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Determination of structure factors in electron diffraction: A bloch wave picture
THE FABRICATION OF TEM GRIDS WITH SILICON MICROMACHINING F. Enquist,
A. Spetz
and M. Armgarth
University of Linksping Department of Physics and Measurement Technol581 83 LinkSping ogy,
The TEM study of ultrathin porous films is somewhat difficult because the In order films are not self-supporting. to study ultrathin metal films for MOSsensor purposes we have constructed a silicon dioxide grid silicon-supported, The grid by means of micromachining. consists of a 50 x 50 micron, silicon dioxide window suspended in a silicon frame, the thickness of the window being The between 500 and 2000 Angstroms. metal film, in our case a 30-Angstrom platinum film, is deposited directly on the grid by means of thermal evaporation. The sample can then, without any further be inserted into the TEM manipulations, for examination. The fabrication process is rather simple and well suited for batch fabriSilicon dioxide with the decation. sired window thickness is grown on the polishedfrontside of a standard (lOO)oriented silicon wafer, the back side of which was previously coated with The nitride is then silicon nitride. patterned to form an appropriate mask for anisotropic etching of the silicon. The silicon is now etched away from the back side through the wafer down to the oxide which is left suspended in the silicon frame. This grid was constr,_,ed to enable us to do TEM studies of MOS gate metals on the very same substrate as used in We believe, however, real applications. that these grids are well suited for TEM studies of any polycrystalline material which can be grown on silicon dioxide, and perhaps especially for studying crystal formation during initial film growth.
DETERMINATION OF STRUCTURE FACTORS ELECTRON DIFFRACTION: A BLOCH WAVE PICTURE
IN
Jon Gj@nnes Department Oslo, Pb.
of Physics, University of 1048 Blindern, 0316 Oslo 3
Determination from intensities
of structure factors in selected area spot
Accurpatterns is, at best, uncertain. ate determination of a few structure factors can be obtained from special effects, i.e., fringe separations or selected features in Kikuchi patterns: critical voltage, IKL method. The applicability of these methods can be extended by convergent-beam diffraction, which also offers new possibilities for intensity measurement. Hence a more extensive analysis of useful effects and features is sought for several situations, emphasizing the description in terms of a small number of Bloch waves. The theoretical analysis in terms of interactions betweenthe Bloch waves is applied to rows and layers in reciprocal space and illustrated by calculations and measurements.
INVESTIGATION OF CRYSTAL STRUCTURE BY CONVERGENT-BEAM DIFFRACTION--APPLICATION TO FAULTED CRYSTALS OF ZrSj Kjersti
Gj@nnes
Department Oslo, Pb.
of Physics, University of 1048 Blindern, 0316 Oslo 3
The microstructure of ZrS3 has been studied by convergent-beam electron diffraction (CBED). Interpretation of spot patterns was found to be complicated by extensive streaking due to faults approximately normal to the beam direction. On the other hand, CBED patterns, though rather complex in appearance, were found to give a ready determination of the Bravais lattice and to allow determination of crystallographic relations. Twins on (001) planes were identified and the mirror symmetry was confirmed. It was also found that by using Kikuchi lines the two possible modifications of ZrS3 could be distinguished from CBED patterns.
CHARACTERIZATION OF UNMELTED POWDER PARTICLES IN VACUUM PLASMA SPRAYED NiCoCrAlY COATINGS B. Gudmundsson
and B. E. Jacobson
LinkSping Institute of Technology, of Physics and Measurement Dept. Technology, S-581 83 Linkijping
Protective coatings prepared by Plasma Spray Deposition always contain a certain amount of unmelted powder
A. Spetz
and M. Armgarth
University of Linksping Department of Physics and Measurement Technol581 83 LinkSping ogy,
The TEM study of ultrathin porous films is somewhat difficult because the In order films are not self-supporting. to study ultrathin metal films for MOSsensor purposes we have constructed a silicon dioxide grid silicon-supported, The grid by means of micromachining. consists of a 50 x 50 micron, silicon dioxide window suspended in a silicon frame, the thickness of the window being The between 500 and 2000 Angstroms. metal film, in our case a 30-Angstrom platinum film, is deposited directly on the grid by means of thermal evaporation. The sample can then, without any further be inserted into the TEM manipulations, for examination. The fabrication process is rather simple and well suited for batch fabriSilicon dioxide with the decation. sired window thickness is grown on the polishedfrontside of a standard (lOO)oriented silicon wafer, the back side of which was previously coated with The nitride is then silicon nitride. patterned to form an appropriate mask for anisotropic etching of the silicon. The silicon is now etched away from the back side through the wafer down to the oxide which is left suspended in the silicon frame. This grid was constr,_,ed to enable us to do TEM studies of MOS gate metals on the very same substrate as used in We believe, however, real applications. that these grids are well suited for TEM studies of any polycrystalline material which can be grown on silicon dioxide, and perhaps especially for studying crystal formation during initial film growth.
DETERMINATION OF STRUCTURE FACTORS ELECTRON DIFFRACTION: A BLOCH WAVE PICTURE
IN
Jon Gj@nnes Department Oslo, Pb.
of Physics, University of 1048 Blindern, 0316 Oslo 3
Determination from intensities
of structure factors in selected area spot
Accurpatterns is, at best, uncertain. ate determination of a few structure factors can be obtained from special effects, i.e., fringe separations or selected features in Kikuchi patterns: critical voltage, IKL method. The applicability of these methods can be extended by convergent-beam diffraction, which also offers new possibilities for intensity measurement. Hence a more extensive analysis of useful effects and features is sought for several situations, emphasizing the description in terms of a small number of Bloch waves. The theoretical analysis in terms of interactions betweenthe Bloch waves is applied to rows and layers in reciprocal space and illustrated by calculations and measurements.
INVESTIGATION OF CRYSTAL STRUCTURE BY CONVERGENT-BEAM DIFFRACTION--APPLICATION TO FAULTED CRYSTALS OF ZrSj Kjersti
Gj@nnes
Department Oslo, Pb.
of Physics, University of 1048 Blindern, 0316 Oslo 3
The microstructure of ZrS3 has been studied by convergent-beam electron diffraction (CBED). Interpretation of spot patterns was found to be complicated by extensive streaking due to faults approximately normal to the beam direction. On the other hand, CBED patterns, though rather complex in appearance, were found to give a ready determination of the Bravais lattice and to allow determination of crystallographic relations. Twins on (001) planes were identified and the mirror symmetry was confirmed. It was also found that by using Kikuchi lines the two possible modifications of ZrS3 could be distinguished from CBED patterns.
CHARACTERIZATION OF UNMELTED POWDER PARTICLES IN VACUUM PLASMA SPRAYED NiCoCrAlY COATINGS B. Gudmundsson
and B. E. Jacobson
LinkSping Institute of Technology, of Physics and Measurement Dept. Technology, S-581 83 Linkijping
Protective coatings prepared by Plasma Spray Deposition always contain a certain amount of unmelted powder