Carbon Nano tube wires to replace Copper wires
Could carbon nano tube wires could replace copper wires which is used as inter connectors in chips?Earlier about 7years before the question was not this could copper wire can replace aluminum interconnectors and it happened aluminium interconnectors were replaced by more conducting copper wires.But the fast moving world demands more and more compact chips with a lot more functions.By 2012 its expected that we require less than 40 nano meter wide interconnectors to make this chips.But at that size the resistance of copper wire is high that it could slow down the signaling.
Last month in the Material Research Society’s spring meeting in San Francisco, a team of scientists from Stanford and Toshiba claimed that they have used carbon nanotubes to make the logic components of silicon CMOS chip.The data transfer rate was about 1GHz close to the range of common microprocessors which comes to about 2 or 3 GHz.Nanotubes can have a current density of 1000 times that of aluminium and silver conductors.
Professor H.S. Philip Wong and his team of Stanford electrical engineering department fabricated 19 ordinary ring oscillator circuit leaving one wire to complete the circuit and they made that connection using the carbon nanotube wires.Surprisingly of the 19 oscillators 16 worked around a frequency of 800mHz and one with a maximum of 1.02GHz.
Though it is made, experts says there are many barriers for its bulk production.The main problem is with the arrangement of nanotubes itself.And today’s manufacturing units have nanotubes with different sizes and different properties and it would result in different speeds in signal transfer.
So there isn’t a perfect method which exist now to arrange nanotubes, the one method we know is electrophoresis by which the nanotubes are attracted to the desired spot to make the circuit but this method in not reliable,Wong and his team tried it on 256 oscillators of which only 19 made success.
Not a single nanotube wire could give much conducting property, a bundle of wire is required to do this so it becomes more complicated to arrange this wire.So it would be herculean task to arrange these wires horizontally on a well stacked integrated chips.So researches were going on to grow nanotube wires at the desired location and temperature.Lot a more to go, to make the world even more compact than we see now.