Light emitting diode and manufacturing method thereof
A light emitting diode comprises a substrate, a buffer layer, a semiconductor layer and a semiconductor light emitting layer. The buffer layer is disposed on the substrate. The semiconductor layer is disposed on the buffer layer. The semiconductor light emitting layer is disposed on the semiconductor layer. A plurality of voids is defined within the semiconductor layer. Each void encloses air therein. A method for manufacturing the light emitting diode is also provided. Light generated by the semiconductor light emitting layer toward the substrate is reflected by the voids to emit out of the light emitting diode.
1. A method for manufacturing a light emitting diode, comprising:
providing a substrate;
forming a semiconductor layer, having a plurality of pillars thereon, on the substrate;
re-crystallizing the semiconductor layer, wherein a plurality of voids is formed between each of adjacent two of the plurality of pillars and within the semiconductor layer, each of the plurality of voids enclosing air therein; and
disposing a semiconductor light emitting layer on the semiconductor layer.
2. The method for manufacturing the light emitting diode as claimed in claim 1 , further comprising forming a buffer layer on the substrate, wherein the semiconductor layer is formed on the buffer layer.
3. The method for manufacturing the light emitting diode as claimed in claim 1 , further comprising:
forming a metal layer on the semiconductor layer;
forming the metal layer to come into a metal mask using heat treatment at a temperature of 500 to 1000° C.;
etching the semiconductor layer to come into the plurality of voids in array; and
removing the metal mask.
4. The method for manufacturing the light emitting diode as claimed in claim 1 , wherein an intersection is formed on a top of the semiconductor layer.
5. The method for manufacturing the light emitting diode as claimed in claim 1 , wherein the semiconductor layer is re-crystallized at a temperature over 1000° C.
6. The method for manufacturing the light emitting diode as claimed in claim 2 , wherein the buffer layer is formed at 450 to 1000° C.
7. The method for manufacturing the light emitting diode as claimed in claim 6 , wherein the semiconductor layer is formed on the buffer layer at 700 to 800° C.
8. The method for manufacturing the light emitting diode as claimed in claim 1 , wherein thickness of the semiconductor layer is between 150 and 250 nm.
9. The method for manufacturing the light emitting diode as claimed in claim 3 , wherein the metal mask comprising a plurality of clusters and a plurality of holes intersecting between the clusters.
10. The method for manufacturing the light emitting diode as claimed in claim 9 , wherein diameter of each of the plurality of clusters is between 50 and 100 nm and diameter of each of the plurality of holes is between 50 and 100 nm.
11. The method for manufacturing the light emitting diode as claimed in claim 1 , wherein the plurality of pillars is formed by MBE.