LIGHT EMITTING DEVICE WITH IMPROVED LIGHT EXTRACTION EFFICIENCY

• US 20100176415A1
• Filed: 01/13/2010
• Published: 07/15/2010
• Est. Priority Date: 01/14/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Youn, Sun-Pil, Lee, Seung-Jae, Kim, Yu-Sik, Hwang, Seong-Deok
• Granted Patent: US 8,319,238 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05005 Structure
• CPC Class Codes: H01L 2224/05026 the internal layer being disposed in a recess of the surface
• CPC Class Codes: H01L 2224/05111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05139 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/05144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05155 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05169 Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/05184 Tungsten [W] as principal constituent
• CPC Class Codes: H01L 2224/05541 Structure
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05611 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05639 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05655 : Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05666 : Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05669 : Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/05684 : Tungsten [W] as principal constituent
• CPC Class Codes: H01L 2224/06102 : the bonding areas being at different heights
• CPC Class Codes: H01L 2224/13 : of an individual bump connector
• CPC Class Codes: H01L 2224/45015 : being circular
• CPC Class Codes: H01L 2224/45139 : Silver (Ag) as principal constituent
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/49107 : on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• 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 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2933/0091 : Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• 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

Abstract

A light emitting device having a high degree of light extraction efficiency includes a substrate, and a light emitting structure disposed on one surface of the substrate, the substrate having an internal reformed region where the index of refraction differs from the remainder the substrate. The ratio of the depth of the reformed region (distance between the other surface of the substrate and the reformed region) to the thickness of the substrate is in a range of between 1/8 and 9/11.

Claims

1. A light emitting device that emits light, the device comprising:

a substrate having first and second surfaces facing in opposite directions, and a reformed region intermediate the surfaces; and

a light emitting structure, comprising a source of the light emitted by the light emitting device, disposed on one of the surfaces of the substrate,

wherein the index of refraction of the reformed region of the substrate is different from that of the remainder of the substrate, and the ratio d/t of the distance d between the other of the surfaces of the substrate and the reformed region to the thickness t of the substrate between the first and second surfaces is in a range of between 1/8 and 9/11.

2. The light emitting device of claim 1, wherein the thickness t of the substrate is in a range of between 80 and 110 μ

M.

3. The light emitting device of claim 1, wherein the distance d is in a range of between 10 and 90 μ

m.

4. The light emitting device of claim 1, wherein the reformed region comprises dots of polycrystalline and the remainder of the substrate is mono-crystalline.

5. The light emitting device of claim 4, wherein the dots of polycrystalline are spaced from one another by a distance of 2 to 12 μ

m in a direction perpendicular to the direction of thickness t of the substrate.

6. The light emitting device of claim 4, wherein the dots of polycrystalline are substantially ellipsoid, and the diameter of each of the dots of polycrystalline, as taken along the major axis thereof, is in a range of 2 to 20 μ

m.

7. The light emitting device of claim 1, wherein index of refraction of the reformed region is greater than or equal to the index of refraction of air and less than the index of refraction of the remainder of the substrate.

8. The light emitting device of claim 1, further comprising first and second electrodes, and wherein the light emitting structure includes a first conductive pattern having a conductivity type, a second conductive pattern having a conductivity type opposite that of the first conductive pattern, and a light emitting pattern interposed between the first and second conductive patterns, and the first and second electrodes are electrically coupled to the first and second conductive patterns, respectively.

9. A light emitting device comprising:

a substrate having first and second surfaces facing in opposite directions, and wherein a layer of the substrate intermediate the first and second surfaces comprises dots of polycrystalline and the remainder of the substrate is mono-crystalline; and

a light emitting structure, comprising a source of the light emitted by the light emitting device, disposed on one of the surfaces of the substrate, and

wherein the distance d between the other of the surfaces of the substrate and the layer of polycrystalline dots is in a range of 10 to 90 μ

m, and

the dots of polycrystalline are spaced from one another in the layer by a distance of 2 to 12 μ

m in a direction perpendicular to the direction of thickness t of the substrate.

10. The light emitting device of claim 9, wherein the ratio d/t of the distance d between the other of the surfaces of the substrate and the layer of polycrystalline dots to the thickness t of the substrate between the first and second surfaces is in a range of between 1/8 and 9/11.