The unique properties of thin layers of graphite known as graphene make the material attractive for a wide range of potential electronic devices. Researchers have now experimentally demonstrated the potential for another graphene application: replacing copper for interconnects in future generations of integrated circuits.
In a paper published in the June 2009 issue of the IEEE journal Electron Device Letters, researchers at the Georgia Institute of Technology report detailed analysis of resistivity in graphene nanoribbon interconnects as narrow as 18 nanometers.
The results suggest that graphene could out-perform copper for use as on-chip interconnects tiny wires that are used to connect transistors and other devices on integrated circuits. Use of graphene for these interconnects could help extend the long run of performance improvements for silicon-based integrated circuit technology.
"As you make copper interconnects narrower and narrower, the resistivity increases as the true nanoscale properties of the material become apparent," said Raghunath Murali, a research engineer in Georgia Tech's Microelectronics Research Center. "Our experimental demonstration of graphene nanowire interconnects on the scale of 20 nanometers shows that their performance is comparable to even the most optimistic projections for copper interconnects at that scale. Under real-world conditions, our graphene interconnects probably already out-perform copper at this size scale."
Beyond resistivity improvement, graphene interconnects would offer higher electron mobility, better thermal conductivity, higher mechanical strength and reduced capacitance coupling between adjacent wires.
"Resistivity is normally independent of the dimension a property inherent to the material," Murali noted. "But as you get into the nanometer-scale domain, the grain sizes of the copper become important and conductance is affected by scattering at th
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Georgia Institute of Technology Research News