Herringbone Buckling Patterns of Compressed Thin Films on Compliant Substrates

2004 ◽  
Vol 71 (5) ◽  
pp. 597-603 ◽  
Author(s):  
X. Chen ◽  
John W. Hutchinson
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Stress State ◽  
Compressive Stress ◽  
Critical Stress ◽  
Metal Film ◽  
Minimum Energy ◽  
Thin Metal Film ◽  
Thermal Expansion Mismatch ◽  
Compliant Substrates

A thin metal film vapor deposited on thick elastomer substrate develops an equi-biaxial compressive stress state when the system is cooled due to the large thermal expansion mismatch between the elastomer and the metal. At a critical stress, the film undergoes buckling into a family of modes with short wavelengths characteristic of a thin plate on a compliant elastic foundation. As the system is further cooled, a highly ordered herringbone pattern has been observed to develop. Here it is shown that the herringbone mode constitutes a minimum energy configuration among a limited set of competing modes.

Fracture Mechanisms of SiNx Thin-films on Compliant Substrates

2008 ◽  
Vol 1078 ◽  
Author(s):  
Alex Z Kattamis ◽  
Kunigunde H Cherenack ◽  
I-Chun Cheng ◽  
Ke Long ◽  
James C Sturm ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Expansion ◽  
Compressive Stress ◽  
Ion Beam ◽  
The Other ◽  
Polymer Substrate ◽  
Fracture Mechanisms ◽  
Compliant Substrates ◽  
Polymer Foils

AbstractThe prospect of large-area electronics on polymers, for flexible applications requires a study of thin film fracture mechanisms. To fabricate thin-film transistor (TFT) backplanes on polymer foils the substrate must first be passivated to protect the polymer substrate from chemicals used during processing and to protect the TFTs from substrate out gassing. Silicon nitride (SiNx) is commonly used for this purpose since it tends to adhere well to polymers and is easily deposited by PE-CVD. When rigid thin films such as SiNx are deposited onto compliant substrates, such as polymer foils, stresses caused by built-in strains and the mismatch in coefficients of thermal expansion can cause fracture. The deposited thin films may fracture, and also the polymer substrate below. Using focused-ion beam milling and scanning electron microscopy we analyzed two distinct thin film fracture morphologies for SiNx films on two different types of polymer substrate. One had a relatively low, the other a relatively high coefficient of thermal expansion. For both SiNx/substrate systems the SiNx was under residual compressive stress and the substrate under tension. In one case the compressive stress in the thin films cause them to debond, buckle, and crack. In the other case the tensile stress in the substrate causes it to tear, followed by the fracture of the SiNx film above.

Correlation of the Stress-Temperature History with Microstructure in A1-0.5Cu and A1-0.15Pd Thin Films

1994 ◽  
Vol 356 ◽  
Author(s):  
D. D. Knorr ◽  
K.P. Rodbell
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Substrate Temperature ◽  
Grain Growth ◽  
Room Temperature ◽  
Temperature History ◽  
Thermal Expansion Mismatch ◽  
Grain Sizes ◽  
Substrate Temperatures ◽  
Precipitate Structure

AbstractBlanket films (1 μm thick) of both A1-0.5Cu and A1-0.15Pd were deposited at room temperature, 150°C, and 300°C. Stress in the as-deposited wafers increased with substrate temperature, as expected from the thermal expansion mismatch on cooling. All conditions were tiicrmally cycled to 450°C three times while continuously monitoring stress. The shapes of the curves were different for the two alloys because precipitates dissolve and reprecipitate in AlCu, but are present over the entire temperature range in AlPd. Lesser differences were evident comparing the stress-temperature behavior for the various substrate temperatures within a single alloy. The precipitate structure also influences the grain growth during thermal cycling, where substantially larger median grain sizes are found in AlCu compared to AlPd.

Effect of Thin Metal Film and Micro Structure of Surface on Condensation Pattern

2017 ◽  
Author(s):  
Tomohito Nishimura ◽  
Yuki Mikoshiba ◽  
Hiroyasu Ohtake ◽  
Koji Hasegawa
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Metal Film ◽  
Hydrophobic Surface ◽  
Thin Metal Film ◽  
Thin Metal ◽  
Micro Structure ◽  
Metal Thin Films ◽  
Structured Surfaces ◽  
Condensation Pattern

The water condensation is important for wide range of industrial systems such as condensers and heat exchangers of steam power plants and refrigerators. The condensation generally has two patterns; filmwise condensation (FWC) and drop-wise condensation (DWC). DWC has one-tenth higher heat transfer coefficient than that of FWC. It has been pointed out by many investigators that DWC occurs on the hydrophobic surface and FWC occurs on hydrophilic surface. However, the durability of those hydrophobic effects was not clear enough. In order to maintain a sufficiently long DWC, it is important to understand the effect of the surface property and structure on the condensation surface in more detail. The recent advancement of MEMS (Micro Electro Mechanical System) technology enables us to change the physical nature the surface in the micro scale. It is expected that the hydrophobic surface by the MEMS technology may kept DWC for a longer time. In the present paper, we experimentally investigate the effects of thin metal film and micro structured surface on condensation pattern. Especially, our condensation experiments were performed with the micro structured surfaces by using etching and the metal thin film surfaces by sputtering for approximately 24 hours. Silicon (Si) wafer was used as a basic surface. For the metal thin films surface, we used sputtered Lead (Pb) and Titanium (Ti) on Si surface. For the micro structured surfaces, micro-structured grid was etched on Si surface with several conditions. In order to obtain the relation between the condensation pattern and surface condition, the surface conditions were measured by laser micro-scope, contact angle meter and atomic force microscope (AFM). For the metal thin films surface, condensation patterns on thin Pb film surface showed DWC. Meanwhile, condensation patterns on thin Ti surfaces showed FWC. From our results, the adsorption forces decreased with increasing contact angle on DWC for Pb. On the other hand, the adsorption forces increased with decreasing contact angle on FWC for Ti. For the micro structured surfaces, condensation pattern was FWC and contact angle decreased in our experimental results. This is because that the condensed water is accumulated in the groove on the micro structure surface.

Experimental Research on Influence of Temperature and Compression on Wrinkle Evolution of Thin Films on Compliant Substrates

2014 ◽  
Vol 609-610 ◽  
pp. 504-508
Author(s):  
Xiao Li Zhao ◽  
Sui Xing Zhang ◽  
Wei Wei An ◽  
Hai Chao Yu ◽  
Zhan Shan Liu
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Thermal Annealing ◽  
Experimental Research ◽  
Metal Film ◽  
External Stimulation ◽  
Influence Of Temperature ◽  
Compliant Substrates ◽  
Surface Wrinkling ◽  
Service Conditions

Wrinkle evolution under temperature and compression was experimentally explored in a metal film deposited on a compliant polymer. After wrinkle formation, the samples undergo thermal annealing in different temperature circumstances. In the range of 75-150°C, the wavelength and amplitude of wrinkles became both smaller as the temperature increased, indicating that annealing effectively releases residual stress and promote material modification. In contrast, compression only changed wrinkle rearrangement, and did not alter the wavelength and amplitude. These results suggest that external stimulation can transform wrinkled surfaces. This work provides the guidance for service conditions of surface wrinkling.

Understanding Surface Instability Patterns in Nanoscale Thin Films

2005 ◽  
Author(s):  
Rui Huang ◽  
Se Hyuk Im ◽  
Yaoyu Pang
Keyword(s):  
Thin Films ◽  
Metal Film ◽  
Nonlinear Models ◽  
Thin Metal Film ◽  
Integrated Systems ◽  
Surface Pattern ◽  
Surface Roughening ◽  
Morphological Instability ◽  
Epitaxial Thin Film ◽  
Surface Patterns

Thin films of nanoscale thickness are common in integrated systems and devices. Subjected to interactions of diverse physical origins, the nanoscale thin films often undergo structural and/or morphological instability and develop a variety of surface patterns. Two examples are discussed in this paper. An epitaxial thin film undergoes surface roughening and form self-assembled quantum dots [1]. A thin metal film bonded to a polymer substrate develops various wrinkle patterns [2]. We develop nonlinear models and numerical methods to simulate the evolution processes. The results reveal very rich dynamics of surface pattern formation and suggest potential means for the control and making of ordered patterns.

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

scholarly journals Observing and controlling a Tamm plasmon at the interface with a metasurface

Nanophotonics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 897-903 ◽  
Author(s):  
Oleksandr Buchnev ◽  
Alexandr Belosludtsev ◽  
Victor Reshetnyak ◽  
Dean R. Evans ◽  
Vassili A. Fedotov
Keyword(s):  
Liquid Crystal ◽  
Metal Film ◽  
Near Infrared ◽  
Thin Metal Film ◽  
Outer Side ◽  
Spectral Position ◽  
External Perturbations ◽  
Dielectric Mirror ◽  
Wavelength Scale ◽  
Sub Wavelength

AbstractWe demonstrate experimentally that Tamm plasmons in the near infrared can be supported by a dielectric mirror interfaced with a metasurface, a discontinuous thin metal film periodically patterned on the sub-wavelength scale. More crucially, not only do Tamm plasmons survive the nanopatterning of the metal film but they also become sensitive to external perturbations as a result. In particular, by depositing a nematic liquid crystal on the outer side of the metasurface, we were able to red shift the spectral position of Tamm plasmon by 35 nm, while electrical switching of the liquid crystal enabled us to tune the wavelength of this notoriously inert excitation within a 10-nm range.

scholarly journals Out-of-Plane Thermal Expansion Coefficient and Biaxial Young’s Modulus of Sputtered ITO Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Chuen-Lin Tien ◽  
Tsai-Wei Lin
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Thermal Stress ◽  
Young’S Modulus ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Young's Modulus ◽  
Heating Temperature ◽  
Glass Substrates ◽  
Ito Thin Films

This paper proposes a measuring apparatus and method for simultaneous determination of the thermal expansion coefficient and biaxial Young’s modulus of indium tin oxide (ITO) thin films. ITO thin films simultaneously coated on N-BK7 and S-TIM35 glass substrates were prepared by direct current (DC) magnetron sputtering deposition. The thermo-mechanical parameters of ITO thin films were investigated experimentally. Thermal stress in sputtered ITO films was evaluated by an improved Twyman–Green interferometer associated with wavelet transform at different temperatures. When the heating temperature increased from 30 °C to 100 °C, the tensile thermal stress of ITO thin films increased. The increase in substrate temperature led to the decrease of total residual stress deposited on two glass substrates. A linear relationship between the thermal stress and substrate heating temperature was found. The thermal expansion coefficient and biaxial Young’s modulus of the films were measured by the double substrate method. The results show that the out of plane thermal expansion coefficient and biaxial Young’s modulus of the ITO film were 5.81 × 10−6 °C−1 and 475 GPa.

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