Light-emitting device

• US 9,947,832 B2
• Filed: 03/17/2017
• Issued: 04/17/2018
• Est. Priority Date: 03/22/2016
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Yamakami, Yuya, Morita, Daisuke
• Primary Examiner(s): YUSHINA, GALINA G
• Application Number:
  US15/462,362
• Publication Number:
  US 20170279007A1
• Time in Patent Office: 396 Days
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light-emitting device includes a semiconductor layered structure; an upper electrode disposed on a portion of an upper surface of the semiconductor layered structure; a lower electrode disposed on a lower surface of the semiconductor layered structure in a region spaced from a region directly under the upper electrode, the lower electrode being reflective; and a protective film disposed continuously on a surface of the upper electrode and the upper surface of the semiconductor layered structure. A thickness of a first portion of the protective film, which is disposed at least in a region directly above the lower electrode, is smaller than a thickness of a second portion of the protective film, which is disposed continuously on the surface of the upper electrode and the upper surface of the semiconductor layered structure adjacent to the portion on which the upper electrode is disposed.

Claims

1. A light-emitting device comprising:

a semiconductor layered structure;

an upper electrode disposed on a portion of an upper surface of the semiconductor layered structure;

a lower electrode disposed on a lower surface of the semiconductor layered structure in a region spaced from a region directly under the upper electrode, the lower electrode being reflective; and

a protective film disposed continuously on a surface of the upper electrode and the upper surface of the semiconductor layered structure,

wherein (i) a thickness of a first portion of the protective film, which is disposed at least in a region directly above the lower electrode, is smaller than (ii) a thickness of a second portion of the protective film, which is disposed continuously on the surface of the upper electrode and the upper surface of the semiconductor layered structure adjacent to the portion on which the upper electrode is disposed.

2. The light-emitting device according to claim 1, wherein the first portion of the protective film is disposed only in the region directly above the lower electrode.

3. The light-emitting device according to claim 1, wherein a thickness of the first portion of the protective film is 40% or less of a thickness of the second portion of the protective film.

4. The light-emitting device according to claim 2, wherein a thickness of the first portion of the protective film is 40% or less of a thickness of the second portion of the protective film.

5. The light-emitting device according to claim 1, wherein an insulating member is disposed on the lower surface of the semiconductor layered structure in a region that includes the region directly under the upper electrode.

6. The light-emitting device according to claim 1, wherein

the upper electrode includes:

an external connecting portion configured to be connected with an external device, and

an extended portion extending from the external connecting portion,

the first portion of the protective film is disposed to be continuous on a surface of the extended portion and on the upper surface of the semiconductor layered structure adjacent to a portion on which the extended portion is disposed,

the second portion of the protective film is disposed continuously on the surface of the extended portion and on the upper surface of the semiconductor layered structure adjacent to the portion on which the upper electrode is disposed.

7. The light-emitting device according to claim 2, wherein

the upper electrode includes:

an external connecting portion configured to be connected with an external device, and

an extended portion extending from the external connecting portion,

the first portion of the protective film is disposed to be continuous on a surface of the extended portion and on the upper surface of the semiconductor layered structure adjacent to a portion on which the extended portion is disposed,

the second portion of the protective film is disposed continuously on the surface of the extended portion and on the upper surface of the semiconductor layered structure adjacent to the portion on which the upper electrode is disposed.

8. The light-emitting device according to claim 3, wherein

the upper electrode includes:

an external connecting portion configured to be connected with an external device, and

an extended portion extending from the external connecting portion,

the first portion of the protective film is disposed to be continuous on a surface of the extended portion and on the upper surface of the semiconductor layered structure adjacent to a portion on which the extended portion is disposed,

the second portion of the protective film is disposed continuously on the surface of the extended portion and on the upper surface of the semiconductor layered structure adjacent to the portion on which the upper electrode is disposed.

9. The light-emitting device according to claim 1, wherein

the upper electrode includes:

a first upper electrode disposed on the portion of the upper surface of the semiconductor layered structure, and

a second upper electrode disposed on the first upper electrode, and

an end portion of the protective film is located between the first upper electrode and the second upper electrode.

10. The light-emitting device according to claim 1, wherein the lower electrode is made of Ag or an alloy whose main component is Ag.

11. The light-emitting device according to claim 1, wherein, in a top view, a periphery of a region of the semiconductor layered structure on which the second portion of the protective film is disposed is spaced from a periphery of the upper electrode by a distance in a range of 15 pm to 30 pm.