Epitaxial formation support structures and associated methods

• US 10,636,942 B2
• Filed: 05/23/2018
• Issued: 04/28/2020
• Est. Priority Date: 12/07/2009
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Sheen, Calvin Wade
• Primary Examiner(s): Smith, Zandra V
• Assistant Examiner(s): Parker, John M
• Application Number:
  US15/987,293
• Publication Number:
  US 20180269356A1
• Time in Patent Office: 706 Days
• CPC Class Codes: B28B 1/16 for producing layered articles coating B28B11/04
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 29/2003 Nitride compounds
• 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 33/32 containing nitrogen
• CPC Class Codes: H01L 33/48 characterised by the semiconductor body packages

Abstract

Epitaxial formation support structures and associated methods of manufacturing epitaxial formation support structures and solid state lighting devices are disclosed herein. In several embodiments, a method of manufacturing an epitaxial formation support substrate can include forming an uncured support substrate that has a first side, a second side opposite the first side, and coefficient of thermal expansion substantially similar to N-type gallium nitride. The method can further include positioning the first side of the uncured support substrate on a first surface of a first reference plate and positioning a second surface of a second reference plate on the second side to form a stack. The first and second surfaces can include uniformly flat portions. The method can also include firing the stack to sinter the uncured support substrate. At least side of the support substrate can form a planar surface that is substantially uniformly flat.

Claims

1. A method of manufacturing a solid state lighting (SSL) device, the method comprising:

providing an uncured support substrate having a coefficient of thermal expansion (CTE) substantially similar to a CTE of N-type gallium nitride (GaN);

sintering the uncured support substrate to produce a cured support substrate having a sintered planar surface that is at least substantially uniformly flat;

bonding a formation structure directly to the sintered planar surface; and

forming an SSL structure over the formation structure.

2. The method of claim 1 wherein the SSL structure includes at least a first semiconductor material, and wherein forming the SSL structure over the formation structure includes epitaxially growing the first semiconductor material directly on the formation structure.

3. The method of claim 1 wherein forming the SSL structure includes epitaxially growing (a) a first semiconductor material on the formation structure, (b) an active region on the first semiconductor material, and (c) a second semiconductor material on the active region, wherein the first semiconductor material contains N-type gallium nitride (GaN), the second semiconductor material contains P-type GaN, and the active region includes at least one of a bulk indium gallium nitride (InGaN), an InGaN single quantum well, and/or Gan/InGaN multiple quantum wells.

4. The method of claim 1, further comprising, prior to bonding the formation structure directly to the sintered planar surface, doping the formation structure with an exfoliation agent to form a bonding region, wherein the exfoliation agent includes hydrogen, boron, helium or a combination thereof.

5. The method of claim 1, further comprising, after forming the SSL structure over the formation structure, removing the support substrate from the SSL device.

6. The method of claim 1, further comprising, after bonding the formation structure directly to the sintered planar surface and prior to forming the SSL structure over the formation structure, removing a portion of the formation structure via chemical mechanical polishing or etching.

7. The method of claim 1 wherein the substantially uniformly flat surface limits warp from the cured support substrate to the SSL structure to less than 25 micrometers.

8. The method of claim 1 wherein the uncured support substrate includes a polycrystalline ceramic, and wherein the formation structure includes an Si (1,1,1) portion.

9. The method of claim 1 wherein the uncured support substrate comprises at least one of Si₃N₄, TiN, ZrN, HfN, AlN, SiO₂, Al₂O₃, AlON, TiC, ZrC, HfC, SiC, and Y₂O₃.

10. The method of claim 1, further comprising, prior to bonding the formation structure directly to the sintered planar surface, machining the planar surface to increase the flatness of the planar surface, wherein machining is limited to a single machine process.

11. The method of claim 10 wherein machining comprises at least one of polishing, grinding or lapping.

12. A method of manufacturing a solid state lighting (SSL) device, comprising:

firing a support substrate having a coefficient of thermal expansion (CTE) substantially similar to a CTE of N-type gallium nitride (GaN), wherein a side of the fired support substrate includes a planar surface that is at least substantially uniformly flat;

attaching a formation structure to the planar surface to form a template structure, the formation structure having a CTE different from the CTE of the support substrate, and the template structure having a CTE substantially similar to the CTE of the support substrate; and

epitaxially growing an SSL structure directly on the formation structure, wherein the SSL structure includes a first semiconductor material, a second semiconductor material, and an active region between the first and second semiconductor materials.

13. The method of claim 12 wherein attaching the formation structure to the planar surface includes directly bonding the formation structure to the planar surface.

14. The method of claim 12 wherein the uniformly flat surface substantially eliminates warp from the support substrate to the SSL structure to less than 25 micrometers.

15. The method of claim 12, further comprising reducing a thickness of the formation structure after the formation structure is attached to the support substrate, wherein a remaining thickness of the formation structure is such that the CTE of the template structure is more influenced by the CTE of the support substrate.

16. The method of claim 15 wherein reducing a thickness further comprises:

implanting a dopant after the formation structure; and

exfoliating the dopant.

17. The method of claim 12 wherein attaching the formation structure includes bonding an Si(1,1,1) wafer directly to the planar surface.