Light-emitting diode chip having a plurality of indentations

1. A light-emitting diode (LED) chip, comprising:

a first semiconductor layer;

an active layer disposed on the first semiconductor layer;

a second semiconductor layer disposed on the active layer;

a plurality of indentations, wherein each indentation extends downward to reach the first semiconductor layer and exposes the first semiconductor layer, wherein each indentation comprises a bottom part and two side surfaces in a cross sectional view;

an exposing area exposing the first semiconductor layer at a side of the LED chip;

a first metal layer disposed on the second semiconductor layer and electrically connecting to the first semiconductor layer; and

a first insulating layer formed on the second semiconductor layer and between the first metal layer and the second semiconductor layer to isolate the first metal layer from the second semiconductor layer;

wherein the first metal layer continuously extends to the plurality of indentations, covers the bottom part, the two side surfaces of each indentation and a top surface of the second semiconductor layer around the two side surfaces and contacts the exposing area; and

wherein the first metal layer comprises a plurality of recesses corresponding to the plurality of indentations.

2. The LED chip as claimed in claim 1 , further comprising a second metal layer disposed on the second semiconductor layer and above the first metal layer.

3. The LED chip as claimed in claim 1 , wherein the plurality of the indentations distributed over a surface of the LED chip.

4. The LED chip as claimed in claim 2 , further comprising a second insulating layer disposed on the first metal layer and between the first metal layer and the second metal layer to isolate the first metal layer from the second metal layer.

5. The LED chip as claimed in claim 1 , further comprising a transparent conductive layer formed on the second semiconductor layer.

6. The LED chip as claimed in claim 1 , wherein the first insulating layer is disposed along the two side surfaces of each indentation.

7. The LED chip as claimed in claim 1 , wherein the first metal layer covers the two side surfaces of each indention to connect to the first semiconductor layer.

8. The LED chip as claimed in claim 1 , further comprising a substrate under the first semiconductor layer, and wherein the first semiconductor layer comprises a side surface connecting to the exposing area and the side surface of the first semiconductor layer connects to a side surface of the substrate.