Texture evolution during shadowing growth of isolated Ru columns

The Ru vertical rods with different lengths were grown by dc magnetron sputtering under oblique angle deposition with substrate rotation. The deposition rate was 4.1±0.20.3em0exnm∕min and the substrate was near room temperature during the growth. The crystalline structure and morphology of these rods were characterized as a function of time by reflection high energy electron diffraction (RHEED), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We observed that the rods developed a (101̄0) texture and the dispersion angle Δθ of the texture evolved in a power law relationship with respect to time t before saturation, Δθ~tᵖ, where p=-0.49±0.01. Through the analysis of the SEM images, we can correlate the evolution of the dispersion of columns tilt angle to the evolution of the texture axis extracted from RHEED patterns. The power law relationship is consistent with our simulations based on a modified needle model.