Properties of DC magnetron sputtered indium-tin oxide films with the assistance of tiny H2O vapor at low temperature

ITO thin films with high optical and electrical performance were prepared by DC magnetron sputtering method with the assistance of tiny H2O vapor during deposition process. ITO films were deposited in a custom built Sunicel Plus200 DC magnetron sputtering system using argon as the main sputtering gas and a small quantity of H2O vapor. For the characterization of ITO film properties, film thickness was measured with a step profiler. The 3D-images of the ITO film surface were characterized by an atomic force microscope (AFM). Film square resistivity was estimated by four-point probe method, and optical transparency was measured by a spectrophotometer. The resulting ITO films exhibited high electrical conductivity as well as high optical transparency and smooth surface morphology. The square resistivity was about 50 Ω/square area sputtered at 200 W at the substrate temperature of 100°C on the position of 10 cm from the sputtering source to substrate center. With the introducing of 2×10-5 Torr H2O vapor during sputtering process the visible light transmittance of approximately 89% in the visible spectral region was achieved.