Strain Silicon (sSi) layers on strain-relaxed SiGe buffer layers are frequently used in order to boost up the carrier mobility. Recently, fabrication techniques based on the use of ultra-thin (300–400nm) SRB layers have been proposed. This study investigates the degradation of such sSi n-MOSFETs after 2-MeV electron irradiation. Owing to the electron irradiation, the drain current slightly increases and a negative shift of the threshold voltage is observed for an electron fluence of 1×10 16 e/cm 2 . The channel electron mobility degradation is about 4%, as derived from the input characteristics.