Synthesis and Evaluation of Tungsten, Tungsten nitride and Tungsten oxide films Prepared in a Magnetron Sputtering System

Document Type : Research Article

Authors

Department of nanomaterials and nanocoatings, Institute for color science and technology,Tehran

/amnc.2012.1.2.3

Abstract

Tungsten, tungsten nitride and tungsten oxide coatings were prepared in a planar magnetron sputtering system at different sputtering conditions. Tungsten films prepared at different sputtering pressures and resulted to a mixture of WO3 and β-W phases while the peak intensity of WO3 phase was the lowest at an optimum sputtering pressure. Tungsten nitride and tungsten oxide coatings were deposited at different partial pressures of reactive gases at constant sputtering pressures. Total pressure was fixed at 9×10-3 torr while P(N2/Ar) ranged between 0.4-5 for nitride coatings and 0.25-2.5 for oxide coatings. At low reactive gas partial pressures, nitride and oxide phases were formed. However, by increasing the gas flow rate, coatings lost their long range order and amorphous like structure was formed. The surface roughness of the films prepared at higher partial pressure of reactive gas was higher. Lower adatoms mobility at higher reactive gas pressures leads to the formation of films with amorphous-like structure and higher roughness. The results showed that oxide films are more sensitive to the partial pressure of reactive gas compared to that of nitride films.

Keywords