Correlation measurement of carrier multiplication noise sources in MOS transistors at low frequencies

Low frequency techniques of cross spectrum and correlation coefficient measurements are presented and applied to investigate drain and substrate noises of MOS transistors when multiplication occurs in the channel. For low substrate currents it is shown that the experimental data agree with theoretical expectations: the correlation coefficient is maximum at low frequencies and reaches its minimum value which is only dependent of the multiplication factor in the upper frequency range. For high substrate currents uncorrelated 1/f noise appears in bulk conductance