Method of fabricating vertical devices using a metal support film

• US 20060097277A1
• Filed: 12/20/2005
• Published: 05/11/2006
• Est. Priority Date: 04/09/2002
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yoo, Myung Cheol
• Granted Patent: US 8,022,386 B2
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements
• 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
• CPC Class Codes: H01L 33/641 characterized by the materials
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

A method of fabricating semiconductor devices, such as GaN LEDs, on insulating substrates, such as sapphire. Semiconductor layers are produced on the insulating substrate using normal techniques. Trenches that define the boundaries of the individual devices are formed through the semiconductor layers and into the insulating substrate, beneficially by inductive coupled plasma reactive ion etching. A first support structure is attached to the semiconductor layers. The hard substrate is then removed, beneficially by laser lift off. A second supporting structure, preferably conductive, is substituted for the hard substrate and the first supporting structure is removed. Individual devices are then diced, beneficially by etching through the second supporting structure. A protective photo-resist layer can protect the semiconductor layers from the attachment of the first support structure. A conductive bottom contact (possibly reflective) can be inserted between the second supporting structure and the semiconductor layers.

Claims

1-9. -9. (canceled)

10. A vertical topology light emitting device, comprising:

a light emitting device having an upper electrical contact over the conductive adhesion layer and an epitaxial buffer layer;

a conductive adhesion structure having a first side adjacent the epitaxial buffer layer and a second side; and

a conductive thick film formed on the second side;

wherein electrical current can flow between the conductive thick film and the upper electrical contact.

11. A vertical topology light emitting device according to claim 10, wherein the epitaxial buffer layer comprises an epitaxial GaN layer.

12. A vertical topology light emitting device according to claim 11, further including an n-GaN layer on the buffer layer, an active layer on the n-GaN layer, a p-GaN layer on the active layer, and wherein the upper electrical contact includes at least a p-type contact on the p-GaN layer.

13. A vertical topology light emitting device according to claim 12, wherein the active layer includes AlInGaN.

14. A vertical topology light emitting device according to claim 13, wherein the active layer includes a quantum well.

15. A vertical topology light emitting device according to claim 12, wherein the upper electrical contact further comprising a p-transparent contact disposed between the p-type contact and the p-GaN layer.

16. A vertical topology light emitting device according to claim 11, further including a reflective structure disposed between the epitaxial buffer layer and the conductive adhesion structure.

17. The vertical topology light emitting device according to claim 16, wherein the reflective contact structure includes a titanium layer.

18. The vertical topology light emitting device according to claim 17, wherein the reflective contact structure further includes an aluminum layer.

19. The vertical topology light emitting device according to claim 10, wherein the conductive adhesion structure includes a Cr adhesion layer.

20. The vertical topology light emitting device according to claim 19, wherein the conductive adhesion structure further an Au adhesion layer.

21. The vertical topology light emitting device according to claim 10, wherein the thick film support is less than 100 microns thick.

22. The vertical topology light emitting device according to claim 21, wherein the thick film support includes Cu or Al.

23-61. -61. (canceled)