Formation of Pores in Thin Germanium Films under Implantation by Ge + Ions

Results are presented of a study of the morphology of germanium films nanostructured by ion implantation. Film samples were grown by magnetron sputtering in an ultrahigh-vacuum installation and then irradiated with 40 keV Ge + ions at fluences in the range of (1.8–8) × 10 16 ions/cm 2 . Scanning electron microscopy demonstrated that vacancy complexes with diameters of ~50–150 nm are gradually formed in the bulk of implanted germanium with increasing implantation fluence. After a certain implantation fluence is reached, the complexes emerge on the surface, thereby forming a developed surface profile of the irradiated films.