Dependence of film composition and thicknesses on optical and electrical properties of ITO–metal–ITO multilayers

ITO–metal–ITO (IMI) multilayers have been prepared by DC-magnetron reactive sputtering in an vertical Inline sputtering system. AgCu films with different film thicknesses were used as metallic layers. The transmission and the reflection of the multilayers were measured, as well as the film thickness and the sheet resistance. The complex indices of refraction both of ITO and of AgCu were calculated from the measured data. By theoretical simulations an optimization of material composition and of film thicknesses has been carried out. With the IMI multilayer a sheet resistance of 5.7 Ω/sq. and a maximum transmission of about 83% was achieved. The performance of the multilayers as transparent conducting materials was compared by using a figure of merit proposed by Haacke.