An aspect of the invention provides a method of manufacturing a method of manufacturing a semiconductor element comprises the steps of: growing epitaxially a semiconductor layer on top of a semiconductor substrate; forming a patterned portion of the grown semiconductor layer by forming a pattern by a patterning process on top of the grown semiconductor layer; removing a portion of the semiconductor layer other than the patterned portion by a first etching method with a first etchant; and immersing a resultant from the first etching method in a second etchant that etches only the semiconductor substrate by a second etching method thereby removing the substrate from the semiconductor layer.