A semiconductor light emitting device, comprising: a conductive substrate; a light emitting structure including a first-conductivity type semiconductor layer, an active layer, and a second-conductivity type semiconductor layer which are sequentially formed on the conductive substrate; a first contact layer electrically connected to the first-conductivity type semiconductor layer between the conductive substrate and the first-conductivity type semiconductor layer and including at least one exposed region wherein the second-conductivity type semiconductor layer, the active layer, and the first-conductivity type semiconductor layer are not provided; a conductive via extending from the conductive substrate, passing through the first contact layer, the first-conductivity type semiconductor layer, and the active layer, and electrically connected to the inside of the second-conductivity type semiconductor layer; an insulator electrically separating the conductive substrate from the first contact layer, the first-conductivity type semiconductor layer, and the active layer; a passivation layer formed to cover at least a side surface of the active layer in the light emitting structure; an uneven structure formed on a path of light emitted from the active layer; and characterised in that it further comprises an etch stop layer composed of a material different from a material of the first contact layer and disposed on at least the region in which the light emitting structure is not disposed over the top surface of the first contact layer, the etch stop layer having an etching characteristic different from a semiconductor material constituting the light emitting structure. a conductive substrate; a light emitting structure including a first-conductivity type semiconductor layer, an active layer, and a second-conductivity type semiconductor layer which are sequentially formed on the conductive substrate; a first contact layer electrically connected to the first-conductivity type semiconductor layer between the conductive substrate and the first-conductivity type semiconductor layer and including at least one exposed region wherein the second-conductivity type semiconductor layer, the active layer, and the first-conductivity type semiconductor layer are not provided; a conductive via extending from the conductive substrate, passing through the first contact layer, the first-conductivity type semiconductor layer, and the active layer, and electrically connected to the inside of the second-conductivity type semiconductor layer; an insulator electrically separating the conductive substrate from the first contact layer, the first-conductivity type semiconductor layer, and the active layer; a passivation layer formed to cover at least a side surface of the active layer in the light emitting structure; an uneven structure formed on a path of light emitted from the active layer; and characterised in that it further comprises an etch stop layer composed of a material different from a material of the first contact layer and disposed on at least the region in which the light emitting structure is not disposed over the top surface of the first contact layer, the etch stop layer having an etching characteristic different from a semiconductor material constituting the light emitting structure.