EUV ablation of organic polymers at a high fluence

High Power Laser Science and Engineering ◽

10.1017/hpl.2014.31 ◽

2014 ◽

Vol 2 ◽

Author(s):

Chiara Liberatore ◽

Klaus Mann ◽

Matthias Müller ◽

Ladislav Pina ◽

Libor Juha ◽

...

Keyword(s):

Extreme Ultraviolet ◽

Preliminary Investigation ◽

Surface Region ◽

Polymer Materials ◽

Near Surface ◽

Polymer Molecules ◽

Nanosecond Pulses ◽

Volatile Products ◽

Discharge Laser

Abstract A preliminary investigation on short-wavelength ablation mechanisms of poly(methyl methacrylate) (PMMA) and poly (1,4-phenylene ether ether-sulfone) (PPEES) by extreme ultraviolet (EUV) radiation at 13.5 nm using a table-top laser-produced plasma from a gas-puff target at LLG (Göttingen) and at 46.9 nm by a 10 Hz desktop capillary discharge laser operated at the Institute of Physics (Prague) is presented. Ablation of polymer materials is initiated by photo-induced polymer chain scissions. The ablation occurs due to the formation of volatile products by the EUV radiolysis removed as an ablation plume from the irradiated material into the vacuum. In general, cross-linking of polymer molecules can compete with the chain decomposition. Both processes may influence the efficiency and quality of micro(nano)structuring in polymer materials. Wavelength is a critical parameter to be taken into account when an EUV ablation process occurs, because different wavelengths result in different energy densities in the near-surface region of the polymer exposed to nanosecond pulses of intense EUV radiation.

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Amortization and Recrystallization of 6H-SiC by ion Beam Irradiation

MRS Proceedings ◽

10.1557/proc-339-197 ◽

1994 ◽

Vol 339 ◽

Cited By ~ 4

Author(s):

V. Heera ◽

R. Kögler ◽

W. Skorupa ◽

J. Stoemenos

Keyword(s):

Ion Irradiation ◽

Ion Beam ◽

Surface Region ◽

Ion Beam Irradiation ◽

Surface Layers ◽

Near Surface ◽

Transmission Electron ◽

Amorphous Surface ◽

Amorphous Sic

ABSTRACTThe evolution of the damage in the near surface region of single crystalline 6H-SiC generated by 200 keV Ge+ ion implantation at room temperature (RT) was investigated by Rutherford backscattering spectroscopy/chanelling (RBS/C). The threshold dose for amorphization was found to be about 3 · 1014 cm-2, Amorphous surface layers produced with Ge+ ion doses above the threshold were partly annealed by 300 keV Si+ ion beam induced epitaxial crystallization (IBIEC) at a relatively low temperature of 480°C For comparison, temperatures of at least 1450°C are necessary to recrystallize amorphous SiC layers without assisting ion irradiation. The structure and quality of both the amorphous and recrystallized layers were characterized by cross-section transmission electron microscopy (XTEM). Density changes of SiC due to amorphization were measured by step height measurements.

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Volatile Evolution from Polymer Materials Induced by Irradiation with Accelerated He++ Ions

MRS Proceedings ◽

10.1557/proc-851-nn8.9 ◽

2004 ◽

Vol 851 ◽

Author(s):

Julian.J. Murphy ◽

Christopher.J. Wetteland

Keyword(s):

Ion Beam ◽

Surface Region ◽

Energetic Particles ◽

Thin Layers ◽

Polymer Materials ◽

Particle Radiation ◽

Chemical Changes ◽

Near Surface ◽

Particle Irradiation ◽

Pass Through

ABSTRACTExperimentally investigating ageing caused by irradiation with energetic particles is very difficult. Radioactive sources can be employed but these are difficult to handle and contaminate the material being irradiated precluding subsequent chemical and physical characterisation. The penetration of energetic particles also tends to be small so any change is localised in the near surface region so only a small amount of material is irradiated. Analysing changes in such thin layers causes a number of problems. To simulate ageing induced by particle radiation polymer samples have been exposed to fast He++ ions in an accelerated ion beam. The ions pass through a 10μm thick window of Havar foil before impacting upon the sample. Volatile species evolved from the materials upon bombardment are contained within the irradiation chamber by the foil window. Analysis of such species is shown to be a highly sensitive probe for investigating chemical changes in the exposed materials. A number of important chemical changes induced in polymer materials have been identified. Trends in the relative rates of volatile evolution have been identified which correlate with chemical changes identified in other radiation experiments. As these experiments are performed at far slower irradiation rates the large acceleration factors used in ion beam irradiation are discussed along with the implications for using ion beams to simulate alpha particle irradiation.

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Formation and phase transition of VO2 precipitates embedded in sapphire

Journal of Materials Research ◽

10.1557/jmr.1999.0348 ◽

1999 ◽

Vol 14 (6) ◽

pp. 2602-2610 ◽

Cited By ~ 15

Author(s):

Laurence A. Gea ◽

J. D. Budai ◽

L. A. Boatner

Keyword(s):

Phase Transition ◽

Transition Temperature ◽

Single Crystals ◽

Surface Region ◽

Optical Quality ◽

Host Lattice ◽

Near Surface ◽

Thermally Induced ◽

Metal Phase Transition

Crystallographically coherent precipitates of vanadium dioxide (VO2) have been formed in the near-surface region of single crystals of sapphire (Al2O3) using a combination of ion implantation and thermal treatments. As in the case of either bulk VO2 single crystals or thin films of VO2, the thermally induced semiconductor-to-metal phase transition of the embedded VO2 precipitates is accompanied by a large hysteretic change in the infrared optical transmission. The VO2 precipitate transition temperature (Tc = 72 to 85 °C) is higher than that of bulk VO2 (Tc = 68 °C) and is sensitive to the implantation conditions. The present results show that the damage resulting from the coimplantation of vanadium and oxygen into an Al2O3 host lattice dictates the final microstructure of the VO2 precipitates and, consequently, affects the transition temperature, as well as the optical quality of the VO2/Al2O3 surface-nanocomposite precipitate system.

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Epitaxial Growth of AlN on Si Substrates with Intermediate 3C-SiC as Buffer Layers

MRS Proceedings ◽

10.1557/proc-572-407 ◽

1999 ◽

Vol 572 ◽

Cited By ~ 1

Author(s):

S. Q. Hong ◽

H. M. Liaw ◽

K. Linthicum ◽

R. F. Davis ◽

P. Fejes ◽

...

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Surface Region ◽

Buffer Layers ◽

Organometallic Vapor Phase Epitaxy ◽

Near Surface ◽

Si Substrates ◽

Gas Source ◽

Sic Film

ABSTRACTSingle crystalline AlN was successfully grown on a 3C-SiC coated Si (111) substrate by organometallic vapor phase epitaxy. The 3C-SiC film was obtained via the conversion of the Si near-surface region to SiC using gas-source molecular beam epitaxy. The quality of the AlN was mainly controlled by that of the SiC. The effects of Si pits and SiC hillocks formed during the conversion on subsequent AlN growth are discussed. Process optimization is suggested to improve the SiC buffer layer for subsequent AlN deposition.

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Исследование свойств солнечных элементов на основе селективного контакта MoO-=SUB=-x-=/SUB=-/Si с помощью спектроскопии полной проводимости

Письма в журнал технической физики ◽

10.21883/pjtf.2021.16.51324.18779 ◽

2021 ◽

Vol 47 (16) ◽

pp. 24

Author(s):

А.И. Баранов ◽

Д.А. Кудряшов ◽

А.В. Уваров ◽

И.А. Морозов ◽

А.А. Максимова ◽

...

Keyword(s):

Deposition Temperature ◽

Room Temperature ◽

Surface Region ◽

Admittance Spectroscopy ◽

Radiation Defects ◽

Capture Cross ◽

Sectional Area ◽

Cross Sectional ◽

Near Surface

The possibility of using admittance spectroscopy to characterization the quality of ITO/MoOx/n-Si structures is shown. It has been demonstrated that magnetron sputtering of ITO layer at room temperature leads to radiation defects formation in the near-surface region of Si near the MoOx/Si interface with a depth of 0.13 and 0.26 eV below the conduction band with a capture cross-sectional area of (1–5)∙10^-19 and (5–10)∙10^-19 cm^-2, respectively. An increase in the deposition temperature of the ITO layer to 130 °C allows to reduce the concentration below the sensitivity leading to a significant improvement of solar cells characteristic.

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Preparation of cross-sectional samples for near-surface TEM studies

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012669x ◽

1987 ◽

Vol 45 ◽

pp. 380-381

Author(s):

R.C. Dickenson ◽

K.R. Lawless

Keyword(s):

Standard Sample ◽

Surface Region ◽

Specimen Preparation ◽

Thick Sheet ◽

Drill Bit ◽

Sample Holder ◽

Metal Interface ◽

Cross Sectional ◽

Near Surface ◽

Cold Worked

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.

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The Effects of Ion Implantation on the Surface Features of Inconel 600

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118333 ◽

1985 ◽

Vol 43 ◽

pp. 288-289

Author(s):

John D. Rubio

Keyword(s):

Grain Boundary ◽

Ion Implantation ◽

Nuclear Power ◽

Power Plants ◽

Surface Region ◽

Selective Dissolution ◽

Boundary Region ◽

Near Surface ◽

Inconel 600 ◽

Steam Generator Tubing

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

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Microstructural changes of Aluminum Nitride after laser irradiation and electroless copper deposition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170918 ◽

1994 ◽

Vol 52 ◽

pp. 636-637

Author(s):

S. Cao ◽

A. J. Pedraza ◽

L. F. Allard

Keyword(s):

Aluminum Nitride ◽

Laser Irradiation ◽

Electroless Deposition ◽

Thermal Evaporation ◽

Surface Region ◽

Near Surface ◽

Laser Patterning ◽

Electroless Copper ◽

Excimer Laser Irradiation ◽

Laser Effect

Excimer-laser irradiation strongly modifies the near-surface region of aluminum nitride (AIN) substrates. The surface acquires a distinctive metallic appearance and the electrical resistivity of the near-surface region drastically decreases after laser irradiation. These results indicate that Al forms at the surface as a result of the decomposition of the Al (which has been confirmed by XPS). A computer model that incorporates two opposing phenomena, decomposition of the AIN that leaves a metallic Al film on the surface, and thermal evaporation of the Al, demonstrated that saturation of film thickness and, hence, of electrical resistance is reached when the rate of Al evaporation equals the rate of AIN decomposition. In an electroless copper bath, Cu is only deposited in laser-irradiated areas. This laser effect has been designated laser activation for electroless deposition. Laser activation eliminates the need of seeding for nucleating the initial layer of electroless Cu. Thus, AIN metallization can be achieved by laser patterning followed by electroless deposition.

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Current Progress in Biomedical Applications of Chitosan-Carbon Nanotube Nanocomposites: A Review

Mini-Reviews in Medicinal Chemistry ◽

10.2174/1389557520666200513120407 ◽

2020 ◽

Vol 20 (16) ◽

pp. 1619-1632

Author(s):

Katarzyna Pieklarz ◽

Michał Tylman ◽

Zofia Modrzejewska

Keyword(s):

Carbon Nanotube ◽

Medical Science ◽

Antimicrobial Properties ◽

Polymer Materials ◽

Biological Macromolecules ◽

Medical Sciences ◽

New Generation ◽

High Degree ◽

Dressing Materials

The currently observed development of medical science results from the constant search for innovative solutions to improve the health and quality of life of patients. Particular attention is focused on the design of a new generation of materials with a high degree of biocompatibility and tolerance towards the immune system. In addition, apart from biotolerance, it is important to ensure appropriate mechanical and technological properties of materials intended for intra-body applications. Knowledge of the above parameters becomes the basis for considerations related to the possibilities of choosing the appropriate polymer materials. The researchers' interest, as evidenced by the number of available publications, is attracted by nanobiocomposites based on chitosan and carbon nanotubes, which, due to their properties, enable integration with the tissues of the human body. Nanosystems can be used in many areas of medicine. They constitute an excellent base for use as dressing materials, as they exhibit antimicrobial properties. In addition, they can be carriers of drugs and biological macromolecules and can be used in gene therapy, tissue engineering, and construction of biosensors. For this reason, potential application areas of chitosan-carbon nanotube nanocomposites in medical sciences are presented in this publication, considering the characteristics of the system components.

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