Method for determining when a critical film thickness will be reached in a grease-lubricated seal

2013 ◽  
Vol 2013 (5) ◽  
pp. 14
Keyword(s):  
Film Thickness ◽  
Critical Film Thickness

scholarly journals Влияние напряжения смещения и скорости осаждения на структуру и коэрцитивность пленок NiFe

2020 ◽  
Vol 62 (12) ◽  
pp. 2174
Author(s):  
А.С. Джумалиев ◽  
C.Л. Высоцкий ◽  
В.К. Сахаров
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Film Thickness ◽  
Deposition Rate ◽  
Entire Range ◽  
Soft Magnetic Properties ◽  
Supercritical State ◽  
Dc Magnetron Sputtering ◽  
Soft Magnetic ◽  
Critical Film Thickness

Influence of the bias voltage Ub and the deposition rate  on the structure, grain size D, and coercivity Hc of NiFe films with the thickness d from 30 to 980 nm, grown onto Si / SiO2 substrates by DC magnetron sputtering, was studied. In the case Ub = 0, the decrease of  from ≈ nm/min to ≈ 7 nm/min is accompanied by the increase of the critical film thickness dcr from dcr ≈ 220 nm to dcr ≈ 270 nm. In this case, Hc in the films with d < dcr is characterized by the dependence Hc ~ D6 and varies from ~ 1 to ~ 20 Oe. In the case of Ub = -100 V, the effect of the deposition rate on the coercivity is much more noticeable. At ν = 7 and 14 nm / min, the films demonstrate soft magnetic properties (Нс ≈ 0.15 - 1.4 Oe) and the absence of dcr for the entire range of studied thicknesses. The films obtained at ν = 21 and 27 nm / min turn into the “supercritical” state at d ≥ dcr ≈ 520 nm, and, in the region d < dcr, they are characterized by the dependence Hc ~ D3 and by the increase of coercivity from ~ 0.35 to ~ 10 Oe.

Comparison of the Fracture Behavior of Brittle ILD Films used in the BEOL in Dry and Wet Environment using Nanoindentation

2006 ◽  
Vol 914 ◽  
Author(s):  
Eva Simonyi ◽  
Michael Lane ◽  
Erik Liniger ◽  
Alfred Grill
Keyword(s):  
Fracture Toughness ◽  
Film Thickness ◽  
Manufacturing Process ◽  
Fracture Behavior ◽  
Imaging Methods ◽  
Afm Imaging ◽  
Critical Film Thickness ◽  
Low K

AbstractDuring the manufacturing process of the BEOL the low-k brittle ILD dielectrics are exposed to wet environments. These environments could and do affect the films fracture toughness, the so called critical film thickness, above which spontaneous cracking occurs. Nanoindentation combined with AFM imaging methods allow to study these phenomena.

Surfactant Effects on Fluid-Elastic Instabilities of Liquid-Lined Flexible Tubes: A Model of Airway Closure

1993 ◽  
Vol 115 (3) ◽  
pp. 271-277 ◽  
Author(s):  
D. Halpern ◽  
J. B. Grotberg
Keyword(s):  
Film Thickness ◽  
Surfactant Concentration ◽  
Evolution Equations ◽  
Liquid Films ◽  
Nonlinear Evolution Equations ◽  
Small Airways ◽  
Airway Closure ◽  
Elastic Tubes ◽  
Critical Film Thickness ◽  
The Stability

A theoretical analysis is presented predicting the closure of small airways in the region of the terminal and respiratory bronchioles. The airways are modelled as thin elastic tubes, coated on the inside with a thin viscous liquid lining. This model produces closure by a coupled capillary-elastic instability leading to liquid bridge formation, wall collapse or a combination of both. Nonlinear evolution equations for the film thickness, wall position and surfactant concentration are derived using an extended version of lubrication theory for thin liquid films. The positions of the air-liquid and wall-liquid interfaces and the surfactant concentration are perturbed about uniform states and the stability of these perturbations is examined by solving the governing equations numerically. Solutions show that there is a critical film thickness, dependent on fluid, wall and surfactant properties above which liquid bridges form. The critical film thickness, εc, decreases with increasing mean surface-tension or wall compliance. Surfactant increases εc by as much as 60 percent for physiological conditions, consistent with physiological observations. Airway closure occurs more rapidly with increasing film thickness and wall flexibility. The closure time for a surfactant rich interface can be approximately five times greater than an interface free of surfactant.

Surface stress effects on the critical film thickness for epitaxy

1989 ◽  
Vol 55 (12) ◽  
pp. 1197-1198 ◽  
Author(s):  
R. C. Cammarata ◽  
K. Sieradzki
Keyword(s):  
Film Thickness ◽  
Surface Stress ◽  
Stress Effects ◽  
Critical Film Thickness

Low Temperature Intermixing Reactions Between Silicon and Metals

1981 ◽  
Vol 10 ◽  
Author(s):  
Akio Hiraki ◽  
T. Narusawa ◽  
W. M. Gibson
Keyword(s):  
Film Thickness ◽  
Metal Film ◽  
Dielectric Constants ◽  
Semiconductor Surface ◽  
Free Electrons ◽  
Coulombic Interaction ◽  
Screening Model ◽  
Energy Gaps ◽  
Deposited Metal ◽  
Critical Film Thickness

Metal films such as gold, copper, nickel and palladium exhibit an interfacial intermixing reaction at room temperature with semiconductors with energy gaps Eg less than about 2.5 eV or dielectric constants ε larger than about 81. We have proposed a model2 of the triggering mechanism of this interfacial reaction based on the ability of a metal to screen coulombic interaction by its mobile free electrons. Such a screening may disturb the electron distribution responsible for the covalent bonding, and consequently it may make the semiconductor surface reactive towards the metal. In this respect, there must be a critical film thickness for the deposited metal film to behave as a true metal with sufficient mobile free electrons for the screening; therefore the reactivity of the semiconductor surface for the intermixing reaction must be dependent on the thickness of the deposited metal film. In favour of the screening model, we show that the reactivity of a silicon surface for intermixing or silicide formation with a gold or palladium film depends clearly on the film thickness.

The Stress Driven Islands Formation in Epitaxial Films and Solid HE4 Films.

1992 ◽  
Vol 280 ◽  
Author(s):  
Michael A. Grinfeld
Keyword(s):  
Surface Energy ◽  
Shear Modulus ◽  
Film Thickness ◽  
Epitaxial Films ◽  
Morphological Instability ◽  
Thin Solid Films ◽  
Solid Films ◽  
Mismatch Stress ◽  
Critical Film Thickness ◽  
Morphological Patterns

ABSTRACTWe discuss the static and quasi-static problems appearing in the theory of morphological instability of interfaces. The approach has allowed to predict the corrugations in He4 films and to explain the dislocation-free Stranski-Krastanow pattern of epitaxial growth of thin solid films with the critical film thickness H = σμ/τ2 (σ is a surface energy, μ- the shear modulus, and τ - the mismatch stress). In this paper we discuss possible morphological patterns of corrugations and their changes which appear in result of the stress driven “rearrangement” destabilization of originally flat interfaces.

Indentation fracture of low-dielectric constant films: Part II. Indentation fracture mechanics model

2008 ◽  
Vol 23 (9) ◽  
pp. 2443-2457 ◽  
Author(s):  
Dylan J. Morris ◽  
Robert F. Cook
Keyword(s):  
Dielectric Constant ◽  
Film Thickness ◽  
Film Stress ◽  
Low Dielectric Constant ◽  
Silicon Substrates ◽  
Instrumented Indentation ◽  
Indentation Fracture ◽  
Low Dielectric ◽  
Mechanics Model ◽  
Critical Film Thickness

Part I [D.J. Morris and R.F. Cook,J. Mater. Res.23,2429 (2008)] of this two-part work explored the instrumented indentation and fracture phenomena of compliant, low-dielectric constant (low-κ) films on silicon substrates. The effect of film thickness and probe acuity on the fracture response, as well as the apparent connection of this response to the perceived elastic modulus, were demonstrated. These results motivate the creation of a fracture model that incorporates all of these variables here in Part II. Indentation wedging is identified as the mechanism that drives radial fracture, and a correction is introduced that adjusts the wedging strength of the probe for the attenuating influence of the relatively stiff substrate. An estimate of the film fracture toughness can be made if there is an independent measurement of the film stress; if not, a critical film thickness for channel-cracking under the influence of film stress may be estimated.

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