Hot-carrier damage is a major issue in the long-term reliability of metal-oxide-semiconductor field effect transistors (MOSFETs), Hot-carrier induced damages have been shown to degrade various MOSFET characteristics-threshold voltage, channel charge mobility, parasitic drain and source resistances, and parasitic drain capacitance. The degradation induces changes in the small-signal s parameters of MOSFETs. Further experimental results indicate that such damages also degrade the radio frequency (rf) noise characteristics of a LLD n-type MOSFET (NMOSFET). The minimum noise figure (NFmin,) and the normalized noise resistance (r(n))-two key noise parameters--increase due to hot-carrier stress. The optimal reflection coefficient (Gamma(opt)) versus frequency curve also changes with increase stressing. The degradation in the rf noise characteristics of the LDD NMOSFET implies a serious issue in designing reliable, low-noise rf circuits with MOSFETs.