Surface vs.BulkNoise inSOIFour-Gate Transistors

Low-frequency noise characteristics offour-gate transistors (G4FETs)arepresented distinguishing thesurface conduction (MOSFET mode)andvolumeconduction (JFETmode). Astheconducting channel movesfromthesurface tothebulkweobserve that: (i) the noise level dramatically decreases and(ii) thenature ofthenoise changes. Thevalidity oftheexisting noise models fordifferent conduction modes isdiscussed.