Effects of an additional magnetic field in ITO thin film deposition by magnetron sputtering

Indium tin oxide (ITO) thin films were deposited on glass substrates at low temperature (100 °C) and under a range of magnetic fields driven from the currents of a solenoid coil placed inside the magnetron sputtering apparatus. Electrons moving in a specific direction by the Lorentz force collide with neutral ITO particles with a higher collision likelihood. Eventually, the magnetic field plays a key role in increasing the ionized ITO particles. Therefore, this study examined the influence of the magnetic fields by the solenoid coil near the target on the structural, surface morphologies, electrical, and optical properties of these thin films. As a result, with increasing coil current from 0 A to 0.2 A, the electrical resistivity of the ITO films decreased from 1.23×10−3 Ω cm to 5.57×10−4 Ω cm. As complementary results, hall mobility and carrier concentration increased slightly, which were attributed to crystal growth, density and grain size of the ITO film. Furthermore, X-ray diffraction showed that increasing the ITO ion density by the magnetic field in the deposition process was effective in inducing the preferential growth of the (222) orientation of the film.