Interface states analysis in atomically thin MoS$_{\mathrm{2}}$ FET*

Two-dimensional (2D) materials such as MoS$_{\mathrm{2}}$ have recently attracted much attention for use in next-generation field-effect transistors (FETs). The interface between the channel and gate insulator should be seriously considered especially for atomically thin channel devices. Defects in MoS$_{\mathrm{2}}$ as well as dangling bonds from gate oxide could contribute to the interface states. At present, interface states density ($D_{\mathrm{it}})$ of MoS$_{\mathrm{2}}$ FET extracted by various kinds of electrical measurements is largely scattered and very large. This large $D_{\mathrm{it\thinspace }}$should affect carrier transport seriously. Here, in order to gain insight to reduce $D_{\mathrm{it}}$, we study the correlation between interface states and carriers in terms of random telegraphic signals (RTSs) analysis, which complements noise study of MoS$_{\mathrm{2}}$. RTSs measurements for multi-probe devices confirm that the defects at the channel/insulator interface cause RTSs. Moreover, conductance method is also applied for dual-gated MoS$_{\mathrm{2}}$ FET to extract $D_{\mathrm{it}}$ and its time constant. In this talk, we focus on the RTSs analysis and conductance measurements for thin MoS$_{\mathrm{2}}$ FET to study interface states.