Staff directory

Xavier Borrisé Nogue

Research Engineer
xavier.borrise(ELIMINAR)@icn2.cat - Tel. +34937372638
Nanofabrication Facility

Publications

2017

  • Metamirrors Based on Arrays of Silicon Nanowires with Height Gradients

    Otte M.A., Garcia-Martin A., Borrise X., Sepulveda B. Advanced Optical Materials; 5 (4, 1600933) 2017. 10.1002/adom.201600933.

    [No abstract available]


2015

  • Activity-tunable nanocomposites based on dissolution and in situ recrystallization of nanoparticles on ion exchange resins

    Alonso A., Vigués N., Rodríguez-Rodríguez R., Borrisé X., Muñoz M., Muraviev D.N., Mas J., Muñoz-Berbel X. RSC Advances; 5 (109): 89971 - 89975. 2015. 10.1039/c5ra16081b. IF: 3.840

    This work proposes the use of cationic ion exchange resins as a platform for in situ formation and recrystallization of nanoparticles as a way to dynamically modulate their activity by changing their structure/composition. Here applied to Ag@Co-nanoparticles in cationic resins, this protocol may be expanded to other materials, opening the possibility to modulate activity with a simple and economic approach. This journal is © The Royal Society of Chemistry 2015.


  • Au cylindrical nanocup: A geometrically, tunable optical nanoresonator

    Kovylina M., Alayo N., Conde-Rubio A., Borrisé X., Hibbard G., Labarta A., Batlle X., Pérez-Murano F. Applied Physics Letters; 107 (3, 033102) 2015. 10.1063/1.4927053. IF: 3.302

    The optical response of Au cylindrical metallic nanostructures (nanocups) with very thin walls is studied by means of finite difference time domain simulations. The simulations predict that, by changing the geometry of the nanocups, they behave as tunable optical nanoresonators with strong near-field enhancement. This opens up the possibility to use them simultaneously as container and field enhancer. Nanocups have been produced by an on-purpose designed fabrication route that combines nanoimprint lithography, definition of an intermediate hard mask, and metal lift-off. The fabrication route offers a manifold of supplementary advantages: thorough control of geometrical parameters; versatility of compositional design, including multishell nanocups; precise positioning of nanocups over the substrate; and low-cost and fast manufacturing of large areas of desirable density without loss of resolution, all processes being compatible with high throughput, low cost production, thus enabling future commercial applications. © 2015 AIP Publishing LLC.


  • Creation of guiding patterns for directed self-assembly of block copolymers by resistless direct e-beam exposure

    Evangelio L., Fernandez-Regulez M., Borrise X., Lorenzoni M., Fraxedas J., Perez-Murano F. Proceedings of SPIE - The International Society for Optical Engineering; 9423 (942326) 2015. 10.1117/12.2085830. IF: 0.000

    We present a novel approach for the creation of guiding patterns to direct the self-assembly of block copolymers. A neutral layer of a brush polymer is directly exposed by electrons, causing the cross-linking of the brush molecules, and thus changing its local affinity. The advantage relies on the achievable resolution and the reduction of the process steps in comparison with deep UV and conventional electron beam lithography, since it avoids the use of a resist. We envision that this method will be highly valuable for the investigation of novel high-chi DSA materials and complex guiding pattern designs, where pattern placement and resolution is becoming critical. © 2015 SPIE.


  • Creation of guiding patterns for directed self-assembly of block copolymers by resistless direct e-beam exposure

    Evangelio L., Fernández-Regúlez M., Borrisé X., Lorenzoni M., Fraxedas J., Pérez-Murano F. Journal of Micro/ Nanolithography, MEMS, and MOEMS; 14 (3, 033511) 2015. 10.1117/1.JMM.14.3.033511. IF: 1.335

    We present an approach for the creation of guiding patterns to direct the self-assembly of block copolymers. A neutral layer of a brush polymer is directly exposed by electrons, causing the cross-linking of the brush molecules, and thus changing its local affinity. The advantage relies on the achievable resolution and the reduction of the process steps in comparison with deep UV and conventional electron beam lithography, since it avoids the use of a resist. We envision that this method will be highly valuable for the investigation of high-chi directed self-assembly materials and complex guiding pattern designs, where pattern placement and resolution are becoming critical. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE).


  • Fabrication of functional electromechanical nanowire resonators by focused ion beam implantation

    Llobet J., Gerbolés M., Sansa M., Bausells J., Borrisé X., Perez-Murano F. Journal of Micro/ Nanolithography, MEMS, and MOEMS; 14 (3, 15026SSP) 2015. 10.1117/1.JMM.14.3.031207. IF: 1.335

    A fast and flexible fabrication method that allows the creation of silicon structures of various geometries is presented. It is based on the combination of focused ion beam local gallium implantation, selective silicon etching, and diffusive boron doping. The structures obtained by this resistless method are electrically conductive. Freely suspended mechanical resonators of different dimensions and geometries have been fabricated and measured. The resulting devices present a good electrical conductivity which allows the characterization of their high-frequency mechanical response by electrical read-out. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE).


  • Manipulation of competing ferromagnetic and antiferromagnetic domains in exchange-biased nanostructures

    Fraile Rodríguez A., Basaran A.C., Morales R., Kovylina M., Llobet J., Borrisé X., Marcus M.A., Scholl A., Schuller I.K., Batlle X., Labarta A. Physical Review B - Condensed Matter and Materials Physics; 92 (17, 174417) 2015. 10.1103/PhysRevB.92.174417. IF: 3.736

    Using photoemission electron microscopy combined with x-ray magnetic circular dichroism we show that a progressive spatial confinement of a ferromagnet (FM), either through thickness variation or laterally via patterning, actively controls the domains of uncompensated spins in the antiferromagnet (AF) in exchange-biased systems. Direct observations of the spin structure in both sides of the FM/AF interface in a model system, Ni/FeF2, show that the spin structure is determined by the balance between the competing FM and AF magnetic energies. Coexistence of exchange bias domains, with opposite directions, can be established in Ni/FeF2 bilayers for Ni thicknesses below 10 nm. Patterning the Ni/FeF2 heterostructures with antidots destabilizes the FM state, enhancing the formation of opposite exchange bias domains below a critical antidot separation of the order of a few FeF2 crystal domains. The results suggest that dimensional confinement of the FM may be used to manipulate the AF spin structure in spintronic devices and ultrahigh-density information storage media. The underlying mechanism of the uncompensated AF domain formation in Ni/FeF2 may be generic to other magnetic systems with complex noncollinear FM/AF spin structures. ©2015 American Physical Society.


  • Nanoparticles with tunable shape and composition fabricated by nanoimprint lithography

    Alayo N., Conde-Rubio A., Bausells J., Borrisé X., Labarta A., Batlle X., Pérez-Murano F. Nanotechnology; 26 (44, 445302) 2015. 10.1088/0957-4484/26/44/445302. IF: 3.821

    Cone-like and empty cup-shaped nanoparticles of noble metals have been demonstrated to provide extraordinary optical properties for use as optical nanoanntenas or nanoresonators. However, their large-scale production is difficult via standard nanofabrication methods. We present a fabrication approach to achieve arrays of nanoparticles with tunable shape and composition by a combination of nanoimprint lithography, hard-mask definition and various forms of metal deposition. In particular, we have obtained arrays of empty cup-shaped Au nanoparticles showing an optical response with distinguishable features associated with the excitations of localized surface plasmons. Finally, this route avoids the most common drawbacks found in the fabrication of nanoparticles by conventional top-down methods, such as aspect ratio limitation, blurring, and low throughput, and it can be used to fabricate nanoparticles with heterogeneous composition. © 2015 IOP Publishing Ltd.


  • Tailored Height Gradients in Vertical Nanowire Arrays via Mechanical and Electronic Modulation of Metal-Assisted Chemical Etching

    Otte M.A., Solis-Tinoco V., Prieto P., Borrisé X., Lechuga L.M., González M.U., Sepulveda B. Small; 11 (33): 4201 - 4208. 2015. 10.1002/smll.201500175. IF: 8.368

    In current top-down nanofabrication methodologies the design freedom is generally constrained to the two lateral dimensions, and is only limited by the resolution of the employed nanolithographic technique. However, nanostructure height, which relies on certain mask-dependent material deposition or etching techniques, is usually uniform, and on-chip variation of this parameter is difficult and generally limited to very simple patterns. Herein, a novel nanofabrication methodology is presented, which enables the generation of high aspect-ratio nanostructure arrays with height gradients in arbitrary directions by a single and fast etching process. Based on metal-assisted chemical etching using a catalytic gold layer perforated with nanoholes, it is demonstrated how nanostructure arrays with directional height gradients can be accurately tailored by: (i) the control of the mass transport through the nanohole array, (ii) the mechanical properties of the perforated metal layer, and (iii) the conductive coupling to the surrounding gold film to accelerate the local electrochemical etching process. The proposed technique, enabling 20-fold on-chip variation of nanostructure height in a spatial range of a few micrometers, offers a new tool for the creation of novel types of nano-assemblies and metamaterials with interesting technological applications in fields such as nanophotonics, nanophononics, microfluidics or biomechanics. Based on metal-assisted chemical etching using a catalytic gold layer perforated with nanoholes, it is demonstrated how high aspect-ratio nanostructure arrays with directional height gradients can be accurately tailored by: i) control of mass transport through the nanohole array, ii) mechanical properties of the perforated metal layer, and iii) conductive coupling to the surrounding gold film to accelerate the local electrochemical etching process. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Tuning piezoresistive transduction in nanomechanical resonators by geometrical asymmetries

    Llobet J., Sansa M., Lorenzoni M., Borrisé X., San Paulo A., Pérez-Murano F. Applied Physics Letters; 107 (7, 073104) 2015. 10.1063/1.4928709. IF: 3.302

    The effect of geometrical asymmetries on the piezoresistive transduction in suspended double clamped beam nanomechanical resonators is investigated. Tapered silicon nano-beams, fabricated using a fast and flexible prototyping method, are employed to determine how the asymmetry affects the transduced piezoresistive signal for different mechanical resonant modes. This effect is attributed to the modulation of the strain in pre-strained double clamped beams, and it is confirmed by means of finite element simulations. © 2015 AIP Publishing LLC.


2014

  • Determination of heterogeneous electron transfer rate constants at interdigitated nanoband electrodes fabricated by an optical mix-and-match process

    Del Campo, F.J.; Abad, L.; Illa, X.; Prats-Alfonso, E.; Borrisé, X.; Cirera, J.M.; Bai, H.-Y.; Tsai, Y.-C. Sensors and Actuators, B: Chemical; 194: 86 - 95. 2014. 10.1016/j.snb.2013.12.016. IF: 3.840


  • Enabling electromechanical transduction in silicon nanowire mechanical resonators fabricated by focused ion beam implantation

    Llobet, J.; Sansa, M.; Gerbolés, M.; Mestres, N.; Arbiol, J.; Borrisé, X.; Pérez-Murano, F. Nanotechnology; 2014. 10.1088/0957-4484/25/13/135302. IF: 3.672