Compliant bonding structures for semiconductor devices

• US 8,053,905 B2
• Filed: 10/05/2010
• Issued: 11/08/2011
• Est. Priority Date: 03/04/2009
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Neff, James G., Krames, Michael R., Epler, John E., Schiaffino, Stefano
• Primary Examiner(s): Dang; Trung Q
• Application Number:
  US12/897,866
• Publication Number:
  US 20110114987A1
• Time in Patent Office: 399 Days
• Field of Search: 257/778, 257/780, 257/782, 257/E23.003, 438/108
• US Class Current: 257/778
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/1403 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light emitting device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region, a metal p-contact disposed on the p-type region, and a metal n-contact disposed on the n-type region. The metal p-contact and the metal n-contact are both formed on the same side of the semiconductor structure. The light emitting device is connected to a mount by a bonding structure. The bonding structure includes a plurality of metal regions separated by gaps and a metal structure disposed between the light emitting device and the mount proximate to an edge of the light emitting device. The metal structure is configured such that during bonding, the metal structure forms a continuous seal between the light emitting device and the mount.

Claims

1. A structure comprising:

a light emitting device comprising;

a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;

a metal p-contact disposed on the p-type region; and

a metal n-contact disposed on the n-type region;

wherein the metal p-contact and the metal n-contact are both formed on a same side of the semiconductor structure;

a mount; and

a bonding structure disposed between the light emitting device and the mount, the bonding structure comprising;

a plurality of metal regions separated by gaps; and

a metal structure disposed between the light emitting device and the mount proximate to an edge of the light emitting device, wherein the metal structure is configured such that during bonding, the metal structure forms a continuous seal between the light emitting device and the mount.

2. The structure of claim 1 wherein the metal regions comprise gold bumps compressed by bonding the light emitting device to the mount.

3. The structure of claim 1 wherein the metal regions comprise a metal with a Young'"'"'s modulus less than 150 GPa.

4. The structure of claim 1 wherein a portion of the bonding structure underlying the metal n-contact is separated from a portion of the bonding structure underlying the metal p-contact by less than 40 microns.

5. The structure of claim 1 wherein the metal n-contact comprises a center portion and an arm portion, wherein the arm portion extends from the center portion toward an edge of the light emitting device, wherein a portion of the bonding structure underlies the center portion and no portion of the bonding structure underlies the arm portion.

6. The structure of claim 5 further comprising a gap disposed between the mount and the arm portion.

7. The structure of claim 5 wherein the metal n-contact is formed in a trench formed in the semiconductor structure, wherein a top surface of the metal n-contact is recessed relative to a top surface of the metal p-contact.

8. The structure of claim 7 further comprising a dielectric layer disposed between a portion of the metal p-contact and a portion of the metal n-contact, wherein a portion of a top surface of the dielectric layer extends above the top surfaces of the metal n-contact and the metal p-contact.

9. The structure of claim 8 further comprising a portion of the bonding structure disposed between the mount and the portion of the top surface of the dielectric layer extending above the top surfaces of the metal n-contact and the metal p-contact.

10. The structure of claim 1 wherein no bonding structure is formed in an area underlying the metal p-contact, wherein the area with no bonding structure is aligned with a metal trace formed on the mount.

11. The structure of claim 1 wherein the metal structure comprises a continuous, linear metal bump disposed between the light emitting device and the mount proximate to an edge of the light emitting device, wherein the continuous, linear metal bump forms a seal between the light emitting device and the mount.

12. The structure of claim 1 wherein the metal structure comprises a continuous, curved metal bump disposed between the light emitting device and the mount proximate to an edge of the light emitting device, wherein the continuous, curved metal bump forms a seal between the light emitting device and the mount.

13. The structure of claim 1 wherein the metal structure comprises at least two lines of offset metal bumps disposed between the light emitting device and the mount proximate to an edge of the light emitting device, wherein the at least two lines of metal bumps collapse during bonding to form a continuous seal between the light emitting device and the mount.

14. A method of bonding a light emitting device to a mount, the light emitting device comprising a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region, a metal p-contact disposed on the p-type region, and a metal n-contact disposed on the n-type region, wherein the metal p-contact and the metal n-contact are both formed on a same side of the semiconductor structure, the method comprising:

positioning a bonding structure between the light emitting device and the mount, the bonding structure comprising;

a first metal structure disposed between the mount and one of the metal p-contact and the metal p-contact; and

a second metal structure disposed between the light emitting device and the mount proximate to an edge of the light emitting device; and

causing the first and second metal structures to collapse;

wherein the second metal structure forms a continuous seal between the light emitting device and the mount.

15. The method of claim 14 wherein the first metal structure comprises a plurality of metal regions separated by gaps.

16. The method of claim 14 wherein the first metal structure comprises a porous metal.

17. The method of claim 14 wherein the second metal structure comprises a continuous, linear metal bump.

18. The method of claim 14 wherein the second metal structure comprises a continuous, curved metal bump.

19. The method of claim 14 wherein the second metal structure comprises at least two lines of offset metal bumps.