研究目的
To elucidate the role of the incidence angle in the formation of nanostructures on Ge surfaces irradiated with 26 keV Au ions, specifically focusing on the evolution of patterns such as ripples and terraces, and to understand the underlying physical processes including the effects of ion implantation and surface composition changes.
研究成果
The study identifies three topographical regimes for Ge surfaces irradiated with medium-energy Au ions: a sponge-like structure at low angles (0°-30°), rippled patterns at intermediate angles (30°-75°), and terraced structures with progressive break-up at high angles (75°-85°). The evolution is influenced by incidence angle, with transitions driven by mechanisms like vacancy clustering, curvature-dependent sputtering, and nonlinear processes. No ripple rotation occurs, and Au implantation affects surface composition. The findings highlight the complexity of pattern formation and caution against a universal theoretical framework for semiconductor surfaces under ion irradiation.
研究不足
The study is limited to Ge surfaces and Au ions at specific energies and fluences; results may not generalize to other materials or ion types. The analysis relies on surface techniques with limited depth penetration (e.g., XPS sampling depth ~2.3 nm), and shadowing effects at high angles may complicate interpretations. The absence of perpendicular-mode patterns and the specific angular ranges studied constrain the universality of the findings.
