LabAdviser/Technology Research/Fabrication of Hyperbolic Metamaterials using Atomic Layer Deposition/AZO gratings

Procces flow description

All samples were prepared and characterized in a class 100 cleanroom. Si (100) wafers of 150 mm were used as a substrate. The main steps in the gratings manufacturing are shown in a figure below. First, the silicon trenches were realized by deep reactive ion etching (DRIE). Then, the trenches were ALD coated. After the selective removal of the top parts, the silicon core between ALD coatings was etched away during the last step. The final structure represents the highly anisotropic vertical grating. Each fabrication step was carefully evaluated using cross-sectional scanning electron microscopy (SEM) imaging.

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  Scheme of fabrication flow. High aspect ratio Al₂O₃ and TiO₂ nanogratings.