A5072146941- Phase-change materials and chalcogenides
- Chalcogenide Semiconductor Thin Films
- Advanced Memory and Neural Computing
- Liquid Crystal Research Advancements
- Transition Metal Oxide Nanomaterials
- Semiconductor materials and devices
- Solid-state spectroscopy and crystallography
- Ferroelectric and Negative Capacitance Devices
- Thin-Film Transistor Technologies
- Semiconductor materials and interfaces
- Perovskite Materials and Applications
- Spinal Fractures and Fixation Techniques
- Neural Networks and Applications
- Spine and Intervertebral Disc Pathology
- Quantum Dots Synthesis And Properties
- Engineering Technology and Methodologies
- Nonlinear Optical Materials Studies
- Parallel Computing and Optimization Techniques
- Machine Learning in Materials Science
- Nonlinear Optical Materials Research
- Additive Manufacturing Materials and Processes
- Medical Imaging and Analysis
- Additive Manufacturing and 3D Printing Technologies
- Augmented Reality Applications
- Musculoskeletal pain and rehabilitation
Istituto Clinico Sant'Ambrogio
2025
STMicroelectronics (Italy)
2005-2024
STMicroelectronics (Czechia)
2024
Politecnico di Milano
2004-2023
Micron (Italy)
2010-2022
China Classification Society
2022
Istituto Ortopedico Galeazzi
2022
STMicroelectronics (France)
2021
University High School
2019
Micron (United States)
2012-2013
Abstract Modern computation based on von Neumann architecture is now a mature cutting-edge science. In the architecture, processing and memory units are implemented as separate blocks interchanging data intensively continuously. This transfer responsible for large part of power consumption. The next generation computer technology expected to solve problems at exascale with 10 18 calculations each second. Even though these future computers will be incredibly powerful, if they type...
A detailed investigation of the reliability aspects in nonvolatile phase-change memories (PCM) is presented, covering basic related to high density array NVM, i.e., data retention, endurance, program and read disturbs. The retention capabilities endurance characteristics single PCM cells are analyzed, showing that can be stored for 10 years at 110/spl deg/C a resistance difference two order magnitude between cell states maintained more than 10/sup 11/ programming cycles. main mechanisms...
A comprehensive numerical model for chalcogenide glasses is presented, coupling a physically based electrical able to reproduce the threshold switching with local nucleation and growth algorithm account phase transition dynamics. The main ingredients of physics are reviewed analyzed through simplified analytical models, providing deeper insight on origin mechanism in glasses. semiconductorlike three-dimensional full-coupled implementation proposed finally presented its capabilities...
The threshold switching mechanism in amorphous chalcogenides is investigated, showing experimental data that once and for all demonstrate its electronic nature. physical mechanisms responsible the to highly conductive state are discussed impact of cumulative read-out pulses also phase-change transitions induced by usual reading operations memory cells completely negligible.
One of the major concerns for feasibility phase-change memories is reduction programming current. To this aim, several efforts have been dedicated both on cell geometry and material engineering. This paper addresses programming-current minimization by optimization materials, scaling, tradeoff between readout performances cell. A general procedure to find optimum-cell proposed applied a prototype vertical Then, evolution program read through technology nodes analyzed numerical simulations...
Abstract The technological success of phase-change materials in the field data storage and functional systems stems from their distinctive electronic structural peculiarities on nanoscale. Recently, superlattice structures have been demonstrated to dramatically improve optical electrical performances these chalcogenide based materials. In this perspective, unravelling atomistic structure that originates improvements switching time energy is paramount order design nanoscale with even enhanced...
The amorphous phase of chalcogenide material in phase-change memories (PCMs) is subjected to spontaneous and thermal-activated crystallization. This represents a critical reliability issue has be carefully investigated modeled for physically based projection retention failure up ten years. A new three-dimensional percolation model describing the statistical crystallization behavior an intrinsic PCM cell state developed. With this physical model, authors were able calculate resistance...
The time-stability of the electrical characteristics chalcogenide materials is one most important issues for their use in nonvolatile solid state memory applications. In particular conduction glassy phase evolves with time due to two different physical phenomena: crystallization and so-called low conductivity drift. Despite physics having been extensively studied literature, latter mainly described by phenomenological relationships, its comprehension still under discussion. this paper we...
We reported here a comparative study of PCM cell architectures. The developed architectures are considered in program/read efficiency framework and an integration context. Self-Heating approach is slightly more efficient, owing to heat generation happening directly within GST, but shows hazardous technology implementation with Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sb Te xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> ,...
Phase change memory (PCM) device physics comprehension represents an important chapter of future development the PCM‐based architectures and their placement into storage class (SCM) segment hierarchy. Here, a reduction SET RESET currents by more than 60% with respect to conventional GeTe–Sb 2 Te 3 (GST) alloys is demonstrated using phase cells containing (GeTe–Sb )/Sb super‐lattices (SL). Further, it that our SL PCM devices have similar characteristics in terms transition as based on GST,...
In this work, a detailed chemical and crystallographic analysis of basic logic few selected intermediate RESET states Ge-rich Ge-Sb-Te-based (GST) phase-change memories (PCM) is presented, with particular focus on the understanding microscopic mechanisms underlying their electrical characteristics. We demonstrate that GST-based PCM store information not only in crystalline or amorphous phase, as conventional based Ge2Sb2Te5, but also active material stoichiometries: phase characterized by...
The statistical spread of intrinsic data retention times in phase-change memory (PCM) cells is studied. Based on the crystallization and percolation model described part 1, crystalline grain size amorphous volume after loss extracted. From temperature dependence size, authors calculate shape factor for distribution failure times, allowing a prediction PCM large arrays. scaling optimization issues with respect to time are finally addressed
In this letter, we show a compact model that describes the main electrical features of phase change memory (PCM) devices. The coherently reproduces behavior both SET and RESET states with description physics involved phenomena for different bias temperature conditions. For arbitrary programming pulses, is able to generate intermediate mixed distributions and, thus, resistance values between ones. proposed therefore precious tool design multilevel PCM applications.
Low-frequency noise spectral density in chalcogenide-based phase-change memory cells has been measured, discussing the role of trapping centers and static disorder as responsible for a level vitreous insulating state two orders magnitude higher than ordered conducting polycrystalline one. The 1∕f also studied function applied voltage exploited to experimentally investigate transport mechanisms chalcogenide alloys, showing that exponential increase with can be quantitatively explained by...
The scaling analysis of phase-change memory (PCM) cells is an essential step toward validation as a competitive technology in terms array density and current consumption. While the has been addressed companion paper, we focus here on thermal crosstalk, namely, temperature increase 1 bit while adjacent cell being programmed by high-current reset pulse. This parasitic heating may lead to partial crystallization amorphous phase consequent resistance decrease after cycling. Our shows that...
The realization of textured films 2-dimensionally (2D) bonded materials on amorphous substrates is important for the integration this material class with silicon based technology. Here, we demonstrate successful growth by molecular beam epitaxy Sb2Te3 and GeTe/Sb2Te3 superlattices two types substrates: carbon SiO2. X-ray diffraction measurements reveal that out-of-plane alignment grains in layers has a mosaic spread full width half maximum 2.8°. We show good texture SiO2 only obtained an...
Ge-rich GST alloys are the most promising materials for phase-change memory (PCM) to fulfill soldering compliance and tough data retention requirements of automotive applications. Significant efforts have been made engineer those optimize their integration inside fabrication process PCM. In this perspective, physical characterization device material is instrumental in understanding underlying physics, improving process, optimizing interactions between device, itself. Especially, microscopic...
To validate the AO Spine Subaxial Injury Classification System with participants of various experience levels, subspecialties, and geographic regions.A live webinar was organized in 2020 for validation System. The consisted 41 unique subaxial cervical spine injuries associated computed tomography scans key images. Intraobserver reproducibility interobserver reliability were calculated injury morphology, subtype, facet injury. classification system categorized as slight (ƙ = 0-0.20), fair...
The stochastic nature of percolation is shown as a possible issue for retention in PCM devices, due to the occurrence unlikely crystallization events that early decrease device resistance. Failure time dispersions at high temperatures are measured and analyzed through Monte Carlo model. A physical insight into nucleation growth mechanisms thus provided maximum working temperature 105degC extracted guarantee, on large statistics, 10 years data requirement non volatile applications
ZnO-based Schottky junctions fabricated at low temperature are proposed as selectors for crossbar non-volatile memory devices. Rectifying ratio over 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> and forward current density high xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> A/cm xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> reported. Results of the integration with NiO based switching elements also shown.