Nitride semiconductor light-emitting chip, method of manufacture thereof, and semiconductor optical device

• US 20100243988A1
• Filed: 03/25/2010
• Published: 09/30/2010
• Est. Priority Date: 03/27/2009
• Status: Active Grant

• Current Assignee: Sharp Fukuyama Laser Co., Ltd. (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ohta, Masataka, Kamikawa, Takeshi
• Granted Patent: US 8,664,688 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 2304/04 MOCVD or MOVPE
• CPC Class Codes: H01S 5/0202 Cleaving
• CPC Class Codes: H01S 5/02212 Can-type, e.g. TO-CAN housings with emission along or parallel to symmetry axis
• CPC Class Codes: H01S 5/028 Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers
• CPC Class Codes: H01S 5/168 with window regions comprising current blocking layers
• CPC Class Codes: H01S 5/2009 by using electron barrier layers
• CPC Class Codes: H01S 5/2201 in a specific crystallographic orientation
• CPC Class Codes: H01S 5/320275 semi-polar orientation
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser
• CPC Class Codes: H01S 5/4031 Edge-emitting structures

Abstract

A nitride semiconductor light-emitting chip offers enhanced luminous efficacy as a result of an improved EL emission pattern. The nitride semiconductor laser chip (nitride semiconductor light-emitting chip) has a nitride semiconductor substrate having a principal growth plane, and nitride semiconductor layers grown on the principal growth plane of the nitride semiconductor substrate. The principal growth plane of the GaN substrate is a plane having off-angles in both the a- and c-axis directions relative to an m plane, and the off-angle in the a-axis direction is larger than the off-angle in the c-axis direction.

Claims

1. A nitride semiconductor light-emitting chip comprising:

a nitride semiconductor substrate having a principal growth plane; and

a nitride semiconductor layer grown on the principal growth plane of the nitride semiconductor substrate, wherein

the principal growth plane is a plane having off-angles in both a- and c-axis directions relative to an m plane, and

the off-angle in the a-axis direction is larger than the off-angle in the c-axis direction.

2. The nitride semiconductor light-emitting chip according to claim 1, wherein

the off-angle in the a-axis direction and the off-angle in the c-axis direction are each larger than 0.1 degrees.

3. The nitride semiconductor light-emitting chip according to claim 1, wherein

the off-angle in the a-axis direction is larger than 0.1 degrees but 10 degrees or smaller.

4. The nitride semiconductor light-emitting chip according to claim 3, wherein

the off-angle in the a-axis direction is larger than 1 degree but 10 degrees or smaller.

5. The nitride semiconductor light-emitting chip according to claim 1, wherein

the nitride semiconductor layer includes an active layer having a quantum well structure, and

the active layer has one well layer.

6. The nitride semiconductor light-emitting chip according to claim 1, wherein

the nitride semiconductor layer includes an active layer having a quantum well structure, and

the active layer has two well layers.

7. The nitride semiconductor light-emitting chip according to claim 1, wherein

the nitride semiconductor layer includes an active layer having a quantum well structure,

the active layer has a well layer formed of a nitride semiconductor containing In, and

an In composition ratio in the well layer is 0.15 or more but 0.45 or less.

8. The nitride semiconductor light-emitting chip according to claim 1, wherein

the nitride semiconductor substrate is formed of GaN.

13. A semiconductor optical device comprising the nitride semiconductor light-emitting chip according to claim 1.

9. A method of manufacture of a nitride semiconductor light-emitting chip, the method comprising:

a step of preparing a nitride semiconductor substrate having as a principal growth plane a plane having off-angles in both a- and c-axis directions relative to an m plane, the off-angle in the a-axis direction being larger than the off-angle in the c-axis direction; and

a step of stacking, on the principal growth plane of the nitride semiconductor substrate, by an epitaxial growth method, a nitride semiconductor layer including an n-type semiconductor layer, an active layer, and a p-type semiconductor layer, wherein

the step of stacking the nitride semiconductor layer includes a step of forming, from a nitride semiconductor substrate side, the n-type semiconductor layer, the active layer, and the p-type semiconductor layer.

10. The method of manufacture of a nitride semiconductor light-emitting chip according to claim 9, wherein

the step of stacking the nitride semiconductor layer includes a step of forming the p-type semiconductor layer at a growth temperature of 700°

or higher but lower than 900°

C.

11. The method of manufacture of a nitride semiconductor light-emitting chip according to claim 9, wherein

the step of stacking the nitride semiconductor layer includes a step of forming the n-type semiconductor layer at a growth temperature of 900°

or higher but lower than 1300°

C.

12. The method of manufacture of a nitride semiconductor light-emitting chip according to claim 9, wherein

the step of stacking the nitride semiconductor layer includes a step of forming the active layer at a growth temperature of 600°

or higher but 770°

C. or lower.