The Experts below are selected from a list of 128343 Experts worldwide ranked by ideXlab platform
Kinam Kim - One of the best experts on this subject based on the ideXlab platform.
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phase change behavior of stoichiometric ge2sb2te5 in phase change random Access Memory
Journal of The Electrochemical Society, 2007Co-Authors: Jongbong Park, Gyeongsu Park, Hionsuck Baik, Jangho Lee, Hongsik Jeong, Kinam KimAbstract:We observed the atomic structures for each reset and set state in a phase-change random Access Memory fabricated using stoichiometric crystalline Ge 2 Sb 2 Te 5 . The reset state clearly showed a mixture of dome-shaped amorphous and crystal structure surrounding amorphous, but the set state showed abnormally grown large grains due to recrystallization of the amorphous structure. The crystal structure of the recrystallized grain was face-centered cubic. The element analysis indicated that the atomic composition changes to nonstoichiometric phase in the active regions of the reset and the set state, which is Sb-rich and Te-deficient compared to the pristine stoichiometric composition. Analysis showed that thermal interdiffusion of Sb and Te caused nonstoichiometric nature of the material to reach the energetically stable state in the active region.
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Integration of lead zirconium titanate thin films for high density ferroelectric random Access Memory
Journal of Applied Physics, 2006Co-Authors: Kinam Kim, Sung-yung LeeAbstract:Interests are being focused on types of nonvolatile memories such as ferroelectric random Access Memory (FRAM), phase change random Access Memory, or magnetoresistance random Access Memory due to their distinct Memory properties such as excellent write performance which conventional nonvolatile memories do not possess. Among these types of nonvolatile memories, FRAM whose cell structure and operation are almost identical to dynamic random Access Memory (DRAM) can ideally realize cell size and speed of DRAM. Thus FRAM is the most appropriate candidate for future universal Memory where all Memory functions are performed with a single chip solution. Due to the poor ferroelectric properties of downscaled ultrathin lead zirconium titanate (PZT) capacitors as well as technical issues such as hydrogen and plasma related degradation arising from embedding ferroelectric metal-insulator-metal capacitors into conventional complementary metal oxide semiconductor processes, current FRAM still falls far below its ideal...
Joerg Appenzeller - One of the best experts on this subject based on the ideXlab platform.
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fetram an organic ferroelectric material based novel random Access Memory cell
Nano Letters, 2011Co-Authors: Joerg AppenzellerAbstract:Science and technology in the electronics area have always been driven by the development of materials with unique properties and their integration into novel device concepts with the ultimate goal to enable new functionalities in innovative circuit architectures. In particular, a shift in paradigm requires a synergistic approach that combines materials, devices and circuit aspects simultaneously. Here we report the experimental implementation of a novel nonvolatile Memory cell that combines silicon nanowires with an organic ferroelectric polymer—PVDF-TrFE—into a new ferroelectric transistor architecture. Our new cell, the ferroelectric transistor random Access Memory (FeTRAM) exhibits similarities with state-of-the-art ferroelectric random Access memories (FeRAMs) in that it utilizes a ferroelectric material to store information in a nonvolatile (NV) fashion but with the added advantage of allowing for nondestructive readout. This nondestructive readout is a result of information being stored in our cell...
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fetram an organic ferroelectric material based novel random Access Memory cell
Nano Letters, 2011Co-Authors: Joerg AppenzellerAbstract:Science and technology in the electronics area have always been driven by the development of materials with unique properties and their integration into novel device concepts with the ultimate goal to enable new functionalities in innovative circuit architectures. In particular, a shift in paradigm requires a synergistic approach that combines materials, devices and circuit aspects simultaneously. Here we report the experimental implementation of a novel nonvolatile Memory cell that combines silicon nanowires with an organic ferroelectric polymer—PVDF-TrFE—into a new ferroelectric transistor architecture. Our new cell, the ferroelectric transistor random Access Memory (FeTRAM) exhibits similarities with state-of-the-art ferroelectric random Access memories (FeRAMs) in that it utilizes a ferroelectric material to store information in a nonvolatile (NV) fashion but with the added advantage of allowing for nondestructive readout. This nondestructive readout is a result of information being stored in our cell...
S Tehrani - One of the best experts on this subject based on the ideXlab platform.
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low power switching in magnetoresistive random Access Memory bits using enhanced permeability dielectric films
Applied Physics Letters, 2007Co-Authors: Srinivas V Pietambaram, Nicholas D Rizzo, J M Slaughter, R W Dave, J Goggin, K Smith, S TehraniAbstract:We reduced the switching field (Hsw) in arrays of single-layer magnetoresistive random Access Memory elements using enhanced permeability dielectric (EPD) films. This reduction is due to an increased magnetic flux density produced at the bit by increasing the permeability μ of the surrounding dielectric. The authors produced EPD films by embedding superparamagnetic nanoparticles of various sizes in oxides of Al, Mg, or Si. For bits surrounded by EPD, Hsw decreased linearly as μ increased. Using this approach, we reduced Hsw by ≈40% for μ=3.5, without changing the energy barrier to magnetization reversal.
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magnetoresistive random Access Memory using magnetic tunnel junctions
Proceedings of the IEEE, 2003Co-Authors: S Tehrani, M Durlam, Nicholas D Rizzo, M Deherrera, J Janesky, B N Engel, J M Slaughter, J Salter, R W Dave, Brian R ButcherAbstract:Magnetoresistive random Access Memory (MRAM) technology combines a spintronic device with standard silicon-based microelectronics to obtain a combination of attributes not found in any other Memory technology. Key attributes of MRAM technology are nonvolatility and unlimited read and write endurance. Magnetic tunnel junction (MTJ) devices have several advantages over other magnetoresistive devices for use in MRAM cells, such as a large signal for the read operation and a resistance that can be tailored to the circuit. Due to these attributes, MTJ MRAM can operate at high speed and is expected to have competitive densities when commercialized. In this paper, we review our recent progress in the development of MTJ-MRAM technology. We describe how the Memory operates, including significant aspects of reading, writing, and integration of the magnetic material with CMOS, which enabled our recent demonstration of a 1-Mbit Memory chip. Important Memory attributes are compared between MRAM and other Memory technologies.
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thermally activated magnetization reversal in submicron magnetic tunnel junctions for magnetoresistive random Access Memory
Applied Physics Letters, 2002Co-Authors: Nicholas D Rizzo, M Deherrera, J Janesky, B N Engel, J M Slaughter, S TehraniAbstract:We have measured thermally activated magnetization reversal of the free layers in submicron magnetic tunnel junctions to be used for magnetoresistive random Access Memory. We applied magnetic field pulses to the bits with a pulse duration tp ranging from nanoseconds to 0.1 ms. We have measured the switching probability as a function of tp with a fixed field amplitude H, and as a function of H for fixed tp. For both cases, we find good agreement with the switching probability predicted by the Arrhenius–Neel theory for thermal activation over a single energy barrier.
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submicron spin valve magnetoresistive random Access Memory cell
Journal of Applied Physics, 1997Co-Authors: Eugene Youjun Chen, S Tehrani, Theodore Zhu, M Durlam, Herbert GoronkinAbstract:Spin valve magnetoresistive random Access Memory cells with widths varying from 1.5 to 0.25 μm and an aspect ratio of length/width more than 10 were fabricated and tested. In general, the switching field of the free magnetic layer was found to be inversely proportional to the width of the cell. Adequate pinning was shown for cell width down to 0.75 μm. For 0.5 and 0.25 μm wide cells, the switching field of the free magnetic layer is comparable to the pinning field of the other magnetic layer. So the pinned magnetic layer rotates with the free magnetic layer. The giant magnetoresistive ratio of the cell drops dramatically. Potentially, this may be a fundamental problem for this Memory mode. Solutions are proposed.
Peong Hwa Jang - One of the best experts on this subject based on the ideXlab platform.
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detrimental effect of interfacial dzyaloshinskii moriya interaction on perpendicular spin transfer torque magnetic random Access Memory
Applied Physics Letters, 2016Co-Authors: Ik Sun Hong, Peong Hwa JangAbstract:Recently, perpendicular magnetic anisotropy based spin-transfer torque magnetic random Access Memory (STT-MRAM) is drawing a great attention to researchers studying MRAM due to its advantages of having the density of DRAM, fast response time of SRAM and the non-volatility of flash Memory [1]. Moreover, recent studies has shown that the spin orbit coupling, which results in the interfacial perpendicular magnetic anisotropy, and the inversion symmetry breaking at the interface between free layer and heavy metal of magnetic tunnel junction (MTJ) results in antisymmetric exchange interaction named as Dzyaloshinskii-Moriya interaction (DMI).[2]
Satoshi Sugahara - One of the best experts on this subject based on the ideXlab platform.
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nonvolatile static random Access Memory based on spin transistor architecture
Journal of Applied Physics, 2009Co-Authors: Yusuke Shuto, Shuuichirou Yamamoto, Satoshi SugaharaAbstract:The authors proposed and computationally analyzed nonvolatile static random Access Memory (NV-SRAM) architecture using a new type of spin transistor comprised of a metal-oxide-semiconductor field-effect transistor (MOSFET) and magnetic tunnel junction (MTJ) that is referred to as a pseudo-spin-MOSFET (PS-MOSFET). The PS-MOSFET is a circuit approach to reproduce the functions of spin transistors, based on recently progressed magnetoresistive random Access Memory technology. The proposed NV-SRAM cell can be simply configured by connecting two PS-MOSFETs to the storage nodes of a standard SRAM cell.
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Nonvolatile static random Access Memory based on spin-transistor architecture
Journal of Applied Physics, 2009Co-Authors: Satoshi SugaharaAbstract:The authors proposed and computationally analyzed nonvolatile static random Access Memory (NV-SRAM) architecture using a new type of spin transistor comprised of a metal-oxide-semiconductor field-effect transistor (MOSFET) and magnetic tunnel junction (MTJ) that is referred to as a pseudo-spin-MOSFET (PS-MOSFET). The PS-MOSFET is a circuit approach to reproduce the functions of spin transistors, based on recently progressed magnetoresistive random Access Memory technology. The proposed NV-SRAM cell can be simply configured by connecting two PS-MOSFETs to the storage nodes of a standard SRAM cell.The authors proposed and computationally analyzed nonvolatile static random Access Memory (NV-SRAM) architecture using a new type of spin transistor comprised of a metal-oxide-semiconductor field-effect transistor (MOSFET) and magnetic tunnel junction (MTJ) that is referred to as a pseudo-spin-MOSFET (PS-MOSFET). The PS-MOSFET is a circuit approach to reproduce the functions of spin transistors, based on recently progressed magnetoresistive random Access Memory technology. The proposed NV-SRAM cell can be simply configured by connecting two PS-MOSFETs to the storage nodes of a standard SRAM cell.
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nonvolatile static random Access Memory nv sram using magnetic tunnel junctions with current induced magnetization switching architecture
arXiv: Materials Science, 2008Co-Authors: Shuuichirou Yamamoto, Satoshi SugaharaAbstract:We propose and computationally analyze a nonvolatile static random Access Memory (NV-SRAM) cell using magnetic tunnel junctions (MTJs) with magnetic-field-free current-induced magnetization switching (CIMS) architecture. A pair of MTJs connected to the storage nodes of a standard SRAM cell with CIMS architecture enables fully electrical store and restore operations for nonvolatile logic information. The proposed NV-SRAM is expected to be a key component of next-generation power-gating logic systems with extremely low static-power dissipation.
