Metallurgical challenges in microelectronic 3D IC packaging technology for future consumer electronic products

Metallurgical challenges in controlling the microstructural stability of Cu and solder microbumps in 3D IC packaging technology are discussed. Using uni-directional 〈111〉 oriented nanotwinned Cu, the controlled growth of oriented Cu66n5 on the nanotwinned Cu and its transformation to Cu3Sn without Kirkendall voids have been achieved. In order to join a stack of Si chips into a 3D device, multiple reflows of solder microbumps may be required; we consider localized heating to do so by the use of self-sustained explosive reaction in multi-layered Al/Ni thin films of nano thickness. It avoids re-melting of those solder joints which have been formed already in the 3D stacking structure.

[1]  Amit Misra,et al.  Thermal stability of sputtered Cu films with nanoscale growth twins , 2008 .

[2]  Haiyan Wang,et al.  Epitaxial nanotwinned Cu films with high strength and high conductivity , 2008 .

[3]  M. Kunz,et al.  Preferred orientation of 30 μm fine pitch Sn2.5Ag micro-bumps studied by synchrotron polychromatic x-ray Laue microdiffraction , 2012, 2012 IEEE 62nd Electronic Components and Technology Conference.

[4]  C.H. Chang,et al.  High density 3D integration using CMOS foundry technologies for 28 nm node and beyond , 2010, 2010 International Electron Devices Meeting.

[5]  Robert K. Henderson,et al.  A 3×3, 5µm pitch, 3-transistor single photon avalanche diode array with integrated 11V bias generation in 90nm CMOS technology , 2010, 2010 International Electron Devices Meeting.

[6]  Jerrold A. Floro,et al.  Propagation of explosive crystallization in thin Rh–Si multilayer films , 1986 .

[7]  Carl V. Thompson,et al.  Self‐propagating explosive reactions in Al/Ni multilayer thin films , 1990 .

[8]  K. Tu,et al.  Kinetics in Nanoscale Materials , 2014 .

[9]  R. Sekerka,et al.  Stability of a Planar Interface During Solidification of a Dilute Binary Alloy , 1964 .

[10]  C. Thompson,et al.  Explosive silicidation in nickel/amorphous‐silicon multilayer thin films , 1990 .

[11]  C. Zhan,et al.  Development of 30 μm pitch Cu/Ni/SnAg micro-bump-bonded chip-on-chip (COC) interconnects , 2010, Impact.

[12]  Lei Lu,et al.  Ultrahigh Strength and High Electrical Conductivity in Copper , 2004, Science.

[13]  K. N. Tu,et al.  Reliability challenges in 3D IC packaging technology , 2011, Microelectron. Reliab..

[14]  D. Kwong,et al.  Study of 15µm pitch solder microbumps for 3D IC integration , 2009, 2009 59th Electronic Components and Technology Conference.

[15]  Xiaoxu Huang,et al.  Revealing the Maximum Strength in Nanotwinned Copper , 2009, Science.

[16]  Timothy P. Weihs,et al.  Effect of intermixing on self-propagating exothermic reactions in Al/Ni nanolaminate foils , 2000 .

[17]  H. J. Yang,et al.  Morphologies, orientation relationships and evolution of Cu6Sn5 grains formed between molten Sn and Cu single crystals , 2008 .

[18]  Kazuaki Ano,et al.  Kirkendall void formation in eutectic SnPb solder joints on bare Cu and its effect on joint reliability , 2005 .

[19]  Omar M. Knio,et al.  Investigating the effect of applied pressure on reactive multilayer foil joining , 2004 .

[20]  Chih Chen,et al.  Transition from flip chip solder joint to 3D IC microbump: Its effect on microstructure anisotropy , 2013, Microelectron. Reliab..

[21]  Han-wen Lin,et al.  Unidirectional Growth of Microbumps on (111)-Oriented and Nanotwinned Copper , 2012, Science.

[22]  King-Ning Tu,et al.  Dramatic morphological change of scallop-type Cu6Sn5 formed on (001) single crystal copper in reaction between molten SnPb solder and Cu , 2007 .

[23]  C. Thompson,et al.  Quantitative investigation of titanium/amorphous-silicon multilayer thin film reactions , 1990 .

[24]  C. Wickersham,et al.  Explosive crystallization in zirconium/silicon multilayers , 1988 .

[25]  K. Tu,et al.  Solder joints fabricated by explosively reacting nanolayers , 2008 .