Evolution of Structure, Phase Composition, and X-Ray Reflectivity of Multilayer Mirrors Mo–(B + C) after Annealing at 250–1100°C

Article type: Research Article

Authors: Kopilets, I. A. | Kondratenko, V. V. | Fedorenko, A. I. | Zubarev, E. N. | Poltseva, O. V. | Ponomarenko, A. G. | Lyakhovskaya, I. I.

Affiliations: Kharkiv State Polytechnic University, Kharkiv, Ukraine | Institute of Physics, St. Petersburg University, St. Petersburg, Russia

Abstract: Structural, phase, and chemical stabilities of x-ray multilayer mirrors Mo–(B + C) with periods in the range 8–11.5 nm were studied at temperatures of 250–1100°C by small-angle and large-angle x-ray diffraction and electron microscopy methods. Two amorphizations at ~450 and ~750°C and two crystallizations at ~650 and ~850°C of Mo-based layers were observed, which were due to the formation of the molybdenum carbides MoC (hex), γ-MoC, and Mo2C instead of the metal Mo, and to the formation of the molybdenum borides MoB2 and Mo2B5 instead of molybdenum carbides, respectively. Both amorphizations of Mo-based layers were accompanied by smoothing of interfaces and by an increase of the multilayer x-ray reflectivity at λ = 0.154 nm. Both crystallizations of Mo-based layers promoted the development of interface roughness and a decrease of multilayer x-ray reflectivity. The destruction of Mo–(B + C) multilayers at ~ 1100°C was caused by the recrystallization of Mo2B5 layers.

DOI: 10.3233/XST-1996-6202

Journal: Journal of X-Ray Science and Technology, vol. 6, no. 2, pp. 141-149, 1996