A transistor structure and a system including the transistor structure. The transistor structure comprises: a substrate including a first layer comprising a first crystalline material; a tensile strained channel formed on a surface of the first layer and comprising a second crystalline material having a lattice spacing that is smaller than a lattice spacing of the first crystalline material; a metal gate on the substrate; a pair of sidewall spacers on opposite sides of the metal gate; and a source region and a drain region on opposite sides of the metal gate adjacent a corresponding one of the sidewall spacers.