Discussed is a display device having a plurality of semiconductor light-emitting diodes. At least one of the semiconductor light-emitting diodes has a first conductive electrode and a second conductive electrode; a first conductive semiconductor layer on which the first conductive electrode is disposed; a second conductive semiconductor layer that overlaps with the first conductive semiconductor layer, and the second conductive electrode being disposed on the second conductive semiconductor layer; an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer; an undoped semiconductor layer disposed on the second conductive semiconductor layer; and protrusions formed of a porous material allowing electropolishing, and on the undoped semiconductor layer.