Limits to Ion Beam Etching of Mo/Si Multilayer Coatings,
Abstract
Recently ion beam etching of electron beam deposited metal layers on C has resulted in higher x-ray reflection coefficients. In spite of the widely recognized importance of Mo/Si multilayer coatings for projection lithography, little work has been done to use the etching technique on multilayer mirrors made of this combination of materials. As Mo/Si multilayer mirrors of d-values greater than 12nm. have already been made with reflectivities very close to the theoretical maximum 2, our main interest is in multilayers with smaller d-values. We have investigated the effect of ion beam etching on the morphology and surface smoothness of Mo on top of Si layers and of Si on top of Mo layers. In this study we varied the species of the etching ions (Ar and Kr) and the ion energy (from 200 up to 1500 eV). Increased x-ray reflectivities could be observed for every combination of ion species and energy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 05, 1992
- Accession Number
- ADP008071
Entities
People
- Chunsong Lu
- E.j. Puik
- J. Verhoeven
- M.j. Van Der Wiel
- R. Schlatmann
Organizations
- Stichting voor Fundamenteel Onderzoek der Materie