Physical properties of transparent conducting indium doped zinc oxide thin films deposited by pulsed DC magnetron sputtering

Transparent conducting In-doped (1at.%) zinc oxide (IZO) thin films are deposited on glass substrate by bipolar pulsed DC magnetron sputtering. We have investigated the effect of pulse frequency on the physical properties of the IZO films. A highly c-axis oriented IZO thin films were grown in perpendicular to the substrate. At optimal deposition conditions, IZO films with a smoothest surface roughness of ∼3.6 nm, a low-resistivity of 5.8×10^-3 Ωcm, and a high mobility of 14 cm/Vs were achieved. The optical spectra showed a high transmittance of above 85% in the UV-visible region and exhibited the absorption edge of near 350 nm. In micro-Raman, we observed the three phonon modes of host ZnO, which are E₂^low, E₂ ^high, and A₁ modes, and the three additional modes. The origin of three additional modes is attributed to the host lattice defect due to the effect of In dopant and increasing the pulse frequency.