Fundamental origin of excellent low-noise property in 3D Si-MOSFETs ∼ Impact of charge-centroid in the channel due to quantum effect on 1/f noise ∼

We fabricated Si nanowire (NW) nFETs, and used them to experimentally demonstrate the superior noise properties of 3D MOSFETs. By carefully comparing the NWFETs with planar FETs, we found that it was critical to control the location of the centroid of the electron density in the inversion channel in order to obtain a noise spectral density with low magnitude. Self-consistent calculations of the Schrödinger and Poisson equations clearly reveal the advantages of NWFETs in electron distribution due to quantum confinement, specifically in the small gate-overdrive (V_g-V_t) condition. Moreover, by increasing V_d, the range where the NWFET exhibits superior noise properties to a planar FET can be extended to larger V_g-V_t because the effective V_g near the drain is reduced.