Quantitative HAADF STEM of SiGe in presence of amorphous surface layers from FIB preparation

2018 ◽  
Vol 184 ◽  
pp. 29-36 ◽  
Author(s):  
Tim Grieb ◽  
Moritz Tewes ◽  
Marco Schowalter ◽  
Knut Müller-Caspary ◽  
Florian F. Krause ◽  
...  
Author(s):  
R. Vincent

Microanalysis and diffraction on a sub-nanometre scale have become practical in modern TEMs due to the high brightness of field emission sources combined with the short mean free paths associated with both elastic and inelastic scattering of incident electrons by the specimen. However, development of electron diffraction as a quantitative discipline has been limited by the absence of any generalised theory for dynamical inelastic scattering. These problems have been simplified by recent innovations, principally the introduction of spectrometers such as the Gatan imaging filter (GIF) and the Zeiss omega filter, which remove the inelastic electrons, combined with annual improvements in the speed of computer workstations and the availability of solid-state detectors with high resolution, sensitivity and dynamic range.Comparison of experimental data with dynamical calculations imposes stringent requirements on the specimen and the electron optics, even when the inelastic component has been removed. For example, no experimental CBED pattern ever has perfect symmetry, departures from the ideal being attributable to residual strain, thickness averaging, inclined surfaces, incomplete cells and amorphous surface layers.


1994 ◽  
Vol 339 ◽  
Author(s):  
V. Heera ◽  
R. Kögler ◽  
W. Skorupa ◽  
J. Stoemenos

ABSTRACTThe evolution of the damage in the near surface region of single crystalline 6H-SiC generated by 200 keV Ge+ ion implantation at room temperature (RT) was investigated by Rutherford backscattering spectroscopy/chanelling (RBS/C). The threshold dose for amorphization was found to be about 3 · 1014 cm-2, Amorphous surface layers produced with Ge+ ion doses above the threshold were partly annealed by 300 keV Si+ ion beam induced epitaxial crystallization (IBIEC) at a relatively low temperature of 480°C For comparison, temperatures of at least 1450°C are necessary to recrystallize amorphous SiC layers without assisting ion irradiation. The structure and quality of both the amorphous and recrystallized layers were characterized by cross-section transmission electron microscopy (XTEM). Density changes of SiC due to amorphization were measured by step height measurements.


1983 ◽  
Vol 23 ◽  
Author(s):  
S. U. Campisano ◽  
D. C. Jacobson ◽  
J. M. Poate ◽  
A. G. Cullis ◽  
N. G. Chew

ABSTRACTThe formation of amorphous Si by the quench of a thin surface layer melted by fast UV laser irradiation has been investigated. The starting (111) surface layers were either pure or doped with As, Bi, In and Te by implantation. The asimplanted samples were recrystallized by ruby laser irradiation resulting in surface accumulation of Bi,In and Te. For the same UV irradiation condition, the amorphous layer formed in As, Bi, In or Te doped Si is about twice the thickness of the amorphous layer formed on pure Si. In the presence of the surface accumulation of Bi, In or Te, the amorphization results in an inward segregation of the dopant. For In, a very thin metal layer ˜15Å thick, is formed 150Å beneath the amorphous surface. These results show that the amorphous-liquid interfacial segregation coefficients for Bi, In or Te are less than unity and that the amorphous solidification proceeds from the surface and bottom of the liquid layer.


1989 ◽  
Vol 157 ◽  
Author(s):  
M.C. Ridgway ◽  
R.G. Elliman ◽  
J.S. Williams

ABSTRACTIon—beam induced epitaxial crystallization (IBIEC) of amorphous N1Si2 and CoSi2 layers is demonstrated. Epitaxial metal suicide layers on (111) Si substrates were implanted with 40 keV Si ions to form amorphous surface layers. IBIEC of amorphous NiSi2 and CoSi2 layers was induced at 13—74°C with 1.5 MeV Ne ion irradiation and proceeded in a layer—by—layer manner from the original amorphous/crystalline interface with activation energies of 0.26 ± 0.07 and 0.21 ± 0.06 eV for N1Si2 and CoSi2, respectively.


Author(s):  
M. D. Rechtin ◽  
J. Vander Sande ◽  
P. M. Baldo

Metallic glasses have recently evolved as an important new class of materials which can exhibit unexpected and highly desirable physical properties compared to their crystalline counterparts. Recent work on amorphous Nb40Ni60 has shown this alloy to have excellent resistance to displacement radiation damage effects to 900 K. This phenomenon, in conjunction with thermal stability to nearly 1000 K, and excellent mechanical hardness and strength, makes this refractory-transition metal alloy an attractive potential material for radiation environment applications. Some types of metallic glasses are available commercially as thin ribbons or filaments; however, the shape, size, and type of alloy available often limit their applications. In addition, ion implantation has been used to produce amorphous surface layers in some metal- metalloid systems such as Ni-P. This method of surface layer modification may be applied to unusual shapes and sizes.Furthermore, the thermal spike produced by ion implantation results in a cooling rate of ∽1014 K/sec in the vicinity of the collision cascade.


1980 ◽  
Vol 37 (3) ◽  
pp. 330-333 ◽  
Author(s):  
D. M. Follstaedt ◽  
J. A. Knapp ◽  
S. T. Picraux

1981 ◽  
Vol 8 ◽  
Author(s):  
H.W. Bergmann ◽  
B.L. Mordike

ABSTRACTVarious techniques of laser glazing are presented. Rules are given for the choise of systems which are suitable for producing amorphous surface layers. Methods of demonstrating the existence of a truly amorphous layer are discussed. Two examples are given: I) electron beam glazing of Ni-Nb coated single crystals 2) laser beam glazing of Fe-B coated Fe-Cr-C cold working steel.


1990 ◽  
Vol 201 ◽  
Author(s):  
L. A. Bunn ◽  
D. K. Sood

AbstractHigh dose zinc implantation (1×1016 to 6×1016 ions/cm2) into c-axis sapphire at 770K produces amorphous surface layers. Post-implantation annealing at temperatures at and above 800°C show that the modes of recrystallisation are strongly dependant on ion dose. At low doses formation of crystallites of α and γ phase Al2O3 is seen, with no evidence of any planar epitaxial growth at the original crystalline-amorphous interface. The zinc is seen to diffuse isotropically within the crystallised layer and becomes partially substitutional within the crystallites. At high doses, however, the formation of crystallites is inhibited, with the layer remaining amorphous. A more rapid diffusion of zinc is seen in the amorphous Al2O3, with some of the zinc being lost at the surface.


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