Role of Film-Substrate Interaction in Determining the Morphology of Thin Films

1987 ◽  
Vol 103 ◽  
Author(s):  
Marcia H. Grabow ◽  
George H. Gilmer
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Computer Simulations ◽  
Substrate Binding ◽  
Equilibrium Structure ◽  
Metastable States ◽  
Growth Mode ◽  
Substrate Interaction ◽  
Film Substrate

ABSTRACTThe equilibrium structure and metastable states of thin films have been investigated using molecular dynamics computer simulations. The energy as a function of coverage for a variety of film/substrate systems has been determined, and this information has been used to determine the growth mode and the conditions under which the film is dislocation free. In particular, the influence of the strength of the film-substrate binding will be discussed.

Void and Dislocation Microstructure Development in Heteroepitaxial Film Growth

1995 ◽  
Vol 399 ◽  
Author(s):  
Richard W. Smith ◽  
David J. Srolovitz
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Film Growth ◽  
Lattice Misfit ◽  
Two Dimensional ◽  
Microstructure Development ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
Film Substrate ◽  
Edge Dislocations

ABSTRACTTwo dimensional, non-equilibrium molecular dynamics simulations have been performed to examine the microstructures of both homoepitaxial and heteroepitaxial thin films grown on single crystal substrates. The principal microstructural features to develop within these films are small voids and edge dislocations. Voids form near the surface of the growing film as surface depressions between microcolumns pinch off to become closed volumes. These voids often form in such a way as to introduce dislocations into the crystal with their cores positioned within the voids. Dislocations are also formed during heteroepitaxy at the interface between the substrate and film. These dislocations tend to be mobile. When voids are present in the film and when the lattice misfit is low, dislocations tend to be trapped in the voids or pulled toward them due to dislocation image interactions. Once attached to voids, dislocations are effectively pinned there. When voids are absent or when the misfit is high, dislocations are restricted to the film-substrate interface. In the case of heteroepitaxy, dislocations are found to relieve either tensile or compressive misfit stresses. Misfit stresses may also be accommodated, to some extent, merely by the free volume of the voids themselves.

Deposition energy dependence in cluster-assembled thin film densities

2005 ◽  
Vol 908 ◽  
Author(s):  
Kristoffer Meinander ◽  
Tina Clauss ◽  
Kai Nordlund
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Energy Dependence ◽  
Computer Simulations ◽  
Cluster Atom ◽  
Cu Nanoclusters ◽  
Deposition Energy

AbstractMechanical properties of thin films grown by nanocluster deposition are highly dependent on the energy at which the clusters are deposited. Using molecular dynamics computer simulations we have quantitatively studied variations in the properties of copper thin films grown by deposition of Cu nanoclusters, at energies ranging from 5 meV to 10 eV per cluster atom, on a Cu (100) substrate.

Molecular dynamics study on the role of solvation water in the adsorption of hyperactive AFP to the ice surface

2018 ◽  
Vol 20 (39) ◽  
pp. 25365-25376 ◽  
Author(s):  
Joanna Grabowska ◽  
Anna Kuffel ◽  
Jan Zielkiewicz
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulations ◽  
Early Stages ◽  
Ice Surface

Using computer simulations, the early stages of the adsorption of the CfAFP molecule to the ice surface were analyzed.

Surface Reconstruction and Strain Relief in Si1−x-Gex Films on Si(100)

1992 ◽  
Vol 280 ◽  
Author(s):  
Qiuming Yu ◽  
Paulette Clancy
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Dynamics ◽  
Surface Reconstruction ◽  
Experimental Studies ◽  
Equilibrium Structure ◽  
Strain Relief ◽  
Theoretical Predictions ◽  
Weber Potential

ABSTRACTThe equilibrium structure of a variety of Si1−xGex/Si heterostructures have been simulated by Molecular Dynamics, modeled by the Stillinger-Weber potential, to investigate the effect of strain on the surfaces of SiGe thin Alms. It was found that the strain in SiGe/Si(100) thin films was relaxed by the segregation of Ge to the surface. Rebonding of sub-surface atoms into dimers in the presence of a vacancy or cluster of vacancies above them was observed in the ensuing surface reconstruction. For SiGe/Si, the amount of “re-bonded missing dimers” in the top two layers increased with increasing Ge composition. But for Ge/Si(100), a V-shaped twinning defect was observed in the Ge thin film. To further investigate the effect of strain on surface reconstruction, bulk Si and Ge structures were also studied. For bulk Si, several rebonded missing dimers were found at the surface, while for bulk Ge(100), the surface showed a typical 2×1 reconstruction. All these findings corroborate recent experimental studies and theoretical predictions.

scholarly journals The role of nonlinear substrate elasticity in the wrinkling of thin films

2013 ◽  
Vol 371 (1993) ◽  
pp. 20120422 ◽  
Author(s):  
John W. Hutchinson
Keyword(s):  
Thin Films ◽  
Substrate Stiffness ◽  
Modulus Ratio ◽  
Compliant Substrates ◽  
Wide Range ◽  
The Stability ◽  
Film Substrate ◽  
Film Stiffness ◽  
Substrate Elasticity

The role of substrate nonlinearity in the stability of wrinkling of thin films bonded to compliant substrates is investigated within the initial post-bifurcation range when wrinkling first emerges. A fully nonlinear neo-Hookean bilayer composed of a thin film on a deep substrate is analysed for a wide range of the film–substrate stiffness ratio, from films that are very stiff compared with the substrate to those only slightly stiffer. Substrate pre-stretch prior to film attachment is shown to have a significant effect on the nonlinearity relevant to wrinkling. Two dimensionless parameters are identified that control the stability and mode shape evolution of the bilayer: one specifying arbitrary uniform substrate pre-stretch and the other a stretch-modified modulus ratio. For systems with film stiffness greater than about five times that of the substrate the wrinkling bifurcation is stable, whereas for systems with smaller relative film stiffness bifurcation can be unstable, especially if substrate pre-stretch is not tensile.

Role of Nd/Ba substitution on the growth mode and on the structural properties of Nd-rich Re1(NdxBa2−x)Cu3O7−δ (Re=Nd, Y) thin films

2002 ◽  
Vol 372-376 ◽  
pp. 675-678 ◽  
Author(s):  
M. Salluzzo ◽  
C. Aruta ◽  
G. Ausanio ◽  
S. Bals ◽  
A. D'Agostino ◽  
...  
Keyword(s):  
Thin Films ◽  
Structural Properties ◽  
Growth Mode ◽  
Ba Substitution

Role of gold segregation in the growth mode and the morphology of Fe/Au() magnetic thin films

2003 ◽  
Vol 532-535 ◽  
pp. 63-69 ◽  
Author(s):  
R. Belkhou ◽  
R. Flammini ◽  
M. Marsi ◽  
A. Taleb-Ibrahimi ◽  
L. Gregoratti ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Thin Films ◽  
Growth Mode

Scanning Tunneung Microscope Studies of Initial Epitaxial Growth of YBa2Cu3O7-δ Thin Films

1992 ◽  
Vol 263 ◽  
Author(s):  
Xiang-Yang Zheng ◽  
D. H. Lowndes ◽  
Shen Zhu ◽  
R. J. Warmack
Keyword(s):  
Thin Films ◽  
Epitaxial Growth ◽  
Growth Temperature ◽  
Lattice Mismatch ◽  
Growth Mode ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Weber Type ◽  
Film Substrate ◽  
Miscut Angle

ABSTRACTThe initial stages of epitaxial growth of laser ablated YBa2Cu3O7-δ (YBCO) thin films on (001) SrTiO3, LaAlO3, and MgO substrates, and on slightly miscut LaA1O3 and SrTiO3, have been studied with scanning tunneling microscopy (STM). Surface images show that the initial YBCO growth mode can be either of the Stranski- Krastanov or the Volmer-Weber type, depending on the film-substrate lattice mismatch and the growth temperature. A small substrate miscut angle is found to strongly influence the growth mode of YBCO films. Screw dislocation-mediated growth is suppressed, and films grown at 800°C on (001) LaAlO3 substrates with miscut angle of 2.0° along <100> or <110> directions were found to consist of tilted platelets that are epitaxially aligned with the substrate crystal lattice.

Island growth mode in pulsed laser deposited ferroelectric BaTiO3 thin films: The role of oxygen pressure during deposition

2019 ◽  
Vol 545 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Flávia R. Estrada ◽  
Lucas G. M. de Moraes ◽  
Felipe L. A. Vital ◽  
Maíra D. Neme ◽  
Pedro Schio ◽  
...  
Keyword(s):  
Thin Films ◽  
Oxygen Pressure ◽  
Pulsed Laser ◽  
Growth Mode ◽  
Island Growth

Post deposition excimer laser processing of MoSx thin films

1991 ◽  
Vol 6 (6) ◽  
pp. 1350-1357 ◽  
Author(s):  
T.R. Jervis ◽  
J-P. Hirvonen ◽  
M. Nastasi
Keyword(s):  
Thin Films ◽  
Excimer Laser ◽  
Laser Processing ◽  
Environmental Stability ◽  
Substrate Interaction ◽  
Wear Life ◽  
Bonding Properties ◽  
Film Substrate ◽  
Deposited Films ◽  
Post Deposition

We have examined the effect of excimer laser surface processing and doping with Au on the mechanical, tribological, and bonding properties of MoSx thin films. We find that the effects of processing are manifested primarily in the surface of the films, but that there is also some film-substrate interaction during high fluence processing. The changes are sufficient to dramatically alter the wear life of the films. At low loads, laser processing alone reduces the run-in period and increases wear life. At higher loads, processing reduces wear life, although the run-in period is still short. These results are understood in terms of changes in the hardness of the surface of the films. Laser processing renders deposited films insensitive to high humidity storage. After laser processing, Raman spectroscopy shows changes in bonding to that characteristic of single crystal MoS2. Laser doping with Au results in wear life comparable to or greater than that of unprocessed films even at the highest loads used. Thus, laser doped MoSx films show lower initial friction, comparable wear life, and may exhibit greater environmental stability than as-deposited films.

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