Method of fabricating a MOSFET transistor having an anti-halo for modifying narrow width device performance

A method including forming a transistor structure structure comprising a gate electrode over an active region of a substrate, the active region defined by a trench isolation structure and changing a performance of a narrow width transistor with respect to a wide width transistor by introducing a dopant into the active region adjacent an interface defined by the trench isolation structure and the gate electrode. A structure including a gate electrode formed on a substrate, an active region adjacent an interface defined by a trench isolation structure and a gate electrode and an implant within the active region to change a performance of a transistor.