Y. Fu et al., Current and capacitance characteristics of a metal-insulator-semiconductorstructure with an ultrathin oxide layer, SUPERLATT M, 30(2), 2001, pp. 53-60
By self-consistently solving the Schrodinger and Poisson equations, we have
studied theoretically the current and capacitance characteristics of a met
al-oxide-semiconductor structure consisting of an ultrathin oxide layer emb
edded between an n-silicon substrate and n(+)-polycrystalline silicon gate.
It has been shown that due to the finite doping level in the polycrystalli
ne silicon gate and the complication of the energy sublevels in the accumul
ation layer, self-consistent calculation of Schrodinger and Poisson equatio
ns is of vital importance. Decreasing the oxide layer thickness drastically
increases the conduction current density from the substrate to the polycry
stalline silicon gate. The capacitance increases monotonically as a functio
n of the gate bias, it gradually saturates. The theoretical results explain
well our experimental data. (C) 2001 Academic Press.