Enhanced adhesive materials and processes for 3d applications

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 a 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 to said wafers.

A method 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 bon wherein said terminal end of said key is in contact with said metal contact in said lock.

A method of making a polymer composite adhesive suitable to bond metal interconnects in a microelectronic article comprising:

• synthesizing a plurality of carbon nanotubes (CNTs) using a chemical vapor deposition (CVD) method;
• blending a loading level of said plurality of CNTs ranging from about 30% by volume to about 80% by volume, into a polymer base resin, said polymer base resin being compatible with copper and having high thermal conductivity and a temperature stability of at least 350° C.;
• applying an adhesion promoting compound to said blend to facilitate a polymer fill and bond to said plurality of CNTs;
• wherein, in order achieve an optimum level of bond strength and thermal conductivity, a loading level of said plurality of CNTs in said polymer base resin ranges from about 30% by volume to about 80% by volume.

A method of forming a 4D integration circuit system comprising the steps of:

• coating an upper surface of at least four wafers with a layer of CNT/polymer composite;
• bonding said wafers to form a stack comprising said wafers and said CNT/polymer composite, said stack having an edge;
• flipping said stack to rest upright on said edge;
• attaching a chip to said edge;
• said CNT/polymer base composite being compatible with a metal contact pad and having high thermal conductivity and a temperature stability of at least 350° C., said polymer selected from the group consisting of polyimides, polybenzazole, polybenzoxazoles, polyimidazoles, polybenzimidazoles, polyarylenes, polyarylene ethers, polyetheretherketones, polyarylether ketones and polynorbornenes and being in admixture with
• a plurality of carbon nanotubes (CNT), wherein, in order achieve an optimum level of bond strength an 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, said admixture containing or in contact with between about 0.1% and 1% of an adhesion promoting coupling agent is selected from the group consisting of (3-aminopropyl)triethoxysilane, p-aminophenyltrimethoxysilane, 3-[2-(2-aminoethylamnio)ethylamino]propyl-trimethoxysilane, 4-Ti[2-propanolato-tris(3,6-diaza)]hexanolato, 3-methacryloxy-propyl-trimethoxysilane, vinyl 1-trimethoxysilane, 3-isocyanate-propyl-triethoxysilane, mercapto-propyltrimethoxysilane, 3-amino-propyl-triethoxysilane and 3-methacryloxy-propyl-trimethoxysilane.