A design structure is embodied in a machine readable medium for designing, manufacturing, or testing a design. The design structure includes a high-leakage dielectric formed over an active region of a FET and a low-leakage dielectric formed on the active region and adjacent the high-leakage dielectric. The low-leakage dielectric has a lower leakage than the high-leakage dielectric. Also provided is a structure and method of fabricating the structure.