研究目的
To investigate the effect of deposition angle on the fabrication of plasmonic gold nanocones and nanodiscs, focusing on the symmetry and shape of nanostructures formed through the self-shading effect during metal evaporation.
研究成果
The research demonstrates that symmetric metal nanocones can only be formed when the metal deposition direction is almost perfectly perpendicular to the sample surface. Small tilts or lateral shifts during deposition result in asymmetric nanostructures. The findings emphasize the importance of controlling deposition directionality and suggest the potential for fabricating complex interconnected nanocone structures for electrically addressable chips.
研究不足
The study highlights the difficulty in achieving perfectly perpendicular metal deposition to the sample surface, which is crucial for forming symmetric nanocones. The inherent multi-directionality of physical vapor deposition methods and imperfect planar alignment of the substrate can lead to asymmetric nanostructures. These asymmetries are hard to identify in conventional top-view SEM images, suggesting the need for imaging at multiple viewing angles.
1：Experimental Design and Method Selection:
The study utilized electron beam lithography (EBL) and gold electron beam evaporation to fabricate ordered arrays of conical gold nanostructures. The self-shading effect during metal evaporation was exploited to form nanocones inside cylindrical nanowell templates.
2：Sample Selection and Data Sources:
Silicon substrates were cleaned and spin-coated with a positive tone electron beam resist. Hexagonal arrays of circular nanowells with nominal diameters of 50, 100, and 200 nm were patterned by EBL.
3：List of Experimental Equipment and Materials:
A scanning electron microscope (SEM, MIRA3, Tescan) for EBL, an ultra-high vacuum electron beam evaporator (Bestec GmbH) for metal deposition, and a PlasmaPro NGP 80 (Oxford Instruments Ltd.) for O2 plasma treatment.
4：Experimental Procedures and Operational Workflow:
After EBL patterning, the resist was developed, stripped in O2 plasma, and then covered by a titanium adhesion layer and a gold film. The lift-off process was performed to remove the resist and surrounding metal, leaving free-standing nanostructures.
5：Data Analysis Methods:
The shapes of the resulting nanostructures were inspected using SEM imaging at multiple viewing angles to assess symmetry and shape.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
