Evaporated Si films in combination with oxide materials such as SiO_x form promising multilayer mirror coatings for chemical laser applications. However, high infrared absorption and relatively low damage threshold of the Si films presently limit the effectiveness of these multilayer designs.

Lower absorption values and higher damage thresholds have been obtained with sputtered Si films; this improvement apparently results from better film morphology and lower contamination levels in the sputtered films. Other work has shown that hydrogenation of as-deposited Si films can effectively passivate large numbers of bonding-type defects, and this results in further marked reductions in the infrared absorption.

In this paper, we discuss the preparation and absorption optimization of hydrogenated Si films and the formation of SiO₂, Si/SiO₂, and SiH/SiO₂ coatings by reactive sputtering. The morphology and composition of optimally prepared films will be described, and the results of absorption and chemical laser damage measurements are discussed.