Fabrication of W/C Multilayers by Direct Ion Beam Deposition

Abstract

ABSTRACTThe multilayer structures of tungsten and carbon for soft x-ray mirrors were fabricated by the low energy (<100eV) direct ion beam deposition method with various depositing ion energies. The layered structures were observed by cross sectional TEM. The undulated structures were found in the layered structures of the depositing ion energy of 6OeV and lOOeV. It becomes larger as the depositing ion energy increases, and the undulation of the upper layers was larger than that of the under layers. The undulation seems to increase in each carbon layer. These results are quite different from the results of evaluation of thick monolayer films in the previous work. Then, the interfacial composite layer was evaluated by XPS. The tungsten carbide layer was found at the W/ C interface on the C layer. However, we can not find such layer at the interface on the W layer. This result can be explained by the difference of the momentum of the depositing ion.