In this brief, it is clearly demonstrated that a two-parameter noise model is sufficient to accurately extract the MOSFET high-frequency noise performance, as long as channel uniformity is ensured (which corresponds to mainstream CMOS technology). Nevertheless, in the case of asymmetric channel-based MOSFETs, it is shown that a three-parameter noise model is required.
Emam, M., Sakalas, P., Vanhoenacker-Janvier, D., Raskin, J.-P., Lim, T. C., & Danneville, F. (2010). Thermal Noise in MOSFETs: A Two- or a Three-Parameter Noise Model? IEEE Transactions on Electron Devices, 57(5), 1188-1191. https://doi.org/10.1109/TED.2010.2044286 (Original work published 2010)