Semiconductor light emitting device

• US 20070086496A1
• Filed: 02/21/2006
• Published: 04/19/2007
• Est. Priority Date: 10/13/2005
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tanaka, Akira, Onomura, Masaaki, Harada, Yoshiyuki, Katsuno, Hiroshi, Sugawara, Hideto, Hongo, Chie
• Application Number:
  US11/357,408
• Publication Number:
  US 20070086496A1
• Time in Patent Office: Days
• US Class Current: 372/43.10
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 5/2009 by using electron barrier layers
• CPC Class Codes: H01S 5/22 having a ridge or stripe structure
• CPC Class Codes: H01S 5/3216 quantum well or superlattice cladding layers
• CPC Class Codes: H01S 5/3407 characterised by special barrier layers
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

A semiconductor light emitting device comprises: a first cladding layer made of nitride semiconductor of a first conductivity type; an active layer provided on the first cladding layer, the active layer including a first barrier layer made of nitride semiconductor, a second barrier layer made of nitride semiconductor, and a well layer made of nitride semiconductor, the well layer being provided between the first barrier layer and the second barrier layer; and a second cladding layer provided on the active layer, the second cladding layer being made of nitride semiconductor of a second conductivity type. The first and second barrier layers and the well layer contain indium. At least one of the first barrier layer and the second barrier layer has a thickness of 30 nm or more.

Claims

1. A semiconductor light emitting device comprising:

a first cladding layer made of nitride semiconductor of a first conductivity type;

an active layer provided on the first cladding layer, the active layer including a first barrier layer made of nitride semiconductor, a second barrier layer made of nitride semiconductor, and a well layer made of nitride semiconductor, the well layer being provided between the first barrier layer and the second barrier layer; and

a second cladding layer provided on the active layer, the second cladding layer being made of nitride semiconductor of a second conductivity type,

the first and second barrier layers and the well layer containing indium, and

at least one of the first barrier layer and the second barrier layer having a thickness of 30 nm or more.

2. A semiconductor light emitting device of claim 1, wherein the active layer has a multiple quantum well further including two or more of the well layers and one or more inner barrier layers provided between the two or more well layers, and the inner barrier layer contains indium.

3. A semiconductor light emitting device of claim 1, wherein the one of the first barrier layer and the second barrier layer has a thickness of 100 nm or less.

4. A semiconductor light emitting device of claim 1, wherein another of the first barrier layer and the second barrier layer has a thickness of 30 nm or more.

5. A semiconductor light emitting device of claim 4, wherein the active layer has a multiple quantum well further including two or more of the well layers and one or more inner barrier layers provided between the two or more well layers, and the inner barrier layer contains indium.

6. A semiconductor light emitting device of claim 4, wherein the first barrier layer has a thickness of 100 nm or less, and the second barrier layer has a thickness of 100 nm or less.

7. A semiconductor light emitting device of claim 1, wherein the second cladding layer is made of an Al_sGa₁₋

sN (0<

s≦

0.3) layer, or a superlattice multilayer including an Al_sGa<sub>1−

s</sub>N (0<

s≦

0.3) layer and a GaN layer, the well layer is made of In_xGa<sub>1−

x</sub>N (0.05≦

x≦

1.0), the first barrier layer is made of In_yGa<sub>1−

y</sub>N (0<

y≦

0.02), and the second barrier layer is made of In_zGa<sub>1−

z</sub>N (0<

z≦

0.02).

8. A semiconductor light emitting device of claim 1, wherein the first cladding layer, the active layer and the second cladding layer are provided on a GaN substrate.

9. A semiconductor light emitting device of claim 1, further comprising:

an overflow blocking layer having a wider band gap energy than the active layer and provided between the second cladding layer and the active layer,

the overflow blocking layer being provided adjacent to the second cladding layer.

10. A semiconductor light emitting device comprising:

a substrate;

a first cladding layer provided on the substrate, the first cladding layer being made of an Al_sGa<sub>1−

s</sub>N (0<

s≦

0.3) layer of a first conductivity type, or a superlattice multilayer including an Al_sGa<sub>1−

s</sub>N (0<

s≦

0.3) layer and a GaN layer;

an active layer including a first barrier layer made of In_zGa<sub>1−

z</sub>N (0<

z≦

0.02) provided on the first cladding layer, a well layer made of In_xGa<sub>1−

x</sub>N (0.05≦

x≦

1.0) provided on the first barrier layer, and a second barrier layer made of In_yGa<sub>1−

y</sub>N (0<

y≦

0.02) provided on the well layer; and

a second cladding layer provided on the active layer, the second cladding layer being made of an Al_tGa<sub>1−

t</sub>N (0<

t≦

0.3) layer of a second conductivity type, or a superlattice multilayer including an Al_tGa<sub>1−

t</sub>N (0<

t≦

0.3) layer and a GaN layer,

the first barrier layer having a thickness of 30 nm or more, and

the second barrier layer having a thickness of 30 nm or more.

11. A semiconductor light emitting device of claim 10, wherein the substrate is made of GaN.

12. A semiconductor light emitting device of claim 10, wherein the first barrier layer has a thickness of 100 nm or less, and the second barrier layer has a thickness of 100 nm or less.

13. A semiconductor light emitting device of claim 10, wherein the active layer has a multiple quantum well further including two or more of the well layers and one or more inner barrier layers provided between the two or more well layers, the inner barrier layer is made of In_wGa₁₋

wN (0<

w≦

0.02), and light emission produced in the active layer causes lasing.

14. A semiconductor light emitting device of claim 10, further comprising:

a first optical guide layer made of GaN provided between the first cladding layer and the first barrier layer, and

a second optical guide layer made of GaN provided between the second cladding layer and the second barrier layer.

15. A semiconductor light emitting device of claim 14, wherein light emission produced in the active layer causes lasing.

16. A semiconductor light emitting device of claim 10, further comprising:

an overflow blocking layer made of an Al_rGa<sub>1−

r</sub>N(0.2≦

r<

1.0) and provided between the second cladding layer and the active layer,

the overflow blocking layer being provided adjacent to the second cladding layer.

17. A semiconductor light emitting device of claim 16, wherein the overflow blocking layer has the second conductivity type and an impurity concentration higher than 1×

10²⁰ cm<sup>−

3</sup>.

18. A semiconductor light emitting device comprising:

a GaN foundation layer of a first conductivity type;

an active layer including a first barrier layer made of In_zGa<sub>1−

z</sub>N(0<

z≦

0.02) provided on the GaN foundation layer, a well layer made of In_xGa<sub>1−

x</sub>N(0.05≦

x≦

1.0) provided on the first barrier layer, and a second barrier layer made of In_yGa<sub>1−

y</sub>N(0<

y≦

0.02) provided on the well layer; and

a cladding layer provided on the active layer, the cladding layer being made of an Al_tGa<sub>1−

t</sub>N(0<

t≦

0.3) layer of a second conductivity type, or a superlattice multilayer of a second conductivity type including an Al_tGa<sub>1−

t</sub>N(0<

t≦

0.3) layer and a GaN layer,

at least one of the first barrier layer and the second barrier layer having a thickness of 30 nm or more.

19. A semiconductor light emitting device of claim 18, wherein the one of the first barrier layer and the second barrier layer has a thickness of 100 nm or less.

20. A semiconductor light emitting device of claim 18, wherein the active layer has a multiple quantum well further including two or more of the well layers and one or more inner barrier layers provided between the two or more well layers, and the inner barrier layer is made of In_wGa₁₋

wN(0<

w≦

0.02).