Exploring EUV near absorption edge optical constants for enhanced and sensitive grazing incidence reflectivity

A characterization procedures to test multilayers in the EUV and soft X-Ray wavelengths are theoretically studied in this paper. The fact that most candidate elements have absorption edge energies in the EUV and soft X-Ray has demanded extensive studies on the optical constants and their possible impact on multilayer design and reflectivity. Thus, EUV and soft X-Ray multilayers are preliminary designed and tested for various parameters. Effects and impacts of interface roughness, interlayer thickness, optical constants fluctuations, different phases of interlayer compounds on the reflectivity of multilayers are investigated in this piece of work. Two theoretical models are used each contributing different properties of the multilayers. Near absorption edge and off-absorption edge wavelengths are compared and contrasted to investigate what optical constants near the resonance edges can render in the EUV and soft X-Ray regime. Almost in all simulations the near absorption edge reflectivity have shown superior sensitivity to fluctuations of various design parameters. In addition, possible engineering tips of near absorption edge optical constants are indicated.