Light-emitting element

• US 8,546,836 B2
• Filed: 06/10/2011
• Issued: 10/01/2013
• Est. Priority Date: 08/27/2010
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Kamiya, Masao, Boyama, Shinya, Ushida, Yasuhisa
• Primary Examiner(s): Payen, Marvin
• Application Number:
  US13/067,588
• Publication Number:
  US 20120049236A1
• Time in Patent Office: 844 Days
• Field of Search: 257/99, 257/E33.063
• US Class Current: 257/99
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

A light-emitting element includes a semiconductor laminated structure including a nitride semiconductor, and formed by laminating a first semiconductor layer of a first conductivity type, a light-emitting layer and a second semiconductor layer of a second conductivity type different from the first conductivity type, the first semiconductor layer being exposed by removing a part of the second semiconductor layer and the light-emitting layer, a concave portion formed in the exposed portion of the first semiconductor layer, a first electrode formed on the concave portion and being in ohmic contact with the first semiconductor layer, and a second electrode being in ohmic contact with the second semiconductor layer and formed surrounding the first electrode.

Claims

1. A light-emitting element, comprising:

a semiconductor laminated structure comprising a nitride semiconductor, and formed by laminating a first semiconductor layer of a first conductivity type, a light-emitting layer and a second semiconductor layer of a second conductivity type different from the first conductivity type, the first semiconductor layer being exposed by removing a part of the second semiconductor layer and the light-emitting layer;

a concave portion formed in the exposed portion of the first semiconductor layer,

a first electrode formed on the concave portion and being in ohmic contact with the first semiconductor layer; and

a second electrode being in ohmic contact with the second semiconductor layer and formed surrounding the first electrode,

wherein a plurality of the first electrodes are included and each is shaped like a spot in plan view,

wherein a plurality of the concave portions are included, and

wherein the plurality of the first electrodes are each formed per single one of the plurality of the concave portions.

2. The light-emitting element according to claim 1, wherein the concave portion comprises an inclined surface inclined with respect to a depth direction of the semiconductor laminated structure in plan view.

3. The light-emitting element according to claim 1, wherein the first semiconductor layer comprises an n-type semiconductor layer and the second semiconductor layer comprises a p-type semiconductor layer, and

wherein the first electrode is an n-side electrode and the second electrode is a p-side electrode.

4. The light-emitting element according to claim 3, wherein the p-side electrode comprises an oxide semiconductor.

5. The light-emitting element according to claim 4, wherein the p-side electrode comprises a p-side contact electrode formed on the p-type semiconductor layer, and a p-side upper electrode formed on the p-side contact electrode.

6. The light-emitting element according to claim 5, wherein the p-side upper electrode and the n-side electrode comprise a same material.

7. The light-emitting element according to claim 6, wherein the p-side upper electrode and the n-side electrode comprise a lower part contacting the n-type semiconductor layer or the p-side contact electrode and comprising Ni or Cr, and an upper part formed on the lower part and comprising Au.