Enhancement on carrier mobility in amorphous indium tin oxynitride (ITON) thin films

Indium tin oxynitride (ITON) thin films were deposited by reactive DC magnetron sputtering technique. The samples were deposited onto glass and silicon (100) substrates at room temperature. For this purpose, the sputtering reactive atmosphere was composed of different argon and nitrogen concentrations, to modify the structural, optical and electrical properties of obtained ITON thin films. Energy dispersive spectroscopy (EDS) was used in order to know the chemical composition of the different deposited samples, the nitrogen incorporation in the indium tin oxide structure was verified in all ITON analyzed samples. Additionally, through an infrared absorption spectroscopy study of the deposited films, it was possible to confirm the nitrogen incorporation in the ITO structure for the samples deposited under nitrogen presence. Several absorption bands corresponding to In-N, N-N, In-O, and Sn-O bonds were detected. As the effect of nitrogen incorporation, both crystalline structure and surface morphology are widely affected. On the other hand, the nitrogen presence in the structure leads to increase the carrier mobility reaching a value above 1100 cm(2)/Vs for the sample deposited in a higher nitrogen flux concentration, this result of high mobility raises ITON thin films a promising candidate to be used as an active layer in thin film transistors. The band gap values were calculated using the Tauc parabolic band model from the absorption spectra and it resulted in values near to 4.0 eV. Finally, the obtained transmission values were in the order of 75-80% in the visible region. (C) 2020 Elsevier B.V. All rights reserved.