements of the gate dielectric and interface qualities by the NH3-plasma treatment and the addition of Al2O3 as a buffer layer.NH3-plasma treatment is used to improve the quality of the gate dielectric and interface. Al2O3 is adopted as a buffer layer between HfO2 and MoS2 to decrease the interface-state density. Four groups of MOS capacitors and back-gate transistors with different gate dielectrics are fabricated and their C–V and I–V characteristics are compared. It is found that the Al2O3/HfO2 back-gate transistor with NH3-plasma treatment shows the best electrical performance: high on–off current ratio of 1.53 × 107, higher field-effect mobility of 26.51 cm2/V·s, and lower subthreshold swing of 145 m V/dec.These are attributed to the improvements of the gate dielectric and interface qualities by the NH3-plasma treatment and the addition of Al2O3 as a buffer layer.

关 键 词：MoS2 transistor high-k dielectric NH3-plasma treatment oxygen vacancy mobility 

分 类 号：TN3[电子电信—物理电子学]