Process for fabrication of nitride semiconductor light emitting device

• US 8,173,461 B2
• Filed: 09/25/2006
• Issued: 05/08/2012
• Est. Priority Date: 09/26/2005
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation), Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Showa Denko KK
• Inventors: Urashima, Yasuhito
• Primary Examiner(s): Such, Matthew W
• Assistant Examiner(s): Naraghi, Ali
• Application Number:
  US12/088,076
• Publication Number:
  US 20090170224A1
• Time in Patent Office: 2,052 Days
• Field of Search: 438/463, 438/68, 438 42- 43, 438666-668, 438/707, 438/713, 257/E21.578, 257 79-103
• US Class Current: 438/43
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• 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

The present invention relates to a process for fabrication of a nitride semiconductor light emitting device comprising a substrate, a nitride semiconductor layer on the substrate and electrodes on the nitride semiconductor, the process for fabrication of a nitride semiconductor light emitting device being characterized by device working by laser, followed by etching treatment and then electrode formation.

Claims

1. A process for fabrication of a nitride semiconductor light emitting device comprising a substrate, a nitride semiconductor layer having an upper surface on the substrate and electrodes on the nitride semiconductor, the process for fabrication of a nitride semiconductor light emitting device being characterized by device working by laser, wherein the device working by laser accomplishes formation of grooves in the semiconductor layer of the light emitting device and/or segmenting grooves in the semiconductor layer around the perimeter of the device for isolation into individual light emitting devices followed by forming an inclined surface that is a reverse taper with respect to the upper surface of the nitride semiconductor layer at the laser worked site by etching treatment and then electrode formation.

2. A process for fabrication of a nitride semiconductor light emitting device according to claim 1, characterized in that the laser has a higher energy than the band gap energy of at least a portion of the nitride semiconductor layer.

3. A process for fabrication of a nitride semiconductor light emitting device according to claim 1, characterized in that the etching treatment is wet etching.

4. A process for fabrication of a nitride semiconductor light emitting device according to claim 3, characterized in that the wet etching is wet etching employing orthophosphoric acid.

5. A process for fabrication of a nitride semiconductor light emitting device according to claim 1, characterized in that the etching treatment is dry etching.

6. A process for fabrication of a nitride semiconductor light emitting device according to claim 5, characterized in that the dry etching is dry etching employing a chlorine-based gas.

7. A process for fabrication of a nitride semiconductor light emitting device according to claim 1, characterized in that alignment of laser device working by dry etching is carried out before the laser device working.

8. A process for fabrication of a nitride semiconductor light emitting device according to claim 1, characterized in that at least a portion of the surface of the nitride semiconductor layer after etching is subjected to non-mirror surface treatment.

9. A process for fabrication of a nitride semiconductor light emitting device according to claim 1, characterized in that at least a portion of the electrode formed on the nitride semiconductor after etching treatment is in contact with the inclined surface.