Full-3D Real-Space Simulation of Surface-Roughness Effects in Double-Gate MOSFETs

We present numerical simulations of double-gate (DG)-MOSFETs based on a full-3D self-consistent Poisson-Schrodinger algorithm within the real-space non equilibrium Green's function (NEGF) approach. We include a geometrical description of surface roughness (SR) via an exponential auto-correlation law. In order to simulate rough planar structures we adopt periodic boundary conditions along one of the transverse directions. Transfer characteristics are computed for different realistic values of the root mean square (RMS) of spatial fluctuations whereas SR-limited mobility, which is extracted from effective mobility after subtraction of the ballistic component, presents a non monotonic dependence on the inversion charge density.