LIGHT EMITTING DIODE
Provided is a light emitting diode (LED) mounted on a carrier substrate and including a semiconductor epitaxial structure and at least one electrode pad structure. The semiconductor epitaxial structure is electrically connected to the carrier substrate. The electrode pad structure includes a eutectic layer, a blocking layer and an extension layer. The eutectic layer is adapted for eutectic bonding to the carrier substrate. The blocking layer is between the eutectic layer and the semiconductor epitaxial structure. The blocking layer blocks the diffusion of the material of the eutectic layer in the eutectic bonding process. The extension layer is between the eutectic layer and the semiconductor epitaxial structure. The extension layer reduces the stress on the LED produced by thermal expansion and contraction of the substrate during the eutectic bonding process, so as to prevent the electrode pad structure from cracking, and maintain the quality of the LED.
1 . A light emitting diode, mounted on a carrier substrate and comprising:
a semiconductor epitaxial structure; and
at least one electrode pad structure, wherein the semiconductor epitaxial structure is electrically connected to the carrier substrate through the at least one electrode pad structure, and the at least one electrode pad structure comprises:
a eutectic layer, adapted for eutectic bonding to the carrier substrate;
a blocking layer, disposed between the eutectic layer and the semiconductor epitaxial structure; and
an extension layer, disposed between the blocking layer and the semiconductor epitaxial structure.
2 . The light emitting diode of claim 1 , wherein the eutectic layer comprises at least one material selected from the group consisting of Au, Au/Sn and Sn/Ag/Cu.
3 . The light emitting diode of claim 1 , wherein the blocking layer comprises at least one material selected from the group consisting of Ni, Ti and Pt.
4 . The light emitting diode of claim 1 , wherein the extension layer comprises at least one material selected from the group consisting of Au, Ag, Al, Ni, Ti, Cr and Pt.
5 . The light emitting diode of claim 1 , further comprising an adhesive layer disposed between the extension layer and the semiconductor epitaxial structure.
6 . The light emitting diode of claim 5 , wherein the adhesive layer comprises at least one material selected from the group consisting of Ni, Ti, Cr and Pt.
7 . The light emitting diode of claim 1 , wherein the at least one electrode pad structure comprises a first electrode pad structure and a second electrode pad structure separated from each other.
8 . A light emitting diode, mounted on a carrier substrate and comprising:
a semiconductor epitaxial structure; and
at least one electrode pad structure, wherein the semiconductor epitaxial structure is electrically connected to the carrier substrate through the at least one electrode pad structure, and the at least one electrode pad structure comprises:
a eutectic layer, adapted for eutectic bonding to the carrier substrate; and
an extension layer, disposed between the eutectic layer and the semiconductor epitaxial structure, wherein a material of the extension layer is different from a material of the eutectic layer, and a thickness of the extension layer is greater than 300 nm.
9 . The light emitting diode of claim 8 , wherein the eutectic layer comprises at least one material selected from the group consisting of Au, Au/Sn and Sn/Ag/Cu.
10 . The light emitting diode of claim 8 , wherein the extension layer comprises at least one material selected from the group consisting of Au, Ag, Al, Ni, Ti, Cr and Pt.
11 . The light emitting diode of claim 8 , further comprising an adhesive layer formed between the extension layer and the semiconductor epitaxial structure.
12 . The light emitting diode of claim 11 , wherein the adhesive layer comprises at least one material selected from the group consisting of Ni, Ti, Cr and Pt.
13 . The light emitting diode of claim 8 , wherein the at least one electrode pad structure comprises a first electrode pad structure and a second electrode pad structure separated from each other.