METHOD FOR PRODUCING GROUP III NITRIDE SEMICONDUCTOR LIGHT EMITTING ELEMENT

• US 20120244653A1
• Filed: 03/15/2012
• Published: 09/27/2012
• Est. Priority Date: 03/24/2011
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: TOTANI, Shingo, Deguchi, Masashi
• Granted Patent: US 8,673,677 B2
• Time in Patent Office: Days
• US Class Current: 438/29
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A reflective film including Ag of an Ag alloy is patterned in a uniform thickness without decreasing reflectivity. The reflective film is formed on the entire surface of a first insulating film by sputtering, vacuum deposition or the like, and a barrier metal film having a given pattern is formed on the reflective film by a lift-off method. The reflective film is wet etched using a silver etching liquid. The barrier metal film is not wet etched by the silver etching liquid, and therefore functions as a mask, and the reflective film in a region on which the barrier metal film has been formed remains not etched. As a result, the reflective film having a desired patter can uniformly be formed on the first insulating film.

Claims

1. A method for producing a group III nitride semiconductor light emitting element having a reflective film comprising Ag or an Ag alloy, comprising:

a first step of forming a reflective film;

a second step of patterning a barrier metal film comprising a material having resistance to wet etching on the reflective film;

a third step of wet etching the reflective film using the barrier metal film as a mask; and

a fourth step of forming an insulating film on the barrier metal film.

2. The method for producing a group III nitride semiconductor light emitting element according to claim 1, further comprising a step of conducting dry ashing after the third step and before the fourth step.

3. The method for producing a group III nitride semiconductor light emitting element according to claim 2, wherein the dry ashing is photo-excited ashing.

4. The method for producing a group III nitride semiconductor light emitting element according to claim 1, wherein the patterning of the barrier metal film in the second step is conducted by a lift-off method.

5. The method for producing a group III nitride semiconductor light emitting element according to claim 1, wherein the barrier metal film is Ti, Cr or a conductive oxide.

6. The method for producing a group III nitride semiconductor light emitting element according to claim 1, wherein the barrier metal film has a multilayer structure, and Ti or Cr constitutes an uppermost layer.

7. The method for producing a group III nitride semiconductor light emitting element according to claim 1, wherein the barrier metal film has a multilayer structure, and includes a layer comprising Al or a conductive oxide.

8. The method for producing a group III nitride semiconductor light emitting element according to claim 1, wherein the first step is a step of forming the reflective film on other insulating film.

9. The method for producing a group III nitride semiconductor light emitting element according to claim 1, wherein the reflective film is a p-electrode formed on a p-type layer.

10. The method for producing a group III nitride semiconductor light emitting element according to claim 1, wherein an edge face of the reflective film is the same position as or is inside an edge face of the barrier metal film.