Effects of hydrogen and SiO2 buffer layer insertion on electrical properties of low-resistive indium tin oxide films formed on polyethylene naphthalate films

Abstract

Low-resistivity transparent indium tin oxide (ITO) films were fabricated on flexible polymer substrates by RF-magnetron sputtering. Addition of hydrogen to the sputtering gas was effective in reducing the resistivity of ITO films deposited at room-temperature. Resistivity was further decreased by inserting a SiO2 buffer layer between the substrate and the ITO films. By optimizing the hydrogen pressure and SiO2 thickness, a resistivity of 3.4 × 10−4 Ω·cm was realized with a thickness of about 100 nm while maintaining an optical transparency of more than 85% in the visible range of the optical spectrum.