Semiconductor laser diode with current restricting layer and fabrication method thereof
View Patent ↗Provided are a semiconductor laser diode having a current confining layer and a method of fabricating the same. The semiconductor laser diode includes a substrate, a first material layer deposited on the substrate, an active layer which is deposited on the first material layer and emits a laser beam, and a second material layer which is deposited on the active layer and includes a ridge portion protruding from the active layer and a current confining layer formed by injection of ions into peripheral portions of the ridge portion so as to confine a current injected into the active layer. Therefore, it is possible to fabricate an improved semiconductor laser diode having a low-resonance critical current value that can remove a loss in an optical profile and reduce the profile width of a current injected into the active layer while maintaining the width of the ridge portion.
1. A semiconductor laser diode comprising:
a substrate;
a first material layer deposited on the substrate;
an active layer which is deposited on the first material layer and emits a laser beam; and
a second material layer which is deposited on the active layer and includes a ridge portion protruding perpendicularly to the active layer and a current confining layer formed by injection of ions into a half of a width of a bottom surface of the ridge portion so as to confine a current injected into the active layer.
2. The semiconductor laser diode of claim 1 , wherein the first material layer comprises:
a first compound semiconductor layer deposited on the substrate;
a first clad layer deposited on the first compound semiconductor layer; and
a first wave guide layer which is deposited on the first clad layer and has a larger index of refraction than the first clad layer.
3. The semiconductor laser diode of claim 2 , wherein the first compound semiconductor layer is an n-GaN -based nitride semiconductor layer of an III-V group.
4. The semiconductor laser diode of claim 2 , wherein the first clad layer is an n-AlGaN/GaN layer.
5. The semiconductor laser diode of claim 2 , wherein the index of refraction of the first wave guide layer is smaller than that of the active layer.
6. The semiconductor laser diode of claim 2 , wherein the first wave guide layer is a GaN-based compound semiconductor layer of the III-V group.
7. The semiconductor laser diode of claim 2 , wherein the first compound semiconductor layer further comprises an n-type electrode on its upper portion.
8. The semiconductor laser diode of claim 1 , wherein the active layer is a GaN-based nitride compound semiconductor layer of the III-V group which is an InxAlyGa1-x-yN layer (0≦x≦1, 0≦y≦1 and x+y≦1).
9. The semiconductor laser diode of claim 1 , wherein the second material layer comprises:
a second wave guide layer deposited on the active layer;
a second clad layer which is deposited on the second wave guide layer, has smaller index of refraction than the second wave guide layer, and has the ridge portion; and
a second compound semiconductor layer deposited on the ridge portion.
10. The semiconductor laser diode of claim 9 , wherein the second wave guide layer has a smaller index of refraction than the active layer.
11. The semiconductor laser diode of claim 9 , wherein the second wave guide layer is a GaN-based compound semiconductor layer of the III-V group.
12. The semiconductor laser diode of claim 9 , the second clad layer is a p-AlGaN/GaN layer.
13. The semiconductor laser diode of claim 9 , wherein the second compound semiconductor layer is a p-GaN-based nitride semiconductor layer of the III-V group.
14. The semiconductor laser diode of claim 9 , further comprising a protective layer on the second clad layer and the second compound semiconductor layer.
15. The semiconductor laser diode of claim 14 , further comprising an electrode on the first compound semiconductor layer and the protective layer.
16. The semiconductor laser diode of claim 1 , wherein the substrate is a sapphire substrate.
17. A semiconductor laser diode comprising:
a substrate;
a first material layer deposited on the substrate;
an active layer which is deposited on the first material layer and emits a laser beam; and
a second material layer which is deposited on the active layer and includes a homogenous portion of a ridge portion protruding perpendicularly from the active layer and a current confining layer formed in a half of a width of a bottom surface of the homogeneous ridge portion so as to confine a current injected into the active layer.
18. The semiconductor laser diode of claim 17 , wherein the first material layer comprises:
a first compound semiconductor layer deposited on the substrate;
a first clad layer deposited on the first compound semiconductor layer; and
a first wave guide layer which is deposited on the first clad layer and has a larger index of refraction than the first clad layer.
19. The semiconductor laser diode of claim 18 , wherein the first compound semiconductor layer is an n-GaN-based nitride semiconductor layer of an III-V group.
20. The semiconductor laser diode of claim 18 , wherein the first clad layer is an n-AlGaN/GaN layer.
21. The semiconductor laser diode of claim 18 , wherein the index of refraction of the first wave guide layer is smaller than that of the active layer.
22. The semiconductor laser diode of claim 18 , wherein the first wave guide layer is a GaN-based compound semiconductor layer of the III-V group.
23. The semiconductor laser diode of claim 17 , wherein the active layer is a GaN-based nitride compound semiconductor layer of the III-V group which is an InxAlyGa 1 -x-yN layer (0≦x≦1, 0≦y≦1 and x+y≦1).
24. The semiconductor laser diode of claim 17 , wherein the second material layer comprises:
a second wave guide layer deposited on the active layer;
a second clad layer which is deposited on the second wave guide layer, has smaller index of refraction than the second wave guide layer, and has the ridge portion; and
a second compound semiconductor layer deposited on the ridge portion.
25. The semiconductor laser diode of claim 24 , wherein the second wave guide layer has a smaller index of refraction than the active layer.
26. The semiconductor laser diode of claim 24 , wherein the second wave guide layer is a GaN-based compound semiconductor layer of the III-V group.
27. The semiconductor laser diode of claim 24 , the second clad layer is a p-AlGaN/GaN layer.
28. The semiconductor laser diode of claim 24 , wherein the second compound semiconductor layer is a p-GaN-based nitride semiconductor layer of the III-V group.
29. The semiconductor laser diode of claim 24 , further comprising a protective layer on the second clad layer and the second compound semiconductor layer.
30. The semiconductor laser diode of claim 29 , further comprising an electrode on the first compound semiconductor layer and the protective layer.
31. The semiconductor laser diode of claim 18 , wherein the first compound semiconductor layer further comprises an n-type electrode on its upper portion.
32. The semiconductor laser diode of claim 17 , wherein the substrate is a sapphire substrate.