Semiconductor light emitting device and method for manufacturing the same

A semiconductor light emitting device, comprising:

• a substrate;
• a light emitting structure on an upper surface of the substrate and comprising a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first conductive semiconductor layer and second conductive semiconductor layer;
• and
• a first semiconductor layer between the substrate and a bottom surface of the light emitting structure,
• wherein a bottom surface of the substrate includes a first portion and a second portion around the first portion,
• wherein the first portion includes a first recess and the second portion includes a second recess,
• wherein the first recess and the second recess are formed in a direction toward the upper surface from the bottom surface of the substrate,
• wherein the first recess and the second recess have a different depth from the bottom surface of the substrate,
• wherein the first recess is formed along a transverse direction and a longitudinal direction in the bottom surface of the substrate, and
• wherein the first recess and the second recess have a depth smaller than a thickness of the substrate.