氧等离子体对少层MoS2及其场效应晶体管的影响研究

Effect of oxygen plasma treatment on few-layer MoS2 and its field-effect-transistor

通过氧等离子体对MoS2材料及其场效应晶体管进行处理,用AFM、拉曼光谱、XPS和I-V测试对材料和器件性能进行表征,系统研究了氧等离子体对MoS2材料及其器件性能的影响。实验结果表明,氧等离子体处理可以有效去除MoS2材料和器件制备过程中引入的有机杂质,将MoS2的表面粗糙度降低到了0.27 nm。同时氧等离子体将表层MoS2氧化成MoO3,降低了器件接触区域MoS2与金属之间的费米能级钉扎效应,使器件开关比高达3.3×10^6。对MoS2器件沟道进行处理时,氧离子穿过MoO3插入到MoS2晶格中从而对沟道形成p型掺杂。

The effect of oxygen plasma treatment on few-layer MoS2 materials and its field-effect-transistors was studied. The properties of the material and device were characterized by AFM, Raman spectroscopy, XPS and I-V tests. The experimental results show that oxygen plasma treatment can effectively remove organic impurities introduced during the preparation of MoS2 materials and devices, and the surface roughness of MoS2 to 0.27 nm is also reduced. At the same time, the oxygen plasma oxidizes the surface MoS2 into MoO3, which reduces the Fermi Level Pinning effect between MoS2 and the metal at the device contact interface, leading to the device switching ratio as high as 3.3×10^6. During the plasma treatment on the device channel, oxygen ions can be inserted through MoO3 into the lattice of underlying MoS2, resulting in the formation of p doped MoS2 FET.