Semiconductor light-emitting device for optical communications

• US 6,927,426 B2
• Filed: 04/30/2003
• Issued: 08/09/2005
• Est. Priority Date: 06/19/2002
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Okamoto, Hiroshi, Matsuoka, Takashi
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US10/426,464
• Publication Number:
  US 20030234404A1
• Time in Patent Office: 832 Days
• Field of Search: 257/89, 257/90, 257/94, 257/96, 257/103, 257/88, 257/13, 257/14
• US Class Current: 257/103
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A semiconductor light-emitting device of this invention includes at least a first cladding layer formed on a substrate, a light-emitting structure including an active layer made of In_1−X−YGa_XAl_YN (0≦X, Y≦1, 0≦X+Y<1) and formed on the first cladding layer, and a second cladding layer formed on the light-emitting structure. The active layer is made of a material with a small Auger effect and a small dependency of its band gap energy on environment temperature.

Claims

1. A semiconductor light-emitting device comprising at least:

a first cladding layer formed on a substrate;

a light-emitting structure including an active layer made of In<sub>1−

X−

Y</sub>Ga_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y<

1) and formed on said first cladding layer; and

a second cladding layer formed on said light-emitting structure,

wherein light whose wavelength is longer than 0.65 μ

m (=energy bandgap 1.9 eV) and shorter than 1.65 μ

m (=energy bandgap 0.75 eV) is emitted from said light-emitting structure.

2. A device according to claim 1, further comprising first and second semiconductor layers formed to sandwich the active layer, said first and second semiconductor layers being made of In₁₋

X′

−

Y′

Ga_X′

Al_Y′

N (0≦

X′

, Y′

≦

1, 0≦

X′

+Y′

≦

1) and In<sub>1−

X″

−

Y″</sub>

Ga_X″

Al_Y″

N (0≦

X″

, Y″

≦

1, 0≦

X″

+Y″

≦

1).

3. A device according to claim 1, wherein

said light-emitting structure is constituted by a first light-emitting structure and a second light-emitting structure formed thereon,

the first light-emitting structure is formed from a first active layer sandwiched between barrier layers,

the second light-emitting structure is formed from a second active layer sandwiched between barrier layers, and

the first and second light-emitting structures have different emission wavelengths.

4. A device according to claim 3, wherein the first and second semiconductor light-emitting elements are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y<

1) with different composition ratios.

5. A device according to claim 4, wherein the barrier layers are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y≦

1) having higher bandgap energy than the first and second active layers.

6. A device according to claim 3, wherein the first and second light-emitting structures are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y<

1) with different film thicknesses.

7. A device according to claim 6, wherein the barrier layers are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y≦

1) having higher bandgap energy than the first and second active layers.

8. A device according to claim 1, wherein

said light-emitting structure is constituted by a first light-emitting structure, a second light-emitting structure formed thereon, and a third light-emitting structure formed thereon,

the first light-emitting structure is formed from a first active layer sandwiched between barrier layers,

the second light-emitting structure is formed from a second active layer sandwiched between barrier layers,

the third light-emitting structure is formed from a third active layer sandwiched between barrier layers, and

the first, second, and third light-emitting structures have different emission wavelengths.

9. A device according to claim 8, wherein the first, second, and third semiconductor light-emitting elements are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y<

1) with different composition ratios.

10. A device according to claim 9, wherein the barrier layers are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y≦

1) having higher bandgap energy than the first to third active layers.

11. A device according to claim 8, wherein the first, second, and third semiconductor light-emitting elements are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y<

1) with different film thicknesses.

12. A device according to claim 11, wherein the barrier layers are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y≦

1) having higher bandgap energy than the first to third active layers.

13. A device according to claim 1, wherein

said light-emitting structure is constituted by a first light-emitting structure, a second light-emitting structure, a second light-emitting structure, and a third light-emitting structure arrayed on the substrate,

the first light-emitting structure is formed from a first active layer sandwiched between barrier layers,

the second light-emitting structure is formed from a second active layer sandwiched between barrier layers,

the third light-emitting structure is formed from a third active layer sandwiched between barrier layers, and

the first, second, and third light-emitting structures have different emission wavelengths.

14. A device according to claim 13, wherein the first, second, and third semiconductor light-emitting elements are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y<

1) with different composition ratios.

15. A device according to claim 14, wherein the barrier layers are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y≦

1) having higher bandgap energy than the first to third active layers.

16. A device according to claim 13, wherein the first, second, and third light-emitting structuresare made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y<

1) with different film thicknesses.

17. A device according to claim 16, wherein the barrier layers are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y≦

1) having higher bandgap energy than the first to third active layers.

18. A device according to claim 1, wherein

the active layer is formed from a layer constituted by a plurality of island portions arrayed in the same plane, and

the island portions are made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y<

1).

19. A device according to claim 18, wherein the respective island portions are so arrayed as to be isolated from each other.

20. A device according to claim 18, wherein the layer constituted by the plurality of island portions arrayed in the same plane is covered with a barrier layer made of In₁₋

X−

YGa_XAl_YN (0≦

X, Y≦

1, 0≦

X+Y≦

1) having higher bandgap energy than the island portions.

21. A device according to claim 20, wherein the active layer comprises a multilayer structure formed by stacking the layer constituted by the plurality of island portions arrayed in the same plane and the barrier layer.

22. A device according to claim 18, wherein the island portions are made of InN.