In this paper, we investigate the effect of different process parameters on oxidation-induced strain (OIS) into a doubly-clamped silicon nanowire FET to control and finally, enhance carrier mobility. Spacer technology together with sacrificial thermal oxidation were used to fabricate ≈100 nm wide Si NWs. The built-in tensile stress in the Si NWs was measured using micro-Raman spectroscopy and a maximum of 2.6 GPa was found.