Semiconductor light emitting device and method of fabricating semiconductor light emitting device
View Patent ↗A semiconductor light emitting device has a light emitting element, a first electrode layer, a second electrode layer, a seed electrode layer and a plated layer. The light emitting element has a nitride-based III-V compound semiconductor on a substrate and a light extraction surface. The first electrode layer is provided on the light extraction surface. The second electrode layer is provided on a surface opposite to the light extraction surface. The seed electrode layer is configured to cover the entire surface of the second electrode layer. The plated layer is provided on the seed electrode layer. The light emitting element has a light emitting layer, first conductive type semiconductor layer, and second conductive type semiconductor layer, and has a forward tapered shape of a width which gradually narrows in order of the second conductive type semiconductor layer, the light emitting layer and the first conductive type semiconductor layer.
1. A semiconductor light emitting device, comprising:
a light emitting element comprising a nitride-based III-V compound semiconductor on a substrate, the light emitting element having a light extraction surface;
a first electrode layer on the light extraction surface;
a second electrode layer on a surface opposite to the light extraction surface of the light emitting element;
a seed electrode layer configured to cover a bottom surface and a side surface of the second electrode layer, the seed electrode layer having a step in accordance with an outline of the second electrode layer; and
a plated layer formed under the seed electrode layer, the plated layer having a step in accordance with a shape of the seed electrode layer,
the light emitting element comprises:
a light emitting layer;
a first conductive type semiconductor layer disposed between the light emitting layer and the first electrode layer, and
a second conductive type semiconductor layer disposed between the light emitting layer and the second electrode layer,
the light emitting element has a forward tapered shape of a width which gradually narrows in order of the second conductive type semiconductor layer, the light emitting layer and the first conductive type semiconductor layer.
2. The device according to claim 1 ,
wherein the seed electrode layer comprises:
a first layer which covers the bottom surface and the side surface of the second electrode layer and includes a metal material capable of preventing a metal in the plated layer from being diffused in the second electrode layer; and
a second layer which contacts the first layer and the plated layer and mingles with the metal in the plated layer.
3. The device according to claim 2 ,
wherein the second electrode layer comprises a highly reflective electrode layer which contacts the first layer and reflects light emitted by the light emitting layer;
the first layer has a surface area larger than a surface area of the highly reflective electrode layer; and
the first layer has a thickness larger than a thickness of the highly reflective electrode layer.
4. The device according to claim 1 , further comprising:
a ground electrode layer having a structure of laminating a barrier metal layer and a ground electrode.
5. The device according to claim 1 , further comprising:
an insulating film configured to cover a sidewall of the forward tapered shape of the light emitting element.
6. The device according to claim 1 , wherein the light extraction surface has a rough surface configured to enhance light emission efficiency.