Effect of Multiple Depositions and Annealing Treatments on the Erbium Silicide Nanoislands Self-Assembled on Si(001) Substrates

Erbium silicide nanoislands on Si(001) surface are fabricated by novel multiple depositions and annealing treatments method. The morphological investigations determine that the islands could grow with stable square shapes rather than the shape transformation exhibited in the traditional single time evaporation growth. Size distributions analyses further elucidate the effect of multiple depositions and annealing treatments on the nanoisland growth. It is suggested that strain relaxation and static coalescence play important roles in the cyclic growth. Specifically, after 15 times of the cycles, the larger islands are found to undergo the Ostwald ripening, which make the shape of nanoislands irregular. This gives us the direction to adjust the growth parameters to control the island morphology. Furthermore, the crystalline structure of the Er silicide nanoislands is efficiently characterized by grazing incidence synchrotron x-ray diffraction.