Electrical improvement of CNT contacts with Cu damascene top metallization

We discuss the improvement in the electrical characterization and the performance of 150 nm diameter contacts filled with carbon nanotubes (CNT) and a Cu damascene top metal on 200mm wafers. The excellent agreement between the yield curves for the parallel and single contacts shows that a reliable electrical characterization is obtained. We demonstrate that integration changes improved the resistivity of the CNT contact significantly by reducing it from 11.8·10³ μΩ·cm down to 5.1·10³ μΩ·cm. Finally, a length scaling of the CNT contacts was used to find the individual contributors to the lowering of the single CNT contact resistance.