Nitride-based semiconductor light emitting device and method for fabricating same

• US 7,595,514 B2
• Filed: 04/14/2008
• Issued: 09/29/2009
• Est. Priority Date: 07/19/2007
• Status: Expired due to Fees

• Current Assignee: Foxsemicon Integrated Technology Incorporated
• Original Assignee: Foxsemicon Integrated Technology Incorporated
• Inventors: Lai, Chih-Ming
• Primary Examiner(s): Tran, Thien F
• Application Number:
  US12/102,617
• Publication Number:
  US 20090020781A1
• Time in Patent Office: 533 Days
• Field of Search: 257/79, 257/99, 257/103, 257/E33.064, 257/E33.066
• US Class Current: 257/99
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• 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

An exemplary nitride-based semiconductor light emitting device includes a substrate, a nitride-based multi-layered structure epitaxially formed on the substrate, a first-type electrode and a second-type electrode. The multi-layered structure includes a first-type layer, an active layer, and a second-type layer. The multi-layered structure has a developed mesa structure which at least includes the second-type layer and the active layer and whereby the first-type layer is partially exposed to form an exposed portion. The mesa structure has a roughened top surface and a plurality of roughened side surfaces adjoining the top surface. A crystal growth orientation of the multi-layered structure intersects with <0001> crystal orientation thereof. The first-type electrode and the second-type electrode respectively come into ohmic contact with the first-type layer and the second-type layer.

Claims

1. A nitride-based semiconductor light emitting device, comprising:

a substrate;

a nitride-based multi-layered structure epitaxially formed on the substrate, the multi-layered structure including a first-type layer, an active layer and a second-type layer arranged along a direction away from the substrate in the order written, the second-type layer and the active layer cooperatively forming a developed mesa structure, the first-type layer having an exposed portion, the mesa structure having a top surface facing away from the substrate and a plurality of side surfaces adjoining the top surface, wherein a crystal growth orientation of the multi-layered structure intersects with <

0001>

crystal orientation thereof, and the top surface and the side surfaces are roughened surfaces;

a first-type electrode formed on the exposed portion and brought into ohmic contact with the first-type layer; and

a second-type electrode formed on the top surface and brought into ohmic contact with the second-type layer.

2. The nitride-based semiconductor light emitting device of claim 1, wherein the substrate is a single crystal plate, the single crystal plate has a crystal face on which the multi-layered structure is epitaxially formed, and the crystal growth orientation matches with a crystal orientation of the crystal face.

3. The nitride-based semiconductor light emitting device of claim 2, wherein the single crystal plate is made from a material selected from the group consisting of sapphire, silicon carbide, silicon, gallium arsenide, lithium aluminate, magnesium oxide, zinc oxide, gallium nitride, aluminum nitride and indium nitride.

4. The nitride-based semiconductor light emitting device of claim 1, wherein the first-type layer, the active layer and the second-type layer are made from group III-nitride compound materials.

5. The nitride-based semiconductor light emitting device of claim 1, wherein surface atoms of the multi-layered structure comprises metal atoms and nitrogen atoms.

6. The nitride-based semiconductor light emitting device of claim 1, wherein the crystal growth orientation of the multi-layered structure is substantially perpendicular to the <

0001>

crystal orientation.

7. The nitride-based semiconductor light emitting device of claim 1, wherein the roughened surfaces are formed using a wet etching process.

8. The nitride-based semiconductor light emitting device of claim 1, wherein the top surface and the side surfaces have a plurality of recesses formed thereon.