Surface nanostructures on low energy Zn ion implanted crystalline Si and their thermal evolution at different atmospheres

Cz n-type Si (1 0 0) wafers were implanted with 45 keV Zn ions at a fluence of 1.0 × 1017 ions/cm2. Formation of surface nanostructures, their structures and thermal evolution in different atmospheres have been studied. Our results clearly show that creation of surface nanostructures depends strongly on both annealing temperature and atmosphere. In nitrogen ambient, hemispherical nano-sized bumps could be effectively observed on the Zn-implanted Si surface after annealing at 600 °C, and their sizes increase with the annealing temperature up to 800 °C. However, in the oxygen ambient, hemispherical nano-sized bumps created at 600 °C could be transferred to winding patterns after 800 °C annealing. The results from X-ray photoelectron spectroscopy and grazing X-ray diffraction measurements reveal production of Zn NPs near the Si surface in as-implanted state. The thermal growth and transformation of such NPs during annealing contribute to formation and evolution of the observed surface nanostructures.