Centre Interuniversitaire de MicroElectronique et Nanotechnologies

In metamaterial science local resonance and hybridization are key phenomena strongly influencing the dispersion properties; the metasurface discussed in this article created by a cluster of resonators, subwavelength rods, atop an elastic surface being an exemplar with these features. On this metasurface, band-gaps, slow or fast waves, negative refraction and dynamic anisotropy can all be observed by exploring frequencies and wavenumbers from the Floquet-Bloch problem and by using the Brillouin zone. These extreme characteristics, when appropriately engineered, can be used to design and control the propagation of elastic waves along the metasurface. For the exemplar we consider, two parameters are easily tuned: rod height and cluster periodicity. The height is directly related to the band-gap frequency, and hence to the slow and fast waves, while the periodicity is related to the appearance of dynamic anisotropy. Playing with these two parameters generates a gallery of metasurface designs to control the propagation of both flexural waves in plates and surface Rayleigh waves for half-spaces. Scalability with respect to the frequency and wavelength of the governing physical laws allows the application of these concepts in very different fields and over a wide range of lengthscales.

In part 1 of the current study of haptic displays, a finite element (FE) model of a finger exploring a plate vibrating out-of-plane at ultrasonic frequencies was developed as well as a spring-frictional slider model. It was concluded that the reduction in friction induced by the vibrations could be ascribed to ratchet mechanism as a result of intermittent contact. The relative reduction in friction calculated using the FE model could be superimposed onto an exponential function of a dimensionless group defined from relevant parameters. The current paper presents measurements of the reduction in friction, involving real and artificial fingertips, as a function of the vibrational amplitude and frequency, the applied normal force and the exploration velocity. The results are reasonably similar to the calculated FE values and also could be superimposed using the exponential function provided that the intermittent contact was sufficiently well developed, which for the frequencies examined correspond to a minimum vibrational amplitude of ∼ 1 µm P-P. It was observed that the reduction in friction depends on the exploration velocity and is independent of the applied normal force and ambient air pressure, which is not consistent with the squeeze film mechanism. However, the modelling did not incorporate the influence of air and the effect of ambient pressure was measured under a limited range of conditions, Thus squeeze film levitation may be synergistic with the mechanical interaction.

This article focuses on the design of high-performance coupled slow-wave coplanar waveguide (CS-CPW) in CMOS technologies for the millimeter-wave (mm-wave) frequency bands. First, the theory as well as the electrical model of the CS-CPW are presented. Next, the analytical approach for the calculation of the model parameters is discussed. Then, by using the developed model, two mm-wave backward directional 3-dB couplers are designed in a bipolar complementary metal-oxide-semiconductor (BiCMOS) 55-nm technology for 120- and 185-GHz operation, respectively. Simulation and experimental results demonstrate that the use of the CS-CPW concept leads to state-of-the-art performance, with a good agreement between the analytical model, electromagnetic simulations, and measurement results.

Following the strategy of European Horizon 2020 project and the French national strategy of research, the future of science and technology will be driven by the communicating and smart objects that will extend in many fields of application to meet the societal needs. The CNFM, the French network for education in microelectronics and nanotechnologies, having a long experience in microelectronics education has to tackle this new challenge by shifting the curricula and the practical training of students to a more multidisciplinary way. An innovative strategy based on this approach is presently adopted, that means an orientation of the initial studies towards the applications by keeping the core of the skills. After a presentation of the context facilities, tools and skills of the CNFM network, this paper proposes an evolution of the microelectronic studies adapted to the approach of communicating and smart objects.

Presents a new approach for designing analog switches. Based on a two-current-conveyor cell, the switching element is suitable for continuous-time applications and offers high-linearity, low-noise, and high-frequency characteristics. Parasitic resistance and capacitance are improved and a wide bandwidth is achieved compared to previous approaches of traditional commercial circuits, the major interest of this new building block is to simulate an analog switch dedicated to the implementation of analog networks.

The 21st century will be the era of the fourth industrial revolution with the progressive introduction of the digital society, with smart/connected objects, smart factories driven by robotics, the Internet of Things (IoT) and artificial intelligence. Manufacturing should be performed by the industry entitled 4.0. These are advanced technologies resulting from steady development of information technology associated with new objects and systems that can fulfil manufacturing tasks. The industry 4.0 concept relies largely on the ability to design and manufacture smart and connected devices that are based on microelectronics technology. This evolution requires highly-skilled technicians, engineers and PhDs well prepared for research, development and manufacturing. Their training, which combines knowledge and the associated compulsory know-how, is becoming the main challenge for the academic world. The curricula must therefore contain the basic knowledge and associated know-how training in all the specialties in the field. The software and hardware used in microelectronics and its applications are becoming so complex and expensive that the most realistic solution for practical training is to share facilities and human resources. This approach has been adopted by the French microelectronics education network, which includes twelve joint university centres and 2 industrial unions. It makes it possible to minimize training costs and to train future graduates on up-to-date tools similar to those used in companies. Thus, this paper deals with the strategy adopted by the French network in order to meet the needs of the future industry 4.0.

This letter presents the design of a novel transparent 3 dB Branch-Line Coupler (BLC) using a proprietary self-assembling nano-particle technology based Micro-metal Mesh (MM) conductive film. The transparent MM conductive film has a sheet resistance of 0.7 Ω/sq and a visible-light transmission (VBLT) of 75%, resulting in good conductivity and high transparency, respectively. The proposed transparent BLC is mounted on a 2 mm-thick soda-lime glass substrate of dielectric 5.7 and designed to operate at 2.45 GHz. A layer of MM film on the back of the glass serves as a ground. The transparent BLC delivered measured coupling and transmission values of 3.9 and 4.3 dB, respectively. The transparent BLC can be used as a building block for realizing a transparent Butler Matrix (BM) Beam Forming Network (BFN) for Inter/Intra-Vehicle Wireless Communication (IIVWC) in Intelligent Transport System (ITS). Besides being transparent, the proposed BLC has a measured fractional bandwidth of 38.8% and 0.25 mm profile excluding the glass substrate. These advantages greatly enhance the BLC's potential to be used also as a BM building component that can be mounted onto the glass surfaces of buildings for future 5G indoor wireless communications where beam forming is required.

This article presents the design, experimental results, and modeling of an inversion-mode CMOS varactor integrated in the STMicroelectronics 55-nm BiCMOS technology. The device was characterized from 1 to 325 GHz, demonstrating high-quality factor at millimeter-waves. For instance, a quality factor of 7 at around 190 GHz for a tuning ratio (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> /C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">min</sub> ) greater than 4 was measured. This performance overpasses that of accumulation-mode varactors usually provided in CMOS technologies design kits, for frequencies beyond about 100 GHz. In addition, a smallsignal electrical model is provided from 100 to 250 GHz.

The training in microelectronics and nanotechnologies in France is structured as a national network since more than 30 years. This network is composed of 12 regional common centers including technological and design facilities. The network mission is to support animation and educational activities in this field at a national level. The strategy of innovative projects to maintain both quality and attractiveness to students has been established since 2006. This approach has been reinforced by the support of specific multiannual programs since 2009 and more especially in the frame of Excellence Initiative Program (IDEFI). The first achievements of these pedagogical projects have already been transferred to the menus of the common centers and have already showed all their interest as well at master and engineer degrees, as doctorate studies and lifelong learning.

Among the latest generation of digital technologies, immersive environments, including 360 videos, are&#13;\ngenerating increasing interest in education for the positive impact they may have on students both in&#13;\nterms of engagement and knowledge transfer. However, the educational potential of 360 video is still&#13;\nunder scrutiny. The Supporting Educators’ Pedagogical Activities with 360 video (SEPA360) is an&#13;\nErasmus+ project (2019-2022) (www.sepa360.eu), aimed at deepening the opportunities of 360 video&#13;\nin higher education, and investigating how it supports students' learning processes through real-life&#13;\nvideo scenarios. The partnership also developed Vivista, an educational software to enrich 360 videos,&#13;\nallowing lecturers to embed interaction points such as hotspots, hyperlinks, texts, images or videos,&#13;\nmultiple choice questions, area highlights and other interactive media. This paper presents a case study&#13;\nbased on the design and development of an interactive 360 video, enriched with Vivista, for the threeyear degree course in Food Science and Technology at the University of Florence. The paper starts with&#13;\na discussion of the educational challenges characterising the teaching activity in this area. Then, it&#13;\nfocuses on the design phase which is essential for succeeding in the preparation of the interactive videocontents, making videos more effective and engaging, and stimulating the student's sense of discovery.

In this article, we leverage the power of machine learning algorithms to propose a test methodology for millimeter-wave (mm-wave) integrated circuits. The proposed test strategy is based on identifying the main process degradation mechanisms in a particular device under test (DUT) and then designing dedicated process monitor circuits to characterize this degradation and infer the DUT performance. The resulting process monitors do not load or couple to any of the DUT nodes, and the methodology can be adapted to any mm-wave device without complex codesign. The proposed test methodology is illustrated on a set of 21 fabricated samples of a 65-GHz PA designed in STMicroelectronics 55-nm CMOS technology.

The Internet of Things (IoT) and related objects are becoming more prevalent around the world with exponential growth for the next fifteen years. This evolution implies innovation in many fields of technology, whose core is in microelectronics. Indeed, IoT deals with all societal applications such as health, the environment, transport, energy and communications. Thus, connected objects involve many technological components: sensors and actuators, signal processing circuits, data transmission circuits and systems, energy recovery systems, which directly depend on the performance of microelectronics. To create new connected objects, innovation is the main driver. Innovation results from the combination of a multidisciplinary approach, links between disciplines and the necessary know-how of engineers and technicians. This paper deals with the orientation of pedagogy towards these objectives through the development of dedicated and innovative platforms in microelectronics. These platforms are developed by the French National Microelectronics Education Network (CNFM). After presenting the context of IoT and the evolution of microelectronics technologies, this article highlights the main components of connected objects applied to many societal applications. Each component of the objects requires specific microelectronic devices or circuits. Innovation appears in the nature of platforms, the multidisciplinary approach of training, the permanent links between disciplines, and the adaptation to new educational tools, mainly online. The results of the training on innovative platforms are presented and discussed.\n

We present a noncontact optical metrology measuring the pistons and tip/tilt angles of the 61 hexagonal segments of a compact-sized segmented mirror. The instrument has been developed within the scope of a design study for the European Extremely Large Telescope (E-ELT). It is used as reference sensor for cophasing of the mirror segments in closed-loop control. The mirror shape is also measured by different types of stellar light-based phasing cameras whose performances will be evaluated with regard to a future E-ELT. Following a description of the system architecture, the second part of the paper presents experimental results demonstrating the achieved precision: 0.48 nm rms in piston and 74 nrad rms in tip/tilt.

We study numerically the potential of a multimodal elastic metamaterial to filter and guide Lamb waves in a plate. Using a sub-wavelength array of elongated beams attached to the plate, and combining the coupling effects of the longitudinal and flexural motion of these resonators, we create narrow transmission bands at the flexural resonances of the beams inside the wide frequency bandgap induced by their longitudinal resonance. The diameter of the beams becomes the tuning parameter for selection of the flexural leakage frequency, without affecting the main bandgap. Finally, by combination of the monopolar and dipolar scattering effects associated with the coupled beam and plate system, we create a frequency-based multiplexer waveguide in a locally resonant metamaterial.

The evolution of the fields of microelectronics and nanotechnologies has presently two main orientations: on one hand, the ultra large scale integration with FinFET or FDSOI technologies, and on the other hand, the multidisciplinary approach to insert the new devices in systems, mainly the communicating objects and the smart objects, in terms of applications. This evolution asks to the teachers to adapt the theoretical contents of the courses and to renew the practice in order to create new knowledge, new skills and new know-how. The French national network, CNFM (National Coordination for Education in Microelectronics and nanotechnologies) has deliberately introduced in its strategy the incitation to the multidisciplinary innovative projects in the microelectronics centers of this network. This paper deals with this strategy and gives several recent examples of the application of this strategy.

We investigated spin injection by spin pumping from a spin-injector(NiFe) into a spin-sink to detect spin fluctuations in the spin-sink. By scanning the ordering-temperature of several magnetic transitions, we found that enhanced spin pumping due to spin fluctuations applies with several ordering states: ferromagnetic (Tb) and antiferromagnetic (NiO, NiFeOx, BiFeO3, exchange-biased and unbiased IrMn). Results also represent systematic experimental investigation supporting that the effect is independent of the metallic and insulating nature of the spin-sink, and is observed whether the spin current probe involves electronic or magnonic transport, facilitating advances in material characterization and engineering for spintronic applications.

It has been shown in previous works that non-uniform sampling and processing is a better scheme than the uniform sampling to sample and process low activity signals. Non-uniform sampling technique generates fewer samples, which means less data to process and lower power consumption. Furthermore, asynchronous logic is known to be data-driven. It proves to be more adapted to the non-uniform sampling than synchronous logic. It is thus a better alternative to design low power data-processing circuits. In this paper, we present an overview of the non-uniform sampling scheme. It also describes the architectures of a processing function (Finite Impulse Response filter) in synchronous and asynchronous technologies. These circuits have been implemented on an Altera EP2C8 FPGA in order to extract and compare their activities profiles.

Suppression of superconductivity due to the proximity effect between a superconductor and a ferromagnet can be partially alleviated when a Cooper pair simultaneously samples different directions of the short-range exchange field. The superconductor's critical temperature, ${T}_{C}$, is therefore expected to partially recover when the ferromagnet is in a multidomain state, as opposed to a single-domain state. Here, we discuss series of experiments performed with ferromagnet(Pt/Co)/spacer(IrMn and Pt)/superconductor(NbN) heterostructures. By tuning the various parameters in play, e.g., superconducting coherence length-to-thicknesses ratio, and domain sizes, we obtained up to 10% recovery of the superconducting critical temperature $\mathrm{\ensuremath{\Delta}}{T}_{C}/{T}_{C}$. This large-scale recovery made investigations possible. In particular, from the spacer thickness dependence of $\mathrm{\ensuremath{\Delta}}{T}_{C}/{T}_{C}$, it was possible to deduce the characteristic length for Cooper pair penetration in an IrMn antiferromagnet. This information is crucial for electronic transport, and up to now has been difficult to access experimentally for antiferromagnets.

Microelectronics high education in France is organized through a network composed of twelve centers, six of them having clean-rooms and technological facilities. During the year 2010, some activities moved from microelectronics to nanotechnologies in an effort to adapt our training facilities to the new nanoworld.

In this study, a harmonic-rejection N-path mixer is designed, implemented, calibrated, and measured. The proposed mixer features a wide bandwidth suitable for low-power multi-standard RF front-end receivers while keeping low complexity by opting for only 5 paths rather than 10 and only one stage to perform harmonic rejection up to the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7^{th}$ </tex-math></inline-formula> local oscillator (LO) harmonic. This work employs a calibration strategy to prevent mismatches due to the fabrication process from affecting the system performance. The 0.17-1.2-GHz RF front-end mixer is fabricated in a 28-nm FDSOI technology. Measurements show a harmonic rejection higher than 45 dB for the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{rd}$ </tex-math></inline-formula>, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5^{th}$ </tex-math></inline-formula>, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7^{th}$ </tex-math></inline-formula> LO harmonics, 13 dB gain, 13.3 dB NF, −3.5 dBm in-band IIP3. The total power consumption is only 22 mW for a surface area of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.62\times 0.22~mm^{2}$ </tex-math></inline-formula>.