Time filter

Source Type

Wurenlingen, Switzerland

Holzer C.,University of Leoben | Gobrecht J.,Institute of Polymer Nanotechnology INKA | Schift H.,Paul Scherrer Institute | Solak H.,Eulitha Inc.
Macromolecular Symposia

Via geometrical micro-and nanostructures new functionalities like controlled wetting properties, biological adhesive / dehesive properties or surface patterns for guided self assembly can be added to polymer surfaces. This is especially interesting for medical or biotechnological applications, because there is no new approval process necessary. The whole process from producing the structures via EUV-interference lithography to the injection moulding will be shown. How far the limits for the smallness of these structures on polymers are already pushed forward show the results from our latest injection moulded samples. Grooves of 18 nm width -this means world record! -could be reproduced in an industrial process and in an economical very interesting high-volume production. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Siegfried T.,Paul Scherrer Institute | Ekinci Y.,Paul Scherrer Institute | Ekinci Y.,ETH Zurich | Solak H.H.,Eulitha Inc. | And 2 more authors.
Applied Physics Letters

We report a high-throughput method for the fabrication of metallic nanogap arrays with high-accuracy over large areas. This method, based on shadow evaporation and interference lithography, achieves sub-10 nm gap sizes with a high accuracy of ±1.5 nm. Controlled fabrication is demonstrated over mm 2 areas and for periods of 250 nm. Experiments complemented with numerical simulations indicate that the formation of nanogaps is a robust, self-limiting process that can be applied to wafer-scale substrates. Surface-enhanced Raman scattering (SERS) experiments illustrate the potential for plasmonic sensing with an exceptionally low standard-deviation of the SERS signal below 3 and average enhancement factors exceeding 1 × 10 6. © 2011 American Institute of Physics. Source

Wang L.,Paul Scherrer Institute | Solak H.H.,Eulitha Inc. | Ekinci Y.,Paul Scherrer Institute | Ekinci Y.,ETH Zurich
Proceedings of SPIE - The International Society for Optical Engineering

Metallic wire-grid polarizers (WGP) transmit TM-polarized light (transverse magnetic) and reflect TE polarization (transverse electric) efficiently. They are compact, planar and compatible with integrated circuit (IC) fabrication, which simplifies their use as optical components in nanophotonic, fiber optic, display, and detector devices. In this work, Al bi-layer WGPs were designed and numerically simulated using finite element methods. Optical properties of the polarizers were analyzed in the deep-ultraviolet (DUV) to infrared (IR) regions. It was observed that Al bi-layer WGPs show broadband and high TM transmission and extinction ratio. A comparison of the performances of single and bi-layer WGPs show that the latter is highly advantageous over the former one. An extensive study of the dependence of the optical properties of single and bi-layer WGPs on structural parameters, such as period, metal thickness, and, duty cycle (DC), is provided. Optimal structural parameters are obtained within the feasible parameters in terms of nanofabrication. An Al bi-layer polarizer with a period of 80 nm and a metal layer thickness of 40 nm showed transmission up to 80% and extinction of 40 dB (10 4) and broadband polarizing behavior down to a wavelength of 250 nm. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE). Source

Wang L.,Paul Scherrer Institute | Solak H.H.,Eulitha Inc. | Ekinci Y.,Paul Scherrer Institute | Ekinci Y.,ETH Zurich

Limited beam spot size is a major limitation of interference lithography. This limits the area of patterning and reduces the pattern homogeneity. We describe a scanning exposure technique to circumvent this problem. We show the generation of uniform and seamless gratings with half-pitches down to 35nm over an area of several mm 2 using EUV interference lithography. The presented technique offers a fast and cost-effective method of fabricating one-and two-dimensional periodic nanostructures with improved uniformity and increased patterning area. © 2012 IOP Publishing Ltd. Source

Sarkar S.S.,Paul Scherrer Institute | Sarkar S.S.,Intel Corporation | Solak H.H.,Paul Scherrer Institute | Solak H.H.,Eulitha Inc. | And 2 more authors.
Optics Express

Fresnel zone plates (FZPs) play an essential role in high spatial resolution x-ray imaging and analysis of materials in many fields. These diffractive lenses are commonly made by serial writing techniques such as electron beam or focused ion beam lithography. Here we show that pinhole diffraction holography has potential to generate FZP patterns that are free from aberrations and imperfections that may be present in alternative fabrication techniques. In this presented method, FZPs are fabricated by recording interference pattern of a spherical wave generated by diffraction through a pinhole, illuminated with coherent plane wave at extreme ultraviolet (EUV) wavelength. Fundamental and practical issues involved in formation and recording of the interference pattern are considered. It is found that resolution of the produced FZP is directly related to the diameter of the pinhole used and the pinhole size cannot be made arbitrarily small as the transmission of EUV or x-ray light through small pinholes diminishes due to poor refractive index contrast found between materials in these spectral ranges. We also find that the practical restrictions on exposure time due to the light intensity available from current sources directly imposes a limit on the number of zones that can be printed with this method. Therefore a trade-off between the resolution and the FZP diameter exists. Overall, we find that this method can be used to fabricate aberration free FZPs down to a resolution of about 10 nm. © 2014 Optical Society of America. Source

Discover hidden collaborations