Semiconductor light emitting device and semiconductor light emitting apparatus

• US 7,462,869 B2
• Filed: 03/13/2007
• Issued: 12/09/2008
• Est. Priority Date: 05/17/2004
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Akaike, Yasuhiko, Sugiyama, Hitoshi, Sugawara, Yasuharu, Ohashi, Kenichi
• Primary Examiner(s): SEFER, AHMED N
• Application Number:
  US11/685,375
• Publication Number:
  US 20070145385A1
• Time in Patent Office: 637 Days
• Field of Search: 257/79, 257/95, 257 98- 99, 257/91, 257744-745
• US Class Current: 257/79
• 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 first semiconductor light emitting device includes: a transparent substrate; a light emitting layer; and a roughened region. The transparent substrate has a first major surface and a second major surface, and is translucent to light in a first wavelength band. The light emitting layer is selectively provided in a first portion on the first major surface of the transparent substrate and configured to emit light in the first wavelength band. The roughened region is provided in a second portion different from the first portion on the first major surface. A second semiconductor light emitting device includes: a transparent substrate; a light emitting layer; a first electrode; and at least one groove. The groove is provided on the second major surface of the transparent substrate and extends from a first side face to a second side face opposing the first side face of the transparent substrate.

Claims

1. A semiconductor light emitting device comprising:

a transparent substrate having a first major surface and a second major surface, and being translucent to light in a first wavelength band;

a light emitting layer selectively provided in a first portion on the first major surface of the transparent substrate and configured to emit light in the first wavelength band;

a first electrode provided on the light emitting layer; and

a roughened region provided in a second portion different from the first portion on the first major surface, wherein

the first portion includes a center portion on the first major surface and a periphery portion distantly surrounding the center portion, part of the periphery portion being connected to the center portion,

the second portion is a portion located between the center portion and the periphery portion,

the light emitting layer being not provided in the second portion, and

the first electrode is provided on both of the center portion and the periphery portion of the light emitting layer.

2. A semiconductor light emitting device according to claim 1, wherein irregularities constituting the roughened region have an average bottom length of 0.1to 3micrometers.

3. A semiconductor light emitting device according to claim 1, wherein irregularities constituting the roughened region have an average height of 0.05 to 1.5 micrometers.

4. A semiconductor light emitting device according to claim 1, wherein the first portion has an area of 0.6 to 0.9 times the area of the first major surface.

5. A semiconductor light emitting device according to claim 1, wherein

the transparent substrate is made of GaP, and

the light emitting layer is made of InGaAlP-based compound semiconductor.

6. A semiconductor light emitting device according to claim 1, wherein irregularities constituting the roughened region have an average bottom length of 0.5to 2 micrometers.

7. A semiconductor light emitting device according to claim 1, wherein a part of the first electrode which is provided on the center portion of the light emitting layer and a part of the first electrode which is provided on the periphery portion of the light emitting layer are connected via wiring.