Synthesis of Carbon nanotubes for the interconnect application

1
Synthesis of Carbon nanotubes for the
interconnect application

• Alfonso R. Cecco and Jing Kong
• MARCO Interconnect Focus Center  Workshop _at_ MIT
• March 23, 2005

2
Outline

• Circuit model for nanotube interconnect and
  implications
• Investigation on the synthesis of single-walled
  carbon nanotubes
• Summary

3
Advantages

• Ultra small, perfect crystalline
• High current density 109A/cm2 vs 106A/cm2
• Mechanical stability

F. Kreupl et.al, IEDM proceedings, 2004, B.Q.Wei
et.al, App. Phys. Lett 2001
4
Circuit Model Resistance
F. Kreupl et.al, IEDM proceedings, 2004
5
Resistance including scattering
I

• for l gt mean free path of phonons
• for VltVc, ?ap1.6?m
• for VgtVc, ?op200nm,
• ?zo30nm

Rhigh
Rlow
VC
V
J.Y. Park et.al, Nano Lett., 4, pp517(2004)
6
Resistance Exp. Verification
J.Y. Park et.al, Nano Lett., 4, pp517(2004)
7
Circuit Model Capacitances

• Electrostatic capacitance
  10 to 30 aF/?m
• Quantum capacitance
  400aF/?m
• Electrostatic capacitance dominate

8
Circuit Model Inductances

• Magnetic inductance
  0.2pH/?m
• Kinetic inductance kinetic energy stored in
  current-gt
• 4nH/?m
• Lk 104 Lm !

A. Naeemi et.al, IEDM proceedings, 2004
9
Circuit Model Inductances

• Magnetic inductance
  0.2pH/?m
• Kinetic inductance kinetic energy stored in
  current-gt
• 4nH/?m
• Lk 104 Lm !

A. Naeemi et.al, IEDM proceedings, 2004
10
Effective circuit model for a SWNT

• Wave propagation speed in a single SWNT

11
Single layer vs. bundle
A. Naeemi et.al, IEEE Electron Device Letters,
vol 26, pp84 (2005)
12
Synthesis of SWNT bundles

• Bulk growth
• Controlled surface growth
• Planar
• Vertical

13
H2O-assisted synthesis of SWNT bundles
K. Hata et.al, Science 306, pp1362 (2004)
14
CVD setup
Hydrometer
Ar
H2
600-800C
C2H4
15
Preliminary results
16
Nanotubes from isolated nanoparticles
4X2?m

• Identify nanotube from individual particle

17
Summary

• For the interconnect application it is desirable
  to synthesize bundles of SWNTs in a controlled
  manner
• The assistance of H2O on the growth of bundles of
  SWNTs
• Identifying nanotubes from individual
  nanoparticles