Light emitting device and method for manufacturing the same
Disclosed are a light emitting device and a method for manufacturing the same. A light emitting diode comprises a plurality of Un-GaN layers and a plurality of N-type semiconductor layers, an active layer on the N-type semiconductor layer, and a P-type semiconductor layer on the active layer, wherein at least two of the Un-GaN layers and at least two of the N-type semiconductor layers are alternatively stacked on each other.
1. A light emitting device, comprising:
a plurality of undoped GaN layers and a plurality of N-type semiconductor layers;
an active layer on an upper layer of the plurality of N-type semiconductor layers; and
a P-type semiconductor layer on the active layer,
wherein at least one of the undoped GaN layers and at least one of the N-type semiconductor layers are alternatively stacked on each other.
2. The light emitting device as claimed in claim 1 , wherein the plurality of undoped GaN layers and the plurality of N-type semiconductor layers comprise a sequence of layers including a first undoped GaN layer, a first N-type semiconductor layer, a second undoped GaN layer, and a second N-type semiconductor layer.
3. The light emitting device as claimed in claim 1 , wherein the undoped GaN layers and the N-type semiconductor layers comprise a sequence of layers including a first undoped GaN layer, a first N-type semiconductor layer, a second undoped GaN layer, a second N-type semiconductor layer, a third undoped GaN layer, and a third N-type semiconductor layer.
4. The light emitting device as claimed in claim 1 , wherein the P-type semiconductor layer is directly on the active layer.
5. The light emitting device as claimed in claim 1 , wherein the plurality of N-type semiconductor layers comprise Si.
6. The light emitting device as claimed in claim 2 ,
wherein the first and second N-type semiconductor layers comprise GaN, and
wherein the second N-type semiconductor layer comprise at least two layers.
7. The light emitting device as claimed in claim 2 , wherein the second N-type semiconductor layer has a dislocation density lower than a dislocation density of the first N-type semiconductor layer.
8. The light emitting device as claimed in claim 2 , wherein the second N-type semiconductor layer has an impurity concentration lower than an impurity concentration of the first N-type semiconductor layer.
9. The light emitting device as claimed in claim 2 , wherein the first and second undoped GaN layers have a thickness in a range of 0.5 μm to 1 μm.
10. The light emitting device as claimed in claim 2 , wherein the first and second N-type semiconductor layers have a thickness in a range of 1 μm to 1.5 μm.
11. The light emitting device as claimed in claim 3 , wherein the first, second, and third N-type semiconductor layers comprise GaN.
12. The light emitting device as claimed in claim 3 ,
wherein the second N-type semiconductor layer has a dislocation density lower than a dislocation density of the first N-type semiconductor layer, and
wherein the third N-type semiconductor layer has a dislocation density lower than a dislocation density of the second N-type semiconductor layers.
13. The light emitting device as claimed in claim 3 ,
wherein the second N-type semiconductor layer has an impurity concentration lower than an impurity concentration of the first N-type semiconductor layer, and
wherein the third N-type semiconductor layer has an impurity concentration lower than an impurity concentration of the second N-type semiconductor layer.
14. The light emitting device as claimed in claim 3 , wherein the first, second, and third undoped GaN layers have a thickness in a range of 0.3 μm to 0.6 μm.
15. The light emitting device as claimed in claim 3 , wherein the first, second, and third N-type GaN layers have a thickness in a range of 0.5 μm to 1 μm.
16. A method for manufacturing a light emitting device, the method comprising the steps of:
alternatively forming a plurality of undoped-GaN layers and a plurality of N-type semiconductor layers on a substrate;
forming an active layer on the N-type semiconductor layer; and
forming a P-type semiconductor layer on the active layer,
wherein the undoped-GaN layers and the N-type semiconductor layers are formed by stacking a first undoped-GaN layer, a first N-type semiconductor layer, a second undoped-GaN layer, and a second N-type semiconductor layer, and
wherein the second undoped-GaN layer and the second N-type semiconductor layer are formed by flowing a smaller amount of TMGa into a chamber having a higher temperature and a lower pressure as compared with a condition for manufacturing the first undoped-GaN layer and the first N-type semiconductor layer.
17. The method as claimed in claim 16 , wherein the second N-type semiconductor layer has an impurity concentration lower than an impurity concentration of the first N-type semiconductor layer.
18. A method for manufacturing a light emitting device, the method comprising the steps of:
alternatively forming a plurality of undoped-GaN layers and a plurality of N-type semiconductor layers on a substrate;
forming an active layer on the N-type semiconductor layer; and
forming a P-type semiconductor layer on the active layer,
wherein the undoped-GaN layers and the N-type semiconductor layers are formed by stacking a first undoped-GaN layer, a first N-type semiconductor layer, a second undoped-GaN layer, a second N-type semiconductor layer, a third undoped-GaN layer, and a third N-type semiconductor layer,
wherein the second undoped-GaN layer and the second N-type semiconductor layer are formed by flowing a smaller amount of TMGa into a chamber having a higher temperature and a lower pressure as compared with a condition for manufacturing the first undoped-GaN layer and the first N-type semiconductor layer, and
the third undoped-GaN layer and the third N-type semiconductor layer are formed by flowing a smaller amount of TMGa into a chamber having a higher temperature and a lower pressure as compared with a condition for manufacturing the second undoped-GaN layer and the second N-type semiconductor layer.
19. The method as claimed in claim 18 , wherein impurities implanted into the second N-type semiconductor layer are less than impurities implanted into the first N-type semiconductor layer, and impurities implanted into the third N-type semiconductor layer are less than impurities implanted into the second N-type semiconductor layer.
20. A light emitting device, comprising:
a plurality of first GaN-based semiconductor layers alternatively stacked with a plurality of second GaN-based semiconductor layers;
an active layer on the plurality of first GaN-based semiconductor layers alternatively stacked with the plurality of second GaN-based semiconductor layers; and
a P-type semiconductor layer on the active layer,
wherein each of the plurality of first GaN-based semiconductor layers has a level of doping lower than a level of doping of any one of the plurality of second GaN-based semiconductor layers.
21. The light emitting device as claimed in claim 20 , wherein the plurality of first GaN-based semiconductor layers include at least one undoped GaN-based semiconductor layer.
22. The light emitting device as claimed in claim 20 , wherein the plurality of first GaN-based semiconductor layers and the plurality of second GaN-based semiconductor layers each include two layers.
23. The light emitting device as claimed in claim 20 , wherein the plurality of first GaN-based semiconductor layers and the plurality of second GaN-based semiconductor layers each include three layers.
24. The light emitting device as claimed in claim 20 , wherein the plurality of first GaN-based semiconductor layers and the plurality of second GaN-based semiconductor layers each include more than two layers.
25. The light emitting device as claimed in claim 20 , wherein the active layer is on an uppermost layer of the plurality of first GaN-based semiconductor layers.
26. The light emitting device as claimed in claim 20 , wherein the active layer is on an uppermost layer of the plurality of second GaN-based semiconductor layers.
27. The light emitting device as claimed in claim 20 , wherein the active layer is directly on the plurality of first GaN-based semiconductor layers alternatively stacked with the plurality of second GaN-based semiconductor layers.
28. The light emitting device as claimed in claim 20 , wherein the P-type semiconductor layer is directly on the active layer.
29. The light emitting device as claimed in claim 20 , wherein the plurality of second GaN-based semiconductor layers include N-type semiconductor layers comprising Si.