A method for forming a semiconductor device includes forming a mask layer on a stressed semiconductor layer of a stressed, semiconductor-on-insulator wafer. An isolation trench bounding the stressed semiconductor layer is formed. The isolation trench extends through the mask layer and into the SOI wafer past an oxide layer thereof. A dielectric body is formed in the isolation trench. A relaxation reduction liner is formed on the dielectric body and on an adjacent sidewall of the stressed semiconductor layer. The mask layer on the stressed semiconductor layer is removed.