Low temperature processing of high conductivity and high transparency indium–tin-oxide/Ag alloy/indium–tin-oxide multilayered thin films

Indium–tin-oxide (ITO) thin films and ITO/Ag alloy/ITO multilayered thin films were deposited on glass substrates using a vertical in-line multilayer sputtering system. Ceramic ITO targets were used for the deposition of ITO layers at low substrate temperature of 100 °C. It was observed that the sheet resistance and light transmission of ITO films were affected by the oxygen pressure significantly. The ITO/Ag alloy/ITO multilayered thin films made in the present work had a low sheet resistance (6.9 Ω/□) and a high transmission (87.1%) at 550 nm. Atomic force microscopy (AFM) investigation showed that through selecting proper processing parameters, the surface roughness could be significantly reduced. The surfaces of ITO films were found very smooth by using pulsed-direct current (pulsed-dc) sputtering with introduction of H2O. The work functions of the ITO films and ITO/Ag alloy/ITO multilayered films were increased with oxygen plasma treatment.