Process for Fabricating High Aspect-Ratio Tapered Nanocone Structures

Nanocone structured materials can be used for self-cleaning, anti-glare displays (e.g., glasses, windshields) and increasing solar panel efficiency. The material's unique structure allows for both antifogging and self-cleaning. This technology is a fabrication method for nanocone structures.  

Problem Addressed   

Nanostructured materials are utilized for their superior optical and wetting properties, such as antireflection and superhydrophobicity/hydrophilicity. However, fabricating defect-free nanostructured surfaces with multiple functionality has remained a challenge. Conventional technologies use a single hardmask in the etching process, which limits the final height of the material to the material of the hardmask and its thickness. The proposed technology is based on multi-step plasma etching and uses shrinking masks to achieve more flexible choices in materials and thickness for better control of the height and profile of the nanocone structures.  

Technology

The key feature of this technology is its utilization of mask materials that are etched, but at a much slower rate than the substrate, which allows the tapered nanocone profile. By controlling the etching rate and size of the mask material, the nanocone structure is determined. These nanocones have the advantage of multifunctionality (i.e. antifogging and self-cleaning) because of their high aspect ratio.  

Advantages     

• Anti-glare
• Anti-fog
• Self-clean
• Compatible and adaptable to conventional 2-D lithography techniques
• Both aspect ratio and profile of nanocone structure can be controlled