Influence of the Cs partial pressure on the optical and electrical properties of ITO films prepared by dc sputter type negative metal ion beam deposition

Abstract The influence of cesium (Cs) partial pressure ( P Cs ) in the sputtering atmosphere on the opto-electrical and surface morphological property of ITO thin films deposited onto unheated polycarbonate substrate was investigated. The deposition technique used was a dc sputter type negative metal ion beam source which uses Cs as a surface negative ionization agent. During deposition Ar gas flow rate, deposition pressure and bipolar dc power were kept constant at 30 sccm, 9 × 10 −2 Pa, and 250 W, respectively. As increase P Cs both electrical conductivity and optical transmittance of the film were increased. The lowest resistivity of 5.1 × 10 −4 Ω cm and optical transmittance of 89% at 550 nm were measured in the ITO film deposited at P Cs of 1.7 × 10 −3 Pa. Surface morphology of ITO film was also varied with P Cs and the lowest surface roughness (Ra: 1.16 nm) was obtained a t Cs of 1.7 × 10 −3 Pa.