Influences of Pulse Parameters on Properties of Optical Coatings Deposited by Reactive Pulsed Magnetron Sputtering

摘要

Reactive pulsed magnetron sputtering incorporates a high potential for manufacturing optical multilayer systems (e.g., precision filter components). Only some investigations have been performed to describe the most important properties of such prepared films. A flexible magnetron sputter system using two planar metallic targets supplied with pulsed power equipment was used for reactive deposition of optical coatings. Single layers were investigated as an elementary stage for preparation of multilayer stacks. The pure metallic targets were sputtered in a strictly controlled reactive gas atmosphere. Layers with an optical thickness of λ/4 (for λ = 1550 nm) were deposited on Si wafers and glass substrates. The influence of total sputtering pressure and process temperature on optical and mechanical properties, surface topography and film structure were investigated. Special emphasis was put on detection of the influence of pulse mode and pulse parameters on layer properties. The samples were characterized by spectroscopic ellipsometry (SE), atomic force microscopy (AFM), X-ray diffraction (XRD) and nanoindentation techniques. It was possible to adjust the film properties by fine tuning of the process parameters.