Abstract
Mo/Si multilayer mirrors with a high reflectance at normal incidence in the 130–135-Å spectral region have been deposited by rf magnetron sputtering. A new and quick technique was used to calibrate the deposition rates. Characterization by transmission electron microscopy (TEM) and grazing-incidence x-ray diffraction (XRD) indicated good thickness control of the deposition process and low interface roughness. However, the TEM and, indirectly, the XRD reflectance measurements, indicated that the interfaces are asymmetric. A brief review discussing the origin of the modulation of the Bragg peak intensities in the XRD reflectance is given. An analytical formula was derived for periodic multilayers that describes the effect of asymmetric interfaces on the amplitude of the Bragg peak modulation. Theoretically, in XRD reflectance measurements, any asymmetry in the interdiffusion of the Mo–Si interfaces results in a decrease of the usual amplitude modulation of the Bragg peaks. Extreme-ultraviolet (XUV) reflectance measurements were also made with synchrotron radiation on a new high-resolution reflectometer. The near-normal-incidence peak reflectances measured at λ ≈ 134 A were ~59% for the best multilayer mirrors. Good fits to both XRD and XUV reflectance measurements have been obtained with a model that allows for interface asymmetry.
© 1994 Optical Society of America
Full Article | PDF ArticleMore Like This
Bo Yu, Chunshui Jin, Shun Yao, Chun Li, Yu Liu, Feng Zhou, Benyin Guo, Hui Wang, Yao Xie, and Liping Wang
Appl. Opt. 56(26) 7462-7468 (2017)
Claude Montcalm, Patrick A. Kearney, J. M. Slaughter, Brian T. Sullivan, M. Chaker, Henri Pépin, and Charles M. Falco
Appl. Opt. 35(25) 5134-5147 (1996)
Nicolas Benoit, Sven Schröder, Sergiy Yulin, Torsten Feigl, Angela Duparré, Norbert Kaiser, and Andreas Tünnermann
Appl. Opt. 47(19) 3455-3462 (2008)