Abstract
Recent progress in the fields of physical vapor deposition (PVD), coupled with increased interest in the soft x-ray region of the electromagnetic spectrum, has driven the development of layered synthetic microstructures (LSMs) to the point that useful nongrazing incidence optics based on this technology are used in a variety of applications (e.g., solar astronomy, soft x-ray microscopy, and plasma spectroscopy). Our goal, as a production facility for thin film devices, was to demonstrate the capability for mass production of LSMs having uniform reflectivity performance (2d +/- 1 angstrom, Rp +/- 5) across the surface of a 10 cm diameter planar surface. We achieved this goal through the use of a large vacuum deposition chamber which accommodates a 66 cm diameter rotating substrate platen and two fixed position 15 cm diameter magnetron sputter deposition sources. Deposition flux masks positioned below the substrates in the vacuum process chamber provided the fine control of deposition flux necessary to achieve our uniformity goals. These masks were designed using a computer code that modeled the deposition system geometry and used empirical deposition rate data. Results obtained from soft x-ray mapping of the surface of LSMs fabricated with and without these deposition masks indicates a reduction in layer period (d-spacing) variation of +/- 13 angstroms to +/- 1 angstrom over a 10 cm diameter, and a significant improvement in reflectivity uniformity through the use of deposition masks. We are in the process of expanding our modeling and fabrication work to allow for deposition of multilayer optical coatings onto figured substrates.
