Stress and microstructure evolution during initial growth of Pt on amorphous substrates

2000 ◽  
Vol 15 (11) ◽  
pp. 2540-2546 ◽  
Author(s):  
M. A. Phillips ◽  
V. Ramaswamy ◽  
B. M. Clemens ◽  
W. D. Nix
Keyword(s):  
Thin Film ◽  
Film Growth ◽  
Microstructural Characterization ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Film Stress ◽  
Ex Situ ◽  
Initial Growth ◽  
Plan View ◽  
Areal Fraction

An understanding of the relationship between stress and the corresponding microstructure at various stages of thin film growth might allow prediction and control of both microstructure and film stress during thin film deposition. In the present study, a combination of in situ curvature measurement and ex situ microstructural characterization was used to make correlations between stress and microstructure for the growth of Pt on SiO2. Plan view transmission electron micrographs of Pt films with average thicknesses ranging from 3 to 35 Å show the evolution of microstructure from isolated islands to a coalesced film, in agreement with models for stress behavior during the early stages of film growth. Quantitative measurements of grain size, island size, and areal fraction covered are extracted from these micrographs and, in conjunction with an island coalescence model, used to calculate the magnitude of the tensile stresses generated during coalescence. The predicted curvature is shown to compare favorably with the measured stresses.

scholarly journals A FRACTAL MODEL FOR THE FIRST STAGES OF THIN FILM GROWTH

Fractals ◽  
1996 ◽  
Vol 04 (03) ◽  
pp. 321-329 ◽  
Author(s):  
PABLO JENSEN ◽  
ALBERT-LÁSZLÓ BARABÁSI ◽  
HERNÁN LARRALDE ◽  
SHLOMO HAVLIN ◽  
H. EUGENE STANLEY
Keyword(s):  
Thin Film ◽  
Film Growth ◽  
Dynamical Evolution ◽  
Thin Film Deposition ◽  
Fractal Model ◽  
Film Deposition ◽  
Thin Film Growth ◽  
Small Cluster ◽  
Diffusion Controlled ◽  
Cluster Diffusion

In this paper, we briefly review a model that describes the diffusion-controlled aggregation exhibited by particles as they are deposited on a surface. This model allows us to understand many experiments of thin film deposition. In the Sec. 1, we describe the model, which incorporates deposition, particle and cluster diffusion, and aggregation. In Sec. 2, we study the dynamical evolution of the model. Finally, we analyze the effects of small cluster mobility and show that the introduction of cluster diffusion dramatically affects the dynamics of film growth. Some of these effects can be tested experimentally.

scholarly journals Measurements Of Stress Evolution During Thin Film Deposition

1996 ◽  
Vol 428 ◽  
Author(s):  
E. Chason ◽  
J. A. Floro
Keyword(s):  
Thin Film ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Film Stress ◽  
Radius Of Curvature ◽  
Stress Evolution ◽  
Rectangular Array ◽  
Thin Film Stress ◽  
Ccd Detector

AbstractWe have developed a technique for measuring thin film stress during growth by monitoring the wafer curvature. By measuring the deflection of multiple parallel laser beams with a CCD detector, the sensitivity to vibration is reduced and a radius of curvature limit of 4 km has been obtained in situ. This technique also enables us to obtain a 2-dimensional profile of the surface curvature from the simultaneous reflection of a rectangular array of beams. Results from the growth of SiGe alloy films are presented to demonstrate the unique information that can be obtained during growth.

Thin Film Deposition and Growth Processes by Ionized Cluster Beams

1990 ◽  
Vol 206 ◽  
Author(s):  
I. Yamada ◽  
G.H. Takaoka ◽  
H. Usui ◽  
S.K. Koh
Keyword(s):  
Thin Film ◽  
Cluster Size ◽  
Molecular Beam ◽  
Film Growth ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Atomic Scale ◽  
Cluster Beam ◽  
Film Nucleation ◽  
Cluster Beams

ABSTRACTAtomic scale imaging by STM and TEM of the initial stages of film growth of Ag and Au on graphite substrates indicate that the film nucleation processes are markedly different for ionized cluster beam (ICB) and molecular beam (MBE) deposition. Recent results on measurements of cluster size and formation of epitaxial metal-semiconductor layers by ICB are also discussed.

scholarly journals Thin film stress and microstructure analysis by energy-dispersive diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C724-C724
Author(s):  
Christoph Genzel
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Residual Stress ◽  
Film Growth ◽  
High Energy ◽  
Energy Dispersive ◽  
Film Stress ◽  
Ex Situ ◽  
Near Surface

The most important advantage of energy dispersive (ED) diffraction compared with angle dispersive methods is that the former provides complete diffraction patterns in fixed but arbitrarily selectable scattering directions. Furthermore, in experiments that are carried out in reflection geometry, the different photon energies E(hkl) of the diffraction lines in an ED diffraction pattern can be taken as an additional parameter to analyze depth gradients of structural properties in the materials near surface region. For data evaluation advantageous use can be made of whole pattern methods such as the Rietveld method, which allows for line profile analysis to study size and strain broadening [1] or for the refinement of models that describe the residual stress depth distribution [2]. Concerning polycrystalline thin films, the features of ED diffraction mentioned above can be applied to study residual stresses, texture and the microstructure either in ex-situ experiments or in-situ to monitor, for example, the chemical reaction pathway during film growth [3]. The main objective of this talk is to demonstrate that (contrary to a widespread opinion) high energy synchrotron radiation and thin film analysis may fit together. The corresponding experiments were performed on the materials science beamline EDDI at BESSY II which is one of the very few instruments worldwide that is especially dedicated to ED diffraction. On the basis of selected examples it will be shown that specially tailored experimental setups allow for residual stress depth profiling even in thin films and multilayer coatings as well as for fast in situ studies of film stress and microstructure evolution during film growth.

Multiscale Modeling of CdTe Thin Film Deposition Process

2013 ◽  
Vol 1524 ◽  
Author(s):  
Alexey Gavrikov ◽  
Andrey Knizhnik ◽  
Dmitry Krasikov ◽  
Boris Potapkin ◽  
Svetlana Selezneva ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Growth ◽  
Diffusion Processes ◽  
Kinetic Monte Carlo ◽  
Local Environment ◽  
Multiscale Model ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Photovoltaic Properties

ABSTRACTDeposition of semiconductor films is a key process for production of thin-film solar cells, such as CdTe or CIGS cells. In order to optimize photovoltaic properties of the film a comprehensive model of the deposition process should be build, which can relate deposition conditions and film properties. We have developed a multiscale model of deposition of CdTe film in close space sublimation (CSS) process. The model is based on kinetic Monte Carlo method on the rigid lattice, in which each site can be occupied by either Cd or Te atom. The model tabulates the energy of the site as a function of its local environment. These energies were obtained from first-principles calculates and then approximated with analytical formulas. Based on determined energies of each site we performed exchange (diffusion) processes using Metropolis algorithm. In addition the model included adsorption and desorption processes of Cd and Te2 species. The results of the model show that a steady-state structure of the surface layer is formed during film growth. The model can reproduce transition from film deposition to film etching depending on external conditions. Moreover, the model can predict deposition rates for non-stoichiometric gas compositions.

Confined Capillary Stresses During the Initial Growth of Thin Films on Amorphous Substrates

2002 ◽  
Vol 69 (4) ◽  
pp. 425-432 ◽  
Author(s):  
S. P. A. Gill ◽  
H. Gao ◽  
V. Ramaswamy ◽  
W. D. Nix
Keyword(s):  
Compressive Stress ◽  
Film Growth ◽  
Thin Film Deposition ◽  
Capillary Forces ◽  
Film Deposition ◽  
Initial Growth ◽  
Element Analysis ◽  
Ceramic Substrates ◽  
Compressive Stresses ◽  
Amorphous Substrates

Changes in substrate curvature indicating the existence of compressive stress in isolated crystallites are commonly observed during the initial stages of thin film deposition of metals on glass or ceramic substrates. Following the suggestion of Abermann et al. (R. Abermann et al., 1978, Thin Solid Films, 52, p. 215), we attribute the origin of this compressive stress to the action of capillary forces during film growth. As new atomic layers are deposited, the capillary forces acting on atoms near the surface are stored as transformation strains in the bulk of the crystallites. To test this concept, we propose three models for evaluating the capillary strains and their induced compressive stresses in a crystalline. A finite element analysis is performed to show that the model predictions agree well with experimental data.

A Model for Calculating Substrate Curvature During Coalescence of PT Islands on an Amorphous Substrate

1999 ◽  
Vol 578 ◽  
Author(s):  
M. A. Phillips ◽  
V. Ramaswamy ◽  
B. M. Clemens ◽  
W. D. Nix
Keyword(s):  
Film Growth ◽  
Film Stress ◽  
Plan View ◽  
Amorphous Substrates ◽  
Areal Fraction ◽  
Island Coalescence ◽  
Sputter Deposited ◽  
Evolution Of Microstructure ◽  
Pt Films

AbstractPrevious work using in-situ curvature measurement has shown a correlation between stress and microstructure during the early stages of thin film growth. The model presented here can be used to predict the curvature change of the substrate during part of this growth process. Curvature, and thus film stress, is measured in-situ during growth of sputter-deposited Pt on amorphous substrates. The average film stress is observed to be slightly compressive initially, followed by a change towards a tensile maximum, after which the stress becomes compressive again. Plan view TEM micrographs of Pt films of thicknesses up to 35 Å show the evolution of microstructure from isolated islands to a coalesced film. This evidence suggests that the tensile regime is due to island coalescence. The model calculates the curvature induced in a substrate during the tensile excursion associated with island coalescence, where discontinuous islands are modeled as a series of cracks in an otherwise continuous film. Quantitative measurements of island size and areal fraction covered are extracted from the TEM micrographs and used to predict the curvature during coalescence. The predicted stresses are shown to compare favorably with the measured stresses.

scholarly journals Simulation of the optical coating deposition

2018 ◽  
Vol 7 (1-2) ◽  
pp. 13-22 ◽  
Author(s):  
Fedor Grigoriev ◽  
Vladimir Sulimov ◽  
Alexander Tikhonravov
Keyword(s):  
Thin Film ◽  
Film Growth ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Thin Film Growth ◽  
Structural Parameter ◽  
Optical Coating ◽  
Mathematical Methods ◽  
Density Profiles ◽  
Multi Scale

AbstractA brief review of the mathematical methods of thin-film growth simulation and results of their applications is presented. Both full-atomistic and multi-scale approaches that were used in the studies of thin-film deposition are considered. The results of the structural parameter simulation including density profiles, roughness, porosity, point defect concentration, and others are discussed. The application of the quantum level methods to the simulation of the thin-film electronic and optical properties is considered. Special attention is paid to the simulation of the silicon dioxide thin films.

Laser-Reflectance Interferometry Measurements of Diamond-Film Growth

MRS Bulletin ◽  
1995 ◽  
Vol 20 (5) ◽  
pp. 29-31 ◽  
Author(s):  
Christopher D. Zuiker ◽  
Dieter M. Gruen ◽  
Alan R. Krauss
Keyword(s):  
Film Thickness ◽  
Film Growth ◽  
Substrate Surface ◽  
Diamond Films ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Index Of Refraction ◽  
Ex Situ ◽  
Laser Reflectance

The remarkable properties of diamond, including its hardness, chemical inertness, high thermal conductivity, low coefficient of friction, optical transparency, and semiconducting properties, have led to considerable research in the area of diamond thin-film deposition. Diamond films have been characterized ex situ by a large number of diagnostic techniques including Raman spectroscopy, x-ray diffraction, SEM, and TEM. In situ diagnostics, which can provide information in real time as the film is growing, are less common.Laser-reflectance interferometry (LRI) has been used to monitor the growth of diamond films in situ. The technique involves measuring the intensity of a laser beam reflected from the substrate surface on which the film is growing. The reflected beam is the sum of beams reflected by the gas-diamond interface and the diamond-silicon interface. Oscillations in the reflectivity are observed as the film grows because of interference between the reflected beams. Each oscillation indicates an increase in film thickness of λ/2n, where λ is the laser wavelength and n is the index of refraction of the film. If the index of refraction of the film is known, the thickness and growth rate can be determined in situ. For LRI measurements with 632.8-nm-wavelength HeNe lasers, the index of refraction of diamond films has been found to be within 10% of the bulk diamond value of 2.4. Each oscillation therefore indicates an increase in film thickness of 0.13 μm.The reflectivity measured by LRI is also affected by scattering because of surface roughness.

Molecular-Dynamics Simulations of Laser-Ablation and Ionassisted Thin Film Deposition

1992 ◽  
Vol 285 ◽  
Author(s):  
H. Feil ◽  
J.S.C. Kools ◽  
J. Dieleman
Keyword(s):  
Thin Film ◽  
Molecular Dynamics ◽  
Laser Ablation ◽  
Molecular Dynamics Simulations ◽  
Film Growth ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Fluences ◽  
Cu Thin Film ◽  
Dynamics Simulations

ABSTRACTMolecular dynamics simulations are performed of Cu thin film growth on Cu (111). Ion-Assisted Deposition is simulated by bombarding the substrate with Cu+ ions with a kinetic energy of 80 eV, while 1 eV Cu atoms are used for the simulation of Laser Ablation Deposition. It appears that Ion-Assisted Deposition leads to sputtering, enhanced surface mobility, surface disorder, mixing and rather deep damage. This is discussed in some detail. Laser Ablation Deposition, using laser fluences just above the ablation threshold, does not lead to damage and mixing. Sharper interfaces and more perfect heterostructures and superlattices can be produced using Laser Ablation Deposition.

Sign in / Sign up

Export Citation Format

Share Document