Integration method for directly analyzing interface statistics of periodic multilayers from X‐ray scattering. (1st January 2014)

• Record Type: Journal Article
• Authors: Li, Haochuan; Zhu, Jingtao; Wang, Zhanshan; Chen, Hong; Wang, Yuzhu; Wang, Jie
• Is Part Of: Journal of synchrotron radiation. Volume 21:Part 1(2014)
• Page Start: 97
• Page End: 103
• Publication Date: 2014-01-01
• Subjects: Synchrotron radiation -- Periodicals; Free electron lasers -- Periodicals; 539.73505
• DOI: 10.1107/S1600577513024296
• Languages: English
• ISSNs: 0909-0495

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>An integration method is demonstrated for directly determining the average interface statistics of periodic multilayers from the X‐ray scattering diagram. By measuring the X‐ray scattering diagram in the out‐of‐plane geometry and integrating the scattered intensity along the vertical momentum transfer <italic>q</italic>_{<italic>z</italic>} in an interval, which is decided by the thickness ratio Γ (ratio of sublayer's thickness to periodic thickness), the cross‐correlations between different interfaces are canceled and only the autocorrelations are reserved. Then the multilayer can be treated as a `single interface' and the average power spectral density can be obtained without assuming any vertical correlation model. This method has been employed to study the interface morphology of sputter‐deposited W/Si multilayers grown at an Ar pressure of 1–7 mTorr. The results show an increase in vertical correlation length and a decrease in lateral correlation length with increased Ar pressure. The static roughness exponent α = 0 and dynamic growth exponent <italic>z</italic> = 2 indicate the Edwards–Wilkinson growth model at an Ar pressure of 1–5 mTorr. At an Ar pressure of 7 mTorr, α = 0.35 and <italic>z</italic> = 1.65 indicate the Kardar–Parisi–Zhang growth model.</p> </abstract>