High-kappa dielectrics for advanced carbon-nanotube transistors and logic gates.
The integration of materials having a high dielectric constant (high-kappa) into carbon-nanotube transistors promises to push the performance limit for molecular electronics. Here, high-kappa (approximately 25) zirconium oxide thin-films (approximately 8 nm) are formed on top of individual single-walled carbon nanotubes by atomic-layer deposition and used as gate dielectrics for nanotube field-effect transistors. The p-type transistors exhibit subthreshold swings of S approximately 70 mV per decade, approaching the room-temperature theoretical limit for field-effect transistors. Key transistor performance parameters, transconductance and carrier mobility reach 6,000 S x m(-1) (12 microS per tube) and 3,000 cm2 x V(-1) x s(-1) respectively. N-type field-effect transistors obtained by annealing the devices in hydrogen exhibit S approximately 90 mV per decade. High voltage gains of up to 60 are obtained for complementary nanotube-based inverters. The atomic-layer deposition process affords gate insulators with high capacitance while being chemically benign to nanotubes, a key to the integration of advanced dielectrics into molecular electronics.
Javey
Ali
A
Department of Chemistry, Stanford University, California 94305, USA.
Kim
Hyoungsub
H
Brink
Markus
M
Wang
Qian
Q
Ural
Ant
A
Guo
Jing
J
McIntyre
Paul
P
McEuen
Paul
P
Lundstrom
Mark
M
Dai
Hongjie
H
D002244:Carbon; D004560:Electricity; D036103:Nanotechnology; D014173:Transistors, Electronic
D002244:Carbon