Effect of moving speed during in-line pulsed direct-current magnetron sputtering deposition on the structural and optical properties of Al-doped ZnO films

Abstract

Aluminum-doped zinc oxide (AZO) films were deposited on glass substrates with pulsed direct current (DC) magnetron sputtering. Deposition was carried out in both static and dynamic modes. The pulsed DC sputtering process provided a stable deposition of AZO films without arcing, resulting in good crystallinity, unlike simple DC magnetron sputtering. The growth characteristics of the films sputtered on various moving speeds of the in-line dynamic mode are investigated and compared to those of the static mode. AZO films deposited at a moving speed of 120cm/min showed a dominant (002) orientation, a smooth surface roughness, and a higher figure of merit (FOM), of which properties are similar to those of the static mode. Comparisons of the characteristics obtained at several moving speeds showed that better crystallinity was obtained at the higher moving speed of 120cm/min. This improvement could be attributed to an averaging effect, which is due to more frequent interruption and initiation of the growth at the higher moving speed. Optical transmission characteristics were compared between the static and dynamic modes, and analyzed in terms of the complex indices of refraction and interference effects of light.