Effects of Deposition Angle on The Thin Film Quality of Indium Tin Oxide Grown by Magnetron Sputtering

Indium tin oxide (ITO) has been widely used as a transparent electrode in various applications including solar cells, liquid crystal displays, plasma displays, smart windows, and light emitting diodes (LEDs). Many of these applications require low-temperature deposition of ITO thin film. But it remains a challenge to achieve satisfactory electrical conductivity and optical transmittance at low deposition temperatures. This work proves that the sputtering deposition angle has significant effects on the ITO film microstructure and properties. The ITO thin films are grown by a unique single beam ion source enhanced magnetron sputtering. The sputtering and ion beam directions relative to the substrate surface are varied from 30 to 90 degrees and the film structure and properties are subsequently investigated. X-ray diffraction is used to determine the film microstructure. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to characterize the morphology of the thin films. The thin films’ electrical conductivity and carrier mobility are determined from four-point probe and Hall effect measurements, respectively. Optical transmittance spectra are obtained using UV-Vis spectroscopy. This study contributes to the advancement of thin film growth mechanisms