Gallium nitride-based compound semiconductor device

• US 20050236642A1
• Filed: 07/01/2003
• Published: 10/27/2005
• Est. Priority Date: 07/16/2002
• Status: Active Grant

• Current Assignee: Nitride Semiconductors Co., Ltd.
• Original Assignee: Nitride Semiconductors Co., Ltd.
• Inventors: Sugahara, Tomoya, Sakai, Shiro
• Granted Patent: US 7,700,940 B2
• Time in Patent Office: Days
• US Class Current: 257/103
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• 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

Abstract

An LED emitting light of wavelength mainly 375 nm or below. The LED includes a GaN layer (16), an n-clad layer (20), an AlInGaN buffer layer (22), a light emitting layer (24), a p-clad layer (26), a p-electrode (30), and an n-electrode (32) arranged on a substrate (10). The light emitting layer (24) has a multi-layer quantum well structure (MQW) in which an InGaN well layer and an AlInGaN barrier layer are superimposed. The quantum well structure increases the effective band gap of the InGaN well layer and reduces the light emitting wavelength. Moreover, by using the AlInGaN buffer layer (22) as the underlying layer of the light emitting layer (24), it is possible to effectively inject electrons into the light emitting layer (24), thereby increasing the light emitting efficiency.

Claims

1. A gallium nitride-based compound semiconductor device comprising:

a GaN-based light emitting layer formed above a substrate, wherein

the light emitting layer comprises a multilayer quantum well layer in which an InGaN well layer and an AlInGaN barrier layer are layered.

2. A gallium nitride-based compound semiconductor device according to claim 1, wherein

a compositional ratio of In in the InGaN well layer is 5% or greater and 15% or smaller.

3. A gallium nitride-based compound semiconductor device according to claim 1, wherein

a compositional ratio of In in the InGaN well layer is 5% or greater and 13% or smaller.

4. A gallium nitride-based compound semiconductor device according to claim 1, wherein

a thickness of the InGaN well layer is 1 nm or greater and 2 nm or smaller.

5. A gallium nitride-based compound semiconductor device according to claim 1, wherein

a thickness of the InGaN well layer is 1.3 nm or greater and 1.8 nm or smaller.

6. A gallium nitride-based compound semiconductor device according to claim 1, wherein

a compositional ratio of Al in the AlInGaN barrier layer is 14% or greater and 40% or smaller, and

a compositional ratio of In in the AlInGaN barrier layer is 0.1% or greater and 5% or smaller.

7. A gallium nitride-based compound semiconductor device according to claim 1, wherein

a compositional ratio of Al in the AlInGaN barrier layer is 16% or greater and 40% or smaller, and

a compositional ratio of In in the AlInGaN barrier layer is 0.1% or greater and 3% or smaller.

8. A gallium nitride-based compound semiconductor device according to claim 1, further comprising:

an AlInGaN buffer layer adjacent to the light emitting layer.

9. A gallium nitride-based compound semiconductor device according to claim 8, wherein

a compositional ratio of Al in the AlInGaN buffer layer is 0.5% or greater and 40% or smaller, and

a compositional ratio of In in the AlInGaN buffer layer is 0.1% or greater and 5% or smaller.

10. A gallium nitride-based compound semiconductor device according to claim 8, wherein

a compositional ratio of Al in the AlInGaN buffer layer is 1% or greater and 40% or smaller, and

a compositional ratio of In in the AlInGaN buffer layer is 0.1% or greater and 3% or smaller.

11. A gallium nitride-based compound semiconductor device according to claim 1, wherein

the InGaN well layer and the AlInGaN barrier layer are formed at a temperature of 750°

C. or greater.