Semiconductor light-emitting device with high light-extraction efficiency and method for fabricating the same

A method for fabricating a semiconductor light-emitting device, the method comprising the following steps:

• preparing an uneven substrate having a first upper surface;
• forming a first semiconductor material layer on the first upper surface of the substrate, the first semiconductor material layer having a second upper surface;
• forming a multi-layer structure on the second upper surface of the first semiconductor material layer, the multi-layer structure comprising a light-emitting region;
• and
• forming an ohmic electrode structure on the multi-layer structure;
• wherein the first semiconductor material layer has a refractive index different from those of the substrate and a bottom-most layer of the multi-layer structure to change a moving direction of a light emitted from the light-emitting region through the first semiconductor material layer.

A semiconductor light-emitting device, comprising:

• an uneven substrate having a first upper surface;
• a multi-layer structure, formed on the first upper surface of the substrate, and the multi-layer structure comprising a light-emitting region, the multi-layer structure comprising a light-emitting layer, a first semiconductor material layer, and a second semiconductor material layer, the first semiconductor material layer being formed on the light-emitting layer and having a second upper surface, the second semiconductor material layer being formed on the first semiconductor material layer and having a third upper surface;
• and
• an ohmic electrode structure formed on the multi-layer structure;
• wherein the first semiconductor material layer has a refractive index different from those of the light-emitting layer and the second semiconductor material layer to change a moving direction of a light emitted from the light-emitting layer through the first semiconductor material layer.