Effect of Sputtering Power on Structure and Optical Properties of CuxAlyOz Films

In the present, most of the transparent conductive films have high transmission in visible, while they have low transmission in infrared waveband. In this paper, the infrared transparent conductive films of Cu_xAl_yO_z were prepared by using radio-frequency (R.F.) magnetron sputtering deposition. Influences of sputtering power on structure and optical properties of the Cu_xAl_yO_z films have been investigated. Structure of the Cu_xAl_yO_z films was characterized by means of grazing incidence x-ray diffraction (GIXRD). Thickness, refractive index and extinction coefficient of the Cu_xAl_yO_z films were determined by spectroscopic ellipsometry method. The infrared transmission of the Cu_xAl_yO_z films was measured by Fourier Transform Infrared (FTIR) spectrometer. XRD analyses show that the Cu_xAl_yO_z films remain amorphous with the increase of the sputtering power. With the increasing sputtering power of the Al target, the deposition rate and infrared transmission of the Cu_xAl_yO_z films increase with the decrease in the refractive index.