Effect of hydrogen on sputtering discharge and properties of TiO2 films

Abstract

This article reports on the effect of hydrogen addition into the Ar+O2 discharge mixture on the dc reactive magnetron sputtering process and on the structure of sputtered TiO2 films. The hydrogen plays a key role in reactive sputtering of electrically insulating oxides from metallic targets because it fully eliminates arcing on the sputtered target. The hydrogen also strongly influences the dependence of the partial pressure of oxygen pO2 vs. flow rate of oxygen φO2. Changes in the pO2=f(φO2) dependence caused by the addition of H2 into the Ar+O2 mixture are explained. Special attention is devoted to correlations between deposition parameters, structure, phase composition, optical properties and hydrophilic activity of TiOx≈2 films. It is shown that the presence of H2 in the Ar+O2 mixture does not prevent from the formation of superhydrophilic TiOx≈2 films.