Light emitting device and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-12176458-B2
Application number	US-202318200356-A
Country	US
Kind code	B2
Filing date	May 22, 2023
Priority date	Jul 9, 2018
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

A light emitting device includes a substrate; a pattern of a plurality of protrusions protruding from the substrate; a first semiconductor layer provided on the substrate; an active layer provided on the first semiconductor layer; and a second semiconductor layer provided on the active layer, in which each of the protrusions includes a first layer formed integrally with the substrate and protruding from an upper surface of the base substrate; and a second layer provided on the first layer and formed of a material different from that of the first layer.

First claim

What is claimed is:

1. A light emitting device, comprising:
a substrate;
a pattern of a plurality of protrusions protruding from an upper surface of the substrate in a first direction, the plurality of protrusions arranged side by side in a second direction being perpendicular to the first direction;
a compound semiconductor layer disposed on the upper surface of the substrate;
a mirror layer covering a side surface of the compound semiconductor layer,
wherein each of the plurality of protrusions includes:
a first portion integrally formed with the substrate and protruding from the upper surface of the substrate in the first direction; and
a second portion provided on the first portion and formed of a material different from a material of the first portion,

wherein a refractive index of the first portion is greater than a refractive index of the second portion; and
wherein the second portion of at least one of the plurality of protrusions has a side surface exposed by the compound semiconductor layer and the mirror layer covers the side surface.

2. The light emitting device of claim 1 , wherein a diameter of each of the plurality of protrusions is about 2.5 μm to about 3.5 μm, and a pitch of the pattern is about 2.5 μm or more and about 3.5 μm or less.

3. The light emitting device of claim 1 , wherein a sum of heights of the first portion and the second portion is more than 1.7 μm.

4. The light emitting device of claim 1 , wherein a distance between centers of two adjacent protrusions of the plurality of protrusions in the second direction corresponds to a pitch, and a ratio of a diameter of a protrusion to the pitch of the pattern is about 0.8 to about 1.0.

5. The light emitting device of claim 1 , wherein a diameter of a protrusion is equal to or smaller than a pitch of the pattern.

6. The light emitting device of claim 1 , wherein a ratio of a height of the first portion in the first direction to a height of the second portion in the first direction is about 0.2 to about 1.5.

7. The light emitting device of claim 1 , wherein a height of the second portion is greater than a height of the first portion.

8. The light emitting device of claim 1 , wherein an inclination degree of a side surface of the first portion relative to a plane perpendicular to the first direction is different from an inclination degree of at least a portion of a side surface of the second portion relative to the plane perpendicular to the first direction.

9. A light emitting device, comprising:
a substrate;
a pattern of a plurality of protrusions protruding from an upper surface of the substrate in a first direction, the plurality of protrusions arranged side by side in a second direction being perpendicular to the first direction;
a compound semiconductor layer disposed on the upper surface of the substrate;
an insulation film covering a side surface of the compound semiconductor layer,
wherein each of the plurality of protrusions includes:
a first portion integrally formed with the substrate and protruding from the upper surface of the substrate in the first direction; and
a second portion provided on the first portion and formed of a material different from a material of the first portion,

wherein a refractive index of the first portion is greater than a refractive index of the second portion; and
wherein the second portion of at least one of the plurality of protrusions has a side surface exposed by the compound semiconductor layer and the insulation film covers the side surface.

10. The light emitting device of claim 9 , wherein the insulation film includes a dielectric mirror.

11. The light emitting device of claim 9 , wherein the second portion and the insulation film include a same material.

12. The light emitting device of claim 9 , wherein the plurality of protrusions have shapes in which a width thereof decreases toward the first direction.

13. The light emitting device of claim 9 , wherein the insulation film includes a hole to electrically connect an electrode to the compound semiconductor layer.

14. The light emitting device of claim 9 , wherein the insulation film extends from the exposed side surface of the second portion to an upper surface of the substrate.

15. A light emitting device, comprising:
a substrate;
a pattern of a plurality of protrusions protruding from the substrate in a first direction, the plurality of protrusions arranged side by side in a second direction being perpendicular to the first direction;
a compound semiconductor layer disposed on the substrate;
an insulation film covering a side surface of the compound semiconductor layer,
wherein the plurality of protrusions are formed of a material different from the substrate,
wherein a refractive index of the plurality of protrusions is smaller than a refractive index of the substrate; and
wherein at least one of the plurality of protrusions has a side surface exposed by the compound semiconductor layer and the insulation film covers the side surface.

16. The light emitting device of claim 15 , wherein the plurality of protrusions and the insulation film include a same material.

17. The light emitting device of claim 15 , wherein the plurality of protrusions have shapes in which a width thereof decreases toward the first direction.

18. The light emitting device of claim 15 , wherein the insulation film has a hole to electrically connect an electrode to the compound semiconductor layer.

19. The light emitting device of claim 15 , wherein light generated in the compound semiconductor layer has a light path passing through the plurality of protrusions.

20. The light emitting device of claim 15 , wherein the insulation film extends from the exposed side surface of the at least one of the plurality of protrusions to an upper surface of the substrate.

Assignees

• Seoul Viosys Co Ltd

Inventors

• Min Dae Hong
• Yoon Jun Ho
• Gwak Woo Cheol
• Huh Jin Woo
• Baek Yong Hyun

Classifications

• H10P50/73

  using masks for insulating materials · CPC title

• H10H20/82 Primary

  Roughened surfaces, e.g. at the interface between epitaxial layers · CPC title

• H10H20/8312

  extending at least partially through the bodies · CPC title

• H10H20/01335

  the light-emitting regions comprising nitride materials · CPC title

• H10H20/8215

  characterised by crystalline imperfections, e.g. dislocations; characterised by the distribution of dopants, e.g. delta-doping · CPC title