Semiconductor light-emitting device and method for fabricating the same

Abstract

A semiconductor light-emitting device includes: a substrate; a plurality of semiconductor layers grown on the substrate and including an active layer; and an electrode formed on the semiconductor layers. An opening in which at least a portion of the semiconductor layers is exposed is formed in the substrate. The electrode faces the opening in the substrate and a portion of the substrate surrounding the opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate a semiconductor light-emitting device according to a first embodiment of the present invention. FIG. 1A is a plan view and FIG. 1B is a bottom view.

FIG. 2 is a cross-sectional view taken along the line II-II in FIGS. 1A and 1B.

FIGS. 3A through 3F are cross-sectional views showing respective process steps of a method for fabricating a semiconductor light-emitting device according to the first embodiment in the order of fabrication.

FIGS. 4A and 4B illustrate a semiconductor light-emitting device according to a second embodiment of the present invention. FIG. 4A is a plan view and FIG. 4B is a bottom view.

FIG. 5 is a cross-sectional view taken along the line V-V in FIGS. 4A and 4B.

FIGS. 6A through 6E are cross-sectional views showing respective process steps of a method for fabricating a semiconductor light-emitting device according to the second embodiment in the order of fabrication.

Claims

1. A semiconductor light-emitting device, comprising: a substrate;a plurality of semiconductor layers grown on the substrate and including an active layer; anda first electrode formed on the semiconductor layers,wherein a first opening in which at least a portion of the semiconductor layers is exposed is formed in the substrate,the first electrode faces the first opening in the substrate and a portion of the substrate surrounding the first opening, and ‘the area of the first electrode is larger than the area of the first opening.

2. The semiconductor light-emitting device of claim 1, wherein the first electrode is electrically connected to one of the semiconductor layers of a first conductivity type, the semiconductor light-emitting device further comprises a second electrode electrically connected to another of the semiconductor layers of a second conductivity type,a second opening is formed in the substrate, andthe second electrode is extracted to the opposite side from the first electrode through the second opening.

3. The semiconductor light-emitting device of claim 2, wherein the second electrode on the surface of the other semiconductor layer of the second conductivity type has a comb shape in plan view.

4. The semiconductor light-emitting device of claim 2, wherein a plurality of said second openings are formed in the substrate.

5. The semiconductor light-emitting device of claim 1, wherein the first electrode is electrically connected to one of the semiconductor layers of a first conductivity type, the semiconductor light-emitting device further comprises a second electrode electrically connected to another of the semiconductor layers of a second conductivity type, andthe second electrode is extracted to the same side as the first electrode.

6. The semiconductor light-emitting device of claim 5, wherein the second electrode is formed in the periphery of the first electrode.

7. The semiconductor light-emitting device of claim 1, wherein the first electrode is made of a metal having a thickness of 10 μm or more.

8. The semiconductor light-emitting device of claim 1, wherein a groove portion is formed in a portion of the semiconductor layers exposed in the first opening.

9. The semiconductor light-emitting device of claim 8, wherein the groove portion forms photonic crystal.

10. The semiconductor light-emitting device of claim 1, wherein the first opening has a tapered shape whose diameter increases as the distance from the semiconductor layers increases.

11. The semiconductor light-emitting device of claim 1, wherein a reflection film is formed on an inner wall of the first opening.

12. The semiconductor light-emitting device of claim 11, wherein the reflection film is either a metal film or a multilayer film made of the metal film and an insulating film.

13. The semiconductor light-emitting device of claim 12, wherein the metal film contains aluminum.

14. The semiconductor light-emitting device of claim 1, wherein the semiconductor layers include a p-type semiconductor layer and an n-type semiconductor layer, and an n-type low-resistance layer to which an impurity is added in a high concentration is interposed between the first electrode and the p-type semiconductor layer.

15. The semiconductor light-emitting device of claim 14, wherein the first electrode partially includes a reflection layer containing aluminum.

16. The semiconductor light-emitting device of claim 1, wherein the semiconductor layers are made of nitride semiconductor.

17. The semiconductor light-emitting device of claim 1, wherein the substrate is made of silicon.

18. The semiconductor light-emitting device of claim 17, wherein the substrate has a principal surface whose plane orientation is a (111) plane.

19. A method for fabricating a semiconductor light-emitting device, the method comprising the steps of: (a) forming a groove portion in a principal surface of a substrate;(b) growing a plurality of semiconductor layers including an active layer on the principal surface of the substrate in which the groove portion is formed;(c) forming a first electrode on one of the semiconductor layers of a first conductivity type and forming a second electrode on another of the semiconductor layers of a second conductivity type; and(d) forming, in the substrate, a first opening in which the groove portion is exposed.

20. The method of claim 19, wherein in the step (d), the first opening is formed to be smaller than the first electrode.

21. The method of claim 19, wherein the step (d) further includes the step of forming, in the substrate, a second opening in which the second electrode is exposed.

22. The method of claim 19, wherein in the step (d), the first opening is formed to have a tapered shape whose diameter increases as the distance from the semiconductor layers increases.

23. The method of claim 19, wherein the semiconductor layers are made of nitride semiconductor.