Low-Frequency Noise in High-Current MoS₂ Vertical Field-Effect Transistors with Nanoscale Channel

Two-dimensional (2D) materials such as MoS2 have high potential for nanoelectronics because of their nanometer thickness and unique electrical properties. In this study, high-performance nanoscale channel MoS2 vertical field-effect transistors (VFETs) are fabricated using a simplified scaling method compatible with current micro/nanofabrication technologies. The obtained MoS2 VFET with 10 nm channel length (L) delivers a high current up to 537 μA/μm and an on–off ratio over 3 × 107 at room temperature. Meanwhile, a detailed study of the low-frequency noise (LFN) characteristic is carried out for the fabricated nanoscale MoS2 VFETs. The result shows that all of the MoS2 VFETs fit the classical 1/f noise model in the frequency range from 1 to 105 Hz and follows the carrier number fluctuation theory. The LFN of MoS2 VFETs also fits well with the 1/L relationship in the nanoscale channel conditions, which indicates the LFN is mainly generated in the channel region. As LFN performance may strongly depend on the characteristic size of the device, the relationships of normalized noise level with device area and volumetric oxide trap density with 1/L are evaluated. The fabrication strategy presented here provides a way to achieve high-performance 2D nanoscale devices with simplified fabrication processes and also lays the foundation for the study of LFN in nanoelectronics.