NITRIDE SEMICONDUCTOR ULTRAVIOLET LIGHT-EMITTING ELEMENT

• US 20140158983A1
• Filed: 08/09/2011
• Published: 06/12/2014
• Est. Priority Date: 08/09/2011
• Status: Active Grant

• Current Assignee: Nikkiso Company Limited
• Original Assignee: Soko Kagaku Co Ltd
• Inventors: Pernot, Cyril, Hirano, Akira
• Granted Patent: US 9,356,192 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/18 within the light emitting region
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape

Abstract

A nitride semiconductor ultraviolet light-emitting element is provided with: an underlying structure portion including a sapphire (0001) substrate and an AlN layer formed on the substrate; and a light-emitting element structure portion including an n-type cladding layer of an n-type AlGaN based semiconductor layer, an active layer having an AlGaN based semiconductor layer, and a p-type cladding layer of a p-type AlGaN based semiconductor layer, formed on the underlying structure portion. The (0001) surface of the substrate is inclined at an off angle which is equal to or greater than 0.6° and is equal to or smaller than 3.0°, and an AlN molar fraction of the n-type cladding layer is equal to or higher than 50%.

Claims

1. A nitride semiconductor ultraviolet light-emitting element comprising:

an underlying structure portion including a sapphire (0001) substrate and an AlN layer formed on a (0001) surface of the substrate; and

a light-emitting element structure portion including an n-type cladding layer of an n-type AlGaN based semiconductor layer, an active layer having an AlGaN based semiconductor layer, and a p-type cladding layer of a p-type AlGaN based semiconductor layer, the light-emitting element structure portion formed on a crystal surface of the underlying structure portion,

wherein the (0001) surface of the substrate is inclined at an off angle which is equal to or greater than 0.6° and

is equal to or smaller than 3.0°

, and

an AlN molar fraction of the n-type cladding layer is equal to or higher than 50%.

2. The nitride semiconductor ultraviolet light-emitting element according to claim 1, wherein the off angle is equal to or greater than 1.0°

and is equal to or smaller than 2.5°

.

3. The nitride semiconductor ultraviolet light-emitting element according to claim 1, wherein a peak emission wavelength is equal to or smaller than 300 nm.

4. The nitride semiconductor ultraviolet light-emitting element according to claim 2, wherein a peak emission wavelength is equal to or smaller than 300 nm.

5. The nitride semiconductor ultraviolet light-emitting element according to claim 1, wherein a film thickness of the AlN layer formed on the substrate of the underlying structure portion is equal to or greater than 2.2 μ

m and is equal to or smaller than 6.6 μ

m.

6. The nitride semiconductor ultraviolet light-emitting element according to claim 2, wherein a film thickness of the AlN layer formed on the substrate of the underlying structure portion is equal to or greater than 2.2 μ

m and is equal to or smaller than 6.6 μ

m.

7. The nitride semiconductor ultraviolet light-emitting element according to claim 3, wherein a film thickness of the AlN layer formed on the substrate of the underlying structure portion is equal to or greater than 2.2 μ

m and is equal to or smaller than 6.6 μ

m.

8. The nitride semiconductor ultraviolet light-emitting element according to claim 4, wherein a film thickness of the AlN layer formed on the substrate of the underlying structure portion is equal to or greater than 2.2 μ

m and is equal to or smaller than 6.6 μ

m.