An integrated circuit containing finFETs may be formed with fins extending above isolation oxide. A first finFET and a second finFET have exposed fin heights which are different by at least 25 percent. The exposed fin height is a vertical height of a sidewall of the fin above the isolation oxide. Gates are formed over the fins. In one version, a fin height of the first finFET is less than a fin height of the second finFET; a thickness of the isolation oxide adjacent to fins of the first finFET and the second finFET is substantially uniform. The fin height is the height of a top of the fin above the substrate. In another version, the isolation oxide is thinner at the first finFET than at the second finFET; the fin heights of the first finFET and the second finFET are substantially equal.