Devices and methods for forming semiconductor devices with wider FinFETs for higher tunability of the varactor are provided. One method includes, for instance: obtaining an intermediate semiconductor device; applying a spacer layer over the semiconductor device; etching the semiconductor device to remove at least a portion of the spacer layer to expose the plurality of mandrels; removing the mandrels; etching the semiconductor device to remove a portion of the dielectric layer; forming at least one fin; and removing the spacer layer and the dielectric layer. One intermediate semiconductor device includes, for instance: a substrate; a dielectric layer over the substrate; a plurality of mandrels formed on the dielectric layer, the mandrels including a first set of mandrels and a second set of mandrels, wherein the first set of mandrels have a width twice as large as the second set of mandrels; and a spacer layer applied over the mandrels.