Short channel effect

In electronics, a short-channel effect is an effect whereby a MOSFET in which the channel length is the same order of magnitude as the depletion-layer widths (xdD, xdS) of the source and drain junction, behaves differently from other MOSFETs.

As the channel length L is reduced to increase both the operation speed and the number of components per chip, the so-called short-channel effects arise.

The short-channel effects are attributed to two physical phenomena:

1. the limitation imposed on electron drift characteristics in the channel,
2. the modification of the threshold voltage due to the shortening channel length.

In particular five different short-channel effects can be distinguished:

1. drain-induced barrier lowering and punchthrough
2. surface scattering
3. velocity saturation
4. impact ionization
5. hot electron effect