A design structure is embodied in a machine readable medium for designing, manufacturing, or testing a design. The design structure includes a structure which comprises a high-leakage dielectric formed in a divot on each side of a segmented FET comprised of active silicon islands and gate electrodes thereon, and a low-leakage dielectric on the surface of the active silicon islands, adjacent the high-leakage dielectric, wherein the low-leakage dielectric has a lower leakage than the high-leakage dielectric. Also provided is a structure and method of fabricating the structure.