III-nitride light emitting devices fabricated by substrate removal

• US 20040077114A1
• Filed: 07/29/2003
• Published: 04/22/2004
• Est. Priority Date: 02/05/1999
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds Lighting US LLC (Apollo Global Management, Inc.)
• Inventors: Krames, Michael R., Martin, Paul S., Kish, Fred A. Jr., Coman, Carrie Carter
• Granted Patent: US 6,800,500 B2
• Time in Patent Office: Days
• US Class Current: 438/46
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01S 5/0216 using an intermediate compound, e.g. a glue or solder
• CPC Class Codes: H01S 5/0421 characterised by the semiconducting contacting layers electrodes H01S5/0425
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

A III-nitride light-emitting structure including a p-type layer, an n-type layer, and a light emitting layer is grown on a growth substrate. The III-nitride light-emitting structure is wafer bonded to a host substrate, then the growth substrate is removed. In some embodiments, a first electrical contact and first bonding layer are formed on the III-nitride light-emitting structure. A second bonding layer is formed on the host substrate. In such embodiments, wafer bonding the III-nitride light emitting structure to the host substrate comprises bonding the first bonding layer to the second bonding layer. After the growth substrate is removed, a second electrical contact may be formed on a side of the III-nitride light-emitting device exposed by removal of the growth substrate.

Claims

1. A method of making a light-emitting device, the method comprising:

growing a III-nitride light-emitting structure on a growth substrate, the III-nitride light-emitting structure including a p-type layer, an n-type layer, and a light-emitting layer;

wafer bonding the III-nitride light-emitting structure to a host substrate; and

after wafer bonding the III-nitride light-emitting structure to a host substrate, removing the growth substrate.

2. The method of claim 1 further comprising:

forming a first electrical contact on a side of the III-nitride light-emitting structure opposite the growth substrate;

prior to removing the growth substrate, forming a first bonding layer on the first electrical contact; and

forming a second bonding layer on the host substrate;

wherein wafer bonding the III-nitride light-emitting structure to a host substrate comprises wafer bonding the first bonding layer to the second bonding layer.

3. The method of claim 2 wherein at least one of the first bonding layer and second bonding layer is formed by a technique selected from a group including electron-beam evaporation, sputtering, and electroplating.

4. The method of claim 2 wherein the first bonding layer is selected from a group including silver, nickel, aluminum, gold, and cobalt.

5. The method of claim 2 further comprising:

after removing the growth substrate, forming a second electrical contact on a side of the III-nitride light-emitting structure exposed by removal of the growth substrate.

6. The method of claim 5 wherein the first electrical contact is electrically connected to the p-type layer and the second electrical contact is electrically connected to the n-type layer.

7. The method of claim 2 wherein the first electrical contact comprises silver.

8. The method of claim 2 further comprising:

forming a first substrate electrical contact on a first side of the host substrate; and

forming a second substrate electrical contact on a second side of the host substrate opposite the first side;

wherein the second bonding layer is deposited on the first substrate electrical contact.

9. The method of claim 1 further comprising:

etching mesas through the III-nitride light-emitting structure, the mesas defining individual light-emitting devices; and

singulating the host substrate to form individual light-emitting devices.

10. The method of claim 9 wherein the mesas are etched after removing the growth substrate.

11. The method of claim 1 wherein the host substrate is selected from a group including metals and semiconductors.

12. The method of claim 1 wherein the host substrate is selected from a group including silicon, germanium, glass, copper, and gallium arsenide.

13. The method of claim 1 wherein removing the growth substrate comprises removing the growth substrate by a technique selected from a group including laser melting, mechanical polishing, and etching of a sacrificial layer grown on the substrate prior to growing the III-nitride light-emitting structure.

14. The method of claim 1 further comprising:

forming a first dielectric Bragg reflector mirror and a first electrical contact on a side of the III-nitride light-emitting structure opposite the growth substrate;

after removing the growth substrate, forming a second dielectric Bragg reflector mirror on a side of the III-nitride light-emitting structure exposed by removal of the growth substrate.

15. The method of claim 14 further comprising:

etching away a portion of the second dielectric Bragg reflector mirror to expose a portion of the III-nitride light-emitting structure;

forming a second electrical contact on the portion of the III-nitride light-emitting structure exposed by etching away a portion of the second dielectric Bragg reflector mirror.