UHV deposition of Co thin films on low index Si surfaces

Abstract

XPS and AFM were used to study the effect of hydrogen on the Co-Si reaction, Co growth mode, diffusion behaviour and morphology evolution on Si(001) and Si(111) substrates. The a??Co-Sia?? reaction occurs on both H-terminated and clean surfaces. Co grows in a pseudo-layer-by-layer manner on H-terminated Si surfaces while small close-packed island growth mode is observed on the clean Si surfaces. Upon annealing, Co concentration decreases with annealing time. The presence of hydrogen appears to delay the on-set of Co diffusion. The islands formed on Si(001) surface after annealing are rectangular while triangular islands are observed on Si (111) surface.