SiC TO SiC WAFER BONDING

2002 ◽  
Vol 742 ◽  
Author(s):  
G. N. Yushin ◽  
A. V. Kvit ◽  
R. Collazo ◽  
Z. Sitar

ABSTRACTSiC wafers with an RMS roughness of 1.5 nm were bonded in a dedicated ultrahigh vacuum bonding chamber. Successful fusion of wafers was observed at temperatures as low as 800°C under a uniaxial mechanical stress of 20 MPa. Cross-section transmission electron microscopy (XTEM) of a specimen bonded at 1100°C revealed parts of the interface where wafers were in intimate contact, while other parts contained an up to 3 nm thick amorphous carbon interlayer. The bonded SiC retained its high crystalline quality; no extended defects emanating from the interface were observed within the sampling region. Electrical measurements showed that the azimuthal orientation of the bonded couple significantly influences the electrical character of the junction.

Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.


Author(s):  
L. D. Peachey ◽  
J. P. Heath ◽  
G. Lamprecht

Biological specimens of cells and tissues generally are considerably thicker than ideal for high resolution transmission electron microscopy. Actual image resolution achieved is limited by chromatic aberration in the image forming electron lenses combined with significant energy loss in the electron beam due to inelastic scattering in the specimen. Increased accelerating voltages (HVEM, IVEM) have been used to reduce the adverse effects of chromatic aberration by decreasing the electron scattering cross-section of the elements in the specimen and by increasing the incident electron energy.


2010 ◽  
Vol 16 (6) ◽  
pp. 662-669 ◽  
Author(s):  
S. Simões ◽  
F. Viana ◽  
A.S. Ramos ◽  
M.T. Vieira ◽  
M.F. Vieira

AbstractReactive multilayer thin films that undergo highly exothermic reactions are attractive choices for applications in ignition, propulsion, and joining systems. Ni/Al reactive multilayer thin films were deposited by dc magnetron sputtering with a period of 14 nm. The microstructure of the as-deposited and heat-treated Ni/Al multilayers was studied by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) in plan view and in cross section. The cross-section samples for TEM and STEM were prepared by focused ion beam lift-out technique. TEM analysis indicates that the as-deposited samples were composed of Ni and Al. High-resolution TEM images reveal the presence of NiAl in small localized regions. Microstructural characterization shows that heat treating at 450 and 700°C transforms the Ni/Al multilayered structure into equiaxed NiAl fine grains.


2001 ◽  
Vol 78-79 ◽  
pp. 197-204
Author(s):  
Daisuke Takeuchi ◽  
Hideyuki Watanabe ◽  
Sadanori Yamanaka ◽  
Hidetaka Sawada ◽  
Hideki Ichinose ◽  
...  

2018 ◽  
Vol 24 (6) ◽  
pp. 623-633 ◽  
Author(s):  
Xin Li ◽  
Ondrej Dyck ◽  
Sergei V. Kalinin ◽  
Stephen Jesse

AbstractScanning transmission electron microscopy (STEM) has become the main stay for materials characterization on atomic level, with applications ranging from visualization of localized and extended defects to mapping order parameter fields. In recent years, attention has focused on the potential of STEM to explore beam induced chemical processes and especially manipulating atomic motion, enabling atom-by-atom fabrication. These applications, as well as traditional imaging of beam sensitive materials, necessitate increasing the dynamic range of STEM in imaging and manipulation modes, and increasing the absolute scanning speed which can be achieved by combining sparse sensing methods with nonrectangular scanning trajectories. Here we have developed a general method for real-time reconstruction of sparsely sampled images from high-speed, noninvasive and diverse scanning pathways, including spiral scan and Lissajous scan. This approach is demonstrated on both the synthetic data and experimental STEM data on the beam sensitive material graphene. This work opens the door for comprehensive investigation and optimal design of dose efficient scanning strategies and real-time adaptive inference and control of e-beam induced atomic fabrication.


2000 ◽  
Vol 623 ◽  
Author(s):  
N.D. Zakharov ◽  
A.R. James ◽  
A. Pignolet ◽  
S. Senz ◽  
D. Hesse

AbstractEpitaxial, ferroelectric Ba2Bi4Ti5O18 films grown on LaNiO3/CeO2/ZrO2:Y2O3 epitaxial layers on Si(100) are investigated by cross-section high-resolution transmission electron microscopy (HRTEM). The films are perfectly oriented and consist of well-developed grains of rectangular shape. The grain boundaries are strained and contain many defects, especially a new type of defect, which can be described as a staircase formed by repeated lattice shifts of Δ ∼ c/12 ∼ 4.2 Å in the [001] direction. This repeated shift results in seemingly bent ribbons of stacked Bi2O2 planes, involving, however, individual Bi2O2 planes which remain strongly parallel to the (001) plane. These defects contain an excess of bismuth. Other defects found in the grain interior include mistakes in the stacking sequence originating from the presence of single, well-oriented, non-stoichionietric layers intergrown with the stoichiometric Ba2Bi4Ti5O18 film matrix.


1990 ◽  
Vol 201 ◽  
Author(s):  
R. Jebasinski ◽  
S. Mantl ◽  
K. Radermacher ◽  
P. Fichtner ◽  
W. Jăger ◽  
...  

AbstractThe coarsening of CoSi2 precipitates and the microstructural evolution of (111) Si implanted with 200 keV Co+ ions at 350°C and fluences of 1×1016cm−2 and 6×1016cm−2 were investigated as a function of depth, annealing temperature and annealing time using Rutherford Backscattering Spectroscopy (RBS) and Transmission Electron Microscopy (TEM). After annealing cross-section TEM micrographs show a layered array of platelet-shaped precipitates with preferred facets on {111} planes. The fraction of Co-atoms, that were redistributed during the different annealing temperatures and times, has been used to determine an activation energy for the precipitate coarsening. By applying the Meechan-Brinkman and the change-of-slope methods, we obtained activation energies in the range of 3.2 – 3.6 eV.


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