Impact of Atomic Layer Deposition to Nanophotonic Structures and Devices

Abstract

We review the significance of optical thin films by Atomic Layer Deposition (ALD) method to fabricate nanophotonic devices and structures. ALD is a versatile technique to deposit functional coatings on reactive surfaces with conformal growth of compound materials, precise thickness control capable of angstrom resolution, and coverage of high aspect ratio nano-structures using wide range of materials. ALD has explored great potential in the emerging fields of photonics, plasmonics, nano-biotechnology, and microelectronics. ALD technique uses sequential reactive chemical reactions to saturate a surface with a monolayer by pulsing of a first precursor (metal alkoxides or covalent halides), followed by reaction with second precursor molecules such as water to form the desired compound coatings. The targeted thickness of the desired compound material is controlled by the number of ALD-cycles of precursor molecules that ensures the self-limiting nature of reactions. The conformal growth and filling of TiO 2 and Al 2 O 3 optical materials on nanostructures and their resulting optical properties have been described. The low temperature ALD-growth on various replicated sub-wavelength polymeric gratings is discussed.

Recent Advances in Resonant Waveguide Gratings

“…Deposition techniques such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma deposition, atomic layer deposition (ALD), or RF sputtering allow the creation of waveguiding layers with high uniformity and accuracy, as well as multilayer stacks. The waveguiding layer(s) define primarily the guided mode effective index, and therefore the resonance frequency; accurately controlling the deposition is critical in many applications.…”

Gold Nanoparticles in Photonic Crystals Applications: A Review

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Fabrication of buried nanostructures by atomic layer deposition

“…In this paper we present a fabrication technique that satisfies the requirements stated above. We use Atomic Layer Deposition (ALD) 1 – 3 to grow a thin film of Titanium Dioxide (TiO 2 ) on top of a nanostructured surface-relief profile to form an element with a nearly flat top surface. TiO 2 is an excellent choice as a cover material due to its transparency over a wide spectral bandwidth, stability at high temperatures, relatively large dielectric constant, and high mechanical and chemical robustness.…”