Methods are provided for forming semiconductor devices. One method includes forming a first layer overlying a bulk semiconductor substrate. A second layer is formed overlying the first layer. A plurality of trenches is etched into the first and second layers. Portions of the second layer that are disposed between the plurality of trenches define a plurality of fins. A gate structure is formed overlying the plurality of fins. The first layer is etched to form gap spaces between the bulk semiconductor substrate and the plurality of fins. The plurality of fins is at least partially supported in position adjacent to the gap spaces by the gate structure. The gap spaces are filled with an insulating material.