Nitride semiconductor light emitting device having electrostatic discharge (ESD) protection capacity
View Patent ↗A nitride semiconductor light emitting device including a light emitting diode and a diode formed on a single substrate, in which the light emitting diode and the diode use a common electrode. According to the present invention, an active layer and a p-type nitride semiconductor layer are each divided into a first region and a second region by an insulative isolation layer, and an ohmic contact layer is formed on the p-type nitride semiconductor layer contained in the first region. A p-type electrode is formed on the ohmic contact layer and is extended to the p-type nitride semiconductor layer contained in the second region. An n-type electrode is formed on the p-type nitride semiconductor layer contained in the second region, passes through the p-type nitride semiconductor layer and the active layer contained in the second region, and is connected to the first n-type nitride semiconductor layer.
1. A nitride semiconductor light emitting device, comprising:
a first n-type nitride semiconductor layer formed on a substrate;
an active layer and a p-type nitride semiconductor layer which are sequentially formed on the first n-type nitride semiconductor layer, are each divided into a first region and a second region by an insulative isolation layer;
an ohmic contact layer formed on the p-type nitride semiconductor layer contained in the first region;
a p-type electrode which is formed on the ohmic contact layer, and is extended to the p-type nitride semiconductor layer contained in the second region; and
an n-type electrode which is spaced apart from the p-type electrode, is formed on the p-type nitride semiconductor layer contained in the second region, passes through the p-type nitride semiconductor layer and the active layer contained in the second region, and is connected to the first n-type nitride semiconductor layer.
2. The nitride semiconductor light emitting device according to claim 1 , wherein the p-type electrode has a work function less than that of the p-type nitride semiconductor layer.
3. The nitride semiconductor light emitting device according to claim 1 , wherein the p-type electrode is made of a material selected from among a group comprised of Ti, Cr, Al, Cu, and Au.
4. The nitride semiconductor light emitting device according to claim 1 , further comprising:
a second n-type nitride semiconductor layer additionally formed between the p-type nitride semiconductor layer of the second region and the p-type electrode.
5. The nitride semiconductor light emitting device according to claim 4 , wherein the second nitride semiconductor layer is designed to have a thickness of 50 nm˜200 nm.
6. The nitride semiconductor light emitting device according to claim 1 , wherein the ohmic contact layer has a reflection factor of more than 70%.
7. The nitride semiconductor light emitting device according to claim 1 , wherein the ohmic contact layer includes at least one layer made of a material selected from among a group comprised of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and their combination.