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Analysis and control of optical film growth by in situ real-time spectroscopic ellipsometry

The understanding of the nucleation stage of thin film growth is a key element of the optimization of synthesis parameters in order to obtain high-quality optical coatings with predetermined characteristics. The fabrication of advanced coatings, often consisting of complex non-quarter wave and/or metal dielectric stacks, requires new and more powerful in situ monitoring techniques compared to conventional reflectometry and transmission, or quartz crystal microbalance measurements. We describe the use of in situ real-time spectroscopic ellipsometry (RTSE) for the development of optical materials and for the control of the fabrication of homogeneous and inhomogeneous optical filters. Examples include materials such as Ti02, Si02 and SiNx prepared by plasma-enhanced chemical vapor deposition (PECVD).