Exemplary embodiments provide a semiconductor device including: a semiconductor structure which includes a first-conductive-type semiconductor layer, a second-conductive-type semiconductor layer, and an active layer disposed between the first-conductive-type semiconductor layer and the second-conductive-type semiconductor layer, wherein the semiconductor structure has a first recess passing through the second-conductive-type semiconductor layer, the active layer and a first portion of the first-conductive-type semiconductor layer; and a plurality of second recesses passing through the second-conductive-type semiconductor layer, the active layer and a second portion of the first-conductive-type semiconductor layer, wherein the first recess is disposed along an outer surface of the semiconductor structure, wherein the plurality of second recesses are surrounded by the first recess.