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Inflammatory cytokines play a major role in myeloproliferative neoplasms (MPNs) as regulators of the MPN clone and as mediators of clinical symptoms and complications. Firstly, we investigated the effect of JAK2V617F on 42 molecules linked to inflammation. For JAK2V617F-mutated patients, the JAK2V617F allele burden (%JAK2V617F) correlated with the levels of IL-1&beta, IL-1R&alpha, IP-10 and leptin in polycythemia vera (PV), and with IL-33 in ET, for all other molecules, no correlation was found. Cytokine production was also studied in the human megakaryocytic cell line UT-7. Wild-type UT-7 cells secreted 27/42 cytokines measured. UT-7 clones expressing 50% or 75% JAK2V617F were generated, in which the production of IL-1&beta, IP-10 and RANTES was increased, other cytokines were not affected. Secondly, we searched for causes of chronic inflammation in MPNs other than driver mutations. Since antigen-driven selection is increasingly implicated in the pathogenesis of blood malignancies, we investigated whether proinflammatory glucosylsphingosine (GlcSph) may play a role in MPNs. We report that 20% (15/75) of MPN patients presented with anti-GlcSph IgGs, distinguished by elevated levels of 11 cytokines. In summary, only IL-1&beta, and IP-10 were linked to JAK2V617F both in patients and in UT-7 cells, other inflammation-linked cytokines in excess in MPNs were not. For subsets of MPN patients, a possible cause of inflammation may be auto-immunity against glucolipids.

International audience; A process able to produce at wafer scale patterned electrodes on the vertical sidewalls of trenches is described and investigated in detail. It is based on metal evaporation at oblique incidence through a shadow mask made in a dry photoresist film. A full model of the deposition and patterning process is established in order to map the shape as well as the thickness and density of patterned electrodes with or without wafer rotation. In the case of wafer rotation, the modelling is based on the analogy of each shadow mask edge with the gnomon of a sundial. The final electrode shape is then computed from the trajectories followed by the shadows of the gnomons. Offset of the substrate tilt axis with respect to substrate plane, and position on the wafer surface, are considered in the analysis, as well as the variation of film density with incidence angle. Advantages and limitations of the proposed process are discussed. It is shown that sidewall electrodes isolated or connected to top or bottom electrodes can be simply achieved by a suitable sizing and alignment of the shadow mask but that close electrodes on a given sidewall cannot be mutually isolated when the substrate is rotated. The patterning process is demonstrated in the case of Au/Cr electrodes on the sidewalls of through wafer trenches made in GaAs by deep reactive ion etching.

International audience; Previous studies showed that monoclonal immunoglobulins G (IgGs) of “monoclonal gammopathy of undetermined significance” (MGUS) and myeloma were hyposialylated, thus presumably pro-inflammatory, and for about half of patients, the target of the monoclonal IgG was either a virus—Epstein–Barr virus (EBV), other herpes viruses, hepatitis C virus (HCV)—or a glucolipid, lysoglucosylceramide (LGL1), suggesting antigen-driven disease in these patients. In the present study, we show that monoclonal IgAs share these characteristics. We collected 35 sera of patients with a monoclonal IgA (6 MGUS, 29 myeloma), and we were able to purify 25 of the 35 monoclonal IgAs (6 MGUS, 19 myeloma). Monoclonal IgAs from MGUS and myeloma patients were significantly less sialylated than IgAs from healthy volunteers. When purified monoclonal IgAs were tested against infectious pathogens and LGL1, five myeloma patients had a monoclonal IgA that specifically recognized viral proteins: the core protein of HCV in one case, EBV nuclear antigen 1 (EBNA-1) in four cases (21.1%of IgA myeloma). Monoclonal IgAs from three myeloma patients reacted against LGL1. In summary, monoclonal IgAs are hyposialylated and as described for IgG myeloma, significant subsets (8/19, or 42%) of patients with IgA myeloma may have viral or self (LGL1) antigen-driven disease.

International audience; This paper reports on progress in the analysis of time-domain optical coherence tomography (OCT) applied to the dimensional metrology of through-silicon vias (TSVs), which are vertical interconnect accesses in silicon, enabling three-dimensional (3D) integration in microelectronics, and estimates the deviations from earlier, simpler models. The considered TSV structures are 1D trenches and circular holes etched into silicon with a large aspect ratio. As a prerequisite for a realistic modeling, we work with spectra obtained from reference interferograms measured at a planar substrate, which fully includes the dispersion of the OCT apparatus. Applying a rigorous modal approach, we estimate the differences to a pure ray tracing technique. Accelerating our computations, we focus on the relevant fundamental modes and apply a Fabry–Perot model as an efficient approximation. Exploiting our results, we construct and present an iterative procedure based on the minimization of a merit function, which concludes TSV heights reliably, accurately, and rapidly from measured interferograms.

International audience; We report on progress in Time-Domain OCT (optical coherence tomography) applied to TSV (vertical interconnect accesses in silicon, enabling stacking of devices). Transitioning from the common scalar approach to an electromagnetic one, and combining it with a damped least squares approach, we enhance the accuracy of TSV height measurements.

It is demonstrated that high quality stress-induced birefringence maps in silicon with a high lateral resolution can be obtained by microphotoelasticity in reflection mode at wavelength of 1.31 μm. This technique was applied to inspection of Si-Si wafer bonding defects with variable magnifications. It is shown that defects with an apparent size as small as 20μm in diameter can be observed with a 2μm lateral resolution.

Electrostatically actuated microelectromechanical systems (MEMS) devices integrating a surface micromachined silicon nanowire were batch processed to investigate motion detection with a nanowire piezoresistive gauge. In the proposed implementation, the nanogauge is indirectly coupled to the MEMS structure through an intermediate coupling spring. This design allows an arbitrary choice of MEMS motion detection range and a resolution improvement of in situ nanowire gauge factor measurements. Using this approach, it is demonstrated that an in-plane MEMS displacements up to 180 nm with a noise level down to 0.7 A/Hz1/2 can be achieved. MEMS resonance measurement in air and in vacuum by this method is also demonstrated. Results are compared with ex situ measurements of MEMS displacement by optical microscopy and by integrated capacitive detection.

This paper presents the design of a piezoelectric MEMS Coriolis Vibrating Gyroscope (CVG) based on a single gallium arsenide vibrating structure allowing the measurement of rotation rate along 3 orthogonal sensitive axes. Based on a theoretical and FEM study, we demonstrate that the achieved sensitivities reached for each axis is about 1.6 × 10 −16 C/(°/s). We then demonstrate the feasibility of the realization of simple MEMS structures from C-doped Gallium Arsenide (GaAs) using standard micromachining processes. Finally, we show the fabrication and characterization of GaAs-based tuning fork microresonators as a first step towards a complete 3-axis GaAs MEMS CVG. These resonators show a resonance frequency of 42 350 Hz, a quality factor of 122 000 and a frequency temperature coefficient of 24 ppm/°K, validating the high potential of GaAs as a structural material for 3-axis MEMS CVGs.

The Energy End-use Efficiency and Energy Services Directive (ESD) of the European Union requires the member states to define and attain an overall target of at least 9% annual energy savings between 2008 and 2016. Even if this target is indicative, this is the first international framework mandating countries to report on their energy savings results and prove achievement of their targets. The directive thus also required the development of harmonised calculation methods that can be used by member states for this proof and reporting. Existing literature covers most of the usual issues related to energy savings evaluation, but mostly looking at single, given energy efficiency programmes or policies. The evaluation objective for the ESD implementation is different, as it aims at accounting for the whole energy savings achieved in a country. Moreover, one of the main difficulties is the diversity in history and experience on this topic among the member states. In this context, the European project EMEEES has worked out an integrated system of bottom-up and top-down methods for the measurement of energy savings. The paper presents the overview of its final results. The proposals, inter alia, include 20 bottom-up and 14 top-down case applications of general evaluation methods. They enable more than 90% of the potential energy savings to be measured and reported. They were used as a starting point by the European Commission to develop the methods recently recommended to the member states. Furthermore, the paper briefly discusses the importance of the quantity to be measured—all or additional energy savings—and the effect of measures implemented before the entering into force of the ESD (‘early action’), and what this meant for the methods to be developed. It compares the main elements of calculation needed to ensure consistent results between bottom-up and top-down methods at the overall national level. Finally, general conclusions are drawn about what could be the next steps in developing an evaluation system that enables a high degree of comparability of results between different countries.

Many micro-electro-mechanical-systems (MEMS) are based on the use of resonant mechanical structures. In this paper, we propose scanning electron microscopy techniques that allow a direct characterization of in-plane vibrations of small-size resonators. Implementation and performance of these techniques are illustrated by vacuum quality factor measurements of an electrostatically driven polysilicon Tang resonator and of a high-Q silicon cantilever microbeam excited with an external piezoelectric actuator. These techniques are also expected to be suitable for the dynamical characterization of nanoresonators.

This paper reports the damping control of a MEMS resonator, vibrating at several kilohertz, using tiny p-doped piezoresistive silicon nanowires (SiNW). Due to thermal piezoresistive back action (TPBA), DC-current biasing of the nanobeams induces a strong increase of the damping rate, about 2 decades above the intrinsic damping rate of the resonator. Intrinsic quality factor (QF) around 3.104 is here reduced to 450 thanks to an outstanding efficient TPBA. It is worth noting that QF can be here finely controlled for DC-current as low as a few tens μA, which leads to very low power consumption at constant voltage generator circuitry. This property is highly suitable for numerous applications, such as amplitude modulated resonant sensors (gyrometers, accelerometers…) or high performance resonant sensors, for which an accurate and repeatable control of the QF is required. Furthermore, the proposed mechanism allows bandwidth tuning and temperature compensation of the QF, without inducing parasitic crosstalk signals.

The high specific surface of porous silicon and its high reactivity makes this material a good candidate for chemical sensors based on electrical or electromechanical devices. In this paper, several processes are presented to realize free-standing porous silicon microstructures (membranes and cantilever beams). Good resonance quality factors were measured (Q = 110 and 760 respectively) demonstrating that porous silicon is a suitable material for resonant chemical sensors.

Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920); International audience; Copper planar microcoils were processed by U.V. lithography on SiO2/Si and Kapton®. The coils were packaged on different supports in order to create varying thermal exchange conditions. The electric current was increased step by step until the electric connection breaks, the microcoils remaining free on a thermal point of view. The copper temperature was estimated from its resistivity. It allowed to show that the thermal exchange mode of the wire-bonded microcoils is conductive. The current density was calculated taking into account the deterioration of the coils by oxidation. Its maximum value is linearly decreasing with the thermal exchange ability of the support. The failure modes of the microcoils are related to track melting and oxidation, the current density remaining one order too weak to induce electromigration.

In this paper, we study the resonance frequency resolution of a MEMS resonator based on suspended piezoresistive silicon nanogauges transduction. Nanowire strain gages are attractive for MEMS resonators thanks to their high sensitivity to motion. They have excellent force sensitivity due to their small cross-section area (250×250nm2) and a negligible footprint. Hence, this transduction mean exhibits a very high signal to noise ratio (SNR) of 115dB above a few kHz, which does not limit the excellent resolution frequency required for high performance applications. Thus, resolution frequency down to 35 ppb is here reported, limited by thermo mechanical fluctuations, instrumentation noise and environment stability. Influence of various actuations and damping conditions are investigated and then compared to the Robins' law that estimates resolution for the frequency measurement. Thus, Robin's law is validated for the nanogauge transduction of a MEMS resonator. Eventually, these results can be used to anticipate the outstanding frequency resolution of an ongoing resonant pressure sensor, which has been estimated at only a few ppb.

This paper deals with the conception and realization of a 3 axis gyrometer in GaAs known as CVG (Coriolis Vibrating Gyro), designed thanks to MEMS (Micro Electro Mechanical Systems) technologies. This original 3 axis gyroscope [1] can measure angular rate along the 3 sensing axes using the Coriolis inertial force effect on a single vibrating structure and is particularly well suited for applications where high miniaturization/integration and low consumption are required as attitude control of micro-UAVs (micro-Unmanned Aerial Vehicles) for instance. The proposed design shows important sensibilities along the 3 orthogonal directions. In automotive, aerospace and aeronautical industries, there is an increasing demand for accurate detection of acceleration and angular rate. Usually, objects are in motion in a three-dimensional space. To determine with precision the motion of an object, it is necessary to detect acceleration and angular rate in each of the three different space directions. A common way for multi-axial detection is to use a set of three different mono-axial sensors aligned with each of the three axial directions. Although miniaturized single axis gyroscopes have now reached high performances, 3 axis gyroscopes based on the combination and alignment of such single gyroscopes usually have lower performances than a fully integrated triaxial device because of alignment accuracy. In addition the alignment procedure is typically expensive. That is why, since several years, there is a rising need for monolithic 3 axis gyroscopes for angular rate detection. In this paper we investigate a 3 axis monolithic GaAs CVG structure that allows a single “driving mode” for the three “sensing modes”. This allows: — a reduction of mechanical coupling between the “driving mode” and the “sensing modes” — an easier fabrication owing to a simplified electrode network. — a less complex ASIC (Application Specific Integrated Circuit) design having a smaller size and a lower power consumption. Various designs of 3 axis gyro have been proposed in the literature but few of them show good and equivalent sensitivities along the three sensing axis. In the first section we will examine two interesting designs of CVG selected among published works which also use a single driving mode and three sensing modes. In the second section we described a design that we proposed previously and that has potentially much higher performances. Then we will investigate how GaAs piezoelectricity can be used to build a complete piezoelectric transduction system for this CVG. In the last section, we will give an overview of the transduction system design and of its fabrication process. Finally we will report results of the development of GaAs Deep Reactive Ion Etching (DRIE) which is major step of this fabrication process.

Vacuum encapsulation is required for various microsensors to improve their performances. In the case of wafer level vacuum encapsulation, dedicated techniques must be developed to measure the background pressure in the bonded cavities. In this paper we investigated ex situ measurement techniques based on the measurement by interference microscopy of the deformation and vibrations of the caps as function of an external pressure. Because these techniques detect the equality between external and internal pressure, they do not require any modelling nor prior calibration. Application to wafer level encapsulations fabricated by gold-silicon eutectic wafer bonding demonstrates that a detection limit in the 10−2–10−1 mbar range can be reached for millimetre size caps.

Special attention has been paid in this work to use all possible means to measure an intrinsic quality factor (Q) for silicon beam resonators realized on SOI wafers. Specifically, this work points to the energy dissipation into the support; a model is given and a high insulating system for clamped–clamped and clamped-free configurations has been studied, preserving the resonating element from support damping. Finite element analysis on these structures evidences values of Qsupport higher than 107. Out-of-plane and in-plane vibration Q values up to 1.0 × 105 have been measured under a high vacuum using, respectively, laser Doppler vibrometry and stroboscopic optical microscopy combined with image processing. The results have shown good agreement with thermoelastic theory. However, the observed agreement on the resonator dimension dependences is limited to quality factors lower than 3.0 × 104. Beyond these values, a physical limitation is evidenced in both cases (in-plane and out-of-plane) which does not match with the surface and clamping models listed. The role of the SOI wafer's oxide layer is discussed as a possible source of dissipation.

Recent developments in micro-electro-mechanical systems and micromachining technologies have made possible the development and integration of micromirrors that can be employed for a number of consumer applications such as free space optical switching (Syms in J Lightwave Technol 20(7):1084–1094, 2002; Pan in Micromech Microeng 14(1):129–137, 2004), 2D scanning or image projection (Texas Instruments DLP http://www.dlp.com/). This high level of integration provides many advantages such as reproductivity and improved performance. Obviously, these increased levels of miniaturization raise new characterization and modeling concerns. We present in this paper the design, the fabrication process, the characterization and the behavioral modeling approach of a novel electrostatically actuated bi-axial micromirror. This micro-opto-electro-mechanical system is a result of a joint development between our partners Colibrys and Coventor companies (Colibrys http://www.colibrys.com/ ; Coventor http://www.coventor.com/). In the field of this work, two HDL multi-physics models using Verilog-A language and Matlab have been developed and validated by different experimental measurements.

The future CMOS generations for microelectronics will require advanced doping techniques capable to realize ultra-shallow, highly-doped junctions with abrupt profiles. Recent experiments have shown the potential capabilities of laser processing of Ultra Shallow Junctions (USJ). According to the International Technology Roadmap for Semiconductors, two laser processes are able to reach ultimate predictions: laser thermal processing or annealing (LTP or LTA) and Gas Immersion Laser Doping (GILD). Both processes are based on rapid melting/solidification of the substrate. During solidification, the liquid silicon, which c ontains the dopants, is formed epitaxia lly from the underlying crystalline silicon. In the case of laser thermal annealing dopants are implanted before laser processing. GILD skips the ion-implantation step: in this case dopants are chemisorbed on the Si surface before the laser shot. The dopants are then incorporated and activated during the laser proce ss. Activation is limited to the liquid layer an d this chemisorption/laser shot cycle can be repeated until the desired concentration is reached. In this paper, we investigate the possibilities and limitations of the GILD technique for two different substrat es: silicon bulk and SOI. We also show so me laser doping applications for the fabrication of micro and nanoresonators , widely used in the MEMS Industry. Keywords: laser doping, ultra shallow junctions, impl antation, micro resonator, MEMS, LTP, GILD.

It is demonstrated that stroboscopic optical microscopy combined with image processing is able to detect and map in-plane bi-directional vibrations of microstructures at video rate with a detection limit down to 0.1 nm in the frequency bandwidth 0–4 MHz. Furthermore, this technique was combined with phase shifting stroboscopic interferometry and light pulse delay shifting to provide simultaneously amplitude and phase maps of out-of-plane and in-plane vibrations of micromechanical devices. Application of these techniques is illustrated on Al microdevices with pattern sizes in the micron range.

Optical techniques which were developed for ex situ characterization of static displacements, motions, vibrations and internal strain of micromechanical devices and M(O)EMS are critically reviewed. Their performances and limitations are analysed and improvements which were proposed recently and which are still needed are discussed. It is shown that many optical techniques are available for 1D, 2D or 3D out-of-plane measurements with a lateral resolution in the (sub)micron range, a vertical resolution in the (sub)nanometer range and a frequency range up to a few MHz or more. In contrast, only very few techniques are suitable for in-plane, on wafer or in vacuum measurements.

Out-of-plane optical actuation of thin Al cantilever microbeams was investigated as a function of laser beam power, spot size, modulation frequency and location on the beam. Several microscopic interferometry techniques including quantitative time-averaged interferometry and phase shifting stroboscopic interferometry were used to determine the resonant frequencies, vibration mode shapes and optically induced mean deflection of the microbeams. Transient response measurements by stroboscopic interferometry are also demonstrated. Experimental results show that on-wafer, non-contact, full-field dynamic measurements can be performed up to at least several hundred kHz although a large light power is necessary to actuate Al microbeams. It is demonstrated that dynamical optical actuation tends to saturate as a function of laser beam power and is maximum when the laser spot is located below 1/3 of the beam length. It is also evidenced that fundamental resonant frequencies measured with optical actuation are lower than that measured with piezoelectric actuation. Results are discussed by considering that actuation is dominated by photothermal effects.

The principle of a multilayer monochromator with a narrow bandwidth and a low specular background is recalled. The elaboration of such a monochromator obtained from a Mo/Si multilau-yer mirror is briefly described. The performance of the device measured at 1500 and 98 eV is presented. Le principe d'un monochromateur multicouche a bande passante etroite et presentant un faible fond continu est rappele. Nous decrivons brievement la fabrication d'un tel monochromateur obtenu a partir d'un miroir multicouche Mo/Si. Les performances de ce dispositif mesurees a 1500 et 98 eV sont presentees.

Resonant structures based on the combination of an electromechanical microresonator made in a thick single crystal Si layer and a differential piezoresistive detection with Si nanowires is a recent concept allowing a breakthrough in downscaling physical resonant sensors with equal to better performances. With an optimized design, the vacuum quality factor of these resonant structures will be ultimately limited by thermoelastic damping. Existing analytical models reasonably well predict the thermoelastic damping of transverse vibrations for beam resonators with and without axial stress but their limitations for resonators with more complex geometry is difficult to estimate. In this paper we investigate by Finite Element Method the effect of axial stress and of nanowire strain gages integration on the thermoelastic damping of vibrations of a beam resonator with a central inertial mass. Results show that axial stress effect depends on actuation force and that nanowires mainly alter the thermoelastic damping through an increase of resonator stiffness. As expected thermoelastic damping is reduced when torsional vibration modes are involved. Results are compared or analyzed with published analytical models.

Mirau interferometers are two beam interferometers with coaxial optical beams that are widely used in full-field optical surface profilers. An integrated Mirau interferometer with a MEMS mirror scanner is proposed in this paper. The novelty of the scanner design is the use of self-aligned vertical electrostatic combs made in double SOI wafer technology which allows a large range, bidirectional, and symmetric vertical translation of the reference mirror. Electrostatic and mechanical analytical calculations and Finite Element Modeling simulations were carried out to design and optimize the MEMS scanner. A large bidirectional range (+/−20 μm) motion under 60V applied voltage is achievable. Good flatness of the reference mirror is preserved during motion, what is essential for interferometrie measurements. A fabrication process which minimizes the number of mask levels is proposed. It is based on front and back side Deep Reactive Ion Etching and dry film photoresist lithographic steps.

Microscopic interferometry is a powerful technique for the static and dynamic characterization of micromechanical devices. In this paper we emphasize its capabilities for 3D vibration mode shapes profiling of Al cantilever microbeams and Cr micromachined membranes. It is demonstrated that time-resolved measurements up to 800 kHz can be performed with a lateral resolution in the micrometer range and a vibration amplitude detection limit of 3–5 nm. In addition, with reduced image sizes (256×256), quasi-real time (150–500 ms) visualization of the vibration mode 3D profiles becomes possible. These performances were obtained by using stroboscopic illumination with an array of superluminescent LED and an optimized automatic fast Fourier transform phase demodulation of the interferograms. The results are compared with theoretical shapes of the vibration modes and with point measurements of the vibration spectra.

A new soft-x-ray multilayer monochromator with an improved resolution and a low specular background is presented. The principles of the device, based on the use of a lamellar multilayer amplitude grating (LMAG), are summarized. The techniques of fabrication of the monochromator (multilayer deposition, UV lithography and reactive ion etching) are given. The performance of this new monochromator at photon energies around 1500 eV is demonstrated. Copyright © 2001 John Wiley & Sons, Ltd.

In this paper, realization process and electroplated copper and permalloy properties are presented in order to fabricate micro-coils. RF electrical and magnetic characterizations of the first devices with 40 turns obtained for low frequencies application are exposed showing an inductive behavior under 220 MHz ( L =320 nH) and a capacitive behavior above. Experimental results are compared with calculations. A comparative magnetic field measurement is performed using micro-coils and AMR.

A new kind of xuv multilayer monochromator with a narrow spectral bandwidth is introduced. This monochromator is based on a Mo/Si multilayer mirror etched according to the profile of a lamellar grating. The fabrication of such a device involving multilayer deposition, UV lithography and reactive ion etching is presented. The monochromator has been characterized by means of the synchrotron radiation around the Si–L edge (100 eV). A reduction of the bandwidth has been observed with respect to the unpatterned mirror by a factor close to 3.

In this paper, electrodeposition of copper films and copper lines with direct and pulse currents is compared. In the first step, electrical and physicochemical characterizations of the copper films are realized, and the optimized electrodeposition parameters are so determined. The use of pulse reverse current is also investigated. In the second step, these parameters are applied to micromolding. Copper lines are electro-deposited and compared in order to determine the more suitable current mode for micromolding.

In conjunction with a remote-controlled smart-sensors project (Villegas M, Bildstein P and Nicole P 1997 Translateur de frequence micro-ondes pour capteur intelligent autonome Proc. 10eme Journees Nationales Microondes (St Malo, 21-23 May 1997) pp 270-1), this study concerns the validation of a radio-frequency microelectromechanical system combining micromechanical capacitive functions and microwave data communication functions. In this project, we have focused on the back-modulation function used for data re-emission. We decided to develop this function with a microelectromechanical mixer made as a passive microwave frequency shifter using an integrated silicon micromechanical capacitive structure. The principles, together with electromechanical considerations, the technology of the silicon implantation, and some first experimental results are described in this paper. The main interest lies in the characterization of the device: both electrical and mechanical properties are tested in parallel to assist us in improving the system and defining a new micromechanical frequency-translator prototype.

Electrodeposited Ni 80 Fe 20 magnetic films are used in storage devices and are usually used for MEMS. In this paper, we present some fundamental results concerning the influence of electrodeposition conditions on the films characteristics. In the first step, permalloy electrodeposition has been studied on copper evaporated films without resist patterns. The growth rate varies linearly as function of the current density (typically 120 nm min −1 for 10 mA cm −2 ). The variation of the alloy composition with deposition parameters is consistent with the so-called anomalous deposition effect, i.e., a preferential deposition of iron. The composition is the same for films with thickness in the range 0.6–20 μm and the Fe concentration decreases with current density. An alloy Ni 80 Fe 20 with a density close to the bulk value is obtained for a current density of 14.5 mA cm −2 . Characterization of magnetic properties with a vibrating magnetometer shows that good properties can be obtained (coercivity=0.35 Oe for a thickness of 600 nm). These results are applied to the patterning of permalloy by electrodeposition through photoresist molds.

Free standing single-crystal silicon cantilever beams were fabricated by a SCREAM-like process which uses dry etching. Typical dimensions are length 200 μm, width 2–3 μm, thickness 2–3 μm. Cantilever beams were initially upward deflected by depositing a tungsten layer with a tensile stress. The electrostatic vertical actuation of the composite beam is investigated by biasing it with respect to the grounded substrate and lateral driving electrodes. A voltage of 10 V is sufficient to induce a large displacement of the beam free end up to 8 μm. A precise positioning is obtained with a good repeatability.

A low-cost gray-tone mask fabrication for thick resist UV lithography is described. The experimental relation between the theoretical transmission and the remaining resist thickness after development is presented.

Freestanding microring structures intended for the measurement of tensile stress or strain in thin films are analysed by linear buckling FEM analysis with thermal loads. It is shown that varying the tie length is helpful for increasing the strain measurement range of narrow devices while limiting the sensitivity factor variation and the wafer surface consumption. This reduces the need for large-diameter microstructures to measure low strain values and allows strain measurements in films with different thicknesses with a lower variation of the relative accuracy.

The evaluation of environmental and energy efficiency policy is a priority for a public agency such as ADEME which is responsible for implementing policy decisions in these domains. The breadth and variety of public instruments used and the availability of statistics make the experience acquired in France a good subject for the application of the methodology and interpretation of techno-economic energy efficiency indicators (EEIs). Using over 200 explanatory EEIs (the ‘techno-economic effects’), we have evaluated and characterized the sectoral trends in energy efficiency over 20 years (1973–1993), in particular as a function of the allocation of the 60 billion francs of public funds, while pointing out the methodological limitations. Final demand, responding to socio-economic pressures alone, should have risen by 47 Mtoe (Million ton oil equivalent). However, over the same period, due to energy management policy resulting from government efforts and market forces, savings of 33 Mtoe were achieved, the equivalent of 25% of the analysed final demand in 1993. It is also observed that the repercussions of the oil price countershock have not entirely receded. Although each instrument has shown some degree of efficacy, it seems that the optimal solution involves a combination of these instruments, with variations according to the sector and price context.

An improvement of a classical electrodeposition process through a photoresist mold for electrostatic side-drive micromotor fabrication is proposed. A step of selective and quasi-conformal deposition is used to reduce the air gap and bearing clearance below the value allowed by the maximum photoresist aspect ratio. This will allow the fabrication of variable-capacitance micromotors with better operation characteristics.

This paper introduces a novel energy harvesting technique and an associated packaged device aimed at powering intracardiac active medical devices by scavenging energy from ordinary blood pressure variations. We present the innovative concept of a micro-bellows packaged implant that deforms due to cyclic blood pressure variations in the cardiac cavities. This bellows transmits stresses on a spiral-shaped piezoelectric transducer that converts mechanical deformations into electric energy. The particular shapes of the different components (bellows and spiral) are designed to dramatically increase the mechanical energy that is harvested. The miniature bellows design, fabrication through electrodeposition for high compliance and hermeticity, and experimental characterization are presented. The specific challenges that arise in spiral shapes piezoelectric harvesters working in bending mode are discussed and we present a method to predict the non-trivial optimal electrode placements for maximum efficiency. This design process is completed by an associated microfabrication method and three types of piezoelectric bimorph spiral samples with doubled-sided microstructured electrode patterns are presented. The experimental performances of these prototypes are confronted to numerical simulation. A power of 4.15 μW/cm3 at 1.5 Hz has been obtained for the best design and we predict that tens of micro-Watts per cubic centimeter could be obtained using similar design process and material.

Silicon-on-insulator (SOI) wafers made by direct wafer bonding are widely used as starting substrates for microelectromechanical systems (MEMS) fabrication. Adding another layer next to the SiO2 SOI, or replacing it with another material, will be a way to tailor the SOI wafers further. Atomic layer deposition (ALD) can be used to deposit pinhole-free nanometer-thin conformal and smooth inorganic films at low temperatures, making it of interest for many applications in MEMS. In this work, the direct wafer bonding of ALD TiO2, and Al2O3 for reference, is investigated, eventually in order to fabricate SOI wafers with buried ALD oxides. Finding suitable process conditions for TiO2 bonding was challenging: bonding could not be made for TiO2 deposited directly on SiO2 or Si, and annealing at 1100°C gave non-continuous Ti-containing layers. Using a 2-nm Al2O3 under-layer and annealing at 700°C gave void-free bonding with continuous TiO2 and a bond strength of approximately 1600 mJ/m2, enabling the fabrication of SOI wafers with buried TiO2.

3D Integration of miniaturized systems at wafer level generates new needs of metrology and defects inspection for the control of temporary or permanent wafer bonding, of wafer thinning, of via interconnects technology and of wafer/die stacks. In this paper we demonstrate the capabilities of a versatile optical measurement system combining several microscopy and interferometry techniques in the visible and near infrared wavelength range.

Electrostatically actuated MEMS devices integrating surface micromachined silicon piezoresistive nanowires were batch processed to investigate a silicon nanowire detection scheme allowing an arbitrary choice of MEMS motion detection range and an increase of nanowire gauge factor measurement stress resolution. It is demonstrated that an in-plane MEMS displacements up to 180 nm with a resolution down to a few Angstroms can be achieved as well as a MEMS resonance detection. Results are compared with ex-situ MEMS optical microscopy and in-situ capacitive measurements of MEMS displacement.

This paper deals with the design and fabrication of a 3-axis Coriolis Vibrating micro Gyro (µCVG), based on a single planar monolithic structure. The presented µCVG design ensures a high mechanical coupling between one single driving mode and each one of the 3 sensing modes when the structure is subjected to Coriolis acceleration, with limited mechanical cross-coupling between vibration modes. The structure is made of a semi-conducting material with a cubic lattice, such as Silicon (Si) or Gallium Arsenide (GaAs). GaAs was particularly investigated for its piezoelectric properties, allowing both the actuation and the detection of the mechanical vibrations.

In MEMS industry, silicon-on-insulator (SOI) wafers are gaining ground from blank silicon wafers as the main starting substrate. Tailored SOI wafers available in the market contain for example buried cavities or a buried gettering layer. Adding another layer in addition to the thermal SiO 2 insulator, or replacing it with another material altogether, could be a way to tailor the properties of SOI wafers further. In this work, the direct wafer bonding of ALD TiO 2 , and Al 2 O 3 for reference, is investigated, eventually in order to fabricate SOI wafers with other buried ALD oxides.

This paper presents simulations and microfabrication of different parts of high fidelity electrodynamic MEMS loudspeakers with high electroacoustic conversion efficiency. The originality of the structure lies on the use of rigid silicon membranes suspended by a whole set of silicon beams instead of flexible polymer membranes usually found in MEMS loudspeakers. The microspeaker structure includes a planar copper microcoil electroplated on the silicon membrane and permanent magnets bonded on the substrate. Microstructure of the silicon membrane was optimized using FEM simulations for providing both rigidity and lightness of the mobile part. The results presented on a deep RIE etched 15 mm diameter silicon membrane structured with 40 stiffening ribs and on a 30 µm thick microcoil with 35 turns experimentally show the feasibility of key stages required for manufacturing of MEMS microspeakers with outstanding properties.

We show that the recombination energy of the direct band gap photoluminescence of germanium can be controlled by an external mechanical stress. The deformation is provided by an apparatus used for blister test. This strain leads to a significant change of the room temperature direct band gap recombination of germanium. An energy red-shift up to 60 meV is demonstrated for the room temperature photoluminescence of a thin germanium membrane (125 nm wavelength shift from 1535 to 1660 nm). This photoluminescence shift is correlated to the inplane tensile strain present in the film. A biaxial tensile strain larger than 0.6 % is achieved by this method. The wavelength shift is correlated to the predicted band gap shift as obtained from a 30 band k. p formalism. An excellent agreement is obtained between the experimental band gap shift and the theoretical one. This mechanical deformation allows to approach the direct band gap condition for germanium. We will discuss the possibility to achieve lasing with n-doped layers and the application of an external mechanical stress.

The study of anchoring on silicon surfaces with [001], [111] and [110] orientation shows that a nematic liquid crystal orients itself parallel to the two-fold axes of the surfaces. For [001] orientation, this leads to a bistable anchoring. For [111] orientation, the expected tristable anchoring is not observed, and only one anchoring direction is induced.

The objective of this work is to develop a reliable image processing technique to measure the vibration parameters on every part of MEMS resonators using microscopic images of the vibrating devices. Images of resonators vibrating in high frequencies are characterized by the blurs whose point spread functions (PSFs) are expressed in a parametric form with two parameters - vibration orientation and magnitude. We find it necessary to use the reference image (image of the still object) when analyzing the blur image, to achieve a subpixel-level accuracy. The orientation of the vibration is identified by applying the Radon transform on the difference between the reference image and the blur image. A blur image is usually modeled as a convolution of the PSF of the vibration with the reference image and added noise terms, assuming uniform vibration across the view. The vibration magnitude could then be recovered by using a minimum mean-squared error (MMSE) estimator to find the optimal PSF with the identified orientation. However, in real images only parts of the image belong to the vibrating object and the vibration may not be uniform over all parts of it. To overcome that problem, we use local optimization with a mean of weighted squared errors (MWSE) as the cost function instead of MSE. Indeed, it is capable of suppressing non-vibrating high-frequency components of the image. Sensitivity analysis and experiments on real images have been performed.

In this paper, an original differential VBA: the ISA-100 structure including an isolating system is presented in order to explore the fundamentals parameters for the miniaturization of such devices (4 to 1 mum thick beam). The bias stability of the sensor depends directly on the frequency stability of each beam, and thus requires a high quality factor Q. Q values up to 2.4 times 105 have been measured for 3 mum thick resonators. But high Q values are an advantage up to a certain extent. Indeed as the sensitive element gets thinner and Q values get higher, resonators are more susceptible to nonlinear effects. Experiments have revealed a nonlinear behaviour for a deflection lower than 10 nanometers. The influence of the Q-factor on the nonlinear behaviour of the VBA and then on its resolution (noise level) and frequency stability is studied.

Many micro-electro-mechanical-system (MEMS) are based on the use of resonant mechanical structures. In this paper, we propose scanning electron microscopy techniques that allow a direct characterization of in-plane vibrations of small-size resonators. Implementation and performance of these techniques are illustrated by vacuum quality factor measurements of an electrostatically-driven polysilicon Tang resonator and of a high Q silicon cantilever microbeam excited with an external piezoelectric actuator. These techniques are also expected to be suitable for the dynamical characterization of nanoresonators.