Showing papers by "STMicroelectronics published in 2021"

Silicon-germanium receivers for short-wave-infrared optoelectronics and communications

Abstract: Integrated silicon nanophotonics has rapidly established itself as intriguing research field, whose outlets impact numerous facets of daily life. Indeed, nanophotonics has propelled many advances in optoelectronics, information and communication technologies, sensing and energy, to name a few. Silicon nanophotonics aims to deliver compact and high-performance components based on semiconductor chips leveraging mature fabrication routines already developed within the modern microelectronics. However, the silicon indirect bandgap, the centrosymmetric nature of its lattice and its wide transparency window across optical telecommunication wavebands hamper the realization of essential functionalities, including efficient light generation/amplification, fast electro-optical modulation, and reliable photodetection. Germanium, a well-established complement material in silicon chip industry, has a quasi-direct energy band structure in this wavelength domain. Germanium and its alloys are thus the most suitable candidates for active functions, i.e. bringing them to close to the silicon family of nanophotonic devices. Along with recent advances in silicon-germanium-based lasers and modulators, shortwave-infrared receivers are also key photonic chip elements to tackle cost, speed and energy consumption challenges of exponentially growing data traffics within next-generation systems and networks. Herein, we provide a detailed overview on the latest development in nanophotonic receivers based on silicon and germanium, including material processing, integration and diversity of device designs and arrangements. Our Review also emphasizes surging applications in optoelectronics and communications and concludes with challenges and perspectives potentially encountered in the foreseeable future.

IntAct: A 96-Core Processor With Six Chiplets 3D-Stacked on an Active Interposer With Distributed Interconnects and Integrated Power Management

Abstract: In the context of high-performance computing, the integration of more computing capabilities with generic cores or dedicated accelerators for artificial intelligence (AI) application is raising more and more challenges. Due to the increasing costs of advanced nodes and the difficulties of shrinking analog and circuit input output signals (IOs), alternative architecture solutions to single die are becoming mainstream. Chiplet-based systems using 3D technologies enable modular and scalable architecture and technology partitioning. Nevertheless, there are still limitations due to chiplet integration on passive interposers—silicon or organic. In this article we present the first CMOS active interposer, integrating: 1) power management without any external components; 2) distributed interconnects enabling any chiplet-to-chiplet communication; and3) system infrastructure, design-for-test, and circuit IOs. The IntAct circuit prototype integrates six chiplets in FDSOI 28-nm technology, which are 3D-stacked onto this active interposer in 65-nm process, offering a total of 96 computing cores. Full scalability of the computing system is achieved using an innovative scalable cache-coherent memory hierarchy, enabled by distributed network-on-chips, with 3-Tbit/s/mm2 high bandwidth 3D-plug interfaces using 20- $\mu \text{m}$ pitch micro-bumps, 0.6-ns/mm low latency asynchronous interconnects, while the six chiplets are locally power-supplied with 156-mW/mm2 at 82%-peak-efficiency dc–dc converters through the active interposer. Thermal dissipation is studied showing the feasibility of such approach.

SiGe HBTs and BiCMOS Technology for Present and Future Millimeter-Wave Systems

Abstract: This paper gives an overall picture from BiCMOS technologies up to THz systems integration, which were developed in the European Research project TARANTO. The European high performance BiCMOS technology platforms are presented, which have special advantages for addressing applications in the submillimeter-wave and THz range. The status of the technology process is reviewed and the integration challenges are examined. A detailed discussion on millimeter-wave characterization and modeling is given with emphasis on harmonic distortion analysis, power and noise figure measurements up to 190 GHz and 325 GHz respectively and S-parameter measurements up to 500 GHz. The results of electrical compact models of active (HBTs) and passive components are presented together with benchmark circuit blocks for model verification. BiCMOS-enabled systems and applications with focus on future wireless communication systems and high-speed optical transmission systems up to resulting net data rates of 1.55 Tbit/s are presented.

Rapid detection of bacterial pathogens in blood through engineered phages-beads and integrated Real-Time PCR into MicroChip

Abstract: The invasion of pathogens into the bloodstream can produce a systemic inflammatory response syndrome that, if not promptly treated, rapidly evolves in acute life-threatening dysfunction of remote organs (septic shock). Current conventional diagnostic tests are microbial blood cultures that need days for results. Therefore, it is crucial the availability of rapid and reliable pathogens detection for prompt diagnosis. In this work, we developed a new method for fast and sensitive detection of bacteria in blood based on the integration of pathogen capture through engineered M13 phages and molecular detection via PCR in miniaturized silicon microchip. Engineered M13 phage-clones exposing specific peptides able to bind Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and a novel identified phage clone, 9IIIB5, for Staphylococcus epidermidis, were used to functionalize magnetic beads and capturing/concentrate the pathogens. Due to the stability of beads-phage-bacteria complex, PCR inhibitors present in the blood were easily removed without detachment of captured bacteria. The complex was used as target for direct amplification into miniaturized silicon chip by a multiplex PCR followed by Real-Time PCR. The procedure was very fast (less than 3 hs) and sensitive (10 cells/reaction) enabling molecular detection inside to the critical period for clinical decision in sepsis. It could be applied to detect pathogens present in very few numbers or in a metabolically inactive state. The results here presented pay the way to future development of portable genetic Point-of-Care in the rapid identification of microorganisms present in the blood stream or also in different matrices, such as waters and foods.

SymBIST : Symmetry-Based Analog and Mixed-Signal Built-In Self-Test for Functional Safety

Abstract: We propose a Built-In Self-Test (BIST) paradigm for analog and mixed-signal (A/M-S) Integrated Circuits (ICs), called symmetry-based BIST ( SymBIST ). SymBIST exploits inherent symmetries in an A/M-S IC to construct signals that are invariant by default, and subsequently checks those signals against a tolerance window. Violation of invariant properties points to the occurrence of a defect or abnormal operation. SymBIST is designed to serve as a functional safety mechanism. It is reusable ranging from post-manufacturing test, where it targets defect detection, to on-line test in the field of operation, where it targets low-latency detection of transient failures and degradation due to aging. We demonstrate SymBIST on a Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC). SymBIST features high defect coverage, short test time, low overhead, zero performance penalty, and has a fully digital interface making it compatible with modern digital test access mechanisms.

Silicon photonics for terabit/s communication in data centers and exascale computers

Abstract: Silicon Photonics Technology using sub micrometer SOI platform, which commercially emerged at the beginning of the century, has now gained market shares in the field of fiber optic interconnects, from Inter-to Intra-Data Center communications. With growing demands in terms of aggregated bandwidth, scalability, transceiver form factor, and cost, Silicon Photonics is expected to play a growing role, especially with the foreseeable need to co-package photonic transceivers with next generation Ethernet switches. This new paradigm will be possible only with an evolution of existing Silicon Photonics manufacturing platforms, in order to solve the challenges of 3D packaging, laser integration, reflow-compatible optical connectors and high efficiency, low footprint modulators. Achieving these challenges may pave the way to Terabit scale communications in Data Centers and High Performance Computing Systems (HPC).

Reconfigurable Flat Optics with Programmable Reflection Amplitude Using Lithography-Free Phase-Change Material Ultra-Thin Films

Abstract: We experimentally demonstrate a very large dynamic optical reflection modulation from a simple unpatterned layered stack of phase-change materials ultrathin films. Specifically, we theoretically and experimentally demonstrate that properly designed deeply sub-wavelength GeSbTe (GST) films on a metallic mirror produce a dynamic modulation of light in the near-infrared from very strong reflection (R > 80%) to perfect absorption (A > 99, 97%) by simply switching the crystalline state of the phase-change material. While the amplitude of modulation can lead to an optical contrast up to 10 6 , we can also actively "write" intermediate levels of reflection in between extreme values, corresponding to partial crystallization of the GST layer. We further explore several layered system designs and provide guidelines to tailor the wavelength efficiency range, the angle of operation and the degree of crystallization leading to perfect absorption.

Modeling and Simulating Electromagnetic Fault Injection

Abstract: Electromagnetic fault injection (EMFI) has recently gained popularity as a mean to induce faults because of its inherent advantages. Despite this popularity, there is only a little information on how EMFI generates faults. Within this context, this article aims at filling this lack by proposing a complete understanding and modeling of EM induction on integrated circuits (ICs). The presented model is confronted to experiments to endorse its soundness.

New Approaches and Understandings in the Growth of Cubic Silicon Carbide

Abstract: In this review paper, several new approaches about the 3C-SiC growth are been presented. In fact, despite the long research activity on 3C-SiC, no devices with good electrical characteristics have been obtained due to the high defect density and high level of stress. To overcome these problems, two different approaches have been used in the last years. From one side, several compliance substrates have been used to try to reduce both the defects and stress, while from another side, the first bulk growth has been performed to try to improve the quality of this material with respect to the heteroepitaxial one. From all these studies, a new understanding of the material defects has been obtained, as well as regarding all the interactions between defects and several growth parameters. This new knowledge will be the basis to solve the main issue of the 3C-SiC growth and reach the goal to obtain a material with low defects and low stress that would allow for realizing devices with extremely interesting characteristics.

Freehand System for Antenna Diagnosis Based on Amplitude-Only Data

Abstract: This article presents a portable system for freehand antenna diagnosis and characterization based on amplitude-only data. The amplitude-only samples are acquired by moving a handheld probe, which is tracked by a motion capture system, in front of the antenna under test (AUT) aperture. The acquired measurements are processed using the phaseless sources reconstruction method to compute an equivalent current distribution on the AUT aperture. Finally, the radiation pattern of the AUT can be obtained by evaluating the corresponding radiation integrals. Unlike previous work, the use of amplitude-only data avoids the need of a phase reference, paving the way to the diagnosis and characterization of antennas under operational conditions. This fact, together with the handheld capabilities, makes the system very convenient for measurements of already deployed and onboard antennas. Moreover, these amplitude-only acquisitions also simplify the required hardware. The system has been validated through measurements in a wide frequency range from $Ka$ -band up to 300 GHz. Despite that one cannot expect the same degree of accuracy that can be achieved under laboratory conditions (including an anechoic environment and highly accurate positioners), the system shows excellent capabilities to detect malfunctions, such as wrong amplitude/phase distributions, as well as a fair estimation of the far field.

Improving reliability engineering in product development based on design theory: the case of FMEA in the semiconductor industry

Abstract: In industry, the failure mode and effect analysis (FMEA) methodology is one of the main tools used for reliability management in product design and development. However, the academic literature highlights several shortcomings of the FMEA methodology. Therefore, the main purposes of this paper are the analysis of the weaknesses of FMEA, the improvement of the method, and the implementation of a new methodology able to support quality and reliability management in a more efficient way. Motivated by these objectives, a formal new methodology is proposed by extending the classic FMEA methodology through C-K design theory. To test the effectiveness of the proposed approach and analyze the acceptance of this method by users, a case study is conducted in STMicroelectronics, one of the European leaders in the semiconductor industry.

Miniaturized electrochemical biosensor based on whole-cell for heavy metal ions detection in water.

Abstract: The heavy metals pollution represents one of the important issues in the environmental field since it is involved in many pathologies from cancer, neurodegenerative, and metabolic diseases. We propose an innovative portable biosensor for the determination of traces of trivalent arsenic (As(III)) and bivalent mercury (Hg(II)) in water. The system implements a strategy combining two advanced sensing modules consisting in (a) a whole cell based on engineered Escherichia coli as selective sensing element towards the metals and (b) an electrochemical miniaturised silicon device with three microelectrodes and a portable reading system. The sensing mechanism relies on the selective recognition from the bacterium of given metals producing the 4-aminophenol redox active mediator detected through a cyclic voltammetry analysis. The miniaturized biosensor is able to operate a portable, robust, and high-sensitivity detection of As(III) with a sensitivity of 0.122 µA ppb-1 , LoD of 1.5 ppb, and a LoQ of 5 ppb. The LoD value is one order of magnitude below of the value indicated to WHO to be dangerous (10 μg/L). The system was proved to be fully versatile being effective in the detection of Hg(II) as well. A first study on Hg(II) showed sensitivity value of 2.11 µA/ppb a LOD value of 0.1 ppb and LoQ value of 0.34 ppb. Also in this case, the detected LOD was 10 times lower than that indicated by WHO (1 ppb). These results pave the way for advanced sensing strategies suitable for the environmental monitoring and the public safety.

A sampling-based approach for managing lot release in time constraint tunnels in semiconductor manufacturing

Abstract: For the sake of product yield and quality considerations, time constraints (TCs) are imposed between process operations in various multi-product manufacturing systems. Often spanning a number of op...

Ultra-compact binary neural networks for human activity recognition on RISC-V processors

Abstract: Human Activity Recognition (HAR) is a relevant inference task in many mobile applications. State-of-the-art HAR at the edge is typically achieved with lightweight machine learning models such as decision trees and Random Forests (RFs), whereas deep learning is less common due to its high computational complexity. In this work, we propose a novel implementation of HAR based on deep neural networks, and precisely on Binary Neural Networks (BNNs), targeting low-power general purpose processors with a RISC-V instruction set. BNNs yield very small memory footprints and low inference complexity, thanks to the replacement of arithmetic operations with bit-wise ones. However, existing BNN implementations on general purpose processors impose constraints tailored to complex computer vision tasks, which result in over-parametrized models for simpler problems like HAR. Therefore, we also introduce a new BNN inference library, which targets ultra-compact models explicitly. With experiments on a single-core RISC-V processor, we show that BNNs trained on two HAR datasets obtain higher classification accuracy compared to a state-of-the-art baseline based on RFs. Furthermore, our BNN reaches the same accuracy of a RF with either less memory (up to 91%) or more energy-efficiency (up to 70%), depending on the complexity of the features extracted by the RF.

Front and back channels coupling and transport on 28 nm FD-SOI MOSFETs down to liquid-He temperature

Abstract: 28 nm FD-SOI technology is electrically characterized aiming at cryogenic applications. Electrostatics and transport are evaluated and compared while lowering temperature from 300 K down to 4.2 K. Split CV technique is applied in both long and short channel transistors thanks to multiple parallel structures designed to increase the gate area. FD-SOI versatility is shown over a wide temperature range of operation, as the back gate tuning efficiency is preserved at low temperatures. Insights on back gate bias behavior at room and low temperatures are obtained and the electrostatic coupling between front and back channels can be successfully modelled by using 1D Poisson-Schrodinger calculation from 300 K down to 4.2 K. A generic form of empirical models for the effective mobility is found to be useful for cryogenic operation, since the phonon scattering contribution presents strong temperature dependence. While long channel MOSFETs exhibit strong mobility improvement, short channel transistors show lower mobility gain with temperature reduction.

Design, Fabrication, Characterization, and System Integration of a 1-D PMUT Array for Medical Ultrasound Imaging

Abstract: Micromachined Ultrasonic Transducer (CMUT and PMUT) technologies are playing a fundamental role in the development of novel applications such as ultra-portable medical imaging systems. This paper presents the design, fabrication, characterization, and system integration of a 1-D PMUT array for low-frequency diagnostic imaging applications. The PMUT array was fabricated using a sol-gel PZT thin film-based MEMS technology from STMicroelectronics. The 1-D array was integrated into an ultrasound probe and acoustic characterization and imaging tests were carried out using the ULA-OP 256 open scanner. The two-way frequency response of the PMUT had a center frequency of 2.5 MHz and a -6dB fractional bandwidth of 81%, and peak transmit and receive sensitivities assessed at the transducer surface of 31 kPa/V and 3.2 mV/kPa, respectively. In vitro and in vivo scans of a tissue-mimicking phantom and of a carotid artery, respectively, were successfully carried out demonstrating the potentiality of this PMUT technology for medical imaging applications.

Non-Imaging Digital CMOS-SOI-MEMS Uncooled Passive Infra-Red Sensing Systems

Abstract: This paper presents a novel non-imaging digital passive Infra-Red (PIR) sensing system using a CMOS-SOI-MEMS transistor as the thermal sensor, which replaces the traditional pyroelectric sensors and outperforms thermopiles. The mosaic sensors, which are manufactured by nano-fabrication methods in standard FABs, exhibit enhanced performance and robust manufacturing on wafer level processing and vacuum packaging. Mirror optics instead of Fresnel plastic lenses provides enhanced performance at low-cost. The essential aspects of the design of the mirrors for curtain sensors and presence sensors are presented. The overall measured performance for detecting human targets at extended ranges and hot spots detection are reported. The overall performance of the sensing systems indicate why they are most suitable for consumer electronics, including smart homes, wearables, Internet of Things (IoT) and mobile applications.

Thinking Outside the Superbox

Abstract: Designing a block cipher or cryptographic permutation can be approached in many different ways. One such approach, popularized by AES, consists in grouping the bits along the S-box boundaries, e.g., in bytes, and in consistently processing them in these groups. This aligned approach leads to hierarchical structures like superboxes that make it possible to reason about the differential and linear propagation properties using combinatorial arguments. In contrast, an unaligned approach avoids any such grouping in the design of transformations. However, without hierarchical structure, sophisticated computer programs are required to investigate the differential and linear propagation properties of the primitive. In this paper, we formalize this notion of alignment and study four primitives that are exponents of different design strategies. We propose a way to analyze the interactions between the linear and the nonlinear layers w.r.t. the differential and linear propagation, and we use it to systematically compare the four primitives using non-trivial computer experiments. We show that alignment naturally leads to different forms of clustering, e.g., of active bits in boxes, of two-round trails in activity patterns, and of trails in differentials and linear approximations.

Reduced order modelling and experimental validation of a MEMS gyroscope test-structure exhibiting 1:2 internal resonance.

Abstract: Micro-Electro-Mechanical Systems revolutionized the consumer market for their small dimensions, high performances and low costs. In recent years, the evolution of the Internet of Things is posing new challenges to MEMS designers that have to deal with complex multiphysics systems experiencing highly nonlinear dynamic responses. To be able to simulate a priori and in real-time the behavior of such systems it is thus becoming mandatory to understand the sources of nonlinearities and avoid them when harmful or exploit them for the design of innovative devices. In this work, we present the first numerical tool able to estimate a priori and in real-time the complex nonlinear responses of MEMS devices without resorting to simplified theories. Moreover, the proposed tool predicts different working conditions without the need of ad-hoc calibration procedures. It consists in a nonlinear Model Order Reduction Technique based on the Implicit Static Condensation that allows to condense the high fidelity FEM models into few degrees of freedom, thus greatly speeding-up the solution phase and improving the design process of MEMS devices. In particular, the 1:2 internal resonance experienced in a MEMS gyroscope test-structure fabricated with a commercial process is numerically investigated and an excellent agreement with experiments is found.

Silicon-On-Nothing ScAlN pMUTs

Abstract: This work presents a promising microfabrication technique employing the silicon-on-nothing (SON) process to form a $2\ \mu\mathrm{m}$ thick continuous monocrystalline silicon membrane over a vacuum cavity of $1\ \mu\mathrm{m}$ in depth. Utilizing the SON process, high fill-factor piezoelectric micromachined ultrasonic transducer (pMUT) arrays on an 8-inch silicon wafer with cavity widths ranging from $170\ \mu\mathrm{m}$ down to $38\ \mu\mathrm{m}$ have been demonstrated. Devices are designed with 15% scandium-doped aluminum nitride as the piezoelectric layer of the pMUT for both air-coupled and water-coupled applications. The air-coupled pMUTs show a peak displacement frequency from 0.8 to 1.6 MHz with a $Q$ -factor between 120 to 194. The water-coupled pMUT arrays show a transmit pressure measured by a needle hydrophone, in DI water at a distance of 20 mm, ranging between 0.4 to 6.9 kPa/V with peak frequency between 5 to 13.4 MHz and fractional bandwidth 56 to 36%, respectively. The piezoelectric-over-SON process proposed here has the potential to gain traction in low-cost and high-yield pMUT manufacturing.

Long-Term Characterization of a New Wide-Angle Micromirror With PZT Actuation and PZR Sensing

Abstract: This work presents a long-term characterization of a newly designed microelectromechanical-system (MEMS) micromirror capable of achieving a field-of-view (FOV) of almost 94°. The process used to fabricate the device allows to combine piezoelectric (PZT) actuation and piezoresistive (PZR) sensing of the tilt angle, enabling testing under closed loop control. Consistently with the adopted design guidelines, which considered fatigue limits on the silicon springs, the tested devices are able to withstand up to 3.6 billion continuous operating cycles in an uncontrolled laboratory environment when operated in resonant mode at 500 Hz. [2020-0366]

Innovative 3D Microfluidic Tools for On-Chip Fluids and Particles Manipulation: From Design to Experimental Validation.

Abstract: Micromixers are essential components in lab-on-a-chip devices, of which the low efficiency can limit many bio-application studies. Effective mixing with automation capabilities is still a crucial requirement. In this paper, we present a method to fabricate a three-dimensional (3D) poly(methyl methacrylate) (PMMA) fluidic mixer by combining computer-aided design (CAD), micromilling technology, and experimental application via manipulating fluids and nanoparticles. The entire platform consists of three microfabricated layers with a bottom reservoir-shaped microchannel, a central serpentine channel, and a through-hole for interconnection and an upper layer containing inlets and outlet. The sealing process of the three layers and the high-precision and customizable methods used for fabrication ensure the realization of the monolithic 3D architecture. This provides buried running channels able to perform passive chaotic mixing and dilution functions, thanks to a portion of the pathway in common between the reservoir and serpentine layers. The possibility to plug-and-play micropumping systems allows us to easily demonstrate the feasibility and working features of our device for tracking the mixing and dilution performances of the micromixer by using colored fluids and fluorescent nanoparticles as the proof of concept. Exploiting the good transparency of the PMMA, spatial liquid composition and better control over reaction variables are possible, and the real-time monitoring of experiments under a fluorescence microscope is also allowed. The tools shown in this paper are easily integrable in more complex lab-on-chip platforms.

Prediction of state anxiety by machine learning applied to photoplethysmography data.

Abstract: Background As the human behavior is influenced by both cognition and emotion, affective computing plays a central role in human-machine interaction. Algorithms for emotions recognition are usually based on behavioral analysis or on physiological measurements (e.g., heart rate, blood pressure). Among these physiological signals, pulse wave propagation in the circulatory tree can be assessed through photoplethysmography (PPG), a non-invasive optical technique. Since pulse wave characteristics are influenced by the cardiovascular status, which is affected by the autonomic nervous activity and hence by the psychophysiological state, PPG might encode information about emotional conditions. The capability of a multivariate data-driven approach to estimate state anxiety (SA) of healthy participants from PPG features acquired on the brachial and radial artery was investigated. Methods The machine learning method was based on General Linear Model and supervised learning. PPG was measured employing a custom-made system and SA of the participants was assessed through the State-Trait Anxiety Inventory (STAI-Y) test. Results A leave-one-out cross-validation framework showed a good correlation between STAI-Y score and the SA predicted by the machine learning algorithm (r = 0.81; p = 1.87∙10-9). The preliminary results suggested that PPG can be a promising tool for emotions recognition, convenient for human-machine interaction applications.

H -Band Substrate-Integrated Discrete-Lens Antenna for High Data Rate Communication Systems

Abstract: A substrate-integrated discrete-lens antenna manufactured in standard printed-circuit-board (PCB) technology is demonstrated in $H$ -band (225–325 GHz). The arrays composed of phase-shifting unit cells and a waveguide-fed planar focal source are designed on a single PCB stack with five metal layers and multiple low-loss dielectric substrates in a monolithic module of $20\times 20\times4.52$ mm3. The linearly polarized unit cells are based on arc-shaped resonators placed between two perpendicular polarizing grids. They achieve eight transmission phase states with less than 1 dB average insertion loss and 27% 1 dB bandwidth. Two antenna prototypes with radiating apertures of $6.6\times6.6$ mm2 and $10.56\times10.56$ mm2 are designed, fabricated, and measured. They demonstrate linearly polarized pencil-beam radiation patterns with low sidelobes, low cross-polarization, an experimental gain of 20.6/23.1 dBi at 327/332 GHz, and 3 dB gain bandwidth of 26.3%/17.2%. The impact of manufacturing tolerances is detailed both at unit-cell level and antenna level.

System-Level Test: State of the Art and Challenges

Abstract: System-level test (SLT) is gaining in importance in modern test flows. This paper summarizes recent industrial findings from three companies and discusses some of the still open questions. The first two reports focus on the optimization potentials due to defect coverage overlaps between SLT and other test insertions. Results observed on approximately 20 million manufactured 28nm and 40nm automotive system-on-chip (SoC) designs are reported. Costs and benefits of SLT are discussed and the potentials of a test results analytics platform are identified. The third report explores the role of marginalities among SLT fails. The post-silicon investigation of a CPU block in a 7nm 5G mobile SoC product aims at achieving a better understanding, whose fails are due to random variations versus systematic factors.