Physical origin of the excess thermal noise in short channel MOSFETs

The physical origin of the excess thermal noise in short channel MOSFETs is explained based on numerical noise simulation. The impedance field represe ntation and extraction method demonstrate that the drain current noise is d ominated by source side contributions. Analysis identifies local sc channel resistance variations as the primary controlling factor. The nonlocal natu re of velocity results in a smaller derivative of the velocity with respect to the field which in turn causes a higher local ac resistance near the so urce junction.