Semiconductor light emitting device having angled side surface

• US 7,038,245 B2
• Filed: 03/13/2003
• Issued: 05/02/2006
• Est. Priority Date: 03/14/2002
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Akaike, Yasuhiko, Konno, Kuniaki, Kondo, Katsufumi, Nitta, Koichi, Nakamura, Takafumi, Endo, Yoshiki
• Primary Examiner(s): MAI, ANH D
• Application Number:
  US10/388,376
• Publication Number:
  US 20030197191A1
• Time in Patent Office: 1,146 Days
• Field of Search: 438/29, 438 31- 35, 438/460, 438/462, 257 94- 95, 257/98, 257/103, 257/615, 257/620, 257627-628, 257/79, 257/88
• US Class Current: 257/95
• CPC Class Codes: H01L 2224/32245 the item being metallic
• 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 2224/73265 Layer and wire connectors
• 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 2924/10155 being other than a cuboid
• CPC Class Codes: H01L 2924/10158 at the passive surface
• 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 33/38 with a particular shape

Abstract

For the purpose of enhancing the light extracting efficiency, improving the production yield and elongating the lifetime of a semiconductor light emitting element or a semiconductor light emitting device using the element, a semiconductor light emitting element comprises: a light emitting layer that emits light; and a substrate transparent to the light emitted from the light emitting layer. The substrate defines a top surface supporting the light emitting layer thereon; a bottom surface opposed to the top surface and side surfaces connecting the top surface and the bottom surface. Each of the side surfaces is composed of first side surface extending from the top surface toward the bottom surface, second side surface extending from the first side surface toward the bottom surface, and third side surface extending from the second side surface toward the bottom surface. The third side surfaces incline to diverge toward the top surface, and the second side surfaces incline to diverge more toward the top surface to extract part of the light from the light emitting layer externally. The first side surfaces are formed by cleavage along cleavable planes.

Claims

1. A semiconductor light emitting element comprising:

a light emitting layer for emitting light; and

a substrate transparent to the light emitted from the light emitting layer, and having;

a top surface on which the light emitting layer is formed;

a bottom surface opposed to the top surface; and

side surfaces connecting the top surface and the bottom surface,

wherein each of the side surfaces is composed of a first side surface extending from the top surface toward the bottom surface, a second side surface extending from the first side surface toward the bottom surface, and a third side surface extending from the second side surface toward the bottom surface,

wherein the third side surface inclines to diverge toward the top surface, and the second side surface inclines to diverge more toward the top surface to extract part of the light from the light emitting layer externally,

wherein;

the substrate is made of GaP,

the substrate is an off-axis (100) GaP substrate and the off-axis angle of the substrate is equal to or larger than 5° and

equal to or smaller than 30°

,

the first side surfaces are cleavable planes, and

the second side surfaces have a plurality of depressions and protrusions having a height equal to or higher than 1 μ

m and equal to or lower than 2 μ

m.

2. A semiconductor light emitting element according to claim 1 wherein the light emitting layer includes InGaAlP layer.

3. A semiconductor light emitting element according to claim 1 wherein the angle of inclination of the second side surfaces relative to the direction vertical to the top surface is equal to or larger than 20°

and equal to or smaller than 40°

.

4. A semiconductor light emitting element according to claim 1 wherein the third side surfaces have a plurality of depressions and protrusions having a height equal to or higher than 1 μ

m and equal to or lower than 2 μ

m.