Abstract

The use of artificial multilayer structures (MLS) as wavelength dispersive elements has proven of great importance in soft x-ray (2 to 15 nm) spectroscopy. Much of the early work in this field has concentrated on structures consisting of alternating layers of a pair of materials, one of high atomic number (most commonly tungsten) and one of low atomic number (most commonly carbon). Although the ideal performance of multilayer pairs can be calculated,¹ the performance of a MLS can be substantially degraded by imperfections introduced in their manufacture. In particular, it has become clear that optimum performance of MLS is strongly dependent upon the quality of the interfaces (roughness, interdiffusion, etc.) between the two materials. These interface properties are dependent upon the chemical-metallurgical properties of the materials chosen. Since such properties are typically not amenable to theoretical prediction, the choice of good layer pairs is typically an Edisonian process. The purpose of this paper is to explore the soft x-ray diffracting properties of the material pair Mo-B₄C. We will concentrate on the ways in which the measured diffraction behavior deviates from ideality and, especially, possible reasons for this non-ideality.

© 1992 Optical Society of America