Microstructural Changes in W-Polycide Gates Capped with A Thin Polysilicon Layer

1998 ◽  
Vol 523 ◽  
Author(s):  
Y. O. Kima ◽  
J. Bevk ◽  
M. Furtsch ◽  
G. E. Georgiou ◽  
W. Mansfield ◽  
...  

AbstractWe find that sheet resistance of tungsten polycide can be reduced up to 40% by depositing thin polysilicon layers on the top of the films. Transmission electron microscopy shows no significant differences in the crystal structure, grain size, or dislocation density inside the films by adding a polysilicon cap, but it clearly shows roughening of the top interface. Auger depth profiling shows substantial reduction of the Si/W ratio in the capped films. Both results imply that the excess Si segregates to both polysilicon interfaces, effectively lowering the Si/W ratio and resulting in a low sheet resistance.

2014 ◽  
Vol 783-786 ◽  
pp. 2701-2706 ◽  
Author(s):  
Chuan Ting Wang ◽  
Alan G. Fox ◽  
Terence G. Langdon

High-pressure torsion (HPT) was conducted on disks of commercial purity Ti under applied pressures of 3 and 6 GPa. Measurements of the Vickers microhardness showed improving hardness homogeneity with increasing numbers of HPT turns. Transmission electron microscopy demonstrated that a higher HPT pressure leads to a smaller grain size after straining and these grains contain a high dislocation density with arrays of twins. This is consistent with the higher hardness of the Ti samples processed by HPT under 6 GPa pressure.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2849
Author(s):  
Marcin Jan Dośpiał

This paper presents domain and structure studies of bonded magnets made from nanocrystalline Nd-(Fe, Co)-B powder. The structure studies were investigated using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Mössbauer spectroscopy and X-ray diffractometry. On the basis of performed qualitative and quantitative phase composition studies, it was found that investigated alloy was mainly composed of Nd2(Fe-Co)14B hard magnetic phase (98 vol%) and a small amount of Nd1.1Fe4B4 paramagnetic phase (2 vol%). The best fit of grain size distribution was achieved for the lognormal function. The mean grain size determined from transmission electron microscopy (TEM) images on the basis of grain size distribution and diffraction pattern using the Bragg equation was about ≈130 nm. HRTEM images showed that over-stoichiometric Nd was mainly distributed on the grain boundaries as a thin amorphous border of 2 nm in width. The domain structure was investigated using a scanning electron microscope and metallographic light microscope, respectively, by Bitter and Kerr methods, and by magnetic force microscopy. Domain structure studies revealed that the observed domain structure had a labyrinth shape, which is typically observed in magnets, where strong exchange interactions between grains are present. The analysis of the domain structure in different states of magnetization revealed the dynamics of the reversal magnetization process.


1995 ◽  
Vol 378 ◽  
Author(s):  
G. Kissinger ◽  
T. Morgenstern ◽  
G. Morgenstern ◽  
H. B. Erzgräber ◽  
H. Richter

AbstractStepwise equilibrated graded GexSii-x (x≤0.2) buffers with threading dislocation densities between 102 and 103 cm−2 on the whole area of 4 inch silicon wafers were grown and studied by transmission electron microscopy, defect etching, atomic force microscopy and photoluminescence spectroscopy.


Author(s):  
Nabraj Bhattarai ◽  
Subarna Khanal ◽  
Pushpa Raj Pudasaini ◽  
Shanna Pahl ◽  
Dulce Romero-Urbina

Citrate stabilized silver (Ag) colloidal solution were synthesized and characterized for crystallographic and surface properties by using transmission electron microscopy (TEM) and zeta potential measurement techniques. TEM investigation depicted the size of Ago ranges from 5 to 50 nm with smaller particles having single crystal structure while larger particles with structural defects (such as multiply twinned, high coalescence and Moire patterns). ?-potential measurement confirms the presence of Ag+ in nAg stock solution. The shift in ?-potential measurement by +25.1 mV in the filtered solution suggests the presence of Ag+ in Ago nanoparticles.


1997 ◽  
Vol 505 ◽  
Author(s):  
Kwame Owusu-Boahen ◽  
Alexander H. King

ABSTRACTWe have used transmission electron microscopy (TEM) to study the microstructure of thin gold films which were grown on 〈100〉 rock salt. The samples were annealed on the rock salt substrate or on a gold TEM specimen grid. Films annealed on rock salt had a larger mean grain size than those annealed on TEM grids. All of the annealed films have a 〈111〉 preferred orientation. Several cracks are observed in the film annealed on rock salt. Plastic yielding of the film was identified by the presence of dislocations, and is caused by tensile stress derived from grain growth. In spite of the uniform texture of the films, the observed dislocations were concentrated only in some individual grains, while their surrounding grains remained dislocation-free. Yielded grains showed no difference of orientation that would lead to higher Schmid factors, so other predictors of yielding must be considered.


1989 ◽  
Vol 4 (2) ◽  
pp. 248-256 ◽  
Author(s):  
T. M. Shaw ◽  
S. L. Shinde ◽  
D. Dimos ◽  
R. F. Cook ◽  
P. R. Duncombe ◽  
...  

We have used transmission electron microscopy and optical microscopy to examine the effect that grain size and heat treatment have on twinning and microcracking in polycrystalline Y1Ba2Cu3O7−δ. It is shown that isothermal oxygenation heat treatments produce twin structures consisting of parallel twins, with a characteristic spacing that increases with increasing grain size. Slow cooling through the temperature range where the orthorhombic-to-tetragonal transformation induces twinning, however, produces a structure consisting of a hierarchical arrangement of intersecting twins, the scale of which appears to be independent of grain size. It is also shown that the microcracking induced by anisotropic changes in grain dimensions on cooling or during oxygenation can be suppressed if the grain size of the material is kept below about 1 μm. The results are examined in the light of current models for transformation twinning and microcracking and the models used to access the effect other processing variables such as oxygen content, doping or heat treatment may have on the microstructure of Y1Ba2Cu3O7−δ.


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