Ahmed Ziani

EUV reflectivity and stability of tri-component Al- based multilayers

We report on further development of three-material multilayer coatings made with a use of aluminum for the extreme ultra-violet (EUV) applications such as solar physics, high-order harmonic generation or synchrotron radiation. It was found that an introduction of refractory metal in Al-based periodic stack helps to reduce significantly an interfacial roughness and provides for a higher theoretical reflectance in the spectral range from 17 to 40 nm. The normal incidence reflectivity as high as 55 % at 17 nm, 50 % at 21 nm and 42 % at 30 nm was achieved with the new Al/Mo/SiC and Al/Mo/B4C multilayer mirrors, which have been optimized, fabricated and characterized with x-rays and synchrotron radiation. A good temporal and thermal stability of the tri-component Al-based multilayers has been observed over 3 years.

LaTiO x N y Thin Films, Measurement and Application to Microwave Device

This paper reports about three issues: a non-destructive method for dielectric measurement of materials; the first microwave dielectric measurement of a new birth dielectric LaTiOxNy material, and a topology for X-band phase shifter based on tuneable ferroelectric thin films interdigital capacitors.

Aluminum based multilayers systems synthesized by ion beam sputtering for Extreme UV

In this paper, we present the development of Al-based multilayer mirrors for the spectral range [17 nm - 34 nm]. The purpose of presented study is to optimize the deposition of Al-based multilayers by the ion beam sputtering (IBS) technique according to several parameters such as the ion beam current and the angle of inclination of targets, which allowed us to vary the energy of ad-atoms deposited onto a substrate. We expected to achieve good reflectivity values for both two- and three-material stacks: aluminum/molybdenum Al/Mo, aluminum/molybdenum/boron carbide Al/Mo/B4C and aluminum/molybdenum/silicon carbide Al/Mo/SiC. We have undertaken a series of structural and chemical analyses of these systems. We present their optical characteristics in the EUV range.