Raith Micrograph Award 2011

Dear community, dear participants,

One more time the Raith Micrograph Award caused many Raith system users to busily share their work with Raith and their worldwide community of electron and ion beam lithography users in R&D.

Raith would like to express our gratitude to every participant who makes for this award by submitting his results, and is looking forward to your commitment for next year's Raith Micrograph Award 2012.

Raith presents those participants, who unfortunately could not be awarded despite of their consummate submissions, with a little thank-you-gift and keep our fingers crossed for you next time. Raith will contact you by e-mail before long.

Focussing on the criterion "uniqueness of nanostructure", the quality of the image as well as the description of the work, we are glad to declare the winners of this award:

Amadeu Griol / Universitat Politecnica de Valencia, Valencia Nanophotonics Technology Center, Spain

It is mandatory the interconnection of PIC (photonic integrated circuits) devices to other technologies such as microelectronics and fibre optics. The small dimensions of the waveguiding solutions, needed for integration, become a tedious drawback to achieve efficient coupling ports to optical fibres. For instance, the designed dimensions of the integrated waveguides are 480x220 nm in the case of SOI technology or 1100x300 nm for SiN technology. In both cases the dimensions are much smaller than those of a single mode fibre (SMF) that shows in standard fibres a Gaussian profile of 10 microns of diameter (Mode Field Diameter, MFD). This is a big issue that requires specific designs in order to reduce the insertion losses of the PIC device. Low efficient coupling has a big impact in the device performance, especially inside a system, affecting to the reach of links, signalling rates, receiver sensitivity requirements, and so on. Gratings couplers consist of periodical patterns that allows vertical coupling. (No shot settings)

Co-author(s): All NTC fabrication group, especially Juan Hurtado and Laurent Bellieres

Integrated photonic technology requires the development of specific fabrication processes in order to address the implementation of the submicrometer features of the PIC (Photonic integrated circuits). Fabrication processes are critical for the performance of the devices. Photonic waveguides at the scale of 1 µm for SiN or 0.5 µm for SOI require very accurate fabrication. Imperfections in the nanometer scale (round 10 nm) induce a big amount of scattering of power and therefore to propagation losses. The low tolerance of the technology is directly related to its integration capacity and sensitivity. Therefore tight control of the fabrication process must be achieved, to enable the viability of this nanophotonic technology. Circuits tune functions could be carried out to overcome fabrication tolerances by using microheaters.

Co-author(s): All NTC fabrication group, especially Juan Hurtado and Laurent Bellieres

Silicon phoXonic crystal structures that allow a simultaneous control of both photonic and phononic waves. The final goal is to push the performance of optical devices well beyond the state of the art by this radically new approach. By merging both fields (nanophotonics and nanophononics) within a same platform, novel unprecedented control of light and sound in very small regions will be achieved. (No shot settings)

Co-author(s): Tailphox project, All NTC fabrication group, especially Juan Hurtado and Laurent Bellieres

Thales de Oliveira / CIC nanoGUNE Consolider, Self-Assembly, San Sebastian, Spain

Lateral Spin Valves with Integrated Dielectric Mask

The micrograph depicts a lateral spin valve capped with a SiO2 integrated mask. The device was fabricated in three lithographic steps using a RAITH150-TWO system. In the first step, ferromagnetic electrodes spaced 30-100nm from each other are patterned. Interconnects and contact pads are efficiently exposed in the second step. In the third step, the device is capped with SiO2 and only the spin valve junctions and contact pads are available for electrical contact.

Co-author(s): Alexander Bittner, Luis E. Hueso

Lars Hiller / Technische Universität Ilmenau, Institut für Mikro- und Nanotechnologien MacroNano®, Germany

Wide-bandgap "Nano bay barnacles" for nano biomechanical systems

500 x 500 nm containers etched in 3C-SiC(100) grown on Si. Firstly a PMMA two layer system was applied to the specimen, which was exposed in a Raith 150 Electron Beam Lithography system. After development a 30 nm thick AlN was applied by sputter deposition. Due to that, the side walls of the exposed areas in the PMMA become covered as well and remain as thin walls after the lift-off process, appearing as “bags” standing on the SiC surface. During the Electron Cyclotron Resonance (ECR) etching process in a SF6/Ar gas mixture, the sidewalls remain upright and are still stable after several minutes of etching due to the high selectivity (transparent crown). The resulting structures remind of bay barnacles, animals which can be found on coasts all over the world, covering rocks and even ships. The container structures created in this way consist of AlN and SiC, which are both biocompatible materials with outstanding properties. For that reason it could be possible to use the container arrays for depositing and raising highly organized cell structures or for storing single virus samples.

Ang Li / NEST - Scuola Normale Superiore, Italy

45° tilted SEM micrograph of a regular array of InAs/InSb heterostructured nanowires. In each wire the narrow InAs, the thicker InSb and the top metal particle are visible.

Co-author(s): Lucia Sorba, Daniele Ercolani

Sebastian Gautsch / EPFL Neuchâtel, IMT SAMLAB, Switzerland

This Nanomamba was realized by patterning a 1.5 um thick MAN resist by e-beam. The design shape was a simple square. Due to electron scattering, the top square shape becomes rounded after a certain depth and an undercut is obtained at the bottom due to insufficient exposure dose. When evaporating a 300nm thick Al2O3 layer on this structure, the square shape of the resist at the top creates the opening for the eyes of our snake. Due to the undercut, the film is interrupted and creates the teeth of our friend. When observing the structure at the right angle, on obtains this nice Mamba face. In fact, all the sidewalls of the structure are symmetrical.

Stefan Kalchmair / TU Wien, Center for Micro- and Nanostructures, Austria

Nano-pillars covered with a Ti/Au cap. Looks like a romantic couple in a winter landscape, surrounded by little children.

Teena James / Johns Hopkins University, Chemical engineering, MD, Baltimore, USA

Planar 2D nanostar patterns were written with e-beam lithography . While plasma etching the underlying Si layer, the 2D metal nanopatterns ( Ni /Sn) folded to form 3D nanostructures as a result of the stress generated due to coalescence of Sn grains.

Co-author(s): Dr. David Gracias

Congratulations to all winners !!!