E. Jalaguier

Bio: E. Jalaguier is an academic researcher from European Automobile Manufacturers Association. The author has contributed to research in topics: Silicon & Flash memory. The author has an hindex of 11, co-authored 36 publications receiving 398 citations.

Robust Compact Model for Bipolar Oxide-Based Resistive Switching Memories

Abstract: Emerging nonvolatile memories based on resistive switching mechanisms pull intense research and development efforts from both academia and industry. Oxide-based resistive random access memories (OxRAM) gather noteworthy performances, such as fast WRITE/READ speed, low power, high endurance, and large integration density that outperform conventional flash memories. To fully explore new design concepts, such as distributed memory in logic or biomimetic architectures, robust OxRAM compact models must be developed and implemented into electrical simulators to assess performances at a circuit level. In this paper, we propose a physics-based compact model used in electrical simulator for bipolar OxRAM memories. After uncovering the theoretical background and the set of relevant physical parameters, this model is confronted to experimental electrical data. The excellent agreement with these data suggests that this model can be confidently implemented into circuit simulators for design purpose.

Investigation of the impact of the oxide thickness and RESET conditions on disturb in HfO 2 -RRAM integrated in a 65nm CMOS technology

Abstract: In this work, a comprehensive investigation of disturb in HfO2-Resistive Random Access Memories (RRAM) integrated in an advanced 65nm technology is presented. The effects of the oxide thickness and RESET conditions on disturb immunity of the High-Resistance-State (HRS) are explored. Constant Voltage Stress is applied on a large amount of samples at various temperatures. Data are collected and analyzed on a statistical basis. The SET dependence to the RESET conditions is investigated and correlated to the length of the induced depleted gap along the conductive filament. The conduction mechanism of the HRS is correlated to the failure/SET process of the RRAM device through a voltage acceleration model. It is shown that thicker dielectric oxide and stronger RESET conditions give rise to longer failure times.

CMOS compatible strategy based on selective atomic layer deposition of a hard mask for transferring block copolymer lithography patterns

Abstract: A generic, CMOS compatible strategy for transferring a block copolymer template to a semiconductor substrate is demonstrated. An aluminum oxide (Al(2)O(3)) hard mask is selectively deposited by atomic layer deposition in an organized array of holes obtained in a PS matrix via PS-b-PMMA self-assembly. The Al(2)O(3) nanodots act as a highly resistant mask to plasma etching, and are used to pattern high aspect ratio (>10) silicon nanowires and nanopillars.

Investigation of Hybrid Molecular/Silicon Memories With Redox-Active Molecules Acting as Storage Media

Abstract: In this paper, a physical investigation of hybrid molecular/Si memory capacitor structures is proposed, where redox-active molecules act as storage medium. Fc and ZnAB3P porphyrin were grafted on (100) Si with both a direct bond and a chemical linker in order to investigate the electron transfer properties of the molecule/Si system. The chemical structures of the molecular layers were analyzed with X-ray photoelectron spectroscopy. Cyclic voltammetry and impedance spectroscopy were also performed on capacitor structures in order to characterize the charge transfer between the redox molecules and the Si and the effect of an organic linker on its rate. To explain our results, an original electrical model of molecule/Si memory structures is proposed. Calculated data are compared to impedance results for the cases of Fc either directly grafted or with linker. The model allows us to give a theoretical confirmation of the influence of the linker over the redox energy and on the time constant of the molecular capacitor. Finally, density functional theory calculations provide an in-depth physical insight of the effect of the linker over the Fc redox energy. The results obtained in this paper show the strong impact of the engineering of the redox molecules and their linker on the electron transfer properties.

Microscopic understanding of the low resistance state retention in HfO 2 and HfAlO based RRAM

Abstract: We study in detail the impact of alloying HfO 2 with Al (Hf 1−x Al 2x O 2+x ) on the device characteristics through materials characterization, electrical measurements and atomistic simulation. Indeed, movements of individual oxygen atoms inside the dielectric are at the heart of RRAM operations. Therefore, we performed diffusion barrier calculations relative to the oxygen vacancy (VO) movement involved in R on data retention. Calculations are performed at the best level using ab initio techniques. Our study provides an insight on the improved R on stability of Hf 1−x Al 2x O 2+x RRAM, via a simple explanation based on its higher atomic density (atoms/cm3) associated with shorter bond lengths between cations and anions in the presence of Al.

Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends

Abstract: Atomic layer deposition (ALD) is gaining attention as a thin film deposition method, uniquely suitable for depositing uniform and conformal films on complex three-dimensional topographies. The deposition of a film of a given material by ALD relies on the successive, separated, and self-terminating gas–solid reactions of typically two gaseous reactants. Hundreds of ALD chemistries have been found for depositing a variety of materials during the past decades, mostly for inorganic materials but lately also for organic and inorganic–organic hybrid compounds. One factor that often dictates the properties of ALD films in actual applications is the crystallinity of the grown film: Is the material amorphous or, if it is crystalline, which phase(s) is (are) present. In this thematic review, we first describe the basics of ALD, summarize the two-reactant ALD processes to grow inorganic materials developed to-date, updating the information of an earlier review on ALD [R. L. Puurunen, J. Appl. Phys. 97, 121301 (2005)], and give an overview of the status of processing ternary compounds by ALD. We then proceed to analyze the published experimental data for information on the crystallinity and phase of inorganic materials deposited by ALD from different reactants at different temperatures. The data are collected for films in their as-deposited state and tabulated for easy reference. Case studies are presented to illustrate the effect of different process parameters on crystallinity for representative materials: aluminium oxide, zirconium oxide, zinc oxide, titanium nitride, zinc zulfide, and ruthenium. Finally, we discuss the general trends in the development of film crystallinity as function of ALD process parameters. The authors hope that this review will help newcomers to ALD to familiarize themselves with the complex world of crystalline ALD films and, at the same time, serve for the expert as a handbook-type reference source on ALD processes and film crystallinity.

Recommended Methods to Study Resistive Switching Devices

Abstract: Resistive switching (RS) is an interesting property shown by some materials systems that, especially during the last decade, has gained a lot of interest for the fabrication of electronic devices, with electronic nonvolatile memories being those that have received the most attention. The presence and quality of the RS phenomenon in a materials system can be studied using different prototype cells, performing different experiments, displaying different figures of merit, and developing different computational analyses. Therefore, the real usefulness and impact of the findings presented in each study for the RS technology will be also different. This manuscript describes the most recommendable methodologies for the fabrication, characterization, and simulation of RS devices, as well as the proper methods to display the data obtained. The idea is to help the scientific community to evaluate the real usefulness and impact of an RS study for the development of RS technology. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

A review of emerging non-volatile memory (NVM) technologies and applications

Abstract: This paper will review emerging non-volatile memory (NVM) technologies, with the focus on phase change memory (PCM), spin-transfer-torque random-access-memory (STTRAM), resistive random-access-memory (RRAM), and ferroelectric field-effect-transistor (FeFET) memory. These promising NVM devices are evaluated in terms of their advantages, challenges, and applications. Their performance is compared based on reported parameters of major industrial test chips. Memory selector devices and cell structures are discussed. Changing market trends toward low power ( e.g. , mobile, IoT) and data-centric applications create opportunities for emerging NVMs. High-performance and low-cost emerging NVMs may simplify memory hierarchy, introduce non-volatility in logic gates and circuits, reduce system power, and enable novel architectures. Storage-class memory (SCM) based on high-density NVMs could fill the performance and density gap between memory and storage. Some unique characteristics of emerging NVMs can be utilized for novel applications beyond the memory space, e.g. , neuromorphic computing, hardware security, etc . In the beyond-CMOS era, emerging NVMs have the potential to fulfill more important functions and enable more efficient, intelligent, and secure computing systems.

Resistive Random Access Memory (RRAM): an Overview of Materials, Switching Mechanism, Performance, Multilevel Cell (mlc) Storage, Modeling, and Applications

Abstract: In this manuscript, recent progress in the area of resistive random access memory (RRAM) technology which is considered one of the most standout emerging memory technologies owing to its high speed, low cost, enhanced storage density, potential applications in various fields, and excellent scalability is comprehensively reviewed. First, a brief overview of the field of emerging memory technologies is provided. The material properties, resistance switching mechanism, and electrical characteristics of RRAM are discussed. Also, various issues such as endurance, retention, uniformity, and the effect of operating temperature and random telegraph noise (RTN) are elaborated. A discussion on multilevel cell (MLC) storage capability of RRAM, which is attractive for achieving increased storage density and low cost is presented. Different operation schemes to achieve reliable MLC operation along with their physical mechanisms have been provided. In addition, an elaborate description of switching methodologies and current voltage relationships for various popular RRAM models is covered in this work. The prospective applications of RRAM to various fields such as security, neuromorphic computing, and non-volatile logic systems are addressed briefly. The present review article concludes with the discussion on the challenges and future prospects of the RRAM.

The use of atomic layer deposition in advanced nanopatterning

Abstract: Atomic layer deposition (ALD) is a method that allows for the deposition of thin films with atomic level control of the thickness and an excellent conformality on 3-dimensional surfaces. In recent years, ALD has been implemented in many applications in microelectronics, for which often a patterned film instead of full area coverage is required. This article reviews several approaches for the patterning of ALD-grown films. In addition to conventional methods relying on etching, there has been much interest in nanopatterning by area-selective ALD. Area-selective approaches can eliminate compatibility issues associated with the use of etchants, lift-off chemicals, or resist films. Moreover, the use of ALD as an enabling technology in advanced nanopatterning methods such as spacer defined double patterning or block copolymer lithography is discussed, as well as the application of selective ALD in self-aligned fabrication schemes.