The well-known post-kink Lorentzian-like noise overshoot has been empirical
ly correlated to the ac kink effect in the SOI CMOSFET in the past. This wo
rk demonstrates the existence of a 1/f(2) excess noise spectrum (<100 Hz) s
uperimposed upon 1/f noise in partially depleted (PD) floating body SOI CMO
S when devices are biased in the pre-kink region (before the de kink onset
voltage), While the impact ionization phenomenon is negligible in the pre-k
ink region, the new observed pre-kink excess noise provides a new insight i
nto the body voltage instability and current fluctuation in the SOI CMOSFET
.