The influence of source and drain junction depth on the short-channel effect in MOSFETs

This brief investigates the influence of source and drain junction depth on the short-channel effect (SCE) in highly scaled MOSFETs. The established scale length model represents SCE in terms of an exponential function of gate insulator thickness and gate depletion-layer width, but this model fails to account for any influence of source and drain junction depth on SCE. It is shown using two-dimensional finite-element device simulation that the influence of source and drain junction depth on SCE can be represented by an addition of a pre-exponential term to the established scale-length model. For source and drain junction depths that are deeper than the MOSFET´s gate depletion-layer width, SCE is shown with this pre-exponential term to be insensitive to junction depth. Conversely, for source and drain junction depths that are shallower than the MOSFET´s gate depletion-layer width, SCE is shown to improve linearly with decreasing junction depth.