Current LSI technology has progressed rapidly and is pushing toward fabrication of sub-micron dimensioned devices. Several authors have previously used static characteristics, power dissipation, noise, and packing density to look at limiting properties of small devices, although the actual device physics was not considered in detail. As devices become smaller, we expect that the temporal and spatial scales in these devices become sufficiently small that the semi-classical approach to transport theory, as expressed by the Boltzmann transport equation, becomes of questionable validity. In this paper, we address the question of whether our physical understanding of devices and their operation can be extrapolated to small space and time scales, and to what extent the essential quantum electronics prevents a down-scaling. We attempt to lay here a conceptual framework for an ultimate physics of small devices and the modeling necessary to characterize these devices. In this first paper, we work with a dimensional scale of l ∼ 2500 A, the medium small device, leaving a smaller scale to a subsequent work. Although this scale is marginally in a region where the semi-classical approach is valid, extensive modifications must be made to incorporate several new physical effects, including: intra-collision field effect, retarded spatial and temporal non-local effects, two-dimensional quantization, memory effects in the transport parameters, nonlinear screening/descreening, and multiple scattering effects.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering