Body bias dependence of 1/f noise in NMOS transistors from deep-subthreshold to strong inversion

Dependence of 1 / f noise on the body-to-source junction bias voltages (V-B S) between -2.5 and 0.5 V for 0.25-mum NMOS transistors is reported. In sub threshold, 1 / f noise is reduced by about one order of magnitude when the body-to-source junction is forward biased by 0.5 V (V-BS) compared to that for V-BS = 0 V, Which is due to increased depletion layer capacitance as we ll as possibly due to an increased average distance between oxide traps and carriers by the forward bias. On the contrary, in strong inversion, 1 / f noise remains almost constant for the entire Vss range.