Abstract

Reactive-dc-magnetron sputtering has been demonstrated as a viable technique for producing dense films with improved mechanical properties. Recent advances in this process, such as deposition at low pressures and elimination of arcing on the target surface, have resulted in the deposition of films with improved optical properties. Films produced by this technique have very low scatter and absorption values that are comparable to those of ion-beam-sputtered films. Single-layer films of SiO₂, Al₂O₃, Ta₂O₅, and TiO₂ have been deposited and analyzed. The optical and mechanical properties of these films are compared with those of films deposited by ion-beam sputtering and electron-beam evaporation. The films deposited by dc-magnetron sputtering are homogeneous and have excellent index repeatability. This makes it possible to achieve near-theoretical performance in the spectral characteristics of multilayer coatings. A number of multilayer coatings have been produced by this technique, and some of these have physical thicknesses greater than 10 μm. The sensitivity of these coatings to the relative humidity of the surrounding environment was measured, and they were extremely stable.

© 1992 Optical Society of America