<p><i>This paper presents the optimization for obtaining ultra-high aspect ratio nanostructures by GLancing Angle Deposition (GLAD).&nbsp; GLAD is a bottom-up, physical deposition process for creating nanometer-level features by shadows cast by seeds on the substrate at high incident angles.&nbsp; Based on the seeds used, GLAD can be categorized into two types: GLAD with natural seeds and pre-defined seeds (pre-seeds).&nbsp; When natural seeds are used, the seeds are randomly distributed with sub-100 nm sizes, and the percentage of coverage of the substrate is determined simply by the incident angle of the vapor.&nbsp; When the pre-seeds are used, the features can be redistributed and regrouped to generate new periodic nanostructures.&nbsp; This paper discusses&nbsp;how to obtain ultra-high aspect ratio nanopillars from natural seeds and ultra-high aspect ratio nanoribbons from pre-defined line seeds by GLAD.&nbsp; In the discussion on GLAD with natural seeds, an in-depth study on the dependence of the aspect ratio on the incident angle is provided; resolvable nanopillars are obtained with aspect ratio over 1:20, and the growth mechanism is proposed for pillars with high deposition angles.&nbsp; Next, line seeds used in the GLAD process for creating high aspect ratio nanoribbons are discussed.&nbsp; Proper design and process parameters are discussed for controlling the morphologies of nanoribbons.&nbsp; The ultra-high aspect ratio nanostructures are potentially used for applications including sensing, surface property alteration, and the creation of nanoporous structures.</i></p>

Optimization of Ultra-High Aspect Ratio Nanostructures Fabricated Using Glancing Angle Deposition

Paper Proceedings: https://asmedigitalcollection.asme.org/MSEC/MSEC2021/volume/85062

2021 International Manufacturing Science and Engineering Conference (MSEC2021)

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