Exemplary embodiments of the present invention disclose a light-emitting diode (LED) including a semiconductor stack structure including a first semiconductor layer, an active layer, and a second semiconductor layer, the semiconductor stack disposed on a substrate, a conductive substrate disposed on the semiconductor stack structure, and an electrode disposed on the conductive substrate and in ohmic contact with the conductive substrate, wherein the electrode comprises grooves penetrating the electrode and a portion of the conductive substrate.