High resolution HSQ nanopillar arrays with low energy electron beam lithography

Guerfi, Y.; Carcenac, F.; Larrieu, Guilhem

doi:10.1016/j.mee.2013.03.055

Cited by 30 publications

(30 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These nanostructures are fabricated in a topdown approach, where a single layer of negative-tone resist, namely hydrogen silsesquioxane (HSQ), is patterned by electron-beam lithography. 30 Subsequent reactive ion etching in the H = 90 nm Si overlayer of silicon on insulator (SOI) substrates defines the structures. The remaining HSQ-layer on the top of the structures induces an additional SiO 2 capping of approximately 20nm.…”

Section: Sample Preparationmentioning

confidence: 99%

Enhancement of electric and magnetic dipole transition of rare-earth-doped thin films tailored by high-index dielectric nanostructures

et al. 2019

View full text Add to dashboard Cite

We propose a simple experimental technique to separately map the emission from electric and magnetic dipole transitions close to single dielectric nanostructures, using a few nanometer thin film of rare-earth ion doped clusters. Rare-earth ions provide electric and magnetic dipole transitions of similar magnitude. By recording the photoluminescence from the deposited layer excited by a focused laser beam, we are able to simultaneously map the electric and magnetic emission enhancement on individual nanostructures. In spite of being a diffraction-limited far-field method with a spatial resolution of a few hundred nanometers, our approach appeals by its simplicity and high signal-to-noise ratio. We demonstrate our technique at the example of single silicon nanorods and dimers, in which we find a significant separation of electric and magnetic near-field contributions. Our method paves the way towards the efficient and rapid characterization of the electric and magnetic optical response of complex photonic nanostructures.In the last decades, photonic nanostructures emerged as powerful instruments to control light at the subwavelength scale. 1 The interest in nano-optics lies usually in the control of the optical electric field, since the response of materials to rapidly oscillating magnetic fields is extremely weak. Actually, materials with a substantial magnetic response to electromagnetic radiation (i.e. µ = 1) are not known in nature. However, properly designed nanostructures allow to significantly boost the magnetic response. For instance metallic (split-)ring resonators support a magnetic moment which is proportional to the area covered by the ring's aperture. For frequencies in the visible range this area is usually about 10 6 times larger than the equivalent area in atoms, defined by the Bohr radius, which explains the emergence of observable effects related to the optical magnetic field. 2 In consequence, it is possible to overcome the natural limitation to µ = 1 by designing so-called meta-materials, which are ordered arrangements of meta-units like splitring resonators. 3 Using metals requires nanostructures of complex shape to obtain a significant magnetic response. On the other hand, in dielectrics of high refractive index, a magnetic response arises naturally from the curl of the electric field. 4,5 Very simple geometries like spheres 6 or cylinders 7 are actually sufficient to induce a strong magnetic field enhancement. 8 An additional advantage of high-index dielectric nanostructures is their low dissipation. Silicon (Si) for example has a very low absorption through the entire visible range compared to noble metals. 9 This weak absorption associated to the indirect gap in the near infrared becomes cumbersome only for applica- * tions involving propagation of visible light across distances of tens to hundreds of microns. Thus, in submicron dielectric nano-structures the absorption can usually be neglected. 10 In summary, high-index nanostructures seem to provide an appropriate platform to study the co...

show abstract

Section: Sample Preparationmentioning

confidence: 99%

Enhancement of electric and magnetic dipole transition of rare-earth-doped thin films tailored by high-index dielectric nanostructures

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Conventional methods for obtaining periodical nanostructured arrays are lithographic techniques including laser lithography, [ 26,27 ] electron-beam lithography, [28][29][30] X-ray lithography, [ 31 ] atomic force microscope lithography, [ 32 ] scanning tunneling microscopy technology, [ 33 ] and so on. However, these techniques can not be afforded to most laboratories because of their high processing costs and lower production effi ciency.…”

mentioning

confidence: 99%

Spherical Nanoparticle Arrays with Tunable Nanogaps and Their Hydrophobicity Enhanced Rapid SERS Detection by Localized Concentration of Droplet Evaporation

Zhang

Zhou

Liu

et al. 2015

Adv Materials Inter

View full text Add to dashboard Cite

Their properties are usually dependent on morphologies and sizes, and hence the fabrication of controllable uniform micro/nanostructured arrays on a large-scale becomes more important. Conventional methods for obtaining periodical nanostructured arrays are lithographic techniques including laser lithography, [ 26,27 ] electron-beam lithography, [28][29][30] X-ray lithography, [ 31 ] atomic force microscope lithography, [ 32 ] scanning tunneling microscopy technology, [ 33 ] and so on. However, these techniques can not be afforded to most laboratories because of their high processing costs and lower production effi ciency. [ 34 ] In recent decades, with fast development of colloidal science and self-assembly technology, large-scaled monolayer colloidal crystals can be fabricated using highly monodispersed colloidal spheres. [ 35 ] Based on this achievement, another alternative method, colloidal lithography, has been well developed to fabricate multiform periodic micro/nanostructured arrays (i.e., nanoparticle arrays, nanobowl arrays, nanoring arrays, and nanopillar arrays) using these monolayer colloidal crystals as templates or masks [36][37][38][39] by chemical routes including solution-dipping strategy, wet chemical etching, and electrochemical deposition. [40][41][42][43] Such periodic micro/nanostructured array fi lms generally have special rough surfaces, which can be used as SERS-active substrates for detection and identification of organic molecules with trace concentrations. Although chemical routes based on colloidal templates possess advantages of the simple operation, low processing costs, it is still quite diffi cult to achieve micro/nanostructured arrays with very uniform morphology on large-scale by above routes. If these micro/ nanostructured arrays are applied as active substrates in SERS detection, the intensity of SERS spectra in different areas on the sample will fl uctuate in a large range, leading to the failure in practical applications. Whereas other parallel routes, based on physical process method, such as sputtering deposition, pulsed laser deposition, thermal evaporation deposition, atomic layer deposition, and so on, combining with monolayer colloidal crystals template can well resolve these problems. [ 44 ] SERS enhancement activities are mainly dependent on chemical enhancement or local electromagnetic fi eld enhancement at nanoscaled protrusions and cavities. For the latter case, the Periodic hexagonal spherical nanoparticle arrays are fabricated by a sacrificial colloidal monolayer template route by chemical deposition and further physical deposition. The regular network-structured arrays are fi rst templated by colloidal monolayers and then they are changed to novel periodic spherical nanoparticle arrays by further sputtering deposition due to multiple direction deposition and shadow effect between adjacent nanoparticles. The nanogaps between two adjacent spherical nanoparticles can be well tuned by controlling deposition time. Such periodic nanoparticle arrays with gold coatings ...

show abstract

“…After exposure, HSQ was developed by immersion in 25% tetramethylammonium hydroxide (TMAH) for one minute. 44 HSQ patterns were subsequently transferred to the silicon substrate down to the buried oxide by anisotropic reactive ion etching (RIE). Then, the structures were embedded in a 200 nm thick HSQ layer, deposited by spin coating in order to perfectly planarize the sample in a nanometrical range.…”

Section: A Nanofabrication Of Planar Si Structuresmentioning

confidence: 99%

Pushing the limits of optical information storage using deep learning

et al. 2019

View full text Add to dashboard Cite

Diffraction drastically limits the bit density in optical data storage. To increase the storage density, alternative strategies involving supplementary recording dimensions and robust read-out schemes must be explored. Here, we propose to encode multiple bits of information in the geometry of subwavelength dielectric nanostructures. A crucial problem in high-density information storage concepts is the robustness of the information readout with respect to fabrication errors and experimental noise. Using a machine-learning based approach in which the scattering spectra are analyzed by an artificial neural network, we achieve quasi error free read-out of sequences of up to 9 bit, encoded in top-down fabricated silicon nanostructures. We demonstrate that probing few wavelengths instead of the entire spectrum is sufficient for robust information retrieval and that the readout can be further simplified, exploiting the RGB values from microscopy images. Our work paves the way towards high-density optical information storage using planar silicon nanostructures, compatible with mass-production ready CMOS technology.Optical information storage promises perennial longevity, high information densities and low energy consumption compared to magnetic storage media. 1,2The compact disc (CD) and its successors, the DVD and the blue-ray disc, broadly established optical storage in our society. 3,4 Those media are based on storing a single binary digit per diffraction limited area ("zero" or "one"). Several concepts have been proposed to increase the information density in optical storage. Examples are schemes exploiting polarization-sensitive digits, 5 near-field optical recording, 6 the use of fluorescent dyes 7 or three-dimensional approaches like two-photon point-excitation 8 . Yet, all these alternatives suffer from major drawbacks. Either they are hardly superior to commercial planar solutions (polarization-sensitive patterns) or they require very complex storage media (fluorescence) or sophisticated read-out schemes (nearfield recording, two-photon point-excitation). The most promising alternative seemed to be holographic memory, which was proposed in the early 1960ies and makes use of the volume of the storage medium. To date, however, there is still no commercial product available, despite several announcements in the past 20 years. 9,10 In the last decades, photonic nanostructures emerged as powerful instruments to control light at the nanometer scale. 11,12 Localized surface plasmons (LSP) in metal nanoparticles 13 or Mie-type resonances in high-index dielectric structures 14 cover the entire visible spectrum and can be tuned by designing appropriate geometric features. 15,16 Furthermore, the high scattering efficiencies of photonic nanostructures render single-particle spectroscopy relatively easy. In consequence, the idea has been raised to encode information in the rich scattering spectra of plasmonic nanostructures, denser than a single data bit. 17-21 The information density might be even further increased by addre...

show abstract

High resolution HSQ nanopillar arrays with low energy electron beam lithography

Cited by 30 publications

References 14 publications

Enhancement of electric and magnetic dipole transition of rare-earth-doped thin films tailored by high-index dielectric nanostructures

Enhancement of electric and magnetic dipole transition of rare-earth-doped thin films tailored by high-index dielectric nanostructures

Spherical Nanoparticle Arrays with Tunable Nanogaps and Their Hydrophobicity Enhanced Rapid SERS Detection by Localized Concentration of Droplet Evaporation

Pushing the limits of optical information storage using deep learning

Contact Info

Product

Resources

About