A method includes forming a set of fins composed of a first semiconductor material. The method further heats the set of fins to condense the fins and cause growth of a layer of oxide on vertical sidewalls thereof, masking a first sub-set of the fins, forming a plurality of voids in the oxide by removing a second sub-set of fins, where each void has a three-dimensional shape and dimensions that correspond to a three dimensional shape and dimensions of a corresponding removed fin from the second sub-set, and epitaxially growing in the voids a third sub-set of fins. The third sub-set of fins is composed of a second semiconductor material that differs from the first semiconductor material. Each fin of the third subset has a three dimensional shape and dimensions of a corresponding removed fin from the second sub-set. At least one structure formed by the method is also disclosed.