Semiconductor light emitting element, its manufacturing method and semiconductor light emitting device

• US 20050017250A1
• Filed: 06/09/2004
• Published: 01/27/2005
• Est. Priority Date: 06/10/2003
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Konno, Kuniaki, Sugawara, Yasuharu, Fujiwara, Akihiro, Nitta, Koichi, Nakamura, Takafumi
• Granted Patent: US 7,488,989 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/1815 Shape
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table

Abstract

A light emitting element comprises a GaP substrate and a mesa portion. The GaP substrate includes a major surface inclined to the <011> direction from the {100} plane and a side surface covered with inequalities substantially. The mesa portion has a light emitting multi-layer of InGaAlP based material provided on the major surface. A part of a light emitted from the light emitting multi-layer is extracted through the side surface of the GaP substrate.

Claims

1. A light emitting element comprising:

a GaP substrate including;

a major surface inclined to the <

011>

direction from the {100} plane; and

a side surface covered with inequalities substantially;

a mesa portion having a light emitting multi-layer of InGaAlP based material provided on the major surface,

wherein a part of a light emitted from the light emitting multi-layer is extracted through the side surface of the GaP substrate.

2. The light emitting element according to claim 1, wherein a mean depth of the inequalities is greater than 1 micrometer.

3. The light emitting element according to claim 1, wherein a width of the mesa portion is smaller than a width of the major surface of the GaP substrate in any cross-section.

4. The light emitting element according to claim 3, wherein a surrounding wall made of a same material as the mesa portion is provided so as to surround the mesa portion.

5. The light emitting element according to claim 3, further comprising a surrounding trench so as to surround the mesa portion.

6. The light emitting element according to claim 3, further comprising a GaP layer so as to cover the mesa portion.

7. The light emitting element according to claim 3, wherein the GaP substrate has an opposite surface facing the major surface and the side surface includes:

a first tapered portion adjacent to the opposite surface of the GaP substrate; and

a second tapered portion adjacent to the major surface of the Gap substrate,

the first tapered portion widening toward the major surface from the opposite surface, and

the second tapered portion narrowing toward the major surface from the first tapered portion.

8. The light emitting element according to claim 3, further comprising:

an electrode provided on the light emitting multi-layer; and

a reflecting means interposed between the electrode and the light emitting multi-layer,

the reflecting means reflecting a light emitted from the light emitting multi-layer.

9. The light emitting element according to claim 3, further comprising:

an electrode provided on the light emitting multi-layer; and

a current blocking layer which interposes between the electrode and the light emitting multi-layer and prevent the current injected via the electrode.

10. The light emitting element according to claim 9, wherein the current blocking layer reflects the light emitted from the light emitting multi-layer.

11. The light emitting element according to claim 1, the inequalities is formed on the {111} plane.

12. The light emitting element according to claim 1, wherein the inequalities is formed by etching using a liquid or a gas containing fluoric acid.

13. The light emitting element according to claim 1, wherein the major surface inclines at 5-30 degrees to the <

011>

direction from the {100} plane.

14. The light emitting element according to claim 13, wherein the major surface inclines at 15±

1 degrees to the <

011>

direction from the {100} plane.

15. A light emitting device comprising:

a lead frame;

the light emitting element mounted on the lead frame, including a GaP substrate having a major surface inclined to the <

011>

direction from the {100} plane and a side surface having inequalities of which a mean depth is greater than 1 micrometer, a mesa portion having a light emitting multi-layer of InGaAlP based material provided on the major surface,

wherein a part of a light emitted from the light emitting multi-layer is extracted through the side surface of the GaP substrate; and

an epoxy resin in which the lead frame and the light emitting element are encapsulated.

16. The light emitting element according to claim 15, wherein a light reflecting means which reflects a light emitted from the side surface of the GaP substrate.

17. A method for manufacturing a light emitting element comprising:

forming a light emitting multi-layer based on InGaAlP based materials on a tentative semiconductor substrate;

bonding a GaP substrate to a surface of the light emitting multi-layer;

removing the tentative semiconductor substrate;

forming at least two mesa portions on the major surface of the GaP substrate by removing a part of the light emitting multi-layer selectively;

growing a GaP layer so as to cover the mesa portions;

forming a protecting film on the mesa potions;

dicing the GaP substrate so as to separate each mesa portion; and

forming inequalities on an exposed side surface of the GaP substrate after dicing by a liquid or a gas containing fluoric acid.

18. The method for manufacturing the light emitting element according to claim 17, wherein the GaP substrate inclines at 5-30°

to the <

011>

direction from the {100} plane.