Effects of Quantum Confinement on Interdependence between DOS Spectrum and C(V) Characteristic of Si Nanowire-Based MOS Structure

Interrelation between capacitance - gate voltage [C(V)] characteristic and density-of-states (DOS) spectrum [N(E)] is analyzed using experimental C(V) data obtained from silicon-nanowire (SiNW) based metal-oxide-semiconductor (MOS) structure, solution of coupled Schrödinger-Poisson (SP) equations (with full treatment on quantum confinement) and semi-classical Fredholm integral equation (FIE) of the first kind. It is shown that FIE valid for NW-based MOS structures with NW radii a equal to or bigger than 10 nm at temperature T exceeding 38 K. However, significant deviations from FIE is predicted by SP treatment for a = 5 nm and T = 5 K. Such deviation is attributed to considerable effect of quantum confinement not only on N(E) distributions, but also on fundamental statistical distribution functions of electrons.