Fabrication and optical characterization of pedestal micro-structures on DUV210 polymer: waveguides structures towards micro-resonators

International audienceThe paper presents the global design, fabrication and optical characterizations of pedestal waveguides and 2D microresonators made of DUV210 polymer. These particular geometries are achieved thanks to specific deep-UV lithography procedures allowing sub-lambda development coupled to chemical etching able to shape such pedestal configuration on various optical microstructures. Scanning electron microscopy images have confirmed their features. Moreover, such families of pedestal structures were characterized experimentally, including the optical losses measurements for the waveguides and the optical resonance responses for two kinds of microresonators. Optical studies of single mode propagation losses measurements have been performed by a cut back method leading to values close to 20 dB/cm at a 635 nm wavelength. Additionally, resonant spectral analysis has been performed into pedestal rings and racetracks microresonators with a broadband laser source centered at 795 nm, demonstrating the presence of expected theoretical resonances. Free spectral range values of 2.86 nm and 2.51 nm have been measured for these new designed pedestal resonators on DUV210 related to quality factor values superior to 520 and 610 respectively

Top-gate microcrystalline silicon TFTs processed at low temperature (<200ºC)

N-type as well P-type top-gate microcrystalline silicon thin film transistors (TFTs) are fabricated on glass substrates at a maximum temperature of 200 °C. The active layer is an undoped μc-Si film, 200 nm thick, deposited by Hot-Wire Chemical Vapor. The drain and source regions are highly phosphorus (N-type TFTs) or boron (P-type TFTs)-doped μc-films deposited by HW-CVD. The gate insulator is a silicon dioxide film deposited by RF sputtering. Al-SiO 2-N type c-Si structures using this insulator present low flat-band voltage,-0.2 V, and low density of states at the interface D it=6.4×10 10 eV -1 cm -2. High field effect mobility, 25 cm 2/V s for electrons and 1.1 cm 2/V s for holes, is obtained. These values are very high, particularly the hole mobility that was never reached previously

The ThomX project status

Work supported by the French Agence Nationale de la recherche as part of the program EQUIPEX under reference ANR-10-EQPX-51, the Ile de France region, CNRS-IN2P3 and Université Paris Sud XI - http://accelconf.web.cern.ch/AccelConf/IPAC2014/papers/wepro052.pdfA collaboration of seven research institutes and an industry has been set up for the ThomX project, a compact Compton Backscattering Source (CBS) based in Orsay - France. After a period of study and definition of the machine performance, a full description of all the systems has been provided. The infrastructure work has been started and the main systems are in the call for tender phase. In this paper we will illustrate the definitive machine parameters and components characteristics. We will also update the results of the different technical and experimental activities on optical resonators, RF power supplies and on the electron gun

Mise en évidence des défauts profonds dans des structures MIS : Au-POx_xNy_yInz_z-(n)InP par la methode FTDLTS

The new isotherm FTDLTS (Fourier Transform Deep Level Transient Spectroscopy) method has been used to characterize deep level, in Au-PO$_x$N$_y$In$_z$-(n)InP MIS structures in two temperature ranges. The insulator PO$_x$N$_y$In$_z$ is deposited on InP maintained at 360 °C from phosphorus oxinitride solid sample (PON). Three deep centers E ($E_{\rm c} - 0.378$ eV), Z ($E_{\rm c} - 0.836$ eV) and G ($E_{\rm c} - 0.694$ eV), have been detected and characterized. These defects originating from the device fabrication process, are complex defects principally linked to residual impurities, to phosphorus vacancy and to indium vacancy.La nouvelle méthode isotherme appelée FTDLTS (Fourier Transform Deep Level Transient Spectroscopy) a été utilisée pour caractériser des défauts profonds dans des structures MIS : Au-PO$_x$N$_y$In$_z$-(n)InP, dans deux domaines de température de mesure. L'isolant PO$_x$N$_y$In$_z$ a été obtenu à partir de l'évaporation de l'oxynitrure de phosphore (PON) massif sur substrats InP maintenus à 360 °C. Trois défauts E ($E_{\rm c}-$ 0,378 eV), Z ($E_{\rm c} -$ 0,836 eV) et G ($E_{\rm c}-$ 0,694 eV) ont été mis en évidence. Ces défauts qui sont générés lors des processus de réalisation des structures MIS sont des défauts complexes liés principalement aux impuretés résiduelles, aux lacunes de phosphore et aux lacunes d'indium

La microscopie confocale : un support de formation en micro- et nano-électronique au CCMO, pôle CFM de Rennes

L’article présente de l’apport de la microscopie confocale dans les formations en micro- et nano-technologies proposées par le CCMO (Centre Commun de Microélectronique de l’Ouest), pôle CFNM de Rennes. Un focus particulier est porté sur l’observation et la caractérisation à l’échelle micro et nanométrique d’objets (composants, nanofils,…) ou de systèmes microélectroniques (architecture physique de microprocesseurs)

Design of biochip microelectrode arrays for cell arrangement

Times Cited: 0 Frenea, M Lhermite, H Le Pioufle, B Fujita, H 2nd Annual International IEEE/EMBS Conference on Microtechnologies in Medicine and Biology May 02-04, 2002 Madison, wi IEEE/Engn Med & Biol Soc, Natl Inst Hlth, Defense Adv Res Project Agcy, Motorola, NimbleGen Syst Inc, PanVera Corp, Dow Chem Co, GWC Instruments, Venture Invest LLC, Univ Wisconsin-Madison, Dept Biomed Engn, IEEE/Robot & Automat Soc, PromegaInternational audienceThis paper focuses on the use of dielectrophoresis (DEP) for particle arrangement on a biochip. Our aim was to propose a device that enables the positioning of cells at regularly spaced locations using a 2D microelectrode array (prior to electropermeabilization, for instance). Whereas the use of the positive DEP force is mainly restricted to the collection of particles at electrode edges, negative DEP can be used advantageously to confine particles at existing field minima, i.e. away from the electrodes. Three different microelectrode geometries designed for negative DEP are compared in this paper. The first two configurations are composed of two interdigitated networks of triangular and rectangular shape microelectrodes respectively. In the third type of microsystem, electrode plates of opposite polarities are alternated and powered thanks to a multilayer structure. The results obtained show that a matrix arrangement of thousands of particles (such as cells, latex beads) on a large 2D microelectrode array is possible using negative DEP

On the detection of nanoparticle cloud migration by a resonant photonic surface signal towards sedimentation velocity measurements

International audienceMigration and sedimentation of solid particles in a liquid are physical phenomena involving accumulation of soft matter or decantation of fragmented matter. A thorough understanding together with relevant measurements are prerequisites regarding many fields, including medicine, galenic pharmacology, food processing, and the cosmetics industry. In this paper, we investigate the feasibility of monitoring and detecting the migration of a nanoparticle cloud with a resonant light probe. For this purpose, hybrid silicon/silica/UV210 organic integrated photonic racetrack resonators were patterned by thin film processes to be used as sensors measuring the outcome of the impact of a cloud of nanoparticles, the dynamic migration plus sedimentation phenomenon of the nanoparticle cloud in water. A broadband superluminescent diode has been used for the excitation. Then, the spectral characteristics of the resonant guided modes have been analyzed, considering the observed changes while tracking the free spectral range of the transduced comb spectra as a function of time. The way to operate can be summarized as follows: Solutions based on spherical silica nanoparticles of fixed size are prepared and subjected to rheological measurements to obtain their respective viscosities. Next, a millimeter tank filled with water is conveniently placed on the active surface of the sensing chip, prior to the addition of one of the previously mentioned solutions. The series of spectra are acquired during the whole migration sequence and the transduced optical signal is then directly processed and treated by a specific code operated in real time by way of Lagrange interpolation polynomials. Collected data are then compared to a simple theoretical model describing the sedimentation of a spherical particle in water (Stokes' law). Eventually, the implementation of the device in a characterization platform and the development of a specific protocol allows a global treatment, whose description is followed by discussions on measurements and data. Consequently, after the impact of the drop containing the nanoparticles, the monitoring of a first phase regarding their fast cloud migration into the global study volume (with flow of matter plus vortex) eventually followed by their slow sedimentation, can be detected using such a resonant light probe. The overall duration of the first phase associated with sedimentation velocities is in the order of a few tens of µm/min for particles with submicron diameters (several hundreds of nanometers); a first attempt of comparison of this first phase with the results of the classic Stokes model would give a convergence of the values reaching between 9 and 19% for the sedimentation rates