Phase formation within Au and Ge nanoislands by room temperature ion irradiation

We investigate the effects of room-temperature irradiation of Au and Ge nanoislands grown on Si. Our studies show the formation of Au-Ge alloy phase within the islands and wetting of the substrate. High-resolution transmission electron microscopy along with synchrotron radiation-based x-ray reflectivity and grazing incidence x-ray diffraction measurements were performed to characterize the irradiation-induced changes brought into the sequentially deposited Au and Ge island thin films. The results are attributed to the recoil implantation and the transient melting of the nanoislands followed by the formation of crystalline alloy phase.