Y. A. Vainer, A. E. Pestov, K. A. Prokhorov, N. N. Salashchenko, A. A. Fraerman, V. V. Chernov, N. I. Chkhalo

Analysis of cross-correlation of interface roughness in multilayer structures with ultrashort periods

Journal of Experimental and Theoretical Physics 103 (2006) 346–353

The diffusion scattering method is used for studying a series of W/B4C multilayer structures with ultrashort periods (d = 0.8-1.5 nm). A simple theoretical model is described; the model takes into account both the dynamic effects in the interaction of counter-propagating diffuse-scattered waves and the mixing of film materials at the boundaries of the layers. It is shown that multilayer structures with a number of bilayers up to N = 700 and values of periods up to 0.8 nm are multilayer structures, which are well-correlated along the boundaries and exhibit resonance diffuse scattering. For structures with a period d > 1.1 nm, the largest contribution to the imperfection of boundaries comes not from the roughness, but from mixing of the films. The range of minimal periods of multilayer structures, for which the continuity of the films is preserved, is determined. The effect of "smoothing" of the substrate surface is discovered in multilayer structures with intact continuity; this contradicts to a certain extent the assumption concerning complete longitudinal correlation of roughnesses, which forms the basis of the theory.

Cited Articles

1. Holý V., Kuběna J., Ohlídal I., Lischka K., Plotz W.,
   X-ray reflection from rough layered systems,
   Physical Review B 47 (1993) 15896–15903