Wafer-level manufacturing and optimization of CNT-based field-effect transistors

We report on the development and improvement of fabrication procedures to fabricate carbon nanotube-based field-effect transistors at large scale. Special attention is paid to the statistical evaluation of post-process treatments to reliably eval-uate the transistor performance. An experimental study is presented which aims the removal of surfactant residues by applying wet chemical and thermal post-treatments. The effect on the CNTs and transistors are monitored by atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and electrical measurements on transistor arrays. HNO3 and H2O based treatments result in improvement of on-currents, whereas an annealing changes the direction of the hysteresis in transfer characteristics.