Texture analysis of Al-doped ZnO thin films prepared by in-line reactive MF magnetron sputtering

The influence of substrate temperature on the texture of the Al-doped zinc oxide (ZnO:Al or AZO) films prepared by reactive mid-frequency (MF) magnetron sputtering has been studied by means of X-ray texture measurements. All the AZO films are polycrystalline with wurtzite crystal structure. The main texture features found in the films consist of (0 0 2) and (10 1) fibre components. The volume fraction of the (0 0 2) component increases and its spread (halfwidth) decreases with increase of the substrate temperature, indicating an improved crystallinity of the films. The narrowest spread of 8.6degrees with a high volume fraction of 62% is obtained for the film deposited at 150 degreesC. The films with degrading textures are observed at high substrate temperatures above 200 degreesC. It is shown that the electrical properties of the films related to their structural properties. An improvement of the mobility is noted for the film with a high degree of texture. The lowest resistivity of 4.6 x 10(-4) Omega cm with a mobility of 24 cm(2)/V s is obtained for the highly textured film deposited at 150 degreesC. (C) 2003 Elsevier B.V. All rights reserved.