Enhanced adhesive materials and processes for 3d applications

Patent metadata

Field	Value
Publication number	US-2017166784-A1
Application number	US-201514967353-A
Country	US
Kind code	A1
Filing date	Dec 13, 2015
Priority date	Dec 13, 2015
Publication date	Jun 15, 2017
Grant date	—

Abstract

The present invention relates to CNT filled polymer composite system possessing a high thermal conductivity and high temperature stability so that it is a highly thermally conductive for use in 3D and 4D integration for joining device sub-laminate layers. The CNT/polymer composite also has a CTE close to that of Si, enabling a reduced wafer structural warping during high temperature processing cycling. The composition is tailored to be suitable for coating, curing and patterning by means conventionally known in the art.

First claim

What we claim and desire to protect by Letters Patent is:

1 . A polymer based composite adhesive suitable for bonding metal interconnects in a microelectronic article comprising:
a polymer base resin, said polymer being compatible with a metal contact pad and having high thermal conductivity and a temperature stability of at least 350° C., in admixture with a plurality of carbon nanotubes (CNT), wherein, in order achieve an optimum level of bond strength and thermal conductivity, a loading level of said CNT in said polymer base resin ranges from about 30% by volume to about 80% by volume, a length scale of said CNTs being substantially equal to a final bonded adhesive layer thickness so as to maximize said CNT's straddling an adhesive bond line with said length scale of said CNT.

2 . The polymer based composite adhesive defined in claim 1 wherein said polymer base resin is selected from the group consisting of polyimides, polybenzazole, polybenzoxazoles, polyimidazoles, polybenzimidazoles, polyarylenes, polyarylene ethers, polyetheretherketones, polyarylether ketones and polynorbornenes.

3 . The polymer based composite adhesive defined in claim 2 which contains an adhesion promoting coupling agent.

4 . The polymer based composite adhesive defined in claim 3 wherein said metal contact pad is copper.

5 . The polymer composite adhesive defined in claim 2 comprises between about 0.1% and about 1.0% of said adhesion promoting coupling agent and is selected from the group consisting of (3-aminopropyl)triethoxysilane, aminophenyltrimethoxysilane, 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane, 4-Ti[2-propanolato-tris(3,6-diaza)]hexanolato, 3-methacryloxy-propyl-trimethoxysilane, Vinyl 1-trimethoxysilane, 3-Isocyanate-propyl-triexthoxysilane, Mercapto-propyl-trimethoxysilane, 3-Amino-propyl-triethoxysilane and 3-methacryloxy-propyl-trimethoxysilane.

6 . The polymer based adhesive defined in claim 5 wherein said polymers are insoluble and are applied with said CNTs as precursor materials or prepregs.

7 . The polymer based composite adhesive defined in claim 2 wherein the polybenzazoles are polybenzoxazoles (PBO) and polybenzimidazoles (PBI).

8 . The polymer based composite adhesive defined in claim 5 wherein said polymer based adhesive is used as a temporary adhesive and a permanent adhesive.

9 . A 3D integration circuit system comprising a plurality of stacked silicon wafer device layers which are vertically interconnected, each said wafer being provided with at least one through-silicon-via (TSV) forming metal to metal joints enabling communication between said wafer device layers, said wafers being bonded together using a filled polymer composite system adhesive in an interface area provided between adjacent wafers, said adhesive polymer composite system comprising:
a polymer base resin, said polymer being compatible with said metal joint and having high thermal conductivity and a temperature stability of at least 350° C., in admixture with a plurality of carbon nanotubes (CNT), wherein, in order achieve an optimum level of bond strength and thermal conductivity, a loading level of said CNT in said polymer ranges from about 30% by volume to about 80% by volume, a length scale of said CNTs is substantially equal to a final bonded adhesive layer thickness so as to maximize said CNT's straddling an adhesive bond line with said length of said CNT.

10 . The 3D integration circuit system defined in claim 9 wherein said polymer base resin is selected from the group consisting of polyimides, polybenzazole, polybenzoxazoles, polyimidazoles, polybenzimidazoles, polyarylenes, polyarylene ethers, polyetheretherketones, polyarylether ketones and polynorbornenes.

11 . The 3D integration circuit system defined in claim 10 which said adhesion polymer composite system contains between about 0.1% and about 1% of an adhesion promoting coupling agent, and said metal joint is copper.

12 . A method of forming a 3D integration circuit system comprising the steps of:
forming a top wafer and a bottom wafer into a stack by; bonding together said top wafer and said bottom wafer by means of a polymer composite adhesive provided between said top wafer and said bottom wafer, said polymer composite adhesive comprising a polymer base resin, said polymer being compatible with a metal contact pad and having high thermal conductivity and a temperature stability of at least 350° C., in admixture with a plurality of carbon nanotubes (CNT), wherein, in order achieve an optimum level of bond strength and thermal conductivity, a loading level of said CNT in said polymer ranges from about 30% by volume to about 80% by volume, a length scale of said CNTs is substantially equal to a final bonded adhesive layer thickness so as to maximize said CNT's straddling an adhesive bond line with said length of said CNT to form a bonding interface; etching a through silicon via (TSV) from said top wafer through said bonding interface to said bottom wafer after said top wafer and said bottom wafer are bonded to connect said wafers.

13 . A method of forming a 3D integration circuit system comprising the steps of:
Forming a top wafer and a bottom wafer into a stack by; affixing a conductive metal key to an underside of said top wafer; etching a trench in an upper surface of a bottom wafer; inserting a metal contact in said trench; coating an oxide insulation covering said metal contact and said upper surface of said bottom wafer; coating said an upper surface of said oxide insulation with a high temperature polymer composite fill; applying a lithographic pattern to an upper surface of said high temperature polymer composite fill and etching a trench through said high temperature polymer composite fill to said metal contact to form a lock; coating said underside of said top wafer and exposed portions of said key with said high temperature polymer composite; removing a portion of said high temperature polymer composite that encapsulates a terminal end of said key to expose said terminal end; inserting said key into said lock to form a lock and key bond wherein said terminal end of said key is in contact with said metal contact in said lock.

14 . The method of forming a 3D integration circuit system defined in claim 13 wherein said high temperature polymer fill is a polymer base resin, said polymer being compatible with a metal contact pad and having high thermal conductivity and a temperature stability of at least 350° C., in admixture with
a plurality of carbon nanotubes (CNT), wherein, in order achieve an optimum level of bond strength and thermal conductivity, a loading level of said CNT in said polymer base resin ranges from about 30% by volume to about 80% by volume, a length scale of said CNTs being substantially equal to a final bonded adhesive layer thickness so as to maximize said CNT's straddling an adhesive bond line with said length scale of said CNT.

15 . The method of forming a 3D integration circuit system defined in claim 12 wherein said polymer base resin is selected from the group consisting of polyimides, polybenzazole, polybenzoxazoles, polyimidazoles, polybenzimidazoles, polyarylenes, polyarylene ethers, polyetheretherketones, polyarylether ketones and polynorbornenes.

16 . The method of forming a 3D integration circuit system defined in claim 15 which contains from about 0.1% to about 1% of an adhesion promoting coupling agent and said contact pad is copper.

17 . A method of making a polymer composite adhesive suitable to bond metal interconnects in a

Assignees

• Hedrick James L
• Miller Robert Dennis
• Neumayer Deborah Ann
• Purushothaman Sampath
• Rothwell Mary E
• Volksen Willi
• Yu Roy R
• IBM

Inventors

• Hedrick James L
• Miller Robert Dennis
• Neumayer Deborah Ann
• Purushothaman Sampath
• Rothwell Mary E
• Volksen Willi
• Yu Roy R

Classifications

• H10W99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• H10W20/0245

  comprising use of blind vias during the manufacture · CPC title

• H10W20/0234

  comprising etching via holes that stop on pads or on electrodes · CPC title

• H10W72/0198

  batch processes · CPC title

• H10W74/15

  on active surfaces of flip-chip devices, e.g. underfills · CPC title