Fin field-effect-transistor (finFET) structures having two dielectric thicknesses are generally described. In one example, an apparatus includes a semiconductor substrate, a semiconductor fin coupled with the semiconductor substrate, the semiconductor fin having at least a first surface, a second surface, and a third surface, the third surface being substantially parallel to the first surface and substantially perpendicular to the second surface, a spacer dielectric coupled to the second surface of the semiconductor fin, a back gate dielectric having a back gate dielectric thickness coupled to the first surface of the semiconductor fin, and a front gate dielectric having a front gate dielectric thickness coupled to the third surface of the semiconductor fin wherein the back gate dielectric thickness is greater than the front gate dielectric thickness