Generalized guide for MOSFET miniaturization

As MOSFET dimensions are reduced, it is desirable to preserve long-channel MOSFET behavior. In general, lower voltages, shallower junctions, thinner oxides, and heavier doping help to maintain long-channel behavior as channel length is reduced. Our purpose here is to propose a simple, approximate relation between these parameters and the minimum channel length for which long-channel subthreshold behavior will be observed. This relation provides a simple estimate for MOSFET parameters, not requiring reduction of all dimensions by the same scale factor.