Separation of interlayer resistance in multilayer MoS₂ field-effect transistors

We extracted the interlayer resistance between two layers in multilayer molybdenum disulfide (MoS₂) field-effect transistors by confirming that contact resistances (R_contact) measured using the four-probe measurements were similar, within ∼ 30%, to source/drain series resistances (R_sd) measured using the two-probe measurements. R_contact values obtained from gated four-probe measurements exhibited gate voltage dependency. In the two-probe measurements, the Y-function method was applied to obtain the R_sd values. By comparing those two R_contact (∼ 9.5 kΩ) and R_sd (∼ 12.3 kΩ ) values in strong accumulation regime, we found the rationality that those two values had nearly the same properties, i.e., the Schottky barrier resistances and interlayer resistances. The R_sd values of devices with two-probe source/drain electrodes exhibited thickness dependency due to interlayer resistance changes. The interlayer resistance between two layers was also obtained as ∼ 2.0 Ω mm.