He scattering study of the nucleation and growth of Cu(100) from its vapor

Abstract

The nucleation and growth of layers of Cu deposited in ultrahigh vacuum on Cu(100) has been studied by He scattering. The intensity of the specular beam shows oscillations as a function of coverage, with maxima occurring at the completion of successive monolayers. The amplitude of these oscillations depends on both temperature and angle of incidence. An analysis of the dependence with the incident angle at fixed coverage, combined with the Bragg conditions for interference, provides an accurate method for determining the height of the two-dimensional islands formed in the process of crystal growth. We find a value of 1.80\ifmmode\pm\else\textpm\fi{}0.06 A\r{} in excellent agreement with x-ray determination of interlayer spacing of (100) planes. Measurements of the angular profile of the specular peak give an estimation of the average island size at different temperatures.