Growth of Ge/Si(100) Nanostructures by Radio-Frequency Magnetron Sputtering: the Role of Annealing Temperature

Surface morphologies of Ge islands deposited on Si(100) substrates are characterized and their optical properties determined. Samples are prepared by rf magnetron sputtering in a high-vacuum chamber and are annealed at 600°C, 700°C and 800°C for 2 min at nitrogen ambient pressure. Atomic force microscopy, field emission scanning electron microscopy, visible photoluminescence (PL) and energy dispersive x−ray spectroscopy are employed. The results for the annealing temperature-dependent sample morphology and the optical properties are presented. The density, size and roughness are found to be strongly influenced by the annealing temperature. A red shift of ∼0.29 eV in the PL peak is observed with increasing annealing temperature.