Buried reflectors for light emitters in epitaxial material and method for producing same

• US 6,046,465 A
• Filed: 04/17/1998
• Issued: 04/04/2000
• Est. Priority Date: 04/17/1998
• Status: Expired due to Fees

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Kish, Frederick A. Jr., Coman, Carrie C., Chen, Yong, Wang, Shih-Yuan, Krames, Michael R., Corzine, Scott W., Kaneko, Yawara, Kern, R. Scott
• Primary Examiner(s): Utech, Benjamin
• Assistant Examiner(s): CHAMPAGNE, DONALD
• Application Number:
  US09/062,368
• Time in Patent Office: 718 Days
• Field of Search: 428/620, 257/13, 257/79, 257/84, 257/85, 257/94, 257/95, 257/98, 117/9, 117/54, 117/58, 117/84, 117/95, 117/104, 117/106, 117/108
• US Class Current: 257/98
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01S 2304/12 Pendeo epitaxial lateral overgrowth [ELOG], e.g. for growing GaN based blue laser diodes
• CPC Class Codes: H01S 5/0205 during growth of the semiconductor body
• CPC Class Codes: H01S 5/0213 Sapphire, quartz or diamond based substrates
• CPC Class Codes: H01S 5/04257 having positive and negative electrodes on the same side of the substrate
• CPC Class Codes: H01S 5/18305 with emission through the substrate, i.e. bottom emission
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18369 based on dielectric materials
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

A buried reflector 50 in an epitaxial lateral growth layer forms a part of a light emitting device and allows for the fabrication of a semiconductor material that is substantially low in dislocation density. The laterally grown material is low in dislocation defect density where it is grown over the buried reflector making it suitable for high quality optical light emitting devices, and the embedded reflector eliminates the need for developing an additional reflector.

Claims

1. A method for forming a low defect density material having a buried reflector in a material system, comprising the steps of:

applying a first material having a first refractive index over a substrate;

applying a second material having a second refractive index over said first material; and

growing an epitaxial lateral growth layer over said second material, said epitaxial lateral growth layer including an active region oriented substantially perpendicular to said substrate, said epitaxial lateral growth layer partially covering said second material.

2. The method as defined in claim 1, further including the steps of:

applying a first additional layer of said first material over said second layer; and

applying a second additional layer of said second material over said first additional layer.

3. A material system, comprising:

a substrate;

a reflective layer over said substrate; and

an epitaxial lateral growth layer extending over said reflective layer, said epitaxial lateral growth layer including an active region oriented substantially perpendicular to said substrate, said epitaxial lateral growth layer partially covering said reflective layer.

4. The system as defined in claim 3, wherein said reflective layer includes:

a layer of first material having a first refractive index; and

a layer of second material having a second refractive index.

5. The system as defined in claim 3, wherein said epitaxial lateral growth layer has a substantially lower defect rate where it covers said reflective layer than where it covers said substrate.

6. The system as defined in claim 3, wherein said reflective layer is a Bragg reflector.

7. The system as defined in claim 3, wherein said reflective layer is a dielectric material.

8. The system as defined in claim 3, wherein said reflective layer is a semi-conductor material.