Nitride-based semiconductor light-emitting device and method of fabricating the same
A nitride-based semiconductor light-emitting device capable of stabilizing transverse light confinement is obtained. This nitride-based semiconductor light-emitting device comprises an emission layer, a cladding layer, formed on the emission layer, including a first nitride-based semiconductor layer and having a current path portion and a current blocking layer, formed to cover the side surfaces of the current path portion, including a second nitride-based semiconductor layer, while the current blocking layer is formed in the vicinity of the current path portion and a region having no current blocking layer is included in a region not in the vicinity of the current path portion. Thus, the width of the current blocking layer is reduced, whereby strain applied to the current blocking layer is relaxed. Consequently, the thickness of the current blocking layer can be increased, thereby stabilizing transverse light confinement.
1. A nitride-based semiconductor light-emitting device comprising:
an emission layer;
a cladding layer, formed on said emission layer, including a projection portion and a flat portion;
a dielectric blocking layer, formed on the side surface of said projection portion and on said flat portion; and
a semiconductor layer absorbing light emitted from said emission layer, formed on said dielectric blocking layer to fill up side portions of said projecting portion, wherein
said projecting portion and said flat portion are formed by etching.
2. The nitride-based semiconductor light-emitting device according to claim 1 , wherein
said cladding layer consists of Mg-doped AlGaN, and
said semiconductor layer consists of InGaN.
3. The nitride-based semiconductor light-emitting device according to claim 1 , wherein
the thickness of said dielectric blocking layer is smaller than the thickness of said semiconductor layer.
4. The nitride-based semiconductor light-emitting device according to claim 1 , wherein
said semiconductor layer contains at least one element, selected from a group consisting of B, Ga, Al, In and Tl, and N.
5. The nitride-based semiconductor light-emitting device according to claim 1 , wherein
said dielectric blocking layer includes an oxide film or a nitride film containing at least one element selected from a group consisting of Si, Ti and Zr.
6. A method of fabricating a nitride-based semiconductor light-emitting device comprising steps of:
forming an emission layer;
forming a cladding layer on said emission layer;
forming a projecting portion and a flat portion on said cladding layer by etching said cladding layer;
forming a dielectric blocking layer on the side surface of said projection portion and on said flat portion; and
forming a semiconductor layer on said dielectric blocking layer to fill up side portions of said projecting portion.
7. The method of fabricating a nitride-based semiconductor light-emitting device according to claim 6 , wherein
said semiconductor layer is grown under a lower temperature as compared with said dielectric blocking layer.
8. The method of fabricating a nitride-based semiconductor light-emitting device according to claim 6 , wherein
said semiconductor layer absorbs light emitted from said emission layer.
9. The method of fabricating a nitride-based semiconductor light-emitting device according to claim 6 , wherein
said step of forming said emission layer includes a step of forming said emission layer on a GaN substrate.