A lossy substrate model for sub-100 nm, super-100 GHz f/sub T/ RF CMOS noise extraction and modeling

A lossy substrate model is developed to accurately simulate the measured RF noise of 80 nm, super-100 GHz f/sub T/ nMOSFETs. A substrate RLC network built in the model plays a key role responsible for the nonlinear frequency response of noise in 1/spl sim/18 GHz regime, which did not follow the typical thermal noise theory. Good match with the measured S-parameters, Y-parameters, and NF/sub min/ before de-embedding proves the lossy substrate model. The intrinsic RF noise can be extracted easily and precisely by the lossy substrate de-embedding using circuit simulation. The accuracy has been justified by good agreement in terms of I/sub d/, g/sub m/, Y-parameters, and f/sub T/ under a wide range of bias conditions and operating frequencies. The extracted intrinsic NF/sub min/ as low as 0.6/spl sim/0.7 dB at 10 GHz indicates the advantages of super-100 GHz f/sub T/ offered by the sub-100 nm multi-ringer nMOS. The frequency dependence of noise resistance R/sub n/ suggests the substrate RC coupling induced excess channel thermal noise apparent in 1/spl sim/10 GHz regime. The study provides a useful guideline for low noise and low power design by using sub-100 nm RF CMOS technology.