A.A. García, I.S. Hernández, N. Hernández.
Instituto Politécnico Nacional,
Mexico
Keywords: 2D materials, MoS2, CV and IV characterization, MoS2 by RF Sputtering
Summary:
For the last years, Thin Film Transistors (TFTs) based on dichalcogenides materials have raised special interest since these materials are expected to be immune to Short Channel Effects (SCEs). Currently, 2D MoS2 is the most studied semiconductor material due to it possess peculiar characteristics which make it one of the best alternatives to be part of the next generation of electronics. In this work it is presented the electrical characterization by capacitance-voltage (CV) and by current-voltage (I-V) measurements of Metal-Insulator-Semiconductor structures (MIS) with different thicknesses of the semiconductor layer, and Metal-Semiconductor structures (MS), using Molybdenum as the contact and gate metal, HfO2 as dielectric and MoS2 as semiconductor layer. The three layers are deposited at room temperature by RF magnetron sputtering, from targets of the correspondient material. The effect of a thermal annealing on the resistivity of the semiconductor layer is studied and an improvement was found to be in more than two orders after the annealing at 300 °C. The 27nm deposited layer of MoS2 presented P-type conductivity in C-V measurements of MIS capacitors (Mo/HfO2/MoS2/Mo), which seems to be related to plasma etching used during the fabrication processes. The calculated resistivity of the MoS2 layer is in the order of 4.6x10^4 Ω-cm, by the four-probe method, the resistivity of the metal layer was calculated to be around 4x10^-2 Ω-cm and the contact resistance in the MS interface is around 3x10^9 Ω. The C-V characteristics revealed bias stability, an operating range of -1 to 1.5 V and a VFB of 0.5 V, results that indicate that 2D TFTs can be obtained by using this structure.