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Jean-Michel Portal

Bio: Jean-Michel Portal is an academic researcher from Centre national de la recherche scientifique. The author has contributed to research in topics: Resistive random-access memory & Artificial neural network. The author has an hindex of 25, co-authored 136 publications receiving 2047 citations. Previous affiliations of Jean-Michel Portal include Alternatives & Aix-Marseille University.


Papers
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Proceedings ArticleDOI
01 Oct 2019
TL;DR: In this article, the authors study the reliance of brains on approximate memory strategies, which can be translated to AI and show that such systems can exploit the properties of emerging memories without error correction and achieve extremely high energy efficiency.
Abstract: When performing artificial intelligence, CPUs and GPUs consume considerably more energy for moving data between logic and memory units than for doing arithmetic. Brains, by contrast, achieve superior energy efficiency by fusing logic and memory entirely. Currently, emerging memory nanodevices give us an opportunity to reproduce this concept. In this overview paper, we look at neuroscience inspiration to extract lessons on the design of memory-centric neuromorphic systems. We study the reliance of brains on approximate memory strategies, which can be translated to AI. We give the example of a hardware binarized neural network with resistive memory. Based on measurements on a hybrid CMOS/resistive memory chip, we see that such systems can exploit the properties of emerging memories without error correction, and achieve extremely high energy efficiency. Second, we see that brains use the physics of their memory devices in a way much richer than only storage. This can inspire radical electronic designs, where memory devices become a core part of computing. We have for example fabricated neural networks where magnetic memories are used as nonlinear oscillators to implement neurons, and their electrical couplings implement synapses. Such designs can harness the rich physics of nanodevices, without suffering from their drawbacks.

1 citations

Proceedings ArticleDOI
06 May 2014
TL;DR: A multiplexed test structure able to measure a large number of transistor threshold voltages within a scribe line and post-layout simulations are presented to validate the concept for transistor matching characterization.
Abstract: This paper presents a multiplexed test structure able to measure a large number of transistor threshold voltages within a scribe line. To achieve this, switches are used to select a single transistor among others in a small multiplexed array. A study to evaluate the influence of this multiplexing system on electrical measurement is conducted. Post-layout simulations are presented to validate the concept for transistor matching characterization.

1 citations

Proceedings ArticleDOI
01 Sep 2008
TL;DR: The objective of this paper is to evaluate the delay impact of staggered metal filling on the standard cells and their associated local interconnect and the filling impact on RO delay magnifies the one introduced by the front-end process variations (PV).
Abstract: The objective of this paper is to evaluate the delay impact of staggered metal filling (Metal2) on the standard cells and their associated local interconnect (Metal1). A Design Of Experiment (DOE) is used to define a large range of filling pattern shapes and positions. This set of filling patterns is then inserted in a Ring Oscillator (RO). From the filled RO simulations, the RO delay is expressed as a function of the filling pattern features. The maximal timing error between the model and the simulation is 1.3%, validating the model. The filling impact on RO delay magnifies the one introduced by the front-end process variations (PV). Consequently, the filling influence is introduced for the minimal, typical and maximal corners, defined now with Process (P), Voltage (V), Temperature (T) and Filling density (F) characteristics.

1 citations

Proceedings ArticleDOI
08 Oct 2017
TL;DR: In this paper, the impact of post-nitridation annealing (PNA) temperature on a 40nm embedded Flash reliability is studied. But the performance of the Flash tunnel oxide is not analyzed.
Abstract: The impact of CMOS post nitridation annealing (PNA) temperature on a 40nm embedded Flash reliability is studied. Electrical characterizations of the Flash tunnel oxide are carried out on single cell. These are used to explain the better results in terms of endurance and data retention obtained on a 512kB test chip with a lower annealing temperature. This result can be linked with the decrease of nitrogen in the bulk oxide, improving oxide wear out performance against electrical stress and stress induced leakage current (SILC). The on-chip characterization is, here, an invaluable tool to show the extrinsic behavior in the memory array and apply product-like stress.

1 citations

Patent
23 Jul 2015
TL;DR: A nonvolatile memory including a plurality of elementary cells, each cell including a first programmable-resistance storage element connected between first and second nodes of the cell, a first access transistor coupling the second node to a third node of cell, and a second access transistor coupled the second vertex to a fourth vertex of cell as discussed by the authors.
Abstract: A non-volatile memory including a plurality of elementary cells, each cell including: a first programmable-resistance storage element connected between first and second nodes of the cell; a first access transistor coupling the second node to a third node of the cell; and a second access transistor coupling the second node to a fourth node of the cell.

1 citations


Cited by
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Journal ArticleDOI
TL;DR: Most of the NOM can be removed by coagulation, although, the hydrophobic fraction and high molar mass compounds of NOM are removed more efficiently than hydrophilic fraction and the low molarmass compounds.

1,106 citations

Journal ArticleDOI
TL;DR: The review ends with the current status of RRAMs in terms of stability, scalability and switching speed, which are three important aspects of integration onto semiconductors.
Abstract: The resistance switching behaviour of several materials has recently attracted considerable attention for its application in non-volatile memory (NVM) devices, popularly described as resistive random access memories (RRAMs). RRAM is a type of NVM that uses a material(s) that changes the resistance when a voltage is applied. Resistive switching phenomena have been observed in many oxides: (i) binary transition metal oxides (TMOs), e.g. TiO(2), Cr(2)O(3), FeO(x) and NiO; (ii) perovskite-type complex TMOs that are variously functional, paraelectric, ferroelectric, multiferroic and magnetic, e.g. (Ba,Sr)TiO(3), Pb(Zr(x) Ti(1-x))O(3), BiFeO(3) and Pr(x)Ca(1-x)MnO(3); (iii) large band gap high-k dielectrics, e.g. Al(2)O(3) and Gd(2)O(3); (iv) graphene oxides. In the non-oxide category, higher chalcogenides are front runners, e.g. In(2)Se(3) and In(2)Te(3). Hence, the number of materials showing this technologically interesting behaviour for information storage is enormous. Resistive switching in these materials can form the basis for the next generation of NVM, i.e. RRAM, when current semiconductor memory technology reaches its limit in terms of density. RRAMs may be the high-density and low-cost NVMs of the future. A review on this topic is of importance to focus concentration on the most promising materials to accelerate application into the semiconductor industry. This review is a small effort to realize the ambitious goal of RRAMs. Its basic focus is on resistive switching in various materials with particular emphasis on binary TMOs. It also addresses the current understanding of resistive switching behaviour. Moreover, a brief comparison between RRAMs and memristors is included. The review ends with the current status of RRAMs in terms of stability, scalability and switching speed, which are three important aspects of integration onto semiconductors.

950 citations

Journal ArticleDOI
02 Jan 2017
TL;DR: The relevant virtues and limitations of these devices are assessed, in terms of properties such as conductance dynamic range, (non)linearity and (a)symmetry of conductance response, retention, endurance, required switching power, and device variability.
Abstract: Dense crossbar arrays of non-volatile memory (NVM) devices represent one possible path for implementing massively-parallel and highly energy-efficient neuromorphic computing systems. We first revie...

800 citations

Journal ArticleDOI
TL;DR: Emphasis will be placed on the use of bioaccumulation and biomarker responses in air, soil, water and food, as monitoring tools for the assessment of the risks and hazards of PAH concentrations for the ecosystem, as well as on its limitations.
Abstract: Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds with two or more fused aromatic rings. They have a relatively low solubility in water, but are highly lipophilic. Most of the PAHs with low vapour pressure in the air are adsorbed on particles. When dissolved in water or adsorbed on particulate matter, PAHs can undergo photodecomposition when exposed to ultraviolet light from solar radiation. In the atmosphere, PAHs can react with pollutants such as ozone, nitrogen oxides and sulfur dioxide, yielding diones, nitro- and dinitro-PAHs, and sulfonic acids, respectively. PAHs may also be degraded by some microorganisms in the soil. PAHs are widespread environmental contaminants resulting from incomplete combustion of organic materials. The occurrence is largely a result of anthropogenic emissions such as fossil fuel-burning, motor vehicle, waste incinerator, oil refining, coke and asphalt production, and aluminum production, etc. PAHs have received increased attention in recent years in air pollution studies because some of these compounds are highly carcinogenic or mutagenic. Eight PAHs (Car-PAHs) typically considered as possible carcinogens are: benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene (B(a)P), dibenzo(a,h)anthracene, indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene. In particular, benzo(a)pyrene has been identified as being highly carcinogenic. The US Environmental Protection Agency (EPA) has promulgated 16 unsubstituted PAHs (EPA-PAH) as priority pollutants. Thus, exposure assessments of PAHs in the developing world are important. The scope of this review will be to give an overview of PAH concentrations in various environmental samples and to discuss the advantages and limitations of applying these parameters in the assessment of environmental risks in ecosystems and human health. As it well known, there is an increasing trend to use the behavior of pollutants (i.e. bioaccumulation) as well as pollution-induced biological and biochemical effects on human organisms to evaluate or predict the impact of chemicals on ecosystems. Emphasis in this review will, therefore, be placed on the use of bioaccumulation and biomarker responses in air, soil, water and food, as monitoring tools for the assessment of the risks and hazards of PAH concentrations for the ecosystem, as well as on its limitations.

798 citations