RF Noise of 65-nm MOSFETs in the Weak-to-Moderate-Inversion Region

In this letter, the RF noise performance of 65-nm MOSFETs with 60-, 90-, 130-, and 240-nm drawn gate lengths has been extensively investigated in the weak-to-moderate-inversion region for low-power and low-voltage (LPLV) applications. Noise measurements show that although the noise performance is directly related to gate length (Lg), it does not monotonically scale with the inverse of gate length. When biased in the weak-inversion region, a transistor with slightly relaxed gate length, instead of minimum gate length, will benefit from a smaller gate resistance and a smaller equivalent noise resistanceRn. The transistor transconductance (gm), output conductance (gd), unity current gain frequency (fT) , maximum frequency of oscillation (fmax), and noise parameters are extracted as a function of the drain current density and compared among devices with different gate lengths.