The Structural Changes of Indium-Tin Oxide and a-WO₃ Films by Introducing Water to the Deposition Processes

Abstract

Indium-tin oxide (ITO) films and amorphous WO 3 (a-WO 3 ) films were deposited by DC magnetron sputtering and EB evaporation, respectively, under different water partial pressures ( p H 2 O ). The ITO films sputtered under higher p H 2 O showed higher resistivities because of the decrease in hall mobility and had rather different orientation distributions of the crystal axis of the grains. It was found from XPS analyses that the In-O-H bonds which were not found in the films existed at the interface between the glass substrates and the ITO films, and much more of these bonds existed for the higher p H 2 O films. This suggests that the structural change which increased the resistivity occurred at the first stages of the formation of the films. For the a-WO 3 films deposited under high p H 2 O , the decreases of order parameters and increases of W=O bonds were observed by Raman spectroscopy, indicating a decrease in microcrystal sizes.