Ion irradiation-induced welding of a carbon nanotube to a Si (100) surface
- PDF / 229,935 Bytes
- 10 Pages / 612 x 792 pts (letter) Page_size
- 28 Downloads / 178 Views
0908-OO15-01.1
Ion irradiation-induced welding of a carbon nanotube to a Si (100) surface J. Kotakoski and K. Nordlund Accelerator laboratory, P. O. Box 43, FI-00014 University of Helsinki, Finland ABSTRACT Carbon nanotubes (CNTs) are one of the possible building blocks for electronic devices in the transition phase from traditional silicon-based microelectronics towards the fewnanometer regime. Remaining problems in integrating CNTs to the existing technology is the low reactivity of the CNT walls which leads to low conductance between CNTs and the other components. Because recent studies have shown that ion irradiation can be used to modify both the electrical and structural properties of CNTs, we propose that it could also be possible to use ion irradiation with low energies to enhance the conductance of these connections. We have used classical molecular dynamics simulations with empirically tted potentials to examine this possibility by irradiating a single-walled carbon nanotube (SWCNT) on a silicon substrate at room temperature. The nanotube was deposited over a trench created to the silicon substrate so that the nanotube was partly suspended. Low irradiation doses and low energies (0.2 keV–1.2 keV) were used to ensure that the irradiated CNT will not be destroyed. The simulations were carried out for silicon, carbon and neon ions. Our simulations indicate that ion irradiation will increase the number of covalent bonds between the CNT and the Si substrate. When the irradiation dose and energies are low, the damage caused to the SWCNT atomic network can be tolerable when compared to the improvement in the conductance of the contact regions. Furthermore, as the CNTs have high ability to heal the irradiation-induced damage, it is possible that the irradiation will not have a signi cant negative effect to the conductivity of the CNT in a system of this type. INTRODUCTION Carbon nanotubes (CNTs) [1] are one of the alternatives to help the existing semiconductor technology decrease the device sizes towards the desired nanometer-range [2, 3]. Due to their semiconducting and metallic nature, which depends on the atomic structure of each CNT, they can be used either as building blocks for new nanometer-size devices or as wires connecting other devices. Best means towards the transition from the micro to nano scale would be to integrate the existing, cheap and well established, silicon technology and the CNT-based devices. One of the problems in this process is the poor electrical connection between the CNTs and the other devices, which becomes especially important at low temperatures [4–6]. Irradiation with energetic ions has been routinely used in the semiconductor industry to introduce dopants into silicon [7, 8]. Electron and ion irradiation with high energies can also be used to modify the atomic structure of the materials. Similar to conventional
0908-OO15-01.2
materials, irradiation with ions and electrons can also be used to tailor the properties of CNTs. It has for example been shown that, by using irradia
Data Loading...
