A Comparative Study of Surface-Roughness-Induced Variability in Silicon Nanowire and Double-Gate FETs

作者：Cresti Alessandro^*; Pala Marco G; Poli Stefano; Mouis Mireille; Ghibaudo Gerard

来源：IEEE Transactions on Electron Devices, 2011, 58(8): 2274-2281.

DOI：10.1109/TED.2011.2147318

• Double-gate (DG)
• low-field mobility
• nanowire (NW)
• nonequilibrium Green functions (NEGFs)
• phonon scattering
• quantum transport
• surface roughness (SR)

We study the effect of surface roughness (SR) at the Si/SiO(2) interfaces on transport properties of quasi 1-D and 2-D silicon nanodevices by comparing the electrical performances of nanowire (NW) and double-gate (DG) field-effect transistors. We address a full-quantum analysis based on the 3-D self-consistent solution of the Poisson-Schrodinger equation within the coupled mode-space nonequilibrium Green NEGF) formalism. The influence of SR scattering is also compared with phonon (PH) scattering addressed in the self-consistent Born approximation. We analyze transfer characteristics, current spectra, density of states, and low-field mobility of devices with different lateral size, showing that the dimensionality of the quasi 1-D and 2-D structures induces significant differences only for thin silicon thicknesses. Thin NWs are found more sensitive to the SR-induced variability of the threshold voltage with respect to the DG planar transistors.

• 出版日期2011-8