METHOD FOR MANUFACTURING SEMICONDUCTOR LIGHT EMITTING ELEMENT

• US 20110204412A1
• Filed: 10/23/2009
• Published: 08/25/2011
• Est. Priority Date: 10/27/2008
• Status: Abandoned Application

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Showa Denko KK
• Inventors: Sugano, Susumu
• Application Number:
  US13/126,136
• Publication Number:
  US 20110204412A1
• Time in Patent Office: Days
• US Class Current: 257/103
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

Provided is a method for manufacturing a semiconductor light emitting element, by which semiconductor light emitting elements having excellent light extraction efficiency can be manufactured at high yield. The method includes: a grinding step for grinding a surface to be ground (103) of a substrate (11) of a wafer having the substrate (11) and group III nitride semiconductor layers composed of a multilayer structure of a group III nitride semiconductor formed on the substrate (11); a polishing step for adjusting surface roughness (Ra) of the ground surface (103) of the substrate (11) ground by the grinding step to be 3 nm to 25 nm; a laser processing step for providing processed modified portions (41, 42) inside of the substrate (11) by applying a laser beam (L2) along a cut-planned line for dividing the substrate (11) from the side of the ground surface (103) of the substrate (11) having the surface roughness (Ra) adjusted by the polishing step; and a dividing step for dividing the substrate (11) provided with the processed modified portions (41, 42) by the laser processing step, along the processed modified portions (41, 42) and the cut-planned line.

Claims

1. A method for manufacturing a semiconductor light emitting element having group III nitride semiconductor layers, the method comprising:

a grinding step for grinding a surface to be ground of a substrate of a wafer having the substrate and the group III nitride semiconductor layers composed of a multilayer structure of a group III nitride semiconductor formed on the substrate;

a polishing step for adjusting surface roughness Ra of the ground surface of the substrate ground by the grinding step to be 3 nm to 25 nm;

a laser processing step for providing a processed modified portion for an inside of the substrate by applying a laser beam along a cut-planned line for dividing the substrate from the side of the ground surface of the substrate having the surface roughness Ra adjusted by the polishing step; and

a dividing step for dividing the substrate along the processed modified portion and the cut-planned line, the substrate being provided with the processed modified portion by the laser processing step.

2. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein the laser processing step provides a plurality of the processed modified portions discontinuously in a thickness direction of the substrate.

3. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein the laser processing step provides the processed modified portion in a range of two thirds of the inside of the substrate in a thickness direction from the side of the ground surface.

4. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein in the laser processing step the substrate is irradiated with a pulse of the laser beam.

5. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein in the dividing step the substrate is divided to turn a divided surface of the substrate into a rough surface.

6. The method for manufacturing a semiconductor light emitting element according to claim 1, further comprising a dividing-groove forming step for forming a dividing groove in the substrate by applying a laser beam along the cut-planned line from the side of the group III nitride semiconductor layers formed on the substrate.

7. The method for manufacturing a semiconductor light emitting element according to claim 1, further comprising a substrate processing step for forming a plurality of convex portions on a surface of the substrate in advance.

8. The method for manufacturing a semiconductor light emitting element according to claim 7, further comprising a buffer layer forming step for forming a buffer layer composed of a group III nitride semiconductor by sputtering on the surface of the substrate having the convex portions formed thereon.

9. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein the substrate is selected from any one of sapphire and silicon carbide.

10. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein the group III nitride semiconductor layers of the wafer are composed of a multilayer of an n-type semiconductor layer, a light emitting layer and a p-type semiconductor layer that each includes a group III nitride compound semiconductor.

11. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein the substrate has a maximum diameter of about 100 mm or more.

12. A semiconductor light emitting element manufactured by the method for manufacturing a semiconductor light emitting element according to claim 1.