7,305 research outputs found
Organization of Block Copolymers using NanoImprint Lithography: Comparison of Theory and Experiments
We present NanoImprint lithography experiments and modeling of thin films of
block copolymers (BCP). The NanoImprint lithography is used to align
perpendicularly lamellar phases, over distances much larger than the natural
lamellar periodicity. The modeling relies on self-consistent field calculations
done in two- and three-dimensions. We get a good agreement with the NanoImprint
lithography setups. We find that, at thermodynamical equilibrium, the ordered
BCP lamellae are much better aligned than when the films are deposited on
uniform planar surfaces
Fabrication of hydrophobic inorganic coatings on natural lotus leaves for nanoimprint stamps
Hydrophobic inorganic films were obtained by direct deposition of copper or
silicon onto natural lotus leaves by ion beam sputtering deposition technique.
Scanning electron microscopy observations showed a lotus-leaf-like surface
structure of the deposited inorganic films. Hydrophobic nature of the inorganic
films on lotus leaves had been improved compared to the inorganic films
deposited on flat silicon substrates. Water contact angles measured on the
lotus-leaf-like copper and silicon films were 136.3 \pm 8{\deg} and 117.8 \pm
4.4{\deg}, respectively. The hydrophobic lotus-leaf-like inorganic films had
been repeated used as nanoimprint stamps. Negative structures of
lotus-leaf-like inorganic films were obtained on the polystyrene resist layers.Comment: 14 pages, 6 figure
Low loss high index contrast nanoimprinted polysiloxane waveguides
Nanoimprint lithography is gaining rapid acceptance in fields as
diverse as microelectronics and microfluidics due to its simplicity high
resolution and low cost. These properties are critically important for the
fabrication of photonic devices, where cost is often the major inhibiting
deployment factor for high volume applications. We report here on the use
of nanoimprint technology to fabricate low loss broadband high index
contrast waveguides in a Polysiloxane polymer system for the first time
Multi-silicon ridge nanofabrication by repeated edge lithography
We present a multi-Si nanoridge fabrication scheme and its application in nanoimprint\ud
lithography (NIL). Triple Si nanoridges approximately 120 nm high and 40 nm wide separated\ud
by 40 nm spacing are fabricated and successfully applied as a stamp in nanoimprint lithography.\ud
The fabrication scheme, using a full-wet etching procedure in combination with repeated edge\ud
lithography, consists of hot H3PO4 acid SiNx retraction etching, 20% KOH Si etching, 50% HF\ud
SiNx retraction etching and LOCal Oxidation of Silicon (LOCOS). Si nanoridges with smooth\ud
vertical sidewalls are fabricated by using Si 110 substrates and KOH etching. The presented\ud
technology utilizes a conventional photolithography technique, and the fabrication of multi-Si\ud
nanoridges on a full wafer scale has been demonstrated
Integrated 3D Hydrogel Waveguide Out-Coupler by Step-and-Repeat Thermal Nanoimprint Lithography: A Promising Sensor Device for Water and pH
Hydrogel materials offer many advantages for chemical and biological sensoring due to their response to a small change in their environment with a related change in volume. Several designs have been outlined in the literature in the specific field of hydrogel-based optical sensors, reporting a large number of steps for their fabrication. In this work we present a three-dimensional, hydrogel-based sensor the structure of which is fabricated in a single step using thermal nanoimprint lithography. The sensor is based on a waveguide with a grating readout section. A specific hydrogel formulation, based on a combination of PEGDMA (Poly(Ethylene Glycol DiMethAcrylate)), NIPAAm (N-IsoPropylAcrylAmide), and AA (Acrylic Acid), was developed. This stimulus-responsive hydrogel is sensitive to pH and to water. Moreover, the hydrogel has been modified to be suitable for fabrication by thermal nanoimprint lithography. Once stimulated, the hydrogel-based sensor changes its topography, which is characterised physically by AFM and SEM, and optically using a specific optical set-up
Overlay Accuracy Limitations of Soft Stamp UV Nanoimprint Lithography and Circumvention Strategies for Device Applications
In this work multilevel pattering capabilities of Substrate Conformal Imprint
Lithography (SCIL) have been explored. A mix & match approach combining the
high throughput of nanoimprint lithography with the excellent overlay accuracy
of electron beam lithography (EBL) has been exploited to fabricate nanoscale
devices. An EBL system has also been utilized as a benchmarking tool to measure
both stamp distortions and alignment precision of this mix & match approach. By
aligning the EBL system to 20 mm x 20 mm and 8 mm x 8 mm cells to compensate
pattern distortions of order of over 6 inch wafer area, overlay
accuracy better than has been demonstrated. This result can
partially be attributed to the flexible SCIL stamp which compensates
deformations caused by the presence of particles which would otherwise
significantly reduce the alignment precision
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