Fabrication of High Performance Chip-to-Substrate Interconnections

Electroless plating;Assembly;Fabrication;Chip-to-substrate;Interconnect;Copper pillar

He, Ate ; Chemical Engineering

University:Georgia Institute of Technology

Department:Chemical Engineering

关键词: Electroless plating;    Assembly;    Fabrication;    Chip-to-substrate;    Interconnect;    Copper pillar;   

Others  :  https://smartech.gatech.edu/bitstream/1853/14483/1/He_Ate_200705_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

Novel fabrication technologies for high performance electrical and optical chip-to-substrate input/output (I/O) interconnections were developed. This research is driven by the long term performance and integration requirements of high performance chip-to-substrate I/Os, as well as the package reliability demands from semiconductor manufacturing. An electroless copper plating and annealing process was developed to join copper structures to achieve chip-to-substrate assembly by all copper pillar interconnects. The developed copper pillar interconnects provide much higher current carrying capability for chip-to-substrate power/ground input/output distributions and have low electrical parasitic characteristics for high frequency electrical signal communications. This copper bonding process also demonstrates the capability to compensate for misalignments and height variations of bonded structures. A finite element generalized plane deformationmodel was employed to design fully compliant copper pillars to eliminate the need of underfill. Electrical parasitics of copper pillar chip-to-substrate interconnects were studied by the derived formulas for low parasitic requirements. An optimized dimension space for all the criteria was provided on the pillar dimension chart. A novel nanoimprint lithography was developed to combine with photolithography in one process to create high quality features on a macrostructure for chip-to-substrate optical I/O applications. This fabrication process also demonstrated the capability to produce off-angle complex structures.