A method of fabricating epitaxial structures including applying an etch stop to one side of a substrate and then growing at least one epitaxial layer on a first side of said substrate, flipping the substrate, growing a second etch stop and at least one epitaxial layer on a second side of the substrate, applying a carrier medium to the ultimate epitaxial layer on each side, dividing the substrate into two parts generally along an epitaxial plane to create separate epitaxial structures, removing any residual substrate and removing the etch stop.