Adhesive wafer bonding with sacrificial spacers for controlled thickness variation

• US 9,153,548 B2
• Filed: 09/16/2013
• Issued: 10/06/2015
• Est. Priority Date: 09/16/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: LuxVue Techonology Corporation (Apple Inc.)
• Inventors: Chan, Clayton Ka Tsun, Bibl, Andreas
• Primary Examiner(s): MONDT, JOHANNES P
• Application Number:
  US14/027,875
• Publication Number:
  US 20150076528A1
• Time in Patent Office: 750 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B81C 1/00873 characterised by special arrangements of the devices, allowing an easier separation
• CPC Class Codes: B81C 2201/0194 the layer being structured
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2221/68368 used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate
• CPC Class Codes: H01L 2224/034 by blanket deposition of the material of the bonding area
• CPC Class Codes: H01L 2224/0345 Physical vapour deposition [PVD], e.g. evaporation, or sputtering
• CPC Class Codes: H01L 2224/03848 Thermal treatments, e.g. annealing, controlled cooling
• CPC Class Codes: H01L 2224/04026 Bonding areas specifically adapted for layer connectors
• CPC Class Codes: H01L 2224/05016 in side view
• CPC Class Codes: H01L 2224/05023 the whole internal layer protruding from the surface
• CPC Class Codes: H01L 2224/05083 Three-layer arrangements
• CPC Class Codes: H01L 2224/05117 the principal constituent melting at a temperature of greater than or equal to 400°C and less than 950°C
• CPC Class Codes: H01L 2224/05139 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/05144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05155 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05166 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/0519 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/05562 On the entire exposed surface of the internal layer
• CPC Class Codes: H01L 2224/05564 Only on the bonding interface of the bonding area
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05638 : the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
• CPC Class Codes: H01L 2224/05644 : Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05669 : Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/05688 : Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: H01L 2224/06181 : On opposite sides of the body
• CPC Class Codes: H01L 2224/274 : by blanket deposition of the material of the layer connector
• CPC Class Codes: H01L 2224/2745 : Physical vapour deposition [PVD], e.g. evaporation, or sputtering
• CPC Class Codes: H01L 2224/29005 : Structure
• CPC Class Codes: H01L 2224/29007 : Layer connector smaller than the underlying bonding area
• CPC Class Codes: H01L 2224/291 : with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/29111 : Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/29113 : Bismuth [Bi] as principal constituent
• CPC Class Codes: H01L 2224/29139 : Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/29144 : Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/32145 : the bodies being stacked
• CPC Class Codes: H01L 2224/32227 : the layer connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/83 : using a layer connector
• CPC Class Codes: H01L 2224/83005 : being a temporary or sacrificial substrate
• CPC Class Codes: H01L 2224/83409 : Indium [In] as principal constituent
• CPC Class Codes: H01L 2224/83411 : Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/83444 : Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/83815 : Reflow soldering
• CPC Class Codes: H01L 2224/83825 : Solid-liquid interdiffusion
• CPC Class Codes: H01L 2224/8383 : Solid-solid interdiffusion
• CPC Class Codes: H01L 2224/9212 : Sequential connecting processes
• CPC Class Codes: H01L 2224/94 : at wafer-level, i.e. with connecting carried out on a wafer comprising a plurality of undiced individual devices
• CPC Class Codes: H01L 2224/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/00 : Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
• CPC Class Codes: H01L 24/03 : Manufacturing methods
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/06 : of a plurality of bonding areas
• CPC Class Codes: H01L 24/27 : Manufacturing methods
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/92 : Specific sequence of method steps
• CPC Class Codes: H01L 24/94 : at wafer-level, i.e. with connecting carried out on a wafer comprising a plurality of undiced individual devices
• CPC Class Codes: H01L 24/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 25/0753 : the devices being arranged next to each other
• CPC Class Codes: H01L 27/156 : two-dimensional arrays
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01004 : Beryllium [Be]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/0781 : being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/10329 : Gallium arsenide [GaAs]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/1421 : RF devices
• CPC Class Codes: H01L 2924/1431 : Logic devices
• CPC Class Codes: H01L 2924/1434 : Memory
• CPC Class Codes: H01L 33/0093 : Wafer bonding; Removal of the growth substrate

Abstract

A method and structure for forming an array of micro devices is disclosed. An array of micro devices is formed over an array of stabilization posts included in a stabilization layer. Patterned sacrificial spacers are formed between the stabilization posts and between the micro devices. The patterned sacrificial spacers are disposed upon the patterned sacrificial spacers.

Claims

1. A stabilization structure comprising:

a carrier substrate;

a stabilization layer on the carrier substrate, the stabilization layer including an array of stabilization posts;

a sacrificial layer on the stabilization layer;

an array of micro devices over the array of stabilization posts;

wherein the sacrificial layer includes patterned sacrificial spacers between the stabilization posts and between the micro devices; and

wherein the stabilization layer includes contiguous portions and non-contiguous portions directly between the sacrificial layer and the carrier substrate, and the non-contiguous portions correspond to locations where the patterned sacrificial spacers extend completely through the stabilization layer.

2. The stabilization structure of claim 1, wherein the sacrificial layer includes a fine sacrificial layer and a course sacrificial layer.

3. The stabilization structure of claim 2, wherein each stabilization post in the array of stabilization posts includes a stabilization post protrusion disposed above a stabilization post platform, wherein the stabilization post platform is disposed between the stabilization post protrusion and the carrier substrate, the stabilization post protrusion extends through the fine sacrificial layer, and wherein the stabilization post platform is wider than the stabilization post protrusion, and the stabilization post platform does not extend through the fine sacrificial layer.

4. The stabilization structure of claim 1, wherein the micro devices are micro LED devices.

5. The stabilization structure of claim 1, wherein each micro device in the array of micro devices includes a bottom surface that is wider than a corresponding stabilization post directly underneath the bottom surface.

6. The stabilization structure of claim 5, wherein the stabilization posts extend through a thickness of the patterned sacrificial spacers.

7. The stabilization structure of claim 1, wherein the patterned sacrificial spacers span along a side surface of at least a portion of the micro devices in the array of micro devices.

8. The stabilization structure of claim 1, further comprising an array of bottom conductive contacts on bottom surfaces of the array of micro devices.

9. The stabilization structure of claim 1, wherein the stabilization layer includes an array of stabilization cavities that include stabilization cavity sidewalls surrounding the stabilization posts.

10. The stabilization structure of claim 1, wherein the stabilization layer is formed of a thermoset material.

11. The stabilization structure of claim 1, wherein the stabilization layer also includes truncated stabilization posts in the contiguous portions of the stabilization layer that support additional micro devices, wherein the stabilization posts in the array are in non-contiguous portions of the stabilization layer.

12. The stabilization structure of claim 1, wherein the stabilization posts in the array of stabilization posts are separated by a pitch of 1 μ

m to 10 μ

m.

13. The stabilization structure of claim 2, wherein the course sacrificial layer is thicker than the fine sacrificial layer.

14. The stabilization structure of claim 13, wherein the fine sacrificial layer spans directly underneath every micro device of the array of micro devices.

15. The stabilization structure of claim 14, wherein the coarse sacrificial layer spans directly underneath a portion of the micro devices of the array of micro devices, the portion being less than every micro device.

16. The stabilization structure of claim 15, wherein the array of stabilization posts includes a first array of truncated stabilization posts with a first post height, and a second array of stabilization posts with a second post height greater than the first post height.

17. The stabilization structure of claim 16, wherein the first array of truncated stabilization posts is in the contiguous portions of the stabilization layer.

18. The stabilization structure of claim 16, wherein the first post height is approximately the same as a thickness of the fine sacrificial layer directly underneath the array of micro devices.

19. The stabilization structure of claim 16, wherein the second post height is approximately the same as a combined thickness of the fine sacrificial layer and the coarse sacrificial layer directly underneath the array of micro devices.