Flip-chip type nitride semiconductor light emitting diode
View Patent ↗Disclosed herein is a flip-chip type nitride semiconductor light emitting diode. The light emitting diode comprises an n-type nitride semiconductor layer formed on a transparent substrate and having a substantially rectangular upper surface, an n-side electrode which comprises at least one bonding pad adjacent to at least one corner of the upper surface of the n-type nitride semiconductor layer, extended electrodes formed in a band from the bonding pad along four sides of the upper surface of the n-type nitride semiconductor layer and one or more fingers extended in a diagonal direction of the upper surface from the bonding pad and/or the extended electrodes, an active layer and a p-type nitride semiconductor layer sequentially stacked on a region of the n-type nitride semiconductor layer where the n-side electrode is not formed, and a highly reflective ohmic contact layer formed on the p-type nitride semiconductor layer.
1. A flip-chip type nitride semiconductor light emitting diode, comprising:
an n-type nitride semiconductor layer formed on a transparent substrate and having a substantially rectangular upper surface;
an n-side electrode, the n-side electrode comprising at least one bonding pad formed adjacent to at least one corner of the upper surface of the n-type nitride semiconductor layer, extended electrodes formed in a band from the bonding pad along four sides of the upper surface of the n-type nitride semiconductor layer, and one or more fingers extended in a diagonal direction of the upper surface of the n-type nitride semiconductor layer from the bonding pad and/or the extended electrodes;
an active layer and a p-type nitride semiconductor layer sequentially stacked on a region of the n-type nitride semiconductor layer where the n-side electrode is not formed; and
a highly reflective ohmic contact layer formed on the p-type nitride semiconductor layer.
2. The light emitting diode as set forth in claim 1 , wherein the fingers comprise:
a plurality of first fingers extended in parallel to each other in a diagonal direction of a corner of adjacent first and second sides of the upper surface of the n-type nitride semiconductor layer from the extended electrodes formed along the adjacent first and second sides and/or from the bonding pad formed at the corner of the adjacent first and second sides; and
a plurality of second fingers extended opposite to the first fingers and in parallel to each other in a diagonal direction of a corner of adjacent third and fourth sides opposite to the corner of the first and second sides of the upper surface of the n-type nitride semiconductor layer from the extended electrodes formed along the adjacent third and fourth sides and/or from the bonding pad formed at the corner of the adjacent third and fourth sides.
3. The light emitting diode as set forth in claim 2 , wherein the first and second fingers are alternately disposed.
4. The light emitting diode as set forth in claim 1 , further comprising:
a passivation layer formed between the n-side electrode and the highly reflective ohmic contact layer for electrically isolating the n-side electrode and the p-type nitride semiconductor layer.
5. The light emitting diode as set forth in claim 1 , wherein the highly reflective ohmic contact layer comprises at least one layer composed of a material selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and combinations thereof.
6. The light emitting diode as set forth in claim 1 , wherein the highly reflective ohmic contact layer comprises a first layer composed of a material selected from the group consisting of Ni, Pd, Ir, Pt and Zn, and a second layer formed on the first layer and composed of a material selected from the group consisting of Ag and Al.
7. The light emitting diode as set forth in claim 1 , wherein the highly reflective ohmic contact layer comprises a first layer composed of Ni, a second layer formed on the first layer and composed of Ag, and a third layer formed on the second layer and composed of Pt.