Characterization of Interface States in CVD Monolayer MoS₂/Al₂O₃ MOS Capacitors via the Conductance Method

Abstract

MoS2 is one of the transition metal dichalcogenides (TMDCs) that has been extensively studied as a next-generation semiconductor material due to its high carrier mobility in the monolayer limit. However, the atomically thin nature of MoS2 poses challenges for capacitance characteristics measurements by metal-oxide-semiconductor (MOS) capacitors, leading to limited research on the characteristics of their interfaces. In this study, we fabricated MOS capacitors with different device areas using a monolayer MoS2synthesized by chemical vapor deposition and Al2O3 insulator deposited by atomic layer deposition and performed capacitance-voltage measurements. We propose the use of a ring-shaped capacitor which is beneficial for small 2D crystals such as exfoliated TMDCs or materials that cannot yet be synthesized on a large scale, and extracted interface trap densities on the order of 1012 eV −1 cm −2 for devices with different areas, indicating that under the present measurement conditions, series and access resistances do not dominate the extraction of interface trap density using the conductance method.