Abstract

Plasma chemical vapor deposition (PCVD) is not commonly used in the optical coating industry, despite the fact that it can often offer significant advantages over the more conventional optical coating processes. Among these advantages are: (1) Very high coating rates: In intense plasmas high-quality coatings can be deposited locally at 10⁶ Å/min and globally at several g/min in relatively simple equipment. (2) Ease of coevaporation or doping: High efficiency of deposition of any constituent in the plasma allows multiconstituent films through simple mixing of input gases, leading to greater control over important film characteristics such as stress, adhesion, and resistance to chemical attack. (3) Films with very low absorption: High-purity starting materials and equipment without electron guns, electrodes, etc., reduce absorbing contaminant levels well below those practical with sputtering or thermal evaporation.

© 1987 Optical Society of America