Nitride-based semiconductor light-emitting element and manufacturing method thereof
A nitride-based semiconductor light-emitting element includes: a substrate that is an example of a n-type nitride-based semiconductor including a group IV n-type impurity; and an n-side electrode in contact with the substrate. The substrate includes: a surface layer region in contact with the n-side electrode and including a halogen element; and an internal region located across the surface layer region from the n-side electrode. A peak concentration of the group IV n-type impurity in the surface layer region is at least 1.0×10 21 cm −3 . A peak concentration of the halogen element in the surface layer region is at least 10% of the peak concentration of the group IV n-type impurity in the surface layer region. A concentration of the group IV n-type impurity in the internal region is lower than a concentration of the group IV n-type impurity in the surface layer region.
1. A nitride-based semiconductor light-emitting element, comprising: a first n-type nitride-based semiconductor layer including a group IV n-type impurity; and
an n-side electrode in contact with the first n-type nitride-based semiconductor layer, wherein
the first n-type nitride-based semiconductor layer includes
a surface layer region in contact with the n-side electrode, the surface layer region including a halogen element, and
an internal region located across the surface layer region from the n-side electrode,
a peak concentration of the group IV n-type impurity in the surface layer region is at least 1.0×10 21 cm −3 ,
a peak concentration of the halogen element in the surface layer region is at least 10% of the peak concentration of the group IV n-type impurity in the surface layer region, and
a concentration of the group IV n-type impurity in the internal region is lower than a concentration of the group IV n-type impurity in the surface layer region.
2. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the surface layer region has a current density of at least 0.47 kA cm −2 in operation.
3. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
an operation temperature is at least 67 degrees Celsius.
4. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the surface layer region has a thickness of at least 1 nm and less than 100 nm.
5. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the n-side electrode includes: at least one type of metal selected from a group consisting of Ti, Al, Pt, Au, Mo, Sn, In, Ni, Cr, Nb, Ba, Ag, Rh, Ir, Ru, and Hf; or an alloy of at least two types of metal selected from the group.
6. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the group IV n-type impurity is Si.
7. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the halogen element is Cl.
8. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the surface layer region includes a surface in contact with the n-side electrode, the surface being a (000-1) plane.
9. The nitride-based semiconductor light-emitting element according to claim 8 , further comprising:
a principal surface located on a side opposite to the surface layer region relative to the internal region in a laminating direction, wherein
the principal surface is connected to a submount.
10. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the first n-type nitride-based semiconductor layer is an n-type nitride-based semiconductor substrate.
11. The nitride-based semiconductor light-emitting element according to claim 10 , wherein
the n-type nitride-based semiconductor substrate has a thickness of at least 50 μm and at most 150 μm.
12. The nitride-based semiconductor light-emitting element according to claim 10 , further comprising:
a second n-type nitride-based semiconductor layer, a p-type nitride-based semiconductor layer, and a p-side electrode laminated in sequence on the n-type nitride-based semiconductor substrate on a side opposite to a side on which the surface layer region is located.
13. The nitride-based semiconductor light-emitting element according to claim 12 , wherein
the peak concentration of the halogen element in the surface layer region is higher than a peak concentration of the halogen element at an interface between the p-side electrode and the p-type nitride-based semiconductor layer.
14. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the nitride-based semiconductor light-emitting element is a semiconductor laser element that emits laser light having a wavelength band of an oscillation wavelength of at least 365 nm and at most 390 nm, and has light output of at least 1 W.
15. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the nitride-based semiconductor light-emitting element is a semiconductor laser element that emits laser light having a wavelength band of an oscillation wavelength of at least 390 nm and at most 420 nm, and has light output of at least 3 W.
16. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the nitride-based semiconductor light-emitting element is a semiconductor laser element that emits laser light having a wavelength band of an oscillation wavelength of at least 420 nm and at most 460 nm, and has light output of at least 6 W.
17. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the nitride-based semiconductor light-emitting element is a semiconductor laser element that has a resonator length of at least 1300 μm.
18. The nitride-based semiconductor light-emitting element according to claim 1 , wherein
the nitride-based semiconductor light-emitting element is a semiconductor laser element that has a stripe width of at least 50 μm.
19. A nitride-based semiconductor light-emitting element, comprising:
a substrate;
a first n-type nitride-based semiconductor layer disposed on the substrate and including a group IV n-type impurity; and
an n-side electrode disposed on the first n-type nitride-based semiconductor layer on a side opposite to a side on which the substrate is located, the n-side electrode being in contact with the first n-type nitride-based semiconductor layer, wherein
the first n-type nitride-based semiconductor layer includes
a surface layer region in contact with the n-side electrode, the surface layer region including a halogen element, and
an internal region located across the surface layer region from the n-side electrode,
a peak concentration of the group IV n-type impurity in the surface layer region is at least 1.0×10 21 cm −3 ,
a peak concentration of the halogen element in the surface layer region is at least 10% of the peak concentration of the group IV n-type impurity in the surface layer region, and
a concentration of the group IV n-type impurity in the internal region is lower than a concentration of the group IV n-type impurity in the surface layer region.
20. The nitride-based semiconductor light-emitting element according to claim 19 , further comprising:
a p-type nitride-based semiconductor layer and a p-side electrode laminated in sequence above the first n-type nitride-based semiconductor layer on the side opposite to the side on which the substrate is located.