| CPC H10H 20/825 (2025.01) [H10H 20/812 (2025.01)] | 12 Claims |
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1. A nitride semiconductor ultraviolet light-emitting element with a peak emission wavelength within a range of 265 nm to 300 nm comprising:
a light-emitting element structure part in which an n-type layer, an active layer, and a p-type layer made of an AlGaN-based semiconductor of wurtzite structure are stacked vertically, wherein
the n-type layer is composed of an n-type AlGaN-based semiconductor,
the active layer disposed between the n-type layer and the p-type layer has a quantum-well structure having one or more well layers composed of an AlGaN-based semiconductor, the p-type layer is composed of a p-type AlGaN-based semiconductor,
each semiconductor layer in the n-type layer and the active layer is an epitaxially grown layer having a surface on which multi-step terraces parallel to a (0001) plane are formed,
the n-type layer has a plurality of first Ga-rich regions, the plurality of first Ga-rich regions being stratiform regions uniformly distributed in the n-type layer with locally lower AlN mole fraction and including n-type AlGaN regions in which an AlGaN composition ratio is an integer ratio of Al7Ga5N12,
each extending direction of the stratiform regions on a first plane perpendicular to an upper surface of the n-type layer has a portion inclined with respect to an intersection line between the upper surface of the n-type layer and the first plane,
boundary region parts between adjacent terraces of the multi-step terraces of a well layer have a second Ga-rich region with locally lower AlN mole fraction in the same well layer, and
the second Ga-rich region includes an AlGaN region in which an AlGaN composition ratio is an integer ratio of Al1Ga1N2 or Al5Ga7N12 or Al1Ga2N3.
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