Structural and geometrical features of copper seed cones observed by high‐resolution electron microscopy

Structural and geometrical properties of cones developed on Cu surfaces bombarded with obliquely incident Ar⁺ ions while simultaneously supplying ‘‘seeds’’ by sputtering were determined in atomic detail, by means of high‐resolution electron microscopy. The seed materials employed were Mo, W, Ta, Ti, and Pt, and sputtered seed atoms were found to coat the upper cone slopes which received high seed fluxes, independently of seed species. The seed films thus formed were monocrystalline for Mo, W, and Pt, and amorphous or semiamorphous for Ta and Ti. Geometrically, the cones induced by Mo, W, Ta, and Ti were conelike, but those formed on the Pt‐seeded surfaces were tentlike rather than conelike. For the conelike geometries, the tip of seed layer was grown so as to shield the substrate part of the cone from the ion beam. Perhaps, seed atoms must be more resistant to sputtering than target atoms, for seed cones to be conelike.