Submicrometer 3D structures fabrication enabled by one-photon absorption direct laser writing

In this paper, we report gold micro/nanostructures fabricated by a method called lithographically patterned nanostructure by chemical etching (LPNCE). In the LPNCE method, the photoresist layer, composed of pentaerythritol triacrylate (PETA, monomer) and isopropyl thioxanthone (ITX, photoinitiator), is dropped on gold film, and subsequently polymerized via two-photon absorption of 800 nm femtosecond laser. Micro/nanostructures are fabricated by the direct laser writing. The unpolymerized photoresist is washed by isopropanol, and the exposed gold is dissolved by KI 3 aqueous solution. Finally, polymers are removed by NaOH ethanol solution. Arbitrary 2D gold micro/nanostructures can be fabricated quickly by the direct laser writing and chemical etching method. The good electro-conductibility of these micro/nanostructures guarantees wide applications in micro-electronic devices, plasmonics and biosensors, etc.

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Processes of Direct Laser Writing 3D Nano-Lithography

10.20944/preprints201812.0119.v1 ◽

2018 ◽

Cited By ~ 2

Author(s):

Simonas Varapnickas ◽

Mangirdas Malinauskas

Keyword(s):

Photon Absorption ◽

Polymerization Process ◽

Polymerization Reaction ◽

Size Analysis ◽

Direct Laser Writing ◽

Ambient Conditions ◽

Laser Writing ◽

Linear Absorption ◽

Laser Lithography ◽

Direct Laser

Direct laser writing three-dimensional nano-lithography is an established technique for manufacturing functional 3D micro- and nano-objects via non-linear absorption induced polymerization process. In this Chapter an underlying physical mechanisms taking place during nano-confined polymerization reaction, induced by tightly focused ultra-short laser pulses, are reviewed and discussed. The special attention is paid on the effects that directly impact structuring resolution and minimum achievable feature size. Analysis of possible photo-initiation mechanisms as contributing multi-photon absorption and avalanche ionization in pre-polymers under diverse exposure conditions (wavelength, pulse duration) is presented. Feasible structuring of pure (non-photosensitized) and functional nanoparticles doped polymer precursors is justified and benefits of such materials/structures for microoptics, photonics and cell scaffolds are highlighted. The influence of temperature effects (induced by writing process itself or determined by ambient conditions) on polymerization process, observed in different pre-polymers under diverse exposure regimes is outlined. The further adjustment of the structuring resolution is possible via precise control of light polarization and diffusion assisted radical quenching. The work is concluded with a brief outlook on future challenges and perspectives related to refinement of 3D ultra-fast laser lithography fabrication process in the means of application of diverse post-processing methods and research into novel photo-curable materials including inorganic ones.

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Fabrication of Multi-material 3D Structures by the Integration of Direct Laser Writing and MEMS Stencil Patterning

10.31224/osf.io/vng79 ◽

2018 ◽

Author(s):

Jeremy Reeves ◽

Rachael K. Jayne ◽

Lawrence Barrett ◽

Alice E. White ◽

David J. Bishop

Keyword(s):

Optical Characterization ◽

Optical Response ◽

Optically Active ◽

Direct Laser Writing ◽

Laser Writing ◽

Metallic Structures ◽

3D Structures ◽

Active Structure ◽

Direct Laser

The construction of a complex, 3D optical metamaterial challenges conventional nanofabrication techniques. These metamaterials require patterning of both a deformable mechanical substrate and an optically-active structure with ~200 nm resolution and precision. The soft nature of the deformable mechanical materials often precludes the use of resist-based techniques for patterning. Furthermore, FIB deposition approaches produce metallic structures with considerable disorder and impurities, impairing their optical response. In this paper we discuss a novel solution to this nanofabrication challenge -- the integration of direct laser writing and MEMS stencil patterning. We demonstrate a variety of methods that enable this integration and then show how one can produce optically-active, 3D metamaterials. We present optical characterization data on one of these metamaterials to demonstrate the viability of our nanofabrication approach.

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