Self-Aligned Contacting of Carbon Nanotubes

An important prerequisite for the implementation of carbon nanotubes (CNTs) in microelectronic circuits is the evaluation of their electronic properties. For this, the generation of low‐ohmic electrical contacts between CNTs and metallic circuit lines is crucial. We describe a parallel process which does not rely on e‐beam lithography and yields self‐aligned, low‐ohmic contacts on wafer scale. CNTs that are spray deposited on metallic test structures created by optical lithography are subsequently embedded by electroless metallization and annealed. With this method we are able to simultaneously lower the contact resistance of an unlimited number of CNTs. The reduction of the contact resistance depends on the metals involved and the annealing process. This new method enables the statistical evaluation of the CNT quality dependence on synthesis conditions.