Surface figure correction using differential deposition of WSi$_2$
Applied Physics
2024-03-28 v1 Instrumentation and Detectors
Optics
Abstract
The surface figure of an x-ray mirror was improved by differential deposition of WSi layers. DC magnetron sputtering through beam-defining apertures was applied on moving substrates to generate thin films with arbitrary longitudinal thickness variations. The required velocity profiles were calculated using a deconvolution algorithm. Height errors were evaluated after each correction iteration using offline visible light surface metrology. WSi was selected as a promising material since it conserves the initial substrate surface roughness and limits the film stress to acceptable levels. On a 300 mm long flat Si mirror the shape error was reduced to less than 0.2 nm RMS.
Cite
@article{arxiv.2403.17498,
title = {Surface figure correction using differential deposition of WSi$_2$},
author = {Ch. Morawe and P. Bras and S. Labouré and F. Perrin and A. Vivo},
journal= {arXiv preprint arXiv:2403.17498},
year = {2024}
}