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1.13 Electron microscope investigation of structural defects in condensed films
Second
Colloquium
on Thin Films (COTHIF)
which in turn varied with deposition conditions. The relationship between the microtopography of active centres and the electrophysical properties of the semiconductor crystal substrates is discussed. For lead sulphide, thin film formation may occur by the long range mechanism through intermediate amorphous layers. G I Distler and S A Kobzareva (Moscow, USSR). 1.10 Epitaxial
growth of gold on single crystal silver surfaces.
Research on epitaxial growth of thin films of face-centred cubic metal has generally used ionic crystals or cleaved crystal surfaces as substrate. Studies of the growth of metal films on metal have shown that well-defined crystal substrates, at least of microscopic dimensions are necessary. Investigations on the epitaxy of gold films on silver indicated that electrolytically grown silver crystals have advantages as substrates. These crystals exhibit UDto 0.5 mm surfaces of different orientation. The dependence of nucleation of gold on certain parameters is reported with results of examination by electron microscopy and electron diffraction. M Klaus, (Berlin, DDR), (in German).
a double tetrahedral “molecule” it is proposed that the structure be described as a mixture of the trans and cis rotational isomers afforded by this molecular model. Radial distribution curves were calculated for three proportions of the cis and trans configurations corresponding to the atomic arrangements of diamond, wurtzite and an arrangement with non-crystallographic symmetry elements. By comparison of these values with experimental radial distribution curves of vacuum deposited amorphous Ge films, it was found that the atomic arrangement is closest to the wurtzite. R Grigorovici and R Manaila (Bucharest, Rumania). 1.16 Formation of the preferred indium thin films.
orientation
of vacuum
deposited
The dependence of the formation of textured structures on the substrate temperature and residual gas pressure was investigated for vacuum deoosited thin films of indium. It was found that the orientation bf the initial layers is connected with the phase transitions. J F Pocza, A Bama and B P Bama (Budapest, Hungary). 1.17 An introduction to the theory of molecular beams.
1.11 Coalescence
in thin films.
It has previously
The phenomenon of coalescence in vacuum deposited thin films was studied, taking account of nucleation and growth mechanism. Using a variation of the Lifshitz-Slezov hydrodynamic approach, the size distribution function of the nuclei was obtained for two cases of coalescence (a) in the presence of the vapour source and (b) in the absence of the vapour source, as in the annealing of the thin film. The size distribution function shows a maximum which shifts in time towards larger grain size, in accordance with some experimental results. B K Chakraverty, 1.12 Coalescence metal films.
(Grenoble,
France).
of islands in relation to stress build-up in very thin
The tensile stress per unit cross-section of the films showed a marked dependence on the film thickness for silver films deposited on mica strips under a vacuum of l-2 x 1O-5 torr. Experimental values for deposition rates of 2, 7, and 20 &sec are presented. Electron microscope observations carried out in parallel with the stress measurements showed that the rapid increase in thickness just below the maximum stress value was due to coalescence of silver crystallites (islands) to form a continuous film. At thicknesses corresponding to stress maxima, films were continuous but contained some small irregular holes. Continuous observation of the film growth is in progress to establish the kinetics of the coalescence process. K Kinosita, K Maki and K Takeuchi, 1.13 Electron microscope condensed films.
(Tokyo, Japan).
investigation
of
structural
defects
in
The surface growth structure of evaporated chromium films, and other metals, was studied by the replica method. Electron transmission methods were applied to the same samples after thinning by electrolytic polishing. Grain size, distribution and density of dislocations, sizes of free dislocation spaces and their mutual disorientation were determined. The connection between surface growth structure and observed distribution of defects was established by the transmission method. V M Kosevitch, L S Palatnik and L E Chernyakova
(Khurkov,
USSR).
1.14 Defects in thin films of A” Bvl compounds.
Electron diffraction data are presented concerning the structure of cadmium sulphide and cadmium telluride thin films produced by vacuum condensation with molecular beams on various substrates. The possibility of using this type of data to detect stacking faults and microtwins in thin films is discussed as well as a method of determining the percentage of cubic and hexagonal phases from the electron diffraction data. S A Semiletov and Z A Magomedov (Moscow, USSR). 1.15 On the structure of amorphous germanium films. An examination of the atomic radial distribution function of amorphous Ge films as compared to the Ge lattice indicates that peculiarities of the position and occupancy of co-ordinations are not adequately explained by the theory of H Richter and his coworkers particularly with regard to the metastable character of the amorphous state. Considering the amorphous structure as having
332
been shown that the geometrical elements of photometry might be applied to calculations regarding the interaction of molecular beams and surfaces. The field theory of light is increasingly being applied in theoretical photometry anh the terms and equations of the field theory can be transformed to relate to molecular beams. This has, in part, been achieved in the present investigation. Vector fields for -molecular beam propagation are introduced as well as differential and integral correlations. The resulting equations are more general than those of photometry and are only equivalent where no chemical reaction occurs between the particles and the surface of the condensed ahases. The results of some calculations on particular fields are presented. J N Ljubitov
(Moscow,
USSR).
1.18 Equilibria of silicon nuclei formed during the reduction of SiCI, by Hz in the preparations of epitaxial silicon films.
A system of equations determining the stability of nuclei was derived by ascribing different values of the
producing a characteristic
The etch-rate of single crystal germanium surfaces was investigated using a mixture of hydrogen, bromide and hydrogen in the temperature range 400-900°C. Throughout the temperature range 4m65O”C the single crystal surface exhibits a fine-grained structure during the etching process. The nature of this str&ure is described. V J Beliy. F A Kuznetsov (Novosibirsk. pest, Hz&wry).
USSR\
and J Pfeiffer (Budu-
1.20 Regions of stability of SiO, and Si,N, during silicon _ _ prior toepitaxial film deposition. -
etching
The aualitv of e&axial silicon films deoends on the our&y of the seed s&icon surfa’ce. SiO, and S&N, spoii the orientation of the seed surface. Applying thermodynamic equations, regions of stability and instability of SiO, and S&N, were obtained for temperatures and concentrations of N,, 0, and H,O in HZ. For a given concentration of N, in Hz four regions of stability were found, only the last of which corresponds to instability of both contaminants. Etching conditions within this fourth region eliminate these two impurities. W Riedl (Warsaw, Poland). 1.21 On diffusion processes films.
Experimental
in the epitaxial
data on germanium
growth of semiconductor
growth are analysed, making use
Colloquium
on Thin Films (COTHIF)
which in turn varied with deposition conditions. The relationship between the microtopography of active centres and the electrophysical properties of the semiconductor crystal substrates is discussed. For lead sulphide, thin film formation may occur by the long range mechanism through intermediate amorphous layers. G I Distler and S A Kobzareva (Moscow, USSR). 1.10 Epitaxial
growth of gold on single crystal silver surfaces.
Research on epitaxial growth of thin films of face-centred cubic metal has generally used ionic crystals or cleaved crystal surfaces as substrate. Studies of the growth of metal films on metal have shown that well-defined crystal substrates, at least of microscopic dimensions are necessary. Investigations on the epitaxy of gold films on silver indicated that electrolytically grown silver crystals have advantages as substrates. These crystals exhibit UDto 0.5 mm surfaces of different orientation. The dependence of nucleation of gold on certain parameters is reported with results of examination by electron microscopy and electron diffraction. M Klaus, (Berlin, DDR), (in German).
a double tetrahedral “molecule” it is proposed that the structure be described as a mixture of the trans and cis rotational isomers afforded by this molecular model. Radial distribution curves were calculated for three proportions of the cis and trans configurations corresponding to the atomic arrangements of diamond, wurtzite and an arrangement with non-crystallographic symmetry elements. By comparison of these values with experimental radial distribution curves of vacuum deposited amorphous Ge films, it was found that the atomic arrangement is closest to the wurtzite. R Grigorovici and R Manaila (Bucharest, Rumania). 1.16 Formation of the preferred indium thin films.
orientation
of vacuum
deposited
The dependence of the formation of textured structures on the substrate temperature and residual gas pressure was investigated for vacuum deoosited thin films of indium. It was found that the orientation bf the initial layers is connected with the phase transitions. J F Pocza, A Bama and B P Bama (Budapest, Hungary). 1.17 An introduction to the theory of molecular beams.
1.11 Coalescence
in thin films.
It has previously
The phenomenon of coalescence in vacuum deposited thin films was studied, taking account of nucleation and growth mechanism. Using a variation of the Lifshitz-Slezov hydrodynamic approach, the size distribution function of the nuclei was obtained for two cases of coalescence (a) in the presence of the vapour source and (b) in the absence of the vapour source, as in the annealing of the thin film. The size distribution function shows a maximum which shifts in time towards larger grain size, in accordance with some experimental results. B K Chakraverty, 1.12 Coalescence metal films.
(Grenoble,
France).
of islands in relation to stress build-up in very thin
The tensile stress per unit cross-section of the films showed a marked dependence on the film thickness for silver films deposited on mica strips under a vacuum of l-2 x 1O-5 torr. Experimental values for deposition rates of 2, 7, and 20 &sec are presented. Electron microscope observations carried out in parallel with the stress measurements showed that the rapid increase in thickness just below the maximum stress value was due to coalescence of silver crystallites (islands) to form a continuous film. At thicknesses corresponding to stress maxima, films were continuous but contained some small irregular holes. Continuous observation of the film growth is in progress to establish the kinetics of the coalescence process. K Kinosita, K Maki and K Takeuchi, 1.13 Electron microscope condensed films.
(Tokyo, Japan).
investigation
of
structural
defects
in
The surface growth structure of evaporated chromium films, and other metals, was studied by the replica method. Electron transmission methods were applied to the same samples after thinning by electrolytic polishing. Grain size, distribution and density of dislocations, sizes of free dislocation spaces and their mutual disorientation were determined. The connection between surface growth structure and observed distribution of defects was established by the transmission method. V M Kosevitch, L S Palatnik and L E Chernyakova
(Khurkov,
USSR).
1.14 Defects in thin films of A” Bvl compounds.
Electron diffraction data are presented concerning the structure of cadmium sulphide and cadmium telluride thin films produced by vacuum condensation with molecular beams on various substrates. The possibility of using this type of data to detect stacking faults and microtwins in thin films is discussed as well as a method of determining the percentage of cubic and hexagonal phases from the electron diffraction data. S A Semiletov and Z A Magomedov (Moscow, USSR). 1.15 On the structure of amorphous germanium films. An examination of the atomic radial distribution function of amorphous Ge films as compared to the Ge lattice indicates that peculiarities of the position and occupancy of co-ordinations are not adequately explained by the theory of H Richter and his coworkers particularly with regard to the metastable character of the amorphous state. Considering the amorphous structure as having
332
been shown that the geometrical elements of photometry might be applied to calculations regarding the interaction of molecular beams and surfaces. The field theory of light is increasingly being applied in theoretical photometry anh the terms and equations of the field theory can be transformed to relate to molecular beams. This has, in part, been achieved in the present investigation. Vector fields for -molecular beam propagation are introduced as well as differential and integral correlations. The resulting equations are more general than those of photometry and are only equivalent where no chemical reaction occurs between the particles and the surface of the condensed ahases. The results of some calculations on particular fields are presented. J N Ljubitov
(Moscow,
USSR).
1.18 Equilibria of silicon nuclei formed during the reduction of SiCI, by Hz in the preparations of epitaxial silicon films.
A system of equations determining the stability of nuclei was derived by ascribing different values of the
producing a characteristic
The etch-rate of single crystal germanium surfaces was investigated using a mixture of hydrogen, bromide and hydrogen in the temperature range 400-900°C. Throughout the temperature range 4m65O”C the single crystal surface exhibits a fine-grained structure during the etching process. The nature of this str&ure is described. V J Beliy. F A Kuznetsov (Novosibirsk. pest, Hz&wry).
USSR\
and J Pfeiffer (Budu-
1.20 Regions of stability of SiO, and Si,N, during silicon _ _ prior toepitaxial film deposition. -
etching
The aualitv of e&axial silicon films deoends on the our&y of the seed s&icon surfa’ce. SiO, and S&N, spoii the orientation of the seed surface. Applying thermodynamic equations, regions of stability and instability of SiO, and S&N, were obtained for temperatures and concentrations of N,, 0, and H,O in HZ. For a given concentration of N, in Hz four regions of stability were found, only the last of which corresponds to instability of both contaminants. Etching conditions within this fourth region eliminate these two impurities. W Riedl (Warsaw, Poland). 1.21 On diffusion processes films.
Experimental
in the epitaxial
data on germanium
growth of semiconductor
growth are analysed, making use