Provided is a nitride-based semiconductor light emitting device having increased efficiency and power characteristics and method of manufacturing the same. The method may include forming a sacrificial layer on a substrate, forming a passivation layer on the sacrificial layer, forming a plurality of masking dots of a metal nitride on the passivation layer, laterally epitaxially growing a nitride-based semiconductor layer on the passivation layer using the masking dots as masks, forming a semiconductor device on the nitride-based semiconductor layer, and wet etching the sacrificial layer to separate and/or remove the substrate from the semiconductor device.