Effect of sputtering condition on electrical and optical properties of indium-tin oxide thin films ☆

Indium-tin oxide (ITO) thin films were deposited by radio frequency (rf)-magnetron sputtering at different substrate temperatures and oxygen concentrations. Oxygen concentration affects significantly on the electrical and optical properties of ITO films. The best sample was observed at 1% oxygen with the sheet resistance of 227 Ω⁄, resistivity of 56x10-4 Ω.cm, and transmittance (at 550 nm) of 73%. The substrate temperature affects strongly on the surface morphology and electrical properties of ITO films. The size of ITO nanocrystalites increased with the increasing substrate temperature, indicating an improvement of the crystallinity. The sheet resistance and resistivity of ITO films are decreased with raising the substrate temperature, and are around 17 Ω⁄ and 4x10-4 Ω.cm at 400 °C, respectively. The higher substrate temperature shows better optical property.