Evolution of surface morphology at the early stage of Al₂O₃film growth on a rough substrate

Abstract

We present an experimental study of the evolution of the surface of a growing film as a function of the statistical parameters of the virgin substrate roughness. The growth of sputter-deposited Al(2)O(3) films onto Si substrates was followed in situ using an x-ray scattering technique. Despite the use of substrates presenting different roughness correlation length and crystallographic orientation, the evolution of the film roughness is demonstrated to obey the same scaling law, i.e., with the same static and dynamic exponents. Approaches to accurately determine the scaling exponents from x-ray scattering data are discussed.

Growth of nano-dots on the grazing-incidence mirror surface under FEL irradiation

“…16(c) correlates better with the experimental data. Notice that the fractal parameter of 0.2-0.3 and the correlation length of a fraction of micrometer are rather typical of the intrinsic roughness of several tens of nanometers thick films deposited by magnetron sputtering (see, for example, Filatova et al, 2010;Peverini et al, 2007). At the same time, a direct comparison of our calculations and experimental data is not totally correct because we use a simplified case of a 1 +1-dimension surface when modeling the contamination layer growth.…”

“…7(a) (blue curves). In contrast to the BL3M0 mirror, where the well pronounced 'hump' caused by nano-dots is seen, the PSD function of mirror BL0M0 decreases gradually with spatial frequency and demonstrates behavior that is quite typical for the external film surface roughness (see, for example, Peverini et al, 2007;Filatova et al, 2010). The r.m.s.…”

The effect of different etching modes on the smoothing of the rough surfaces

“…Based on a few essential factors that determine the exponents characterizing the scaling behavior, the roughness and growth exponents a and b respectively, are uniquely defined for an universality class. It was shown that the growth exponent for the surface roughness lies in the interval 0.2 70.01 [10]. Its value for the smoothing process, however, has not been established yet.…”

“…It was shown that the roughness usually obeys simple scaling laws. The scaling laws for the roughness process have been established [10]. To the author's knowledge, the scaling laws for the smoothing mechanism have not been determined yet.…”

General laws of X-ray reflection from rough surfaces: II. Conformal roughness

“…At the same time, modern deposition methods result in very small intrinsic roughnesses (0.1-0.2 nm for films several tens of nanometers thick); their correlation lengths are also fairly small (several tenths of a micrometer) [22,23]. Therefore, the film and substrate roughnesses turn out to be com pletely correlated (conformal) in the frequency range ν < 1-10 µm -1 for films with thicknesses from several nanometers to several tens of nanometers [6,22].…”