BONDED INTERMEDIATE SUBSTRATE AND METHOD OF MAKING SAME

• US 20090278233A1
• Filed: 07/24/2008
• Published: 11/12/2009
• Est. Priority Date: 07/26/2007
• Status: Abandoned Application

• Current Assignee: AmberWave Systems Corporation
• Original Assignee: AmberWave Systems Corporation
• Inventors: PINNINGTON, Thomas Henry, Park, Young-Bae, Ladous, Corinne, Olson, Sean, Zahler, James M.
• Application Number:
  US12/178,838
• Publication Number:
  US 20090278233A1
• Time in Patent Office: Days
• US Class Current: 257/615
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• 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 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• 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 33/20 with a particular shape, e.g. curved or truncated substrate

Abstract

A method includes growing a first epitaxial layer of III-nitride material, forming a damaged region by implanting ions into an exposed surface of the first epitaxial layer, and growing a second epitaxial layer of III-nitride material on the exposed surface of the first epitaxial layer. A level of defects present in the second epitaxial layer is less than a level of defects present in the first epitaxial layer.

Claims

1. A method, comprising:

growing a first epitaxial layer of III-nitride material;

forming a damaged region by implanting ions into an exposed surface of the first epitaxial layer; and

;

growing a second epitaxial layer of III-nitride material on the exposed surface of the first epitaxial layer;

wherein a level of defects present in the second epitaxial layer is less than a level of defects present in the first epitaxial layer.

2. The method of claim 1, wherein at least one of the following steps is performed after the ion implantation step and prior to growing the second epitaxial layer:

removing a portion of the implanted region in the first epitaxial layer by an RIE or wet chemical process;

or

annealing the first epitaxial layer at a temperature between 700 C. and 1300 C. wherein an encapsulation layer covers a surface of the first epitaxial layer prior to the annealing step.

3. A method, comprising:

growing a first epitaxial layer of III-nitride material;

forming a weak interface near an exposed surface of the first epitaxial layer by ion implantation;

exfoliating a thin layer from the first epitaxial layer; and

growing a second epitaxial layer of III-nitride material on an exposed surface of the first epitaxial layer;

wherein a level of defects present in the second epitaxial layer is less than a level of defects present in the first epitaxial layer.

4. The method of claim 3, wherein at least one of the following steps is performed after the ion implantation step and prior to growing the second epitaxial layer:

removing a portion of the implanted region in the first epitaxial layer by an RIE or wet chemical process;

or

annealing the first epitaxial layer at a temperature between 700 C. and 1300 C. wherein an encapsulation layer covers a surface of the first epitaxial layer prior to the annealing step.

5. A method, comprising:

forming a weak interface in a single crystal III-nitride material by ion implantation;

exfoliating a III-nitride layer from the III-nitride material; and

growing a III-nitride epitaxial layer on an exposed surface of the III-nitride material;

wherein a level of threading dislocations present in the III-nitride epitaxial layer is at least two orders of magnitude less than a level of threading dislocations present in the single crystal III-nitride material.

6. A structure, comprising:

a highly defective, substantially single crystal semiconductor region comprising a defect structure comprising point defects, extended defects or both that induce oscillations in the strain field on length scales smaller than 100 nm; and

an epitaxial single crystal semiconductor layer formed on the substantially single crystal semiconductor region;

wherein;

the defect structure blocks a propagation of at least a majority of dislocations from the substantially single crystal semiconductor region into the epitaxial single crystal semiconductor layer; and

the epitaxial single crystal semiconductor layer contains a lower density of dislocations than the substantially single crystal semiconductor region.

7. The structure of claim 6, wherein the substantially single crystal semiconductor region comprises a III-nitride region and the epitaxial single crystal semiconductor layer comprises a III-nitride layer.

8. The structure of claim 6, wherein the defect structure is formed by ion implantation into the single crystal semiconductor region.

9. The structure of claim 6, wherein:

the defect structure blocks a propagation of at least a majority of threading dislocations from the substantially single crystal semiconductor region into the epitaxial single crystal semiconductor layer; and

the epitaxial single crystal semiconductor layer contains a lower density of threading dislocations than the substantially single crystal semiconductor region.

10. The structure of claim 6, wherein the defects comprise nanoscale density variations or voids that have characteristic length scales less than 100 nm.

11. The structure of claim 6, wherein the substantially single crystal semiconductor region is selected from a group consisting of:

i) a highly defective region in a bulk semiconductor substrate;

ii) a highly defective region in an epitaxial layer formed on a substrate;

or iii) an exfoliated layer bonded to a handle substrate.

12. A method, comprising:

forming a defect structure comprising point defects, extended defects or both that induce oscillations in the strain field on length scales smaller than 100 nm in a single crystal semiconductor region by ion implantation; and

epitaxially growing a single crystal semiconductor layer on the crystal semiconductor region containing the defect structure;

wherein;

the defect structure blocks a propagation of at least a majority of dislocations from the single crystal semiconductor region containing the defect structure into the single crystal semiconductor layer; and

the single crystal semiconductor layer contains a lower density of dislocations than the single crystal semiconductor region containing the defect structure.

13. The method of claim 12, wherein the single crystal semiconductor region comprises a III-nitride region and the single crystal semiconductor layer comprises a III-nitride layer.

14. The method of claim 12, wherein:

the defect structure blocks a propagation of at least a majority of threading dislocations; and

the single crystal semiconductor layer contains a lower density of threading dislocations than the single crystal semiconductor region containing the defect structure.

15. The method of claim 12, wherein the defects comprise nanoscale density variations or voids that have characteristic length scales less than 100 nm.

16. The method of claim 12, wherein the single crystal semiconductor region is selected from a group consisting of:

i) a bulk semiconductor substrate;

ii) an epitaxial layer formed on a substrate;

or iii) an exfoliated layer bonded to a handle substrate.

17. A method, comprising:

providing substantially single crystal or single crystal III-nitride semiconductor material;

forming a damaged region by implanting ions into an exposed surface of the semiconductor material; and

growing an epitaxial layer of III-nitride semiconductor material on the exposed surface of the semiconductor material;

wherein a level of defects present in the epitaxial layer is less than a level of defects present in the semiconductor material.

18. A method, comprising:

forming a weak interface in a single crystal III-nitride semiconductor material by ion implantation;

exfoliating a III-nitride layer from the III-nitride semiconductor material; and

growing an epitaxial III-nitride semiconductor layer on an exposed surface of the exfoliated III-nitride layer;

wherein the III-nitride epitaxial layer has a defect density below 2×

10⁴ cm<sup>−

2</sup>.

19. The method of claim 18, wherein the single crystal III-nitride material has a defect density above 2×

10⁴ cm<sup>−

2</sup>.

20. A structure, comprising:

a substrate; and

an epitaxial single crystal III-nitride semiconductor layer formed on the substrate, wherein III-nitride epitaxial layer has a defect density below 2×

10⁴ cm<sup>−

2</sup>.

21. The structure of claim 20, wherein:

the substrate comprises a substantially single crystal III-nitride semiconductor region having a defect density above 2×

10⁴ cm<sup>−

2</sup> and a defect structure comprising point defects, extended defects or both that induce oscillations in the strain field on length scales smaller than 100 nm; and

a level of threading dislocations present in the epitaxial single crystal III-nitride layer is at least two orders of magnitude less than a level of threading dislocations present in the single crystal III-nitride region.

22. The structure of claim 21, wherein the semiconductor region is selected from a group consisting of:

i) a highly defective region in a bulk semiconductor substrate;

ii) a highly defective region in an epitaxial layer formed on a substrate;

or iii) an exfoliated layer bonded to a handle substrate.