Crystalline indium-doped zinc oxide thin films prepared by RF magnetron reactive sputtering

Abstract

The characteristic of indium-doped zinc oxide (IZO) thin films are closely related with the composition of the target, the deposition technique, and various process parameters such as the substrate temperature, the deposition pressure, the distance from target to substrate, and so on. In this study, IZO thin films have been deposited onto glass substrates with different deposition pressures by using the radio frequency magnetron reactive sputtering method. The structural, optical, and resistivity properties of IZO thin films were investigated using a field emission scanning electron microscope (FE-SEM), X-ray diffraction patterns (XRD), UV-visible spectroscopy, and Hall-effect analysis. XRD analysis on IZO thin films showed that only the (002) diffraction peak was observable, indicating that the IZO films showed a good c-axis orientation perpendicular to the glass substrates. As the deposition pressure of IZO thin films change from 5 x 10~3 to 5 x 10~2 Torr, the thickness decreased from 220 to 72 nm, the grain size increased from 74 to 23 nm, and the resistivity increased from 2.03 x 10~3 to 1.65 x 10-1 Ωcm. The lowest resistivity value of 2.03 x 10~3 Ωm was obtained for a deposition pressure of 5 x 10~3 Torr.