Abstract
Using quantum mechanical methods that include the full-band structure of Si and SiO, we study two non-classical phenomena that occur in MOS transistors at the nanometer-scale: tunneling through ultrathin oxides and quantum confinement in Si layers. SiO models based on β-cristobalite, β-quartz and tridymite polymorphs have been implemented for the calculation of tunneling current. Limitations of the effective-mass approximation are investigated. In particular, we obtain good agreement between calculated and measured tunneling current densities for a n-poly-Si/SiO/p-Si MOS capacitor and predict the full-band structure in the channels of bulk and double-gate MOSFETs. © 2003 Elsevier Ltd. All rights reserved.