Buffer layer for GaN-on-Si LED

• US 8,686,430 B2
• Filed: 09/07/2011
• Issued: 04/01/2014
• Est. Priority Date: 09/07/2011
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Toshiba Techno Center Inc. (Toshiba Corporation)
• Inventors: Chen, Zhen
• Primary Examiner(s): Such, Matthew W
• Assistant Examiner(s): Harrison, Monica D
• Application Number:
  US13/227,406
• Publication Number:
  US 20130056745A1
• Time in Patent Office: 937 Days
• Field of Search: 257/76, 257/E33.025, 257/E33.056
• US Class Current: 257/76
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0248 Tellurides
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29339 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• 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 33/12 with a stress relaxation structure, e.g. buffer layer

Abstract

A buffer layer of zinc telluride (ZnTe) or titanium dioxide (TiO₂) is formed directly on a silicon substrate. Optionally, a layer of AlN is then formed as a second layer of the buffer layer. A template layer of GaN is then formed over the buffer layer. An epitaxial LED structure for a GaN-based blue LED is formed over the template layer, thereby forming a first multilayer structure. A conductive carrier is then bonded to the first multilayer structure. The silicon substrate and the buffer layer are then removed, thereby forming a second multilayer structure. Electrodes are formed on the second multilayer structure, and the structure is singulated to form blue LED devices.

Claims

1. An apparatus, comprising:

a silicon substrate;

a buffer layer disposed directly on the silicon substrate and comprising an aluminum nitride (AlN) layer and a zinc telluride (ZnTe) layer formed between the silicon substrate and the AlN layer;

a gallium nitride (GaN) template layer disposed on the buffer layer; and

an epitaxial light emitting diode (LED) structure disposed on the GaN template layer, wherein the buffer layer is disposed between the silicon substrate and the epitaxial LED structure, wherein the epitaxial LED structure comprises an active layer disposed between a p-type layer and an n-type layer, and wherein the active layer comprises gallium and nitrogen.

2. The apparatus of claim 1, wherein the ZnTe layer is a single substantially homogenous layer of zinc telluride (ZnTe).

3. The apparatus of claim 1, wherein the buffer layer is less than one hundred nanometers thick.

4. The apparatus of claim 1, wherein the n-type layer of the epitaxial LED structure has a thickness of at least two thousand nanometers.

5. The apparatus of claim 1, wherein the ZnTe layer is directly disposed on the silicon substrate.

6. The apparatus of claim 1, wherein the buffer layer further comprises an aluminum gallium nitride layer disposed between the AlN layer and the GaN template layer.

7. The apparatus of claim 1, wherein the GaN template layer is an undoped GaN layer.

8. An apparatus, comprising:

a silicon substrate;

a buffer layer disposed directly on the silicon substrate and comprising an aluminum nitride (AlN) layer and a titanium dioxide (TiO₂) layer formed between the silicon substrate and the AlN layer;

a gallium nitride (GaN) template layer disposed on the buffer layer; and

an epitaxial light emitting diode (LED) structure disposed on the GaN template layer, wherein the buffer layer is disposed between the silicon substrate and the epitaxial LED structure, wherein the epitaxial LED structure comprises an active layer disposed between a p-type layer and an n-type layer, and wherein the active layer comprises gallium and nitrogen.

9. The apparatus of claim 8, wherein the TiO₂ layer is a single substantially homogenous layer of titanium dioxide (TiO₂).

10. The apparatus of claim 8, wherein the buffer layer is less than one hundred nanometers thick.

11. The apparatus of claim 8, wherein the TiO₂ layer is directly disposed on the silicon substrate.

12. The apparatus of claim 8, wherein the buffer layer further comprises an aluminum gallium nitride layer disposed between the AlN layer and the GaN template layer.

13. The apparatus of claim 8, wherein the GaN template layer is an undoped GaN layer.