Electrical Characterization of Thin Cr/Indium-Tin Oxide Layer 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 600nm in constant Ar gas flow of 30 SCCM. Results show that the lowest contact resistivity belongs to the layer with 600nm thickness. Furthermore Cr/ITO has been studied for different flows of Argon gas 10, 30, 50, and 70 SCCM during the deposition with constant thickness of 600nm Cr thin films, which result gave us the lowest contact resistivity. Experimental results show that specific contact resistance decreases by reducing the flow of argon gas. Analyze of SEM has been performed on the samples. The SEM micrographs show Cr thin films have smaller grains in 10 SCCM argon gas flows, in comparison with other flows of argon gas. The best specific contact for Cr/ITO has been obtained 4.5 x 10(-6) omega m(2) at flow of argon gas 10 SCCM with 600nm thickness.