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 resistance
Rn
. The transistor transconductance (
gm
), output conductance (
gd
), unity current gain frequency (
fT
) , maximum frequency of oscillation (
f

_max
), and noise parameters are extracted as a function of the drain current density and compared among devices with different gate lengths.