Semiconductor light-emitting element
A semiconductor light-emitting element includes: an n-side contact electrode in contact with an n-type semiconductor layer; a p-side contact electrode in contact with a p-type semiconductor layer; an n-side first electrode in contact with the n-side contact electrode; a p-side first electrode in contact with the p-side contact electrode; a first insulating layer covering the n-side and p-side first electrodes; an n-side second electrode on the first insulating layer and in contact with the n-side first electrode; a p-side second electrode on the first insulating layer and in contact with the p-side first electrode; a second insulating layer covering the n-side and p-side second electrodes; an n-side pad electrode on the second insulating layer and in contact with the n-side second electrode; and a p-side pad electrode on the second insulating layer and in contact with the p-side second electrode.
1. A semiconductor light-emitting element comprising:
an n-type semiconductor layer;
an active layer provided on the n-type semiconductor layer and configured to emit deep ultraviolet light having a wavelength of 360 nm or shorter;
a p-type semiconductor layer provided on the active layer;
an n-side contact electrode in contact with an upper surface of the n-type semiconductor layer;
a p-side contact electrode in contact with an upper surface of the p-type semiconductor layer;
an n-side first electrode in contact with an upper surface and a side surface of the n-side contact electrode;
a p-side first electrode in contact with an upper surface and a side surface of the p-side contact electrode;
a first insulating layer that has an n-side first opening provided on the n-side first electrode, has a p-side first opening provided on the p-side first electrode, covers the n-side first electrode outside the n-side first opening, covers the p-side first electrode outside the p-side first opening, and is in contact with the n-type semiconductor layer, the active layer, the p-type semiconductor layer, the n-side first electrode, and the p-side first electrode;
an n-side second electrode provided on the first insulating layer, overlapping the first insulating layer and being in contact with the n-side first electrode in the n-side first opening;
a p-side second electrode provided on the first insulating layer, overlapping the first insulating layer and being in contact with the p-side first electrode in the p-side first opening;
a second insulating layer that has an n-side second opening provided on the n-side second electrode, has a p-side second opening provided on the p-side second electrode, covers the n-side second electrode outside the n-side second opening, covers the p-side second electrode outside the p-side second opening, and is in contact with the first insulating layer, the n-side second electrode, and the p-side second electrode;
an n-side pad electrode provided on the second insulating layer, overlapping the second insulating layer and being in contact with the n-side second electrode in the n-side second opening; and
a p-side pad electrode provided on the second insulating layer, overlapping the second insulating layer and being in contact with the p-side second electrode in the p-side second opening,
wherein the first insulating layer comprises a portion interposed between the n-side first electrode and the n-side second electrode, and a portion interposed between the p-side first electrode and the p-side second electrode, and
wherein the p-side second electrode is provided in an area surrounding the p-side first electrode.
2. The semiconductor light-emitting element according to claim 1 , wherein
each of the first insulating layer and the second insulating layer is made of a single dielectric material, and
each of the n-side first electrode, the p-side first electrode, the n-side second electrode, and the p-side second electrode is a metal multilayer film in which a plurality of metal layers made of different metal materials are stacked.
3. The semiconductor light-emitting element according to claim 2 , wherein
the metal multilayer film includes a plurality of first metal layers made of a first metal material and a plurality of second metal layers made of a second metal material and stacked alternately with the first metal layers,
the topmost layer of the plurality of second metal layers is provided above the plurality of first metal layers,
variation in thickness of the plurality of first metal layers is less than 10%,
variation in thickness of the plurality of second metal layers except for the topmost layer is less than 10%, and
a thickness of the topmost layer is larger than a thickness of the plurality of second metal layers except for the topmost layer by 10% or larger.
4. The semiconductor light-emitting element according to claim 3 , wherein
the metal multilayer film further includes a third metal layer provided below the plurality of first metal layers and the plurality of second metal layers and made of a third metal material having a reflectivity for the deep ultraviolet light higher than reflectivity of the first metal material and the second metal material.
5. The semiconductor light-emitting element according to claim 3 , wherein
the metal multilayer film further includes a fourth metal layer provided above the plurality of first metal layers and the plurality of second metal layers and made of a fourth metal material having a higher conductivity than conductivity of the first metal material and the second metal material.
6. The semiconductor light-emitting element according to claim 1 , wherein
a thickness of the first insulating layer is equal to or larger than a thickness of the n-side first electrode and the p-side first electrode, and a thickness of the second insulating layer is equal to or larger than a thickness of the n-side second electrode and the p-side second electrode.
7. The semiconductor light-emitting element according to claim 1 , wherein
the p-side second electrode covers a side surface of the active layer.
8. The semiconductor light-emitting element according to claim 1 , wherein the n-side second electrode is provided in an area more extensive than a range in which the n-side first electrode is formed.