Oxidising Role of Water Vapour in the 250 Kev D+ Induced Radiolysis of Polyimide Kapton-H

1988 ◽  
Vol 100 ◽  
Author(s):  
U. K. Chaturvedi ◽  
A. Patnaik ◽  
Ramji Pathak ◽  
R. N. Chakraborty ◽  
A. K. Nigam
Keyword(s):  
Partial Pressure ◽  
Water Vapour ◽  
Ion Beam ◽  
Adsorbed Water ◽  
Vacuum System ◽  
Residual Water ◽  
Implantation Time ◽  
Polymeric Surface ◽  
Imide Ring

Residual water vapour present in the vacuum system has been observed to play a dominant oxidising role in the 250 keV D+ induced radiolysis of polyimide (Kapton-H). The partial pressure (pp) of water in the vacuum system decreases sharply as the D+ beam impinges the polymeric surface, but soon after, it recovers to its initial value as the accumulated dose increases. Emission of CO2 is observed which has its maximum at a time when the H2O partial pressure is at a minimum. The CO2 level also returns to its original level with time. This complementary variation of CO2 and H2O confirms that absorbed and adsorbed water molecules are radiolysed by the ion beam and initiate oxidation of the radiolytically evolved CO to yield CO2 on and within the ion implanted surface of the polyimide. Further, the small enhancement in the 28 amu peak (N2 + CO), which exhibits no maximum/minimum over the entire implantation time, can be understood in terms of the evolution of N2 from the imide ring as a result of radiolysis of this nitrogen containing polymers.

scholarly journals CHAPTER 5 Effect of Water Vapour on the High Temperature Oxidation of Stainless Steels

2020 ◽  
Vol 300 ◽  
pp. 107-134
Author(s):  
Somrerk Chandra-ambhorn ◽  
Patthranit Wongpromrat ◽  
Thammaporn Thublaor ◽  
Walairat Chandra-ambhorn
Keyword(s):  
Water Vapour ◽  
Stainless Steels ◽  
Defect Structure ◽  
High Temperature Oxidation ◽  
Surface Reaction ◽  
Adsorbed Water ◽  
Oxide Formation ◽  
Chromium Species ◽  
Temperature Oxidation

This chapter primarily reviews the nature of water vapour when it presents in bulk gas. The change in a ratio between water vapour and corresponding dissociated hydrogen, which determine the thermodynamic stability of the oxide formation, is analysed when the oxidation kinetics are linear and parabolic. When water vapour reaches the solid/gas interface, chromium species volatilisation and oxidation controlled by surface reaction can occur. The adsorbed water vapour can be further incorporated into the oxide possibly in the form of hydrogen defects. The role of these defects on altering the defect structure of the oxide is discussed. Finally, characteristics of the oxide scale on stainless steels formed in the atmosphere containing water vapour are reviewed.

Freeze-fracturing in ultrahigh vacuum: Low-temperature sample holder (4.8 K) and microtome sample holder UHV compatible

1984 ◽  
Vol 42 ◽  
pp. 2-5
Author(s):  
J. Escaig
Keyword(s):  
Partial Pressure ◽  
Water Vapour ◽  
Vacuum Chamber ◽  
Ultrahigh Vacuum ◽  
Vacuum System ◽  
Ion Pump ◽  
Sample Holder ◽  
Pumping Rate ◽  
Residual Atmosphere ◽  
High Vapour Pressure

The protection of fracture faces against contamination by residual hydrocarbons can be obtained by pumping the vacuum chamber under ultrahigh vacuum or by surrounding the preparation by a shroud cooled by liquid nitrogen. Both means help in reducing the partial pressure of water vapour. Nevertheless even if ultrahigh vacuum is combined with a cooling shroud, water vapour remains the main residual gas, as can be seen in the mass spectrum shown by Gross or in that of Fig. 1a. Selective condensation of water vapour on specific sites of fractured membranes can create artefacts resembling intramembranous particles. The most efficient way to reduce the partial pressure of H2O is to bake the whole of the vacuum system (vacuum chamber valve, pump) at temperatures between 200 and 400°C. An ion pump is best suited for that purpose as it maintains its pumping rate at high temperature. Contrary to cryopumps, it does not require a cooled screen, which simplifies the construction and keeps running costs down. Curve 1b shows that after 8 hours of baking (overnight) the partial pressure of water vapour is reduced to 2.10-10 Torr and that the residual atmosphere is mainly composed of hydrogen which, because of its high vapour pressure, cannot be condensed at temperatures over a few Kelvin degrees (peak 28 is mainly produced by the filament of the mass spectrometer itself).

The effects of incorporating water into vacuum-deposited amorphous silicon films

1986 ◽  
Vol 64 (1) ◽  
pp. 16-21 ◽  
Author(s):  
R. Audas ◽  
D. E. Brodie ◽  
J. A. Cowan ◽  
C. J. L. Moore
Keyword(s):  
Partial Pressure ◽  
Water Vapour ◽  
Low Energy ◽  
Room Temperature Resistivity ◽  
Film Properties ◽  
Low Energy Electrons ◽  
Ambient Gases ◽  
Low Energy Electron ◽  
Temperature Resistivity

This paper describes the effects on some of the electrical and optical properties of a-Si: C films prepared by vacuum deposition in controlled ambient gases of N2, O2, H2, and water vapour. This stidy was initiated in an attempt to determine the role of a low-energy electron beam irradiating the substrate and film as the layer grows. We find that depositing an a-Si:C film in a water-vapour environment, at a partial pressure of only 4 × 10−8 Torr, will result in the film having a room-temperature resistivity two thousand times higher than that for "clean" films deposited in a good vacuum with a partial pressure of water vapour near 4 × 10−9 Torr (1 Torr = 133.3 Pa). If the partial pressure of the water vapour is increased, the film resistivity increases and it becomes photoconducting. By comparison, the other gases tested had no measurable effect on the properties of the films, with the exception of oxygen which increases the film resistance. None of these latter films were photoconducting. We conclude that the improvement observed in the film properties when samples are irradiated with low-energy electrons results more from the effects of water vapour and (or) oxygen which can be freed from cold surfaces near the substrate than from a possible restructuring of the film as postulated earlier (1).

An Study of Influence of Imperfections on the Delamination of Diamond-Like Carbon Films

2002 ◽  
Vol 719 ◽  
Author(s):  
Myoung-Woon Moon ◽  
Kyang-Ryel Lee ◽  
Jin-Won Chung ◽  
Kyu Hwan Oh
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Imaging System ◽  
Ion Beam ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Glass Substrates ◽  
Atomic Force ◽  
Initiation And Propagation

AbstractThe role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.

scholarly journals Charged particle single nanometre manufacturing

2018 ◽  
Vol 9 ◽  
pp. 2855-2882 ◽  
Author(s):  
Philip D Prewett ◽  
Cornelis W Hagen ◽  
Claudia Lenk ◽  
Steve Lenk ◽  
Marcus Kaestner ◽  
...  
Keyword(s):  
Charged Particle ◽  
High Throughput ◽  
Nanoimprint Lithography ◽  
Ion Beam ◽  
Ambient Air ◽  
Particle Beam ◽  
Vacuum System ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Charged Particle Beam

Following a brief historical summary of the way in which electron beam lithography developed out of the scanning electron microscope, three state-of-the-art charged-particle beam nanopatterning technologies are considered. All three have been the subject of a recently completed European Union Project entitled “Single Nanometre Manufacturing: Beyond CMOS”. Scanning helium ion beam lithography has the advantages of virtually zero proximity effect, nanoscale patterning capability and high sensitivity in combination with a novel fullerene resist based on the sub-nanometre C60 molecule. The shot noise-limited minimum linewidth achieved to date is 6 nm. The second technology, focused electron induced processing (FEBIP), uses a nozzle-dispensed precursor gas either to etch or to deposit patterns on the nanometre scale without the need for resist. The process has potential for high throughput enhancement using multiple electron beams and a system employing up to 196 beams is under development based on a commercial SEM platform. Among its potential applications is the manufacture of templates for nanoimprint lithography, NIL. This is also a target application for the third and final charged particle technology, viz. field emission electron scanning probe lithography, FE-eSPL. This has been developed out of scanning tunneling microscopy using lower-energy electrons (tens of electronvolts rather than the tens of kiloelectronvolts of the other techniques). It has the considerable advantage of being employed without the need for a vacuum system, in ambient air and is capable of sub-10 nm patterning using either developable resists or a self-developing mode applicable for many polymeric resists, which is preferred. Like FEBIP it is potentially capable of massive parallelization for applications requiring high throughput.

Applications of Energy Beams in Material and Device Processing

1983 ◽  
Vol 23 ◽  
Author(s):  
G.J. Galvin ◽  
L.S. Hung ◽  
J.W. Mayer ◽  
M. Nastasi
Keyword(s):  
Ion Beam ◽  
High Energy ◽  
Ion Beams ◽  
Traditional Role ◽  
Near Surface ◽  
Device Processing ◽  
Composition Modification ◽  
Directed Energy ◽  
Transistor Fabrication

ABSTRACTEnergetic ion beams used outside the traditional role of ion implantation are considered for semiconductor applications involving interface modification for self-aligned silicide contacts, composition modification for formation of buried oxide layers in Si on insulator structures and reduced disorder in high energy ion beam annealing for buried collectors in transistor fabrication. In metals, aside from their use in modification of the composition of near surface regions, energetic ion beams are being investigated for structural modification in crystalline to amorphous transitions. Pulsed beams of photons and electrons are used as directed energy sources in rapid solidification. Here, we consider the role of temperature gradients and impurities in epitaxial growth of silicon.

Role of the Water Vapour Greenhouse Effect in the Forecasting Of Fog Occurrence

2003 ◽  
Vol 107 (2) ◽  
pp. 469-482 ◽  
Author(s):  
P. K. Pasricha ◽  
B. S. Gera ◽  
S. Shastri ◽  
H. K. Maini ◽  
T. John ◽  
...  
Keyword(s):  
Water Vapour ◽  
Greenhouse Effect

Role of Surface Reconstruction and External Ion Beam in the Growth Kinetics of III-V Molecular Beam Epitaxy

1987 ◽  
Vol 94 ◽  
Author(s):  
S. B. Ogale ◽  
M. Thomsen ◽  
A. Madhukar
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Surface Reconstruction ◽  
Molecular Beam ◽  
Ion Beam ◽  
Growth Front ◽  
Kinetic Rates ◽  
Kinetics Of ◽  
Low Temperature Epitaxy

ABSTRACTComputer simulations of III-V molecular beam epitaxy (MBE) show that surface reconstruction induced modulation of kinetic rates could give rise to ordering in alloys. Results are also presented for the possible influence of an external ion beam in achieving low temperature epitaxy as well as smoother growth front under usual conditions.

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