Search results for "electron-beam lithography"
showing 10 items of 36 documents
2D photonic defect layers in 3D inverted opals on Si platforms
2006
Dielectric spheres synthesised for the fabrication of self-organized photonic crystals such as opals offer large opportunities for the design of novel nanophotonic devices. In this paper, we show a hexagonal superlattice monolayer of dielectric spheres inscribed on a 3D colloidal photonic crystal by e-beam lithography. The crystal is produced by a variation of the vertical drawing deposition method assisted by an acoustic field. The structures were chosen after simulations showed that a hexagonal super-lattice monolayer in air exhibits an even photonic band gap below the light cone if the refractive index of the spheres is higher than 1.93.
Au-PVA Nanocomposite Negative Resist for One-Step Three-Dimensional e-Beam Lithography
2009
Au nanoparticles are synthesized in situ upon the electron beam exposure of a poly(vinyl alcohol) (PVA) thin film containing Au(III). The e-beam-irradiated areas are insoluble in water (negative-tone resist), and Au-PVA nanocomposite patterns with a variable profile along the structure can be thus generated (3D lithography) in a single step. A local characterization of the generated patterns is performed by high-resolution transmission electron microscopy and UV-vis localized surface plasmon resonance microspectroscopy. This characterization confirms the presence of crystalline nanoparticles and aggregates.
Growth of osteoblasts on lithographically modified surfaces
2007
Here we report about preliminary investigations on developing substrates for culturing osteoblasts, the cells responsible for production of mineralised bone, by lithographically modifying the surfaces of several materials. The proton beam writing system at the National University of Singapore was used to fabricate high aspect ratio structures in PMMA, while two-dimensional low aspect ratio structures were fabricated using conventional electron beam lithography (EBL) and UV lithography (UVL) in SU-8. It was found that oxygen plasma treatment of structured SU-8 surfaces changed the surface layer and significantly improved cell attachment and proliferation. Cells grown on patterned thick PMMA …
Fabrication of microfluidic devices using MeV ion beam Programmable Proximity Aperture Lithography (PPAL)
2008
Abstract MeV ion beam lithography is a direct writing technique capable of producing microfluidic patterns and lab-on-chip devices with straight walls in thick resist films. In this technique a small beam spot of MeV ions is scanned over the resist surface to generate a latent image of the pattern. The microstructures in resist polymer can be then revealed using a chemical developer that removes exposed resist, while leaving unexposed resist unaffected. In our system the size of the rectangular beam spot is programmably defined by two L-shaped tantalum blades with well-polished edges. This allows rapid exposure of entire rectangular pattern elements up to 500 × 500 μm in one step. By combin…
Efficient photo-thermal activation of gold nanoparticle-doped polymer plasmonic switches
2012
International audience; We report on the photo-thermal activation of dielectric loaded plasmonic switches comprised of gold nanoparticle-doped polymer deposited onto a gold film. The plasmonic switches rely on a multi-mode interferometer design and are fabricated by electron beam lithography applied to a positive resin doped with gold nanoparticles at a volume ratio of 0.52%. A cross-bar switching is obtained at telecom wavelengths by pumping the devices with a visible beam having a frequency within the localized surface plasmon resonance band of the embedded nanoparticles. By comparing the switching performances of doped and undoped devices, we show that for the modest doping level we cons…
Optical Near-Field Properties of Lithographically Designed Metallic Nanoparticles
1999
ABSTRACTWe report on the experimental observation of localized surface plasmons sustained by small metallic particles using a photon scanning tunneling microscope (PSTM). The surface plasmons are excited in gold nanostructures tailored by electron beam lithography. The constant height operation of the PSTM allowed a direct comparison with theoretical computations of the distribution of the optical near-field intensity. Plasmon coupling above a chain of Au particles and electromagnetic energy transfer from a resonantly excited nanoparticle to a nanowire are demonstrated. Our experimental results appear to be in good agreement with theoretical computations based on the Green's Dyadic Techniqu…
Critical current modulation induced by an electric field in superconducting tungsten-carbon nanowires
2021
The critical current of a superconducting nanostructure can be suppressed by applying an electric field in its vicinity. This phenomenon is investigated throughout the fabrication and electrical characterization of superconducting tungsten-carbon (W-C) nanostructures grown by Ga+ focused ion beam induced deposition (FIBID). In a 45 nm-wide, 2.7 μm-long W-C nanowire, an increasing side-gate voltage is found to progressively reduce the critical current of the device, down to a full suppression of the superconducting state below its critical temperature. This modulation is accounted for by the squeezing of the superconducting current by the electric field within a theoretical model based on th…
Bloch Modes Coupling in Photonic Crystal Waveguides
2005
We investigate the properties of Bloch modes inside a photonic crystal waveguide. By using simultaneously a near field optical microscope and a transmittance setup, we demonstrate that Bloch modes having different parity are coupled.
Resist-based silver nanocomposites synthesized by lithographic methods
2010
In this work, the formation of silver metal nanoparticles inside a negative-tone resist based on poly(vinyl alcohol) is achieved by electron beam lithography. The chemistry of this sensitive resist allows the production of nanoparticles as well as the polymer crosslinking by the electron radiation. Due to the presence of the silver nanoparticles, the final composite exhibits a plasmonic behavior, which was characterized by measuring the absorbance. The lithographic properties of the resist have been characterized. The technique has also been exported to UV lithography, where silver nanoparticles are obtained inside the polymeric patterns after optical lithography.
Analysis of the angular acceptance of surface plasmon Bragg mirrors
2007
International audience; We analyze an important aspect of the behavior of surface plasmon polariton (SPP) Bragg mirrors: the dependence of the angular acceptance for reflection on the incidence angle. By means of leakage radiation microscopy, both in direct and Fourier space, we observe that the angular acceptance diminishes for increasing incidence angles. This effect, which can considerably affect the design of devices based on these elements, is shown to be the consequence of the decrease of the bandgap width with increasing incidence angle. (c) 2007 Optical Society of America.