Group III nitride semiconductor light-emitting device
AssigneeToyoda Gosei Co., Ltd.
InventorsYoshiki Saito, Yohei Samura
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Abstract
The present invention provides a Group III nitride semiconductor light-emitting device which prevents an increase in driving voltage, and which has low threading dislocation density as a whole. The light-emitting device includes an embossed substrate. The substrate has, on a main surface thereof, a first region in which protrusions are arranged at a small pitch, and second regions in which protrusions are arranged at a large pitch. The second regions correspond to projection areas of a p-pad electrode and an n-pad electrode as viewed through the main surface of the substrate. The first region corresponds to a projection area, as viewed through the main surface of the substrate, of a region in which neither the p-pad electrode nor the n-pad electrode is formed.
Claims20
A Group III nitride semiconductor light-emitting device, comprising:
- a substrate including an embossed main surface;
- a Group III nitride semiconductor layer formed on the main surface of the substrate;
- and
- non-translucent electrodes which are electrically conducted to the Group III nitride semiconductor layer,
- wherein the substrate comprises a heterogeneous substrate having a chemical composition different from that of the Group III nitride semiconductor layer;
- wherein the heterogeneous substrate includes a first region including a plurality of protrusions, and a second region including a plurality of protrusions which are arranged at a pitch larger than that of the protrusions in the first region, each of the protrusions of the second region has a hexagonal pyramidal shape,
- wherein the second region has a perimeter being included within a region defined by a region perimeter located 6 μm or less outward from a perimeter of a projection area of each of the non-translucent electrodes as viewed through the main surface of the heterogeneous substrate, and is defined by a region perimeter located 6 μm or less inward from the perimeter of the projection area,
- wherein a portion of the semiconductor layer above the second region exhibits a threading dislocation density higher than that of a portion of the semiconductor layer above the first region, and
- wherein light distribution in the second region is larger than light distribution in the first region.
A Group III nitride semiconductor light-emitting device comprising:
- a substrate including an embossed main surface;
- a Group III nitride semiconductor layer formed on the main surface of the substrate;
- and
- non-translucent electrodes which are electrically conducted to the Group III nitride semiconductor layer, the non-translucent electrodes comprising a pad electrode, a plurality of dot electrodes which are distributed with respect to a light-emitting surface, and one or more wiring electrodes for electrically connecting the dot electrodes to the pad electrodes, the wiring electrodes comprising comb electrodes,
- wherein the substrate comprises a heterogeneous substrate including a chemical composition different from that of the Group III nitride semiconductor layer,
- wherein the heterogeneous substrate includes a first region including a plurality of protrusions, and a second region including a plurality of protrusions which are arranged at a pitch larger than that of the protrusions in the first region, and each of the protrusions of the second region has a hexagonal pyramidal shape,
- wherein the second region has a perimeter being included within a region defined by a region perimeter located 6 μm or less outward from a perimeter of a projection area of each of the non-translucent electrodes as viewed through the main surface of the heterogeneous substrate, and is defined by a region perimeter located 6 μm or less inward from the perimeter of the projection area.
A Group III nitride semiconductor light-emitting device, comprising:
- a substrate including an embossed main surface;
- a Group III nitride semiconductor layer formed on the main surface of the substrate;
- and
- non-translucent electrodes which are electrically conducted to the Group III nitride semiconductor layer,
- wherein the substrate comprises a heterogeneous substrate including a chemical composition different from that of the Group III nitride semiconductor layer,
- wherein the heterogeneous substrate includes a first region including a plurality of protrusions, and a second region including a plurality of protrusions which are arranged at a pitch larger than that of the protrusions in the first region,
- wherein the second region has a perimeter being included within a region defined by a region perimeter located 6 μm or less outward from a perimeter of a projection area of each of the non-translucent electrodes as viewed through the main surface of the heterogeneous substrate, and is defined by a region perimeter located 6 μm or less inward from the perimeter of the projection area, and
- wherein a region between a projection area of the non-translucent electrodes as viewed through the main surface of the heterogeneous substrate and an edge of the light-emitting device includes the first region.
Dependencies are inferred from the claim text.