The onset of quantization in ultra-submicron semiconductor devices

Within the next decade or so, it is expected that gate lengths will shrink to 50 nm or less in devices found in integrated circuits. At the same time, the thermal de Broglie wavelength for electrons in Si at 300 K is some 5 nm. How might we expect quantum mechanics to al ise in the transport through these small devices? Here,issues relevant for the quantum transport description of transport in ultra-small devices are discussed, such as the issue of quantum localization-just how small can the minimum-area be in which a single electron can be localized. After discussing such a minimum size, the-localization packet is associated with an 'effective' potential in which sharp discontinuities: are removed from the potential within the device. The replacement of sharp potentials :by smoothed potentials removes much of the driving force for quantization within these device structures. It will be shown that the introduction of such an effective potential:leads to an enhancement of the drain-induced barrier lowering in ultra-small devices, principally:in the 'on' state. (C) 2000 Academic Press.