Mirror figure correction on variable length scales

Autor: A. Vivo, Christian Morawe, François Perrin, Sylvain Labouré, Patrice Bras
Rok vydání: 2021
Předmět:
Zdroj: Advances in X-Ray/EUV Optics and Components XVI.
Popis: The figure errors of an x-ray mirror were reduced by differential deposition of C/Pt layered structures. Different apertures were inserted into the particle beam to correct height errors on variable length scales down to less than 10 mm. The required velocity profile was calculated using a deconvolution algorithm. The film thickness profiles were measured directly by xray reflectivity. Height errors were evaluated using visible light surface metrology. The results of these different techniques are compared and discussed. After two iterations the shape error of a 300 mm long flat Si mirror was reduced by a factor of 5 to less than 1 nm RMS. This work describes the experimental techniques and discusses the achieved accuracy. It also addresses open questions such as roughness evolution, layer stress, and the interpretation of metrology data.
Databáze: OpenAIRE