Investigating modification on electronic properties of bilayer MoS_2 field- effect transistor by low-temperature oxygen plasma treatment

摘要

Two-dimensional layer materials have been of great interest in the promising application of novel nano-electronics in recent years. In this study, we demonstrated the modification on electronic properties of bilayer MoS2 field-effect transistor (FET) by low-temperature oxygen plasma treatment with different radio frequency (RF) power. According to the I-V measurement with Cascade semi-automatic probe station, it was observed that the electronic properties of bilayer MoS2 FET could be improved effectively after low-power oxygen plasma treatment. The analysis of transport properties in MoS2 revealed the modification mechanism of sulphur (S) vacancies by low-power oxygen plasma. Nevertheless, electronic properties of MoS2 FET were degenerated after high-power oxygen plasma treatment for the increase of defect in MoS2, which has been characterized by Raman spectrum and XPS spectrum. Furthermore, it was found that the signal distributions of surface contact potential difference (CPD) and capacitance of MoS2 mono-crystal samples prepared by chemical vapor deposition (CVD) were heterogeneous, which demonstrates that the edge region of MoS2 can be interacted by oxygen plasma more easily owing to the defect and active sites. This study will provide a theoretical basis in the research of next-generation high-performance electronic device.