VLSIs are facing bottlenecks due to long signal delay and short electromigration lifetime of their interconnections. Graphene (Gr) is proposed due to its excellent electrical and thermal properties, and it can be patterned by conventional microelectronic processes.
Many challenges remain for a complete Gr multilayer interconnection: (1) High contact resistance between Gr and Si; (2) Process integration of multi-layer levels Gr interconnection; (3) Deposition temperature of Gr is higher than 1000oC, making it incompatible to the current IC fabrication processes.
We developed two patents for this technology. One is PVD process and amorphous carbon for low-temperature (850oC) Gr deposition on metal interconnects. Temperature can be further reduced. Another is a method to insert Gr into copper interconnects, and current interconnect technology can be used. The method is a simple additional step of immersing the interconnection with Gr on top in the copper sulphate solution for 10 minutes.

A low temperature graphene deposition on VLSI interconnections for backend process compatibility and a method of embed this graphene in VLSI interconnections so that standard mature interconnection processes can be applied.  Electrical and thermal conductions will be via the embedded graphene which are excellent as compared to any metals, and electromigration reliability of such interconnect is also proven to be at least three time higher in lifetime as compare to copper.

This technology can be used for all interconnects in both integrated circuits and printed circuit boards. The cost of this technology is low because it only requires an immersion tank of copper sulphate solution.  Our technology uses a PVD process based on amorphous carbon, so graphene (Gr) deposition on interconnects can also be low temperature and cost-effective.
With Gr alone on copper, the thermal and electrical properties are greatly improved, and its electromigration life is also increased by at least three times, as shown in our experimental results. The technology can also be applied to other metal interconnects. Good interconnections are essential to all electronic circuits, this technology can make an important contribution in the electronics industry.