Nitride Semiconductor Light Emitting Element and Method for Producing Nitride Semiconductor Light Emitting Element

• US 20090294784A1
• Filed: 11/07/2006
• Published: 12/03/2009
• Est. Priority Date: 11/08/2005
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Yamaguchi, Atsushi, Nakahara, Ken
• Granted Patent: US 8,004,006 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

Provided are a nitride semiconductor light emitting element which does not suffer a damage on a light emitting region and has a high luminance without deterioration, even though the nitride semiconductor light emitting element is one in which electrodes are disposed opposite to each other and an isolation trench for chip separation and laser lift-off is formed by etching; and a manufacturing method thereof. An n-type nitride semiconductor layer 2 has a step, formed in a position beyond an active layer 3 when viewed from a p side. Up to the position of this step A, a protective insulating film 6 covers a part of the n-type nitride semiconductor layer 2, the active layer 3, a p-type nitride semiconductor layer 4, the side of a p electrode 5 and a part of the top side of the p electrode 5. The use of a structure having a chip side face covered with the protective insulating film 6 prevents the active layer or the like from being exposed to an etching gas for a long time when an isolation trench for chip separation or laser lift-off is formed by etching.

Claims

1. A nitride semiconductor light emitting element including at least an n side electrode, an n-type nitride semiconductor layer, a light emitting region, a p-type nitride semiconductor layer and a p side electrode in listed order, characterized by comprising a step provided between the light emitting element and the n side electrode, and

a first protective insulating film formed in a laminated direction from the p side electrode to the position of the step.

2. The nitride semiconductor light emitting element according to claim 1, characterized in that

the first protective insulating film has a smaller refractive index than the n-type nitride semiconductor layer and the p-type nitride semiconductor layer.

3. The nitride semiconductor light emitting element according to claim 2, characterized in that

a second protective insulating film is formed outside the first protective insulating film, the second protective insulating film having a smaller refractive index than that of the first protective insulating film.

6. The nitride semiconductor light emitting element according to claim 1, characterized in that

a second protective insulating film is formed outside the first protective insulating film, the second protective insulating film having a smaller refractive index than that of the first protective insulating film.

4. A method for producing a nitride semiconductor light emitting element including at least an n-type nitride semiconductor layer, a light emitting region and a p-type nitride semiconductor layer, in listed order, on a substrate for growth, and the method is for forming an isolation trench for separating the semiconductor layers by etching from the p-type nitride semiconductor layer until the isolation trench reaches the substrate for growth, characterized by comprising:

performing etching up to a position beyond the light emitting region to form a first isolation trench;

stopping the etching thereafter;

forming a first protective insulating film in a laminated direction to the depth of the first isolation trench; and

extending further the first isolation trench by etching to form a second isolation trench reaching the substrate for growth.

5. The method for producing a nitride semiconductor light emitting element according to claim 4, characterized by comprising:

joining a supporting substrate to the top face of the grown layers so that the supporting substrate is opposite to the substrate for growth, after forming the second isolation trench; and

then

splitting the substrate for growth.