Characterization of effective mobility by split C-V technique in MoS2 MOSFETs with high-k/metal gate

Effective mobility in top-gated MoS₂ metal-oxide-semiconductor field-effect transistors (MOSFETs) with HfO₂/TaN gate was investigated. We realized C-V measurements of MoS₂ MOSFETs with a small gate area. The resultant surface carrier concentration dependence of the effective mobility suggested that surface roughness scattering was responsible for the accumulated electron mobility in the fabricated MoS₂ MOSFET. The scanning tunneling microscope image exhibited atomic scale roughness on the cleaved MoS₂ surface. This suggested that the surface roughness should be reduced to improve the performance of MoS₂ MOSFETs.