Solution-Processed Nanoscale Carbon Nanotube Thin-Film Transistors Fabricated By Electromigration

Abstract

Solution-processed carbon nanotube thin-film transistors (CNT-TFTs) have been of great scientific and technological attention due to the merits of fabrication processes and structual integration. Significant improvements in material design and process optimization have resulted in high performance CNT-TFTs which are comparable to or better than conventional ones. However, it is still difficult to realize sub-nano-scaled solution-processed CNT-TFTs suitable for integrated circuits and systems. In order to fabricate a sub-nm gap between source and drain electrodes in the channel region of the solution-processed CNT-TFTs, the DC breakjunction method by applying the electric field to trap Au nanoparticles and to form a short bridge was investigated through electromigration. A gradually ramping electric bias was imposed on the contact junctions, thereby breaking the bridge into a sub-nm gap in TFTs. The combination of surface treatment and vacuum thermal annealing increased the density of the nanotubes in the channel region and improved charge injection between the channel and the source electrode. In this presentation, we will demonstrate the process optimization to realize high-performance solution-processed CNT-TFTs with a channel length of ~20 nm and discuss the effect of surface treatment and vacuum thermal annealing on device performance.