Off-Axis Electron Holography of Nearly-Spherical Faceted Voids in Self-Annealed Implanted Silicon

摘要

Nearly spherical voids, with a size on the order ofsome tens of nanometers, are defects that have recently attracted arenewed interest, due to their capability to getter impurities andpoint defects in silicon. High-resolution electron holography isemployed here to study the three-dimensional configuration ofnearly spherical cavities obtained by l00keV P+ ion bombardmentof a silicon wafer using an ion beam with a power density of about40 W/cm~2 for 4 sec. Reconstructed phase maps have been usedto obtain the qualitative topography of the cavity shape as well asquantitative measurements of the depth variations. Faceting of thenearly spherical voids is discussed in detail.