Thin-film passivation by atomic layer deposition for organic field-effect transistors

The thin-film passivation of organic field-effect transistors (OFETs) using AlOx films grown by atomic layer deposition was investigated. A high-quality AlOx passivation layer was deposited on OFETs at 90 degrees C using trimethylaluminum and water. Despite the low deposition temperature, the 50-nm-thick AlOx passivation layers exhibited a low water-vapor-transmission-rate value of 0.0434 g/m(2)/day. In addition, the mobility of the AlOx-passivated OFETs was only slightly below that of the unpassivated devices (i.e., within 9%). Unlike unpassivated devices, the electric performance of the passivated OFETs remained almost unchanged after 2 months as a result of the excellent barrier properties of the passivation layer. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3000017].