A light-emitting diode comprises a substrate; a semiconductor stack on the substrate, wherein the semiconductor stack comprises a first semiconductor layer, an active layer for emitting a light, and a second semiconductor layer; a first oxide layer on the semiconductor stack, wherein the first oxide layer has a top surface opposite to the semiconductor stack, and the top surface comprises a first region and a second region; and a first pad on the second region; wherein the first region is rougher than the second region, wherein the first oxide layer comprises an impurity, and a concentration of the impurity of the first oxide layer in the first region is higher than that of the impurity of the first oxide layer in the second region.