This paper investigates the impact of extrinsic resistance on the noise performance of deep submicron MOSFETs （metal-oxide-semiconductor field-effect-transistor） using the noise correlation matrix method. Analytical closed-form expressions for calculating the four noise parameters are derived based on the small-signal and noise-equivalent circuit models. The results show strong agreement between simulated and experimental data for MOSFETs with a gate length of 40 nm and dimensions of 4×5 μm （number of gate fingers × unit gate width.