A memory built-in self-repair for high defect densities based on error polarities

Author(s):  
M. Nicolaidis ◽  
N. Achouri ◽  
L. Anghel
Carbon ◽  
2020 ◽  
Vol 168 ◽  
pp. 32-41 ◽  
Author(s):  
Albert Guirguis ◽  
Shyam R. Polaki ◽  
Gopinath Sahoo ◽  
Subrata Ghosh ◽  
Mohammed Kamruddin ◽  
...  

1995 ◽  
Vol 378 ◽  
Author(s):  
Henry Hieslmair ◽  
Scott McHugo ◽  
Eicke Weber

AbstractVarious silicon samples, both single and polycrystalline, were intentionally contaminated and externally gettered using phosphorus, aluminum and co- phosphorus/aluminum gettering. Gettering efficiencies were quantified via diffusion length improvements. Structural characterization was used to correlate defects with low gettering efficiencies. External gettering was found to be particularly effective at recovering diffusion length in large grain polycrystalline silicon and solar grade single crystal silicon despite Fe contamination and high defect densities. One of two explanations is possible, 1) the structural defects are initially undecorated and are completely gettered after Fe contamination, or 2) metal decoration on as-grown structural defects are structurally and/or chemically different from intentional Fe decoration.


Author(s):  
K. R. Carson

Annealed and unannealed commercially available beaten foils were used for much of the very early transmission electron microscopy of metals. The studies were restricted to the few highly malleable metals, so, when electropolishing and chemical techniques were developed that permitted many other materials to be thinned as well, beating all but disappeared. It has been found, however, that mechanical reduction techniques provide a simple and rapid means to obtain electron transparent foils of a wide variety of metals and alloys.Tantalum, titanium, platinum, iron, permalloy, silicon-steel, brass, copper, aluminum, cadmium, tin, solder, and lead have all been beaten directly to foil simply by placing a small piece of the material on a polished steel flat and hammering with a steel mallet. The structures observed in the high melting point materials were characterized by high defect densities not unlike those found after explosive loading. Mechanical twins were observed in copper and platinum, and, in many cases structural evidence existed for localized adiabatic heating. Some of the low melting point materials investigated anneal at ambient temperatures and were observed in various stages of polygonization, recrystallization, and grain growth. Electron diffraction revealed a deformation texture in most materials.


1991 ◽  
Vol 6 (7) ◽  
pp. 1408-1414 ◽  
Author(s):  
C.R.M. Grovenor ◽  
L.T. Romano ◽  
K.P. Mingard ◽  
H-C. Lai ◽  
K.D. Vernon-Parry

Thin films of YBCO and thallium-based superconductor compounds have been deposited with very similar polycrystalline structures. The critical current densities carried by the YBCO films are much lower than measured in the thallium films (>103, as opposed to >104 A/cm2). Grain boundaries in these films have been studied to correlate microstructure with the measured electrical properties. High defect densities and frequent microcracking have been observed at and around the boundaries in the YBCO films, but these defects are not seen in the thallium-based films. We suppose that this difference is because of the higher differential thermal expansion stresses set up in YBCO during cooling. Our observations imply that eventual application of polycrystalline superconducting films prepared by an ex situ process is more likely for the thallium-based materials than for YBCO.


1998 ◽  
Vol 528 ◽  
Author(s):  
Vidya Ramaswamy ◽  
Bruce M. Clemens ◽  
William D. Nix

AbstractResults from in-situ measurements of stress during growth of (111)-textured Ni/Cu multilayers with small and large bilayer periods are presented. In multilayers with small bilayer periods, Ni is in uniform tension and Cu in uniform compression. This behavior is modeled as the growth of a coherent multilayer with alloying in the layers. In multilayers with large bilayer periods, stress relaxation is observed but the measured stresses are much lower than expected based on a Mathews-Blakeslee relaxation process. An alternative stress relaxation mechanism based on high defect densities is presented and discussed.


2003 ◽  
Vol 779 ◽  
Author(s):  
I.M. Robertson ◽  
J. Robach ◽  
B. Wirth ◽  
A. Arsenlis ◽  
Lawrence Livermore

AbstractIn situ straining in the transmission electron microscope has been combined with molecular dynamics computer simulations to investigate the nature of the interaction of glissile dislocations with radiation-produced defects (loops, stacking-fault tetrahedra, and He bubbles), and to determine the mechanisms by which the dislocation loops and stacking-fault tetrahedra are annihilated and defect-free channels are created. The defect pinning strength depends on the defect and on the interaction geometry. The experiments and simulations show that a single interaction is not always sufficient to annihilate a dislocation loop or a stacking-fault tetrahedra and that the nature of the defect may be changed because of the interaction. The edge/screw character of the dislocation is also important as they have different efficiencies for annihilating a defect. The dislocations responsible for creating the defect-free channels are not the preexisting dislocations but originate from grain boundaries and other stress concentrators. Cross-slip of dislocations within the channels is important for clearing and widening the channel and can create new channels. Based on these observations a dispersed-barrier hardening model in which the influence of the radiation defects and dislocation density are combined. The resulting model predicts the observed behavior, including the apparent yield drop at high defect densities.


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