A light emitting device may comprise a first semiconductor layer having a first and second surfaces, the first and second surfaces being opposite surfaces, the first semiconductor layer having a plurality of semiconductor columns extending from the second surface, the plurality of semiconductor columns being separated from each other; a light emitting structure formed over the first semiconductor layer, the light emitting structure including a first conductive semiconductor layer, an active layer and a second semiconductor layer, the light emitting structure having a side surface and an exposed side surface of a semiconductor column closest to the side surface of the light emitting structure being non-aligned with the side surface of the light emitting structure; and a substrate provided adjacent to the plurality of semiconductor columns.