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1998
Conference Paper
Titel
Interchip via technology-three dimensional metallization for vertically integrated circuits
Abstract
Mainstream planar technology is marked by physical and technological limitations, which have a severe impact on system characteristics. The performance, multifunctionality and reliability of microelectronic systems is mainly limited by the wiring between the ICs and subsystems. The on-chip wiring also leads to a critical performance bottleneck for future IC generations which can be solved only temporarily by the introduction of additional metallization layers and innovative materials (copper, low- epsilon dielectrics). 3D IC fabrication creates a basis to overcome these drawbacks and to pave the way for system approaches of an entirely new quality. We realized a three dimensional metallization for vertically integrated circuits (VIC) using a newly developed technology that allows stacking and vertical interchip wiring of completely processed and electrically tested wafers using available microelectronic processes. Wafers are stacked by an aligned bonding process. Vertical electrical co nnections are formed between the uppermost metal levels of the bonded wafers by fabrication and metal refill of high aspect ratio interchip vias. This interchip via (ICV) concept allows the formation of multiple wafer stacks using CMOS compatible materials and process steps exclusively and avoids wafer back processes. The potential of the ICV technology is the realization of some 100000 vertical interconnects per cm2 with 1-4 mu m2 interchip vias, arbitrarily selectable.