Low frequency noise reduction in multilayer WSe2 field effect transistors

We report that noise level was reduced by passivating WSe2 field effect transistors (FETs) with high-k dielectric material. Low frequency noise and I-V characteristics of the device were measured from WSe2 FETs before and after the passivation with ZrO₂ to confirm the effect of passivation by high-k dielectric material. As a result, there was no significant change in the I-V characteristics. In the low frequency noise analysis, our device showed 1/f noise behaviors, in agreement with the carrier number fluctuation (CNF) model. The passivation process contributed to the reduction of trap sites at the top surface, leading to the decrease of noise level at the low current regime. Extracted volume trap densities were reduced from 2.0 × 1020 cm^-3eV^-1 to 8.7 × 10¹⁹ cm^-3eV^-1.