A.1.3 The Concrete MOSFET (II): Sub-Micron Transistors

Reducing the gate length to the point where the depletion depth and the depletion widths of the source-bulk and drain-bulk junctions become a significant fraction of leads to short-channel devices. Although this is a purely electrical phenomenon which is independent of geometrical scale, this transition became important as the minimum feature size, i.e., entered the sub-micron regime. As a first consequence, the framework of simple drain-current equations loses its validity. An empirical equation for is

$$\ensuremath{I_{\mathit{D}}}\xspace = \ensuremath{\beta }\xs... ...}}\xspace }{\ensuremath{U_{\mathit{T}}}\xspace }\right)^\zeta .$$ (A.17)

For an up-to-date discussion of sub-micron devices beyond the following simple introduction see [79,A8,A9,A0].

Figure A.3: Advanced deep-sub-micron MOSFET