Surfactant mediated growth of Sb clusters on Si(1 1 1) surface

Abstract

Adsorption kinetics of Sb onto the Si(1 1 1) surface has been modified by incorporation of a Si(1 1 1)–In(√3×√3) surface phase (θ In = 1 3 ML) . In contrast to Sb adsorption on the clean Si surface, the formation of Sb nano-size clusters with good crystalline quality was observed below ≈200°C. Hemispherical clusters grow up to the saturation coverage of about 3 ML and stabilize in the average diameter and height of 40 and 5 nm, respectively, occupying approximately 15% of the surface (cluster density is estimated at 1.2×10 10 clusters/cm 2). The structure of clusters is determined to be a double-domain rhombohedral with (0 0 0 1) stacking. Both structure and lattice parameters of the clusters coincide with those of bulk Sb. The inter-cluster surface is covered with a Sb(2×1) surface phase ( θ Sb=1 ML). Using reflection high-energy electron diffraction and scanning tunneling microscopy techniques it has been found that indium acts as a surfactant providing layer-by-layer growth of Sb clusters. By increasing the coverage of initial In layer, the higher cluster density can been achieved.