Enhanced Reliability of Top-pinned Perpendicular Magnetic Tunnel Junction by Post-oxidation of Sputtered MgO Barrier

MRS Advances ◽  
2017 ◽  
Vol 2 (4) ◽  
pp. 259-264 ◽  
Author(s):  
Chikako Yoshida ◽  
Hideyuki Noshiro ◽  
Yuichi Yamazaki ◽  
Toshihiro Sugii
Keyword(s):  
Energy Loss ◽  
Error Rate ◽  
Tunnel Junction ◽  
Perpendicular Magnetic Anisotropy ◽  
Magnetic Tunnel Junction ◽  
Sputter Deposition ◽  
Long Endurance ◽  
Electron Energy Loss ◽  
Rf Sputter Deposition

ABSTRACTWe proposed an MgO barrier which is fabricated by combination of rf-sputter deposition of MgO film and subsequent in-situ post oxidation (PO). We found that the perpendicular magnetic anisotropy (PMA) of the CoFeB layer formed on this MgO barrier with PO was improved. We also found that a short error rate reduced drastically and a magnetoresistance (MR) ratio increased about 20% for the magnetic tunnel junction (MTJ) with this MgO barrier with PO. In addition, we showed that this MgO barrier with PO has long endurance life compared with conventional sputtered MgO barriers, and has a potential to operate over 1016 write cycles.Furthermore, we have observed that the PO could suppress the Fe diffusion into the MgO barrier and form Fe-O bonding at MgO/CoFeB interface using electron energy-loss spectroscopy (EELS). The obtained results might be involved to the improvement of PMA and MTJ characteristics.

Nanoscale analysis of a Co-SrTiO3 interface in a Magnetic tunnel junction

2002 ◽  
Vol 746 ◽  
Author(s):  
J.-L. Maurice ◽  
F. Pailloux ◽  
D. Imhoff ◽  
J.-P. Contour ◽  
A. Barthélémy ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Energy Loss ◽  
Electron Energy ◽  
Tunnel Junction ◽  
Electron Energy Loss Spectroscopy ◽  
Magnetic Tunnel Junction ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron ◽  
Electron Energy Loss

ABSTRACTWe use High Resolution Electron Microscopy together with Electron Energy Loss Spectroscopy to analyze the crystallography and the chemical configuration of a Co/SrTiO3 interface in a Co/SrTiO3/La2/3Sr1/3MnO3 magnetic tunnel junction.PACS: 75.47.-m, 75.70.Cn, 68.37.Lp, 79.20.Uv

Investigation of Switching Mechanism in HfO2-Based Oxide Resistive Memories by In-Situ Transmission Electron Microscopy and Electron Energy Loss Spectroscopy

2017 ◽  
Author(s):  
T. Dewolf ◽  
D. Cooper ◽  
N. Bernier ◽  
V. Delaye ◽  
A. Grenier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Hafnium Dioxide ◽  
Switching Mechanism ◽  
Transmission Electron ◽  
Electron Energy Loss

Abstract Forming and breaking a nanometer-sized conductive area are commonly accepted as the physical phenomenon involved in the switching mechanism of oxide resistive random access memories (OxRRAM). This study investigates a state-of-the-art OxRRAM device by in-situ transmission electron microscopy (TEM). Combining high spatial resolution obtained with a very small probe scanned over the area of interest of the sample and chemical analyses with electron energy loss spectroscopy, the local chemical state of the device can be compared before and after applying an electrical bias. This in-situ approach allows simultaneous TEM observation and memory cell operation. After the in-situ forming, a filamentary migration of titanium within the dielectric hafnium dioxide layer has been evidenced. This migration may be at the origin of the conductive path responsible for the low and high resistive states of the memory.

In Situ Analysis of Surface Contaminant Desorption during Low-Temperature Silicon Substrate Cleaning using Reflection Electron Energy Loss Spectrometry

1992 ◽  
Vol 259 ◽  
Author(s):  
Selmer S. Wong ◽  
Shouleh Nikzad ◽  
Channing C. Ahn ◽  
Aimee L. Smith ◽  
Harry A. Atwater
Keyword(s):  
Low Temperature ◽  
Energy Loss ◽  
Electron Energy ◽  
Core Loss ◽  
Temperature Dependent ◽  
Electron Energy Loss Spectrometry ◽  
Analysis Technique ◽  
Chemical Analysis Technique ◽  
Electron Energy Loss

ABSTRACTWe have employed reflection electron energy loss spectrometry (REELS), a surface chemical analysis technique, in order to analyze contaminant coverages at the submonolayer level during low-temperature in situ cleaning of hydrogen-terminated Si(100). The chemical composition of the surface was analyzed by measurements of the C K, O K and Si L2,3 core loss intensities at various stages of the cleaning. These results were quantified using SiC(100) and SiO2 as reference standards for C and O coverage. Room temperature REELS core loss intensity analysis after sample insertion reveals carbon at fractional monolayer coverage. We have established the REELS detection limit for carbon coverage to be 5±2% of a monolayer. A study of temperature-dependent hydrocarbon desorption from hydrogen-terminated Si(100) reveals the absence of carbon on the surface at temperatures greater than 200°C. This indicates the feasibility of epitaxial growth following an in situ low-temperature cleaning and also indicates the power of REELS as an in situ technique for assessment of surface cleanliness.

A Novel Technique for Determining Local Dielectric Function During Ferroelectric to Paraelectric Phase Transformation in Barium Titanate with a Transmission Eels

1995 ◽  
Vol 404 ◽  
Author(s):  
Kalpana S Katti ◽  
Maoxu Qian ◽  
Mehmet Sarikaya
Keyword(s):  
Phase Transformation ◽  
Barium Titanate ◽  
Energy Loss ◽  
Electron Energy ◽  
Dielectric Function ◽  
Optical Parameters ◽  
Edge Structure ◽  
Transmission Electron ◽  
Electron Energy Loss

AbstractIn this work a transmission electron microscopy (TEM) technique was used in obtaining local dielectric properties calculated from optical parameters for dynamic investigation of the effect of cubic to tetragonal phase transformation in barium titanate. In order to obtain in situ local dielectric during phase transformation, Kramers-Kronig relations were applied using the transmission electron energy loss (EELS) measurements. The optical excitations in the EELS spectra were consistent with the band structure results. The Re (1/ε) (real part of the dielectric function) obtained from the energy loss data indicated a change at the phase transformation. A broadening of the valence plasmon excitation suggested an order-disorder nature to the cubic to tetragonal transformation. In situ electron energy loss near edge structure (ELNES) studies from 500–700 eV energy range near the O-K edge exhibited a pre-edge feature that is associated with the Ti-L1, edge which further indicates an order-disorder nature to the phase transformation. The significance of the results is discussed.

scholarly journals In-Situ Study of Nb Oxide Thin Films Using Electron Energy Loss Spectroscopy

2011 ◽  
Vol 17 (S2) ◽  
pp. 798-799
Author(s):  
R Tao ◽  
R Klie ◽  
A Romanenko ◽  
L Cooley
Keyword(s):  
Thin Films ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Oxide Thin Films ◽  
In Situ Study ◽  
Electron Energy Loss

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

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