Site-selective deposition of single-wall carbon nanotubes by patterning self-assembled monolayer for application to thin-film transistors

We have demonstrated a site-selective deposition of uniform single-wall carbon nanotube (SWCNT) thin films on a SiO2/Si substrate using patterned self-assembled monolayers (SAMs). Non-polar octadecyltrichlorosilane (OTS) SAM was patterned by ultraviolet (UV) light through shadow mask. Then polar 3-aminopropyltriethoxysilane (APTES) SAM was selectively formed at the channel area of thin film transistors (TFTs). Finally, SWCNT thin films were selectively deposited on the TFT channel using these patterned SAMs. In this work, 25 TFTs were fabricated simultaneously on the same substrate using semiconductor-enriched SWCNTs (s-SWCNTs) solution. As a result, 23 TFTs showed high on/off current ratios over 104 without any post-treatment. It was confirmed that this method is useful to produce a large number of 11,Ts at a same time and applicable to the low cost production of SWCNT-integrated circuits in near future. (c) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim