Thin-Film Residual Stress Detection Method Based on Flexible Hinges

2012 ◽  
Vol 548 ◽  
pp. 367-371
Author(s):  
Hai Wang ◽  
Yun Hua Tong
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Detection Method ◽  
Stress Detection ◽  
Suspended Structure ◽  
Sacrificial Layers ◽  
Detection Principle

The residual stress introduced in the thin-film process may caused some problems, especially after removing of the sacrificial layers below, the suspended structure may be bended due to the release. In this articles we will develop a new in-situ residual stress detection method based on flexible hinges for thin-film materials, then described the detection principle theoretically and simulated its properties by FEA method.

Residual Stresses for In-Situ Deposition of Thin-Film High-Temperature Superconductors

1994 ◽  
Vol 116 (4) ◽  
pp. 249-257 ◽  
Author(s):  
P. E. Phelan ◽  
M. N. Ghasemi Nejhad
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Residual Stresses ◽  
High Temperature Superconductors ◽  
Oxygen Stoichiometry ◽  
Chemical Shrinkage ◽  
In Situ Deposition ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

Residual stresses are caused by nonuniform thermal expansion and chemical shrinkage taking place during processing. For thin-film high-temperature superconductors, residual stresses result because of the thermal expansion mismatch between the film and substrate, and the introduction of oxygen into the film after in-situ deposition, which makes the unit cell dimensions change (chemical shrinkage) as the oxygen stoichiometry changes. Since both the reliability of the film—especially the bond between the film and substrate—and the film critical temperature are functions of the state of stress, it is important to understand how the residual stresses vary with processing conditions. Here, a three-dimensional residual stress analysis is carried out based on laminate theory, which assumes the lateral dimensions of the entire system to be much larger than its thickness. The normal residual stress components in the film, and the peeling stress at the film/substrate interface, are calculated. The results demonstrate the crucial role that chemical shrinkage plays in the formulation of residual stresses. A large portion of the stresses arises from the initial change of the unit cell dimensions due to changes in the film oxygen stoichiometry. Therefore, the processing temperature, and especially the initial oxygen pressure in the deposition chamber, are the key variables that impact the residual stresses.

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.

scholarly journals Experiments with in-situ thin film telephone cord buckling delamination propagation

2002 ◽  
Vol 749 ◽  
Author(s):  
Alex A. Volinsky
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Compressive Residual Stress ◽  
In Situ Observation ◽  
Crack Healing ◽  
Buckling Delamination ◽  
Film Substrate ◽  
Delamination Propagation ◽  
Analysis Of Motion

ABSTRACTThere are many different stress relief mechanisms observed in thin films. One of the mechanisms involves film debonding from the substrate. In the case of tensile residual stress a network of through-thickness cracks forms in the film. In the case of compressive residual stress thin film buckling and debonding from the substrate in the form of blisters is observed. The buckling delamination blisters can be either straight, or form periodic buckling patterns commonly known as telephone cord delamination morphology.The mechanics of straight-sided blisters is well understood. Current study relies on the in-situ observation of phone cord delamination propagation in different thin film/substrate systems. Both straight and phone cord delaminations are shown to simultaneously propagate in the same film system. Straight-sided blisters propagate several times faster than the phone cords, and may be followed by thin film fracture along the line of maximum film buckling amplitude. Phone cord delaminations originally start as straight-sided blisters, but then deviate to the periodic phone cord geometry due to the fact that the compressive residual stress in the film is biaxial. Digital analysis of motion recordings shows that partial crack “healing” is present at the curved portions of the phone cords due to the “secondary” buckling pushing thin film back to the substrate. These experimental observations allow for the correct interpretation of the telephone cord delamination morphology.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

Growth kinetics of Al2Cu in an Al-1.5Cu thin film by in Situ TEM

1993 ◽  
Vol 51 ◽  
pp. 1172-1173
Author(s):  
M. Park ◽  
S.J. Krause ◽  
S.R. Wilson
Keyword(s):  
Thin Film ◽  
In Situ Tem ◽  
Collector Plate ◽  
Transmission Electron ◽  
Device Processing ◽  
Corrosion Susceptibility ◽  
Precipitation Phenomena ◽  
Semiconductor Chips ◽  
Kinetics Of

Cu alloying in Al interconnection lines on semiconductor chips improves their resistance to electromigration and hillock growth. Excess Cu in Al can result in the formation of Cu-rich Al2Cu (θ) precipitates. These precipitates can significantly increase corrosion susceptibility due to the galvanic action between the θ-phase and the adjacent Cu-depleted matrix. The size and distribution of the θ-phase are also closely related to the film susceptibility to electromigration voiding. Thus, an important issue is the precipitation phenomena which occur during thermal device processing steps. In bulk alloys, it was found that the θ precipitates can grow via the grain boundary “collector plate mechanism” at rates far greater than allowed by volume diffusion. In a thin film, however, one might expect that the growth rate of a θ precipitate might be altered by interfacial diffusion. In this work, we report on the growth (lengthening) kinetics of the θ-phase in Al-Cu thin films as examined by in-situ isothermal aging in transmission electron microscopy (TEM).

“In-Situ Raman Spectroscopy of Electronic Processes in Fullerene Thin Films

2002 ◽  
Vol 725 ◽  
Author(s):  
S.B. Phelan ◽  
B.S. O'Connell ◽  
G. Farrell ◽  
G. Chambers ◽  
H.J. Byrne
Keyword(s):  
Thin Film ◽  
Indium Tin Oxide ◽  
Low Temperatures ◽  
In Situ Raman Spectroscopy ◽  
State Reduction ◽  
In Situ Raman ◽  
Linear Behavior ◽  
Current Voltage ◽  
Solid State Reduction

AbstractThe current voltage characteristics of C60 thin film sandwich structures fabricated by vacuum deposition on indium tin oxide (ITO) with an aluminium top electrode are presented and discussed. A strongly non-linear behavior and a sharp increase in the device conductivity was observed at relatively low voltages (∼2V), at both room and low temperatures (20K). At room temperature the system is seen to collapse, and in situ Raman measurements indicate a solid state reduction of the fullerene thin film to form a polymeric state. The high conductivity state was seen to be stable at elevated voltages and low temperatures. This state is seen to be reversible with the application of high voltages. At these high voltages the C60 film was seen to sporadically emit white light at randomly localized points analogous to the much documented Electroluminescence in single crystals.

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