RE: carbon nanotubes ppt
CARBON NANOTUBES.ppt (Size: 640 KB / Downloads: 161)
As the process technology scales into the nanoscale regime, the impact of onchip communication on performance and reliability continues to increase.
As the interconnect performance depends on both wire and driver transistor characteristics, alternative interconnect and device technologies must be investigated for onchip communication in future integrated circuits.
Increasing resistivity, rising demands on current density and problems due to electromigration of copper interconnects at nanoscale regime, are driving the need for CNT’s as interconnects.
Interconnects in Integrated Circuit distribute Clock and other signals and provide power/ground to the various integrated circuits.
The interconnect in an integrated circuit becoming the dominant factor in determining system performance and power dissipation.
Interconnects are three types:
Local Interconnects Connecting gates and transistors with in a functional block.
Intermediate Interconnects are provides clock and signal distribution with in a functional block.
Global interconnects provides clock and signal distribution between the functional blocks and deliver power/ground to all functions.
Disadvantages of Using Cu Interconnects:
The traditional copper interconnects will suffer from significant increase in resistivity and from electromigration problems due to lower current densities supported by the copper conductor.
The increase in resistivity leads to increase in propagation delay of the signal.
The standard copper (Cu) interconnect will become a major hurdle for onchip communication due to high resistivity and electromigration.
Researches have proved that in copper, burn out occurred at current densities 80 MA/cm2.
Properties of CNTs
Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively. Tensile strength of 63 gigapascals (GPa).
Nanotubes are very good thermal conductors, Low resistivity (~1 μΩ-cm), High current carrying capacity.
The temperature stability of carbon nanotubes is estimated to be up to 2800 °C in vacuum and about 750 °C in air.
Due to nanoscale dimensions, electrons propagate only along the tube's axis. Hence, carbon nanotubes are One-Dimensional.
CNT’s have large current density(10^10A/cm2).
which is 1000 times more than copper.