Nitride semiconductor light emitting device and fabricating method thereof
A nitride semiconductor light emitting device including: a first nitride semiconductor layer; an active layer formed on the first nitride semiconductor layer and including at least one barrier layer grown under hydrogen atmosphere of a high temperature; and a second nitride semi conductor layer formed on the active layer, and a method of fabricating the same are provided. According to the light emitting device and method of fabricating the same, the light power of the light emitting device is increased and the operation reliability is enhanced.
1. A semiconductor light emitting device, comprising:
a first conductive type semiconductor layer;
an active layer formed on the first conductive type semiconductor layer,
wherein the active layer is a multi-quantum well structure having a plurality of well layers alternatively stacked with a plurality of barrier layers; and
a second conductive type semiconductor layer formed on the active layer,
wherein a first well layer of the plurality of well layers has a composition of In X Ga 1-X N (0≦x≦1) with an In (Indium) composition ratio of 10-20%,
wherein a first barrier layer of the plurality of the barrier layers is formed on the first well layer and has a composition of In Y Ga 1-Y N (0≦Y≦1) with an In (Indium) composition ratio of less than 10%,
wherein the active layer comprises 4 to 10 pairs of periodically repeated well layers and barrier layers, each pair including a corresponding barrier layer on a corresponding well layer,
wherein one of the pairs of periodically repeated well layers and barrier layers comprises a seed layer of InN, and
wherein an upper surface of the seed layer is in direct contact with a lower surface of the corresponding well layer and a lower surface of the seed layer is in direct contact with an upper surface of the corresponding barrier layer.
2. The semiconductor light emitting device of claim 1 , wherein the first barrier layer has a thickness of 30-200 Å.
3. The nitride semiconductor light emitting device of claim 1 , wherein the first well layer is interposed between the first barrier layer and the first conductive type semiconductor layer.
4. The semiconductor light emitting device of claim 1 , wherein a second barrier layer of the plurality of the barrier layers is interposed between the first conductive type semiconductor layer and the first well layer.
5. The semiconductor light emitting device of claim 1 , wherein a thickness of the seed layer is less than a thickness of the barrier layer.
6. A semiconductor light emitting device, comprising:
a first conductive type semiconductor layer;
an active layer formed on the first conductive type semiconductor layer; and
a second conductive type semiconductor layer formed on the active layer,
wherein the active layer comprises at least two pairs of periodically repeated well layers and barrier layers, each pair including a corresponding barrier layer on a corresponding well layer, each well layer having a composition of In x Ga 1-x N (0≦x≦1)
wherein at least one of the barrier layers is 30-200 Å thick,
wherein one of the pairs of periodically repeated well layers and barrier layers comprises a seed layer,
wherein the seed layer has a thickness smaller than a well layer thickness, and
wherein an upper surface of the seed layer is in direct contact with a lower surface of a corresponding well layer and a lower surface of the seed layer is in direct contact with an upper surface of a corresponding barrier layer.
7. The semiconductor light emitting device of claim 6 ,
wherein the well layers have a composition of In X Ga 1-X N (0≦x≦1) with an In (Indium) composition ratio of 10-20%, and
wherein the barrier layers have a composition of In Y Ga 1-Y N (0≦Y≦1) with an In (Indium) composition ratio of less than 10%.
8. The semiconductor light emitting device of claim 7 ,
wherein the first conductive type semiconductor layer comprises an n-type semiconductor layer, and
wherein the second conductive type semiconductor layer comprises a p-type semiconductor layer.
9. The semiconductor light emitting device of claim 6 , wherein the seed layer has an In (Indium) composition ratio of more than 10%.
10. The semiconductor light emitting device of claim 6 , wherein
seed layer has an energy gap of In x Ga 1-x N(0≦x≦1) including an infrared ray region to an ultra violet ray region.
11. The semiconductor light emitting device of claim 6 , wherein the seed layer is a continuous layer having a thickness of 20 Å or less.
12. The semiconductor light emitting device of claim 9 , further comprising:
a buffer layer formed under the first conductive type semiconductor layer; and
a substrate formed under the buffer layer.
13. The semiconductor light emitting device of claim 6 ,
wherein the In (Indium) composition ratio of the seed layer is equal to or different from an In (Indium) composition ratio of the corresponding well layer of the two pairs, and
wherein the In (Indium) composition ratio of the corresponding well layer of the two pairs is greater than the In (Indium) composition ratio of the corresponding barrier layer of the two pairs.
14. The semiconductor light emitting device of claim 6 , wherein the seed layer is formed of InN.