LIGHT-EMITTING DEVICE, LIGHT-EMITTING DEVICE ARRAY, OPTICAL RECORDING HEAD, IMAGE FORMING APPARATUS, AND METHOD OF MANUFACTURING LIGHT-EMITTING DEVICE

• US 20130020592A1
• Filed: 05/21/2012
• Published: 01/24/2013
• Est. Priority Date: 07/21/2011
• Status: Active Grant

• Current Assignee: Fujifilm Business Innovation Corp. (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: KONDO, Takashi, TAKEDA, Kazutaka, KINOSHITA, Taku
• Granted Patent: US 8,659,035 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 33/0016 having at least two p-n junctions
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/40 Materials therefor

Abstract

Provided is a light-emitting device including a semiconductor substrate of a first conductivity type, a semiconductor multilayer reflection mirror of the first conductivity type, formed on the semiconductor substrate, a first semiconductor layer of the first conductivity type, formed on the semiconductor multilayer reflection mirror, a second semiconductor layer of a second conductivity type, formed on the first semiconductor layer, a third semiconductor layer of the first conductivity type, formed on the second semiconductor layer, a fourth semiconductor layer of the second conductivity type, formed on the third semiconductor layer, a first electrode formed on a rear surface of the semiconductor substrate, and a second electrode formed on the fourth semiconductor layer, wherein the semiconductor multilayer reflection mirror includes a first selectively oxidized region and a first conductive region adjacent to the first oxidized region, and the first conductive region electrically connects the semiconductor substrate and the first semiconductor layer.

Claims

1. A light-emitting device comprising:

a semiconductor substrate of a first conductivity type;

a semiconductor multilayer reflection mirror of the first conductivity type, formed on the semiconductor substrate;

a first semiconductor layer of the first conductivity type, formed on the semiconductor multilayer reflection mirror;

a second semiconductor layer of a second conductivity type different from the first conductivity type, formed on the first semiconductor layer;

a third semiconductor layer of the first conductivity type, formed on the second semiconductor layer;

a fourth semiconductor layer of the second conductivity type, formed on the third semiconductor layer;

a first electrode formed on a rear surface of the semiconductor substrate; and

a second electrode formed on the fourth semiconductor layer,

wherein the semiconductor multilayer reflection mirror includes a first oxidized region which is selectively oxidized and a first conductive region adjacent to the first oxidized region, and

the first conductive region electrically connects the semiconductor substrate and the first semiconductor layer.

2. The light-emitting device according to claim 1,

wherein at least one of the first to fourth semiconductor layers includes a current confining portion,

the current confining portion includes a second oxidized region which is selectively oxidized and a second conductive region which is surrounded by the second oxidized region, and

the second conductive region is in such a positional relation that the second conductive region overlaps with the first oxidized region.

3. The light-emitting device according to claim 2,

wherein the current confining portion is formed in a semiconductor layer on an anode side.

4. The light-emitting device according to claim 1,

wherein an impurity concentration of at least one semiconductor layer included in the semiconductor multilayer reflection mirror is higher than an impurity concentration of the first semiconductor layer.

5. The light-emitting device according to claim 1,

wherein the semiconductor multilayer reflection mirror includes a plurality of pairs of a high refractive index layer having a relatively high refractive index and a low refractive index layer having a relatively low refractive index, and

the first oxidized region is formed by oxidizing at least the low refractive index layer.

6. The light-emitting device according to claim 5,

wherein the high refractive index layer is a low Al semiconductor layer having a relatively low Al content, and

the low refractive index layer is a high Al semiconductor layer having a relatively high Al content.

7. The light-emitting device according to claim 1,

wherein an impurity concentration of at least one low refractive index layer of the semiconductor multilayer reflection mirror is higher than an impurity concentration of the first semiconductor layer.

8. The light-emitting device according to claim 7,

wherein an impurity concentration of a semiconductor layer adjacent to the first semiconductor layer within the semiconductor multilayer reflection mirror is higher than an impurity concentration of the first semiconductor layer.

9. The light-emitting device according to claim 1,

wherein the first oxidized region is selectively oxidized from a hole that reaches the semiconductor multilayer reflection mirror.

10. The light-emitting device according to claim 1,

wherein the second oxidized region is selectively oxidized from a side surface of a first columnar structure formed on the semiconductor multilayer reflection mirror.

11. The light-emitting device according to claim 1,

wherein when a second columnar structure is formed on the first columnar structure, the second columnar structure includes the fourth semiconductor layer, and the first oxidized region is in such a positional relation that the first oxidized region overlaps with the second columnar structure.

12. The light-emitting device according to claim 1,

wherein a first oxidation distance of the first oxidized region is greater than a second oxidation distance of the second oxidized region.

13. The light-emitting device according to claim 1,

wherein when the first conductivity type is a p-type, and the second conductivity type is an n-type, the current confining portion is formed in the first semiconductor layer.

14. The light-emitting device according to claim 1,

wherein when the first conductivity type is an n-type, and the second conductivity type is a p-type, the current confining portion is formed in the fourth semiconductor layer.

15. A light-emitting device array comprising:

a plurality of the light-emitting devices according to claim 1 which are formed on the semiconductor substrate in an array form;

wherein

a hole for oxidation for forming the first oxidized region is formed between adjacent light-emitting devices.

16. The light-emitting device array according to claim 15,

wherein the hole for oxidation is used for forming the first oxidized regions of each of the adjacent light-emitting devices.

17. The light-emitting device array according to claim 15,

wherein the light-emitting device array is a self-scanning light-emitting device array.

18. An optical recording head using the light-emitting device array according to claim 15.

19. An image forming apparatus comprising the optical recording head according to claim 18.

20. A method of manufacturing a light-emitting device, comprising:

preparing a stacked structure including;

a semiconductor substrate of a first conductivity type,

a semiconductor multilayer reflection mirror of the first conductivity type, formed on the semiconductor substrate,

a first semiconductor layer of the first conductivity type, formed on the semiconductor multilayer reflection mirror,

a second semiconductor layer of a second conductivity type different from the first conductivity type, formed on the first semiconductor layer,

a third semiconductor layer of the first conductivity type, formed on the second semiconductor layer, and

a fourth semiconductor layer of the second conductivity type, formed on the third semiconductor layer;

forming a first columnar structure including at least the fourth semiconductor layer;

forming a second columnar structure including at least the first semiconductor layer under the first columnar structure and forming a hole that reaches the semiconductor multilayer reflection mirror; and

forming a selectively oxidized region in the first semiconductor layer exposed by the second columnar structure and forming a selectively oxidized region in the semiconductor multilayer reflection mirror exposed via the hole.

21. The method of manufacturing a light-emitting device according to claim 20,

wherein the semiconductor multilayer reflection mirror includes a plurality of pairs of a high refractive index layer having a relatively high refractive index and a low refractive index layer having a relatively low refractive index, and

an impurity concentration of at least one low refractive index layer is higher than an impurity concentration of the first semiconductor layer.