Methods are provided for fabricating FinFETs that avoid thickness uniformity problems across a die or a substrate. One method includes providing a semiconductor substrate divided into a plurality of chips, each chip bounded by scribe lines. The substrate is etched to form a plurality of fins, each of the fins extending uniformly across the width of the chips. An oxide is deposited to fill between the fins and is etched to recess the top of the oxide below the top of the fins. An isolation hard mask is deposited and patterned overlying the plurality of fins and is used as an etch mask to etch trenches in the substrate defining a plurality of active areas, each of the plurality of active areas including at least a portion of at least one of the fins. The trenches are filled with an insulating material to isolate between adjacent active areas.