Light emitting device and manufacturing method thereof

A light emitting device, comprising:

• a substrate having a first surface and a second surface, wherein the first surface is flat surfaces and the second surface is uneven surfaces;
• a first conductive semiconductor layer on the substrate and having an irregularly uneven lower surface facing the upper surface of the substrate;
• a buffer layer and a semiconductor layer alternately interposed between the substrate and the first conductive semiconductor layer;
• an In—GaN semiconductor layer on the first conductive semiconductor layer;
• an active layer on the In—GaN semiconductor layer;
• and
• a second conductive semiconductor layer on the active layer,
• wherein the buffer layer includes a first buffer layer and a second buffer layer, and
• wherein the first buffer layer is only disposed on the flat surfaces of the first surface of the substrate.