Bonded intermediate substrate and method of making same

• US 8,101,498 B2
• Filed: 04/21/2006
• Issued: 01/24/2012
• Est. Priority Date: 04/21/2005
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Aonex Technologies Inc. (AmberWave Systems Corporation)
• Inventors: Pinnington, Thomas Henry, Zahler, James M., Park, Young-Bae, Tsai, Charles, Ladous, Corinne, Atwater, Harry A. Jr., Olson, Sean
• Primary Examiner(s): CAO, PHAT X
• Application Number:
  US11/408,239
• Publication Number:
  US 20060255341A1
• Time in Patent Office: 2,104 Days
• Field of Search: 438/455, 438/458, 438/459, 257/617
• US Class Current: 438/455
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 21/2007 Bonding of semiconductor wafers to insulating substrates or to semiconducting substrates using an intermediate insulating layer H01L21/2011 takes precedence; bonding of semiconductor wafers to semiconductor wafers for junction formation H01L21/187
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials

Abstract

An intermediate substrate includes a handle substrate bonded to a thin layer suitable for epitaxial growth of a compound semiconductor layer, such as a III-nitride semiconductor layer. The handle substrate may be a metal or metal alloy substrate, such as a molybdenum or molybdenum alloy substrate, while the thin layer may be a sapphire layer. A method of making the intermediate substrate includes forming a weak interface in the source substrate, bonding the source substrate to the handle substrate, and exfoliating the thin layer from the source substrate such that the thin layer remains bonded to the handle substrate.

Claims

1. A method of making a substrate, comprising:

providing a sintered polycrystalline material handle substrate comprising a diffusion barrier layer which prevents diffusion of a sintering material out of the sintered polycrystalline material of the handle substrate, wherein the diffusion barrier layer of silicon nitride or amorphous silicon carbide substantially encapsulates a top surface and a side surface of the handle substrate;

transferring a thin single crystal layer of a first material which is suitable for epitaxial growth of a single crystal III-nitride semiconductor layer onto the handle substrate having a CTE which is closely CTE matched to a CTE of the III-nitride semiconductor layer;

epitaxially growing a thick single crystal III-nitride semiconductor layer on the thin single crystal layer of the first material; and

removing the handle substrate.

2. The method of claim 1, further comprising removing the thin single crystal layer of the first material such that the thick single crystal III-nitride semiconductor layer forms a free-standing single crystal III-nitride substrate having a thickness of greater than 100 microns.

3. The method of claim 1, wherein the transferring a thin single crystal layer comprises:

forming a weak interface in a GaN source substrate by implanting ions into an N-terminated surface of the GaN source substrate;

bonding the N-terminated surface of the GaN source substrate to the handle substrate; and

exfoliating a thin GaN single crystal layer from the source substrate such that the thin GaN exfoliated single crystal layer remains bonded to the handle substrate and a Ga-terminated surface of the thin GaN single crystal layer is exposed.

4. The method of claim 1, wherein the handle substrate comprises polycrystalline aluminum nitride.

5. The method of claim 1, wherein the thin single crystal layer comprises a single crystal GaN, SiC, or Si(111) layer.

6. The method of claim 1, wherein the handle substrate comprises polycrystalline aluminum nitride and the sintering material comprises yttria.

7. The method of claim 1, wherein the handle substrate comprises polycrystalline aluminum nitride and wherein the diffusion barrier layer comprises a layer of silicon nitride or amorphous silicon carbide located between the polycrystalline aluminum nitride and the thin single crystal layer of a first material.

8. The method of claim 1, wherein the handle substrate further comprises a bonding layer such that the diffusion barrier layer is located between the bonding layer and the sintered polycrystalline material.

9. The method of claim 1, wherein during the step of epitaxially growing a thick single crystal III-nitride semiconductor layer on the thin single crystal layer of the first material, the diffusion barrier covers all exposed surfaces of the handle substrate.

10. A method of making a substrate, comprising:

providing a sintered polycrystalline material handle substrate comprising a diffusion barrier layer of silicon nitride, silicon oxi-nitride, aluminum nitride, aluminum oxi-nitride, alumina or silicon carbide substantially encapsulates a bonding surface of the handle substrate and a side surface or a bottom surface of the handle substrate which prevents diffusion of a sintering material out of the sintered polycrystalline material of the handle substrate;

transferring a thin single crystal layer of a first material which is suitable for epitaxial growth of a single crystal III-nitride semiconductor layer onto the handle substrate having a CTE which is closely CTE matched to a CTE of the III-nitride semiconductor layer;

epitaxially growing a thick single crystal III-nitride semiconductor layer on the thin single crystal layer of the first material; and

removing the handle substrate,

wherein, prior to the step of transferring the single crystal layer, the handle substrate further comprises a bonding layer such that the diffusion barrier layer is located between the bonding layer and the sintered polycrystalline material.

11. The method of claim 10, wherein:

the step of transferring the single crystal layer comprises;

forming a weak interface in a source substrate;

contacting the source substrate to the handle substrate;

bonding the source substrate to the handle substrate; and

exfoliating the thin single crystal layer from the source substrate such that the thin exfoliated single crystal layer remains bonded to the handle substrate;

wherein, prior to contacting the source substrate to the handle substrate, the handle substrate comprises a bonding layer such that the diffusion barrier layer is located between the bonding layer and the sintered polycrystalline material.

12. A method of making a substrate, comprising:

providing a sintered polycrystalline material handle substrate comprising a diffusion barrier layer of silicon nitride, amorphous silicon carbide, alumina, aluminum nitride, or titanium nitride substantially encapsulating a top surface and at least a portion of a side surface or a bottom surface of the handle substrate which prevents diffusion of a sintering material out of the sintered polycrystalline material of the handle substrate;

transferring a thin single crystal layer of a first material which is suitable for epitaxial growth of a single crystal III-nitride semiconductor layer onto the handle substrate having a CTE which is closely CTE matched to a CTE of the III-nitride semiconductor layer;

epitaxially growing a thick single crystal III-nitride semiconductor layer on the thin single crystal layer of the first material; and

removing the handle substrate.

13. The method of making a substrate of claim 12, wherein the diffusion barrier layer substantially encapsulates the top surface, the side surface and the bottom surface of the handle substrate.