VHF Noise due to surface states in MOS devices

Metal-oxide-silicon field-effect transistors display noise performance up to several hundred MHz which is not satisfactorily explained by the thermal noise of the channel resistance. Measurements show exoess noise with a f^-nspectrum which approaches a thermal noise asymptote at about 400 MHz. The noise has been found to be proportional to the drain current and may be represented by an output current generator. However at vhf excess gate noise appears which seems to be caused by the coupling of the gate capacitance to the channel.