The effect of Sb on the oxidation of Ge quantum dots

A study on the dry thermal oxidation of Ge quantum dots is proposed. To find the effect of Sb on the oxidation, two kinds of Ge quantum dots were grown on Si (001) substrate with or without a predeposition of Sb. They were oxidized with conventional dry thermal oxidation method at 900 °C and characterized using transmission electron microscopy. ‘Like in the numerous reports on the dry thermal oxidation of SiGe layers, the oxidation rate of Ge quantum dots directly grown on Si layer without Sb was the same to that of pure Si. However, the oxidation rate of the Ge islands grown with a Sb monolayer was significantly enhanced. This result suggests that the lower activation barrier due to the catalytic effect of Sb is the origin of the enhancement of the oxidation rate of the Ge quantum dots grown on Si.