A method of forming a semiconductor device includes providing a semiconductor substrate and forming a plurality of dummy gate structures in the substrate. The method further includes forming sidewall spacers on sidewalls of the dummy gate structures and forming a plurality of epitaxial growth regions between the dummy gate structures. After forming the plurality of epitaxial growth regions, one of the dummy gate structures is removed to form an isolation trench, which is filled with a dielectric layer to form an isolation feature. The remaining dummy gate structures are removed to form gate trenches, and gate structures are formed in the gate trenches.