scholarly journals Состав и морфология поверхности Si(111) с поверхностной пленкой SiO-=SUB=-2-=/SUB=- разной толщины

2021 ◽  
Vol 55 (11) ◽  
pp. 1045
Author(s):  
Б.Е. Умирзаков ◽  
С.Б. Донаев ◽  
Р.М. Ёркулов ◽  
Р.Х. Ашуров ◽  
В.М. Ротштейн
Keyword(s):  
Surface Roughness ◽  
Electronic Structure ◽  
Film Thickness ◽  
Thermal Oxidation ◽  
Surface Coverage ◽  
Plasma Oscillations

In this work, the composition, morphology, and electronic structure of SiO2 nanofilms of various thicknesses, created by thermal oxidation on the Si(111) surface, have been studied. It is shown that up to a thickness of 30–40 Å, the film has an island character. At d ≥ 60 Å, a homogeneous continuously film of SiO2 is formed and the stoichiometric surface roughness of which does not exceed 1.5 - 2 nm. Regardless of the film thickness of the SiO2 appreciable interdiffusion of atoms at the interface SiO2-Si not observed. The regularities of the change in the composition, the degree of surface coverage, and the energy of plasma oscillations with a change in the thickness of the SiO2/Si(111) films in the range from 20 to 120 Å have been determined.

A new method for quantifying the blocking of coated paperboard

TAPPI Journal ◽  
2010 ◽  
Vol 9 (5) ◽  
pp. 29-35 ◽  
Author(s):  
PAULINE SKILLINGTON ◽  
YOLANDE R. SCHOEMAN ◽  
VALESKA CLOETE ◽  
PATRICE C. HARTMANN
Keyword(s):  
Surface Roughness ◽  
Fatty Acid ◽  
Surface Energy ◽  
Film Thickness ◽  
External Factors ◽  
Additive Concentration ◽  
Pressure Surface ◽  
Fatty Acid Amides ◽  
Coated Surfaces ◽  
Definite Period

Blocking is undesired adhesion between two surfaces when subjected to pressure and temperature constraints. Blocking between two coated paperboards in contact with each other may be caused by inter-diffusion, adsorption, or electrostatic forces occurring between the respective coating surfaces. These interactions are influenced by factors such as the temperature, pressure, surface roughness, and surface energy. Blocking potentially can be reduced by adjusting these factors, or by using antiblocking additives such as talc, amorphous silica, fatty acid amides, or polymeric waxes. We developed a method of quantifying blocking using a rheometer. Coated surfaces were put in contact with each other with controlled pressure and temperature for a definite period. We then measured the work necessary to pull the two surfaces apart. This was a reproducible way to accurately quantify blocking. The method was applied to determine the effect external factors have on the blocking tendency of coated paperboards, i.e., antiblocking additive concentration, film thickness, temperature, and humidity.

Effect of Water Temperature, pH Value, and Film Thickness on the Wettability Behaviour of Copper Surfaces Coated with Copper Using EB-PVD Technique

2019 ◽  
Vol 60 ◽  
pp. 124-141 ◽  
Author(s):  
Naser Ali ◽  
Joao Amaral Teixeira ◽  
Abdulmajid Addali
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Film Thickness ◽  
Water Temperature ◽  
Ph Value ◽  
Surface Wettability ◽  
Copper Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Static Contact

This research investigates the effect of surface roughness, water temperature, and pH value on the wettability behaviour of copper surfaces. An electron beam physical vapour deposition technique was used to fabricate 25, 50, and 75 nm thin films of copper on the surface of copper substrates. Surface topographical analysis, of the uncoated and coated samples, was performed using an atomic force microscopy device to observe the changes in surface microstructure. A goniometer device was then employed to examine the surface wettability of the samples by obtaining the static contact angle between the liquid and the attached surface using the sessile drops technique. Waters of pH 4, 7, and 9 were employed as the contact angle testing fluids at a set of fixed temperatures that ranged from 20°C to 60°C. It was found that increasing the deposited film thickness reduces the surface roughness of the as-prepared copper surfaces and thus causing the surface wettability to diverge from its initial hydrophobic nature towards the hydrophilic behaviour region. A similar divergence behaviour was seen with the rise in temperature of water of pH 4, and 9. In contrast, the water of pH 7, when tested on the uncoated surface, ceased to reach a contact angle below 90o. It is believed that the observed changes in surface wettability behaviour is directly linked to the liquid temperature, pH value, surface roughness, along with the Hofmeister effect between the water and the surface in contact.

Rough Air-Soft Elastohydrodynamic Lubrication

2013 ◽  
Vol 420 ◽  
pp. 30-35
Author(s):  
Khanittha Wongseedakaew ◽  
Jesda Panichakorn
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Modulus Of Elasticity ◽  
Contact Region ◽  
Elastohydrodynamic Lubrication ◽  
Multilevel Methods ◽  
Inlet Temperature ◽  
Film Pressure ◽  
Air Inlet ◽  
Air Film

This paper presents the effects of rough surface air-soft elastohydrodynamic lubrication (EHL) of rollers for soft material under the effect of air molecular slip. The time independent modified Reynolds equation and elasticity equation were solved numerically using finite different method, Newton-Raphson method and multigrid multilevel methods were used to obtain the film pressure profiles and film thickness in the contact region. The effects of amplitude of surface roughness, modulus of elasticity and air inlet temperature are examined. The simulation results showed surface roughness has effect on film thickness but it little effect to air film pressure. When the amplitude of surface roughness and modulus of elasticity increased, the air film thickness decreased but air film pressure increased. However, the air inlet temperature increased when the air film thickness increased.

The Surface-Roughness of Bearing-Surfaces and its Relation to Oil Film Thickness at Breakdown

1949 ◽  
Vol 161 (1) ◽  
pp. 73-79 ◽  
Author(s):  
A. Cameron
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Hydrodynamic Theory ◽  
Quantitative Relation ◽  
Metal Contact ◽  
Initial Contact ◽  
Frictional Drag ◽  
Average Roughness ◽  
Finished Steel ◽  
Oil Film

In this paper the relation of surface roughness of bearing surfaces to allowable film thickness is studied quantitatively with a simple Michell pad apparatus. The pads used were faced with white metal and ran against mild steel collars. The lubricants studied were water, soap solution, paraffin, and light oil. There was little difference in the frictional behaviour of any of the lubricants, except that the aqueous lubricants would not run with very finely finished steel surfaces. The onset of metal to metal contact was detected by an increase in the frictional drag, and also by the change in electrical conductivity between the pad and collar—an extremely sensitive method. The paper shows that there is, at any rate for this system, a quantitative relation between the total surface roughness of the rubbing surfaces and the calculated oil film thickness both at the initial metal to metal contact and seizure. Initial contact occurs when the outlet film thickness, calculated from normal hydrodynamic theory, falls to three times the maximum surface roughness and seizure occurs when it is double the average roughness.

Effect of Rolling Velocity and Maximum Hertzian Pressure on Fluid Film in Steady State EHL Line Contact with Rough Surface and Linear Piezoviscosity

2014 ◽  
Vol 592-594 ◽  
pp. 1371-1375
Author(s):  
Nitesh Talekar ◽  
Punit Kumar
Keyword(s):  
Surface Roughness ◽  
Steady State ◽  
Film Thickness ◽  
Rough Surface ◽  
Computer Code ◽  
Fluid Film ◽  
Line Contact ◽  
Rolling Velocity ◽  
Load Carrying ◽  
Lubricated Contact

Consideration of surface roughness in steady state EHL line contact is the first step towards understanding the lubrication of rough surface problem. Current paper investigates the use of sinusoidal waviness in the contact; more precisely it gives performance of real fluid in EHL line contact. The effect of various parameters like rolling velocity (U) and maximum Hertzian pressure (ph) on surface roughness by using properties of linear and exponential piezo-viscosity is taken into consideration to evaluate behavior of pressure distribution of load carrying fluid film and film thickness. Full isothermal, Newtonian simulation of EHL problem gives described effects. Spiking or fluctuation of pressure and film thickness curves is expected to show presence of irregularities on the surface chosen and amount of fluctuation depends on certain parameters and intensity of irregularities present. Rolling side domain of-4.5 ≤ X ≤ 1.5 with grid size ∆X=0.01375 is selected. A computer code is developed to solve Reynolds equation, which governs the generation of pressure in the lubricated contact zone is discritized and solved along with load balance equation using Newton-Raphson technique.

Residual Stress Measurement in Silicon Substrate After Local Thermal Oxidation Using Microscopic Raman Spectroscopy

1991 ◽  
Vol 226 ◽  
Author(s):  
Hideo Miura ◽  
Hiroshi Sakata ◽  
Shinji Sakata Merl
Keyword(s):  
Residual Stress ◽  
Raman Spectroscopy ◽  
Tensile Stress ◽  
Oxide Film ◽  
Film Thickness ◽  
Silicon Dioxide ◽  
Thermal Oxidation ◽  
Silicon Substrate ◽  
Nitride Film ◽  
Oxide Film Thickness

AbstractThe residual stress in silicon substrates after local thermal oxidation is discussed experimentally using microscopic Raman spectroscopy. The stress distribution in the silicon substrate is determined by three main factors: volume expansion of newly grown silicon–dioxide, deflection of the silicon–nitride film used as an oxidation barrier, and mismatch in thermal expansion coefficients between silicon and silicon dioxide.Tensile stress increases with the increase of oxide film thickness near the surface of the silicon substrate under the oxide film without nitride film on it. The tensile stress is sometimes more than 100 MPa. On the other hand, a complicated stress change is observed near the surface of the silicon substrate under the nitride film. The tensile stress increases initially, as it does in the area without nitride film on it. However, it decreases with the increase of oxide film thickness, then the compressive stress increases in the area up to 170 MPa. This stress change is explained by considering the drastic structural change of the oxide film under the nitride film edge during oxidation.

Modifications of the electronic structure of Ni/Cu(001) as a function of the film thickness

1997 ◽  
Vol 56 (8) ◽  
pp. R4398-R4401 ◽  
Author(s):  
P. Srivastava ◽  
N. Haack ◽  
H. Wende ◽  
R. Chauvistré ◽  
K. Baberschke
Keyword(s):  
Electronic Structure ◽  
Film Thickness

A benchtop capillary flow layer-by-layer (CF-LbL) platform for rapid assembly and screening of biodegradable nanolayered films

Lab on a Chip ◽  
2016 ◽  
Vol 16 (23) ◽  
pp. 4601-4611 ◽  
Author(s):  
Ziye Dong ◽  
Ling Tang ◽  
Caroline C. Ahrens ◽  
Zhenya Ding ◽  
Vi Cao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Capillary Flow ◽  
Layer By Layer

We report a benchtop platform to systematically study film thickness, surface roughness, biocompatibility and degradation of a series of biodegradable nanolayered films.

How Small Is Too Small ? Understanding The Electronic Structure Of Atomic-Scale Transistors

1999 ◽  
Vol 5 (S2) ◽  
pp. 120-121
Author(s):  
D. A. Muller ◽  
T. Sorsch ◽  
S. Moccio ◽  
F. H. Baumann ◽  
K. Evans-Lutterodt ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electrical Properties ◽  
Thermal Oxidation ◽  
Electronic Devices ◽  
Local Environment ◽  
Gate Oxide ◽  
Atomic Scale ◽  
Gate Oxides ◽  
Bulk Properties ◽  
Commercial Use

The transistors planned for commercial use ten years from now in many electronic devices will have gate lengths shorter than 130 atoms, gate oxides thinner than 1.2 nm of SiO2 and clock speeds in excess of 10 GHz. It is now technologically possible to produce such transistors with gate oxides only 5 silicon atoms thick[l]. Since at least two of those 5 atoms are not in a local environment similar to either bulk Si or bulk SiO2, the properties of the interface are responsible for a significant fraction of the “bulk” properties of the gate oxide. However the physical (and especially their electrical) properties of the interfacial atoms are very different from .bulk Si or bulk SiO2. Further, roughness on an atomic scale can alter the leakage current by orders of magnitude.In our studies of such devices, we found that thermal oxidation tends to produce Si/SiO2 interfaces with 0.1-0.2 nm rms roughness.

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