Effects of Random Distribution of Dopants in Nano-Scaled MOSFETs

Achieving adequate control of SCE for nano MOSFETs will be difficult. Exceedingly high values of channel doping will be needed to control these effects, and high doping will lead both to reduced mobility and increased band-to-band tunneling leakage current. Furthermore, the total number of dopant atoms in the channel for such small MOSFETs is relatively small, which leads to large and irreducible statistical variation in the number and placement of the atoms, and hence to unacceptable statistical variation in Vt, and degrades the short channel characteristics and subthreshold slope through an increase of penetration of the drain electric field lines in the channel region. So the simplest model of quantum transport in Nano-Devices is to describe the problem in terms of the scattering of the electron wave-function by a spatially varying potential. Here, we assume that this potential is situated between two electron reservoirs, each of which emits particles with an equilibrium distribution into the scattering region which is doped by impurity.