Fin stacks including a silicon germanium alloy portion and a silicon portion are formed on a surface of a substrate. Sacrificial gate structures are then formed straddling each fin stack. Silicon germanium alloy portions that are exposed are oxidized, while silicon germanium alloy portions that are covered by the sacrificial gate structures are not oxidized. A dielectric material having a topmost surface that is coplanar with a topmost surface of each sacrificial gate structure is formed, and thereafter each sacrificial gate structure is removed. Non-oxidized silicon germanium alloy portions are removed suspending silicon portions that were present on each non-oxidized silicon germanium alloy portion. A functional gate structure is then formed around each suspended silicon portion. The oxidized silicon germanium alloy portions remain and provide stress to a channel portion of the suspended silicon portions.