Abstract

Thick multilayer coatings deposited by dc-magnetron sputtering cause an unacceptable level of stress-induced distortion in coated components. This is because all the dc-magnetron-sputtered films in our studies had a relatively high compressive stress. The compressive stress in sputtered films is due to bombardment of the growing film by energetic species. Previous studies have shown that the compressive stress of ion-beam-sputtered films was reduced by using post-deposition baking. This stress modification technique was used to reduce the compressive stress of dc-magnetron-sputtered single-and multilayer films. The materials investigated in this study were SiO₂, Al₂O₃, Ta₂O₅, and TiO₂. The films were baked at temperatures between 200 and 300°C (392 and 572°F) for approximately 3 h. The amount of change in the stress was dependent on the material and the baking temperature. Thick multilayer films with a total stress near zero were produced bu using this technique.

© 1992 Optical Society of America