Structures and Electrical Properties of Tin Doped Indium Oxide (ITO) Films Deposited on Different Substrates by Sputtering with H2O Introduction

ITO films were deposited on three different substrates, Si, non-alkaline glass, and SiOx coated glass, by dc magnetron sputtering with/without H2O introduction. H2O partial pressure during the deposition was controlled to be 6.7 x 10 Pa. The structural and electrical properties of the films were analyzed in detail. The ITO films deposited with the H2O introduction showed amorphous structure and higher crystallization temperature during post-annealing in N2. Such effects of the H2O introduction on the microstructure of the films were different for each substrate. The ITO films deposited on the Si substrate showed the lighter effects, whereas the films on SiOx coated glass showed the much heavier effects. In both cases, the effects were stronger for the thinner film thicknesses, implying that the interface between ITO films and the substrate should be strongly affected by the H2O introduction. The amorphous ITO films deposited under the higher H2O partial pressure contained less microcrystalline residues after wet-etching. Such films were analyzed by secondary ion mass spectroscopy (SIMS) to have much higher hydrogen concentrations inside the films.