We have performed in situ oxide contamination and XUV reflectance vs angle of incidence studies on fresh aluminum and silicon films evaporated in an ultrahigh vacuum system (base pressure 2 X 10-10 Torr). Our ellipsometric measurements indicate that a surface monolayer of oxide forms on aluminum (1 h at 2 X 10-8-Torr oxygen) and silicon (1 h at 10-7-Torr oxygen). The monolayer formation time is inversely proportional to oxygen pressure. Our reflectance vs angle of incidence measurements at 58.4-nm wavelength indicate that unoxidized aluminum and silicon coatings can be used as multifacet retroreflectors with net retroreflectances in excess of 75% for aluminum and 50% for silicon.

Date Published: 9 August 1988
PDF: 5 pages
Proc. SPIE 0830, Grazing Incidence Optics for Astronomical and Laboratory Applications, (9 August 1988); doi: 10.1117/12.942198

Published in SPIE Proceedings Vol. 0830:
Grazing Incidence Optics for Astronomical and Laboratory Applications
C. Stuart Bowyer, Editor(s)