Chromium thin film deposition on ITO substrate by RF sputtering

To obtain a suitable ohmic contact with the lowest resistivity, chromium (Cr) thin films were deposited on transparent conductive oxide indium tin oxide (ITO) by RF sputtering method in argon atmosphere and its electrical properties were optimized. The deposition of Cr thin film has been performed for the layers with thickness of 150, 300 and 600 nm in constant Ar gas flow of 30 SCCM. Results show that the lowest contact resistivity belongs to the layer with 600 nm thickness. Furthermore, Cr/ITO has been studied for five different RF powers of 100, 150, 200, 250 and 300 W. Experimental results show that specific contact resistance of Cr/ITO contact decreases in condition of depositing chromium thin films on ITO at higher RF powers. Analysis of SEM has been performed on the samples. The SEM micrographs show Cr thin films have smaller grains at RF power of 150 W, in comparison with other RF powers. The lowest specific contact resistivity for Cr/ITO has been obtained 4.7 9 10^-2 Ω cm^2 at RF power of 150 W with 600 nm thickness of chromium thin films.