Competing cluster growth: The Cu/Sn/Si(111) system

The phase separation competition of two thin film systems with a thermodynamic propensity toward clustering was studied. Copper and tin bilayers of approximately 40 monolayer total thickness were deposited on Si(111) surfaces, then annealed at temperatures between 300 degreesC and 600 degreesC. At intermediate ratios of Sn and Cu amounts deposited, two different shapes of clusters coexist on the Si(111) surface, while Sn covers the Cu bearing structures at higher amounts, leading to an apparent Sn Ostwald ripening growth dominated by a single characteristic length.