Diffraction from surface growth fronts

Abstract

The characteristics of a multilayer stepped surface structure relevant to the growth of thin films has been described in the reciprocal space based on the dynamic scaling description of the interface growth. It is shown that the angular intensity distribution of a diffraction beam, in general, contains a \ensuremath{\delta} function at the central peak position and a diffuse intensity which is a sum of an infinite number of special functions with different widths. At the vicinity of the in-phase diffraction condition, the \ensuremath{\delta} intensity is the dominant component in the angular profile, which shows a steady decay as a function of the growth time. In contrast, at the near out-of-phase diffraction condition, the angular profiles become purely diffusive and time invariant. This time-invariant behavior reflects the dynamic scaling characteristics of thin-film growth. The applications of the theory to techniques such as x-ray diffraction, electron diffraction, and light scattering are discussed. It is shown that the growth exponents associated with the growth parameters such as the surface width can be easily obtained from the measured diffraction intensity using these diffraction techniques.