Group III-V nitride-based semiconductor substrate and group III-V nitride-based light emitting device
A group III-V nitride-based semiconductor substrate is formed of a group III-V nitride-based semiconductor single crystal containing an n-type impurity. The single crystal has a periodical change in concentration of the n-type impurity in a thickness direction of the substrate. The periodical change has a minimum value in concentration of the n-type impurity not less than 5×10 17 cm −3 at an arbitrary point in plane of the substrate.
1. A group III-V nitride-based semiconductor substrate, comprising:
a group III-V nitride-based semiconductor single crystal containing an n-type impurity,
wherein the single crystal comprises a repetitive, periodical change in concentration of the n-type impurity in a thickness direction of the substrate, and
the periodical change comprises a minimum value in concentration of the n-type impurity not less than 5×10 17 cm −3 at an arbitrary point in plane of the substrate.
2. The group III-V nitride-based semiconductor substrate according to claim 1 , wherein:
the periodical change comprises an amplitude being not more than 2×10 18 cm -3 at an arbitrary point in plane of the substrate.
3. The group III-V nitride-based semiconductor substrate according to claim 1 , wherein:
the group III-V nitride-based semiconductor single crystal comprises a hexagonal gallium nitride.
4. The group III-V nitride-based semiconductor substrate according to claim 3 , wherein:
the substrate comprises on a surface thereof a gallium face on a C-face of the hexagonal gallium nitride.
5. The group III-V nitride-based semiconductor substrate according to claim 1 , wherein:
the substrate comprises a mirror-polished surface.
6. The group III-V nitride-based semiconductor substrate according to claim 1 , wherein:
the n-type impurity comprises silicon.
7. The group III-V nitride-based semiconductor substrate according to claim 1 , wherein:
the n-type impurity comprises oxygen.
8. The group III-V nitride-based semiconductor substrate according to claim 1 , wherein:
the substrate comprises a diameter not less than 50 mm.
9. A group III-V nitride-based light emitting device, comprising:
the group III-V nitride-based semiconductor substrate according to claim 1 , and
an active layer formed on the substrate, the active layer comprising a group III-V nitride-based semiconductor.
10. A group III-V nitride-based light emitting device, comprising:
the group III-V nitride-based semiconductor substrate according to claim 2 , and
an active layer formed on the substrate, the active layer comprising a group III-V nitride-based semiconductor.
11. A group III-V nitride-based light emitting device, comprising:
the group III-V nitride-based semiconductor substrate according to claim 3 , and
an active layer formed on the substrate, the active layer comprising a group III-V nitride-based semiconductor.
12. A group III-V nitride-based light emitting device, comprising:
the group III-V nitride-based semiconductor substrate according to claim 4 , and
an active layer formed on the substrate, the active layer comprising a group III-V nitride-based semiconductor.
13. A group III-V nitride-based light emitting device, comprising:
the group III-V nitride-based semiconductor substrate according to claim 5 , and
an active layer formed on the substrate, the active layer comprising a group III-V nitride-based semiconductor.
14. A group III-V nitride-based light emitting device, comprising:
the group III-V nitride-based semiconductor substrate according to claim 6 , and
an active layer formed on the substrate, the active layer comprising a group III-V nitride-based semiconductor.
15. A group III-V nitride-based light emitting device, comprising:
the group III-V nitride-based semiconductor substrate according to claim 7 , and
an active layer formed on the substrate, the active layer comprising a group III-V nitride-based semiconductor.
16. A group III-V nitride-based light emitting device, comprising:
the group III-V nitride-based semiconductor substrate according to claim 8 , and
an active layer formed on the substrate, the active layer comprising a group III-V nitride-based semiconductor.